Posted on by Nancy Atkinson

13 MORE Things That Saved Apollo 13, part 6: The Mysterious Longer-Than-Expected Communications Blackout

The jettisoning of elements during the critical last hours of the Apollo 13 mission is shown in this sequence drawing. Credit: NASA.

Join Universe Today in celebrating the 45th anniversary of Apollo 13 with insights from NASA engineer Jerry Woodfill as we discuss various turning points in the mission.

The final scenes of the movie Apollo 13 depict the spacecraft’s dramatic reentry into Earth’s atmosphere. As the seconds count beyond the time radio blackout should have lifted, the Capcom calls for Apollo 13’s crew to answer, but there is no response.

Everyone’s thoughts run through the possibilities: Had the heat shield been compromised by shrapnel from the exploded oxygen tank? Had the previously finicky hatch failed at this critical time? Had the parachutes turned to blocks of ice? Had the Inertial Measurement Unit (IMU) gyros failed, having inadequate time to warm-up causing the capsule to skip off the atmosphere, or incinerate with the crew in a fiery death plunge to Earth?

Of course, the crew finally did answer, but confirmation that Lovell, Haise and Swigert had survived reentry came nearly a minute and a half later than expected.

Some might feel director Ron Howard may have over-sensationalized the re-entry scenes for dramatic effect. But in listening to the actual radio communications between Mission Control and the ARIA 4 aircraft that was searching for a signal from the Apollo 13 crew, the real drama is just as palpable – if not more — than in the movie.

For virtually every reentry from Mercury through Apollo 12, the time of radio blackout was predictable, almost to the second. So why did Apollo 13’s radio blackout period extend for 87 seconds longer than expected, longer than any other flight?

The view in Mission Control after Apollo 13 landed safely. Credit: NASA.
The view in Mission Control after Apollo 13 landed safely. Credit: NASA.

During the Apollo era, the radio blackout was a normal part of reentry. It was caused by ionized air surrounding the command module during its superheated reentry through the atmosphere, which interfered with radio waves. The radio blackout period for the space shuttle program ended in 1988 when NASA launched the Tracking and Data Relay Satellite System (TDRS), which allowed nearly constant communication between the spacecraft and Mission Control.

It is difficult to find official NASA documentation about the extended radio blackout time for Apollo 13. In the mission’s Accident Review Board Report, there’s no mention of this anomaly. The only discussion of any communication problem comes in a section about reentry preparations, after the Service Module was jettisoned. There was a half-hour period of very poor communications with the Command Module due to the spacecraft being in a poor attitude with the Lunar Module still attached. Some of the reentry preparations were unnecessarily prolonged by the poor communications, but was more of a nuisance than an additional hazard to the crew, the report said.

In numerous interviews that I’ve done and listened to in preparation for this series of articles, when those involved with the Apollo 13 mission are asked about why the blackout period was longer than normal, the answer normally comes as a hedged response, with the crew or a flight director indicating they don’t know exactly why it happened. It seems analysis of this has defied a reasonable and irrefutable scientific explanation.

Overall view showing some of the activity in the Mission Operations Control Room during the final 24 hours of the Apollo 13 mission. From left to right are Shift 4 Flight Director Glynn Lunney, Shift 2 Flight Director Gerald Griffin, Astronaut and Apollo Spacecraft Program Manager James McDivitt, Director of Flight Crew Operations Deke Slayton and Shift 1 Flight Surgeon Dr. Willard Hawkins. Credit: NASA.
Overall view showing some of the activity in the Mission Operations Control Room during the final 24 hours of the Apollo 13 mission. From left to right are Shift 4 Flight Director Glynn Lunney, Shift 2 Flight Director Gerald Griffin, Astronaut and Apollo Spacecraft Program Manager James McDivitt, Director of Flight Crew Operations Deke Slayton and Shift 1 Flight Surgeon Dr. Willard Hawkins. Credit: NASA.

At an event at the Smithsonian Air & Space Museum in 2010, Apollo 13 Flight Director Gene Kranz said he never heard an answer or explanation that he believed, and Fred Haise chuckled and said, “We just did Ron Howard a favor!”

Jim Lovell gave the most detailed response – which is the one most often given as a likely explanation — suggesting it perhaps had to do with a shallowing reentry angle problem, with a strange space-like breeze that seemed to be blowing the spacecraft off-course with respect to entry.

“I think the reason why it was longer was the fact we were coming in shallower than we had planned,” Lovell said at the 2010 event. “Normally we come in from a Moon landing and have to hit the atmosphere inside a very narrow pie-shaped wedge and I think we were continually being pushed off that wedge. The reason was, we found out about 2-3 months after from analysis, was the lander’s venting of cooling vapor. The way we cool the electronic systems in LM was to pass water through a heat exchanger, and that water evaporates into space. That evaporation — which would be insignificant during a normal lunar landing mission — was going on for the 4 days we were using the LM as a lifeboat, acting as a small force, forcing us off the initial trajectory.”

Coming in on a shallower trajectory would result in a longer period in the upper atmosphere where there was less deceleration of the spacecraft. In turn, the reduced pace of deceleration lengthened the time that the heat of reentry produced the ionized gasses that would block communications.

The Apollo 13 spacecraft heads toward a splashdown in the South Pacific Ocean. Note the capsule and its parachutes just visible against a gap in the dark clouds. Credit: NASA.
The Apollo 13 spacecraft heads toward a splashdown in the South Pacific Ocean. Note the capsule and its parachutes just visible against a gap in the dark clouds. Credit: NASA.

But NASA engineer Jerry Woodfill offers additional insight into the communication delays. He recently spoke with Jerry Bostick, the Flight Dynamics Officer (FIDO) for Apollo 13, who told him, “Many believe the added time resulted from the communication signal skipping, like a stone, over layers of the upper atmosphere because of the shallow entry angle.”

“Bostick likened the radio signals to a stone skipping on a pond, and finally, the signal found a location to sink Earthward,” Woodfill said.

However, this explanation too, leaves questions. Woodfill said he has studied the “signal skipping” phenomenon, and has found information to both support and refute the concept by virtue of when such an occurrence could be expected.

“The consensus was it is a night time phenomena,” Woodfill said. “Apollo 13 entered in daylight in the Pacific and in Houston. Nevertheless, the question to this day demonstrates just how near Apollo 13 came to disaster. If the radio signal almost skipped off the Earth’s atmosphere, one wonders, just how very close was Apollo 13’s capsule and crew near to a fatal skipping into the oblivion of space as well.”

Another “angle” on Apollo 13’s reentry was how it very nearly escaped another potential disaster: landing in a typhoon.

A group of flight controllers gather around the console of Shift 4 Flight Director Glynn Lunney (seated, nearest camera) in the Mission Operations Control Room. Their attention is drawn to a weather map of the proposed landing site in the South Pacific. Among those looking on is Christopher Kraft, Manned Spacecraft Center Deputy Director, (standing, in black suit, right). Credit: NASA.
A group of flight controllers gather around the console of Shift 4 Flight Director Glynn Lunney (seated, nearest camera) in the Mission Operations Control Room. Their attention is drawn to a weather map of the proposed landing site in the South Pacific. Among those looking on is Christopher Kraft, Manned Spacecraft Center Deputy Director, (standing, in black suit, right). Credit: NASA.

“A tropical storm is a retro’s (retrofire officer) worst nightmare,” said Woodfill. “Knowing how unpredictable the movement and intensity of such storms are makes selecting a landing site difficult. No NASA reentry had ever landed in a tropical storm, and Apollo 13 might be the first. Among NASA scientists are meteorologists, and by their best science, they predicted that Tropical Storm Helen would move into the designated Apollo 13 landing site the day of reentry and splashdown.”

If Apollo 13 had splashed down amidst the storm, the capsule may have drifted and been lost at sea. To conserve the entry battery power, the beacon light recovery system had been deactivated. The crew would have been invisible to those looking for the capsule bobbing up and down in the Pacific Ocean. They eventually would have had to blow the hatch, and the Apollo 13 capsule likely would have sunk, similar to Gus Grissom’s Liberty Bell during the Mercury program. But the crew of Apollo 13 might not have been as fortunate as Grissom who had helicopter rescuers overhead quickly pulling him to safety.

However, the decision was made to ignore the weather forecasts, which ended up being fortuitous because Helen ultimately changed course. But then there was the uncertainty of the entry location due to the ‘shallowing’ the spacecraft was experiencing.

“Once more, the retro made the decision to ignore that shallowing at reentry in the same fashion as he had ignored the weathermen’s ominous prediction,” said Woodfill. “In both instances, the retro was correct. He rightly predicted that the drift would not be a problem in the final stages of reentry after the lander was jettisoned. Again, this was altogether fortuitous in that no one knew the lander’s cooling system was the source of the drift. Earlier, however, the retro had compensated for the shallowing drift by bringing Apollo 13 into the correct entry corridor angle via first having the crew fire the lander’s descent engine and later the lander’s thrusters.”

An approximate representation of Apollo 13’s re-entry groundtrack. Click the image for access to a larger pdf version.
An approximate representation of Apollo 13’s re-entry groundtrack. Click the image for access to a larger pdf version.

As it turned out those mysterious extra seconds caused by coming in at a shallow angle were also fortuitous.

While the added time of communications blackout was nail-biting, the more shallow and longer angle “added to the downrange path of Apollo 13, dropping the capsule in calm water so near the waiting aircraft carrier Iwo Jima that the accuracy was among the finest of the program,” Woodfill said.

Revisiting the length of the communications blackout, there are some discrepancies in various sources about the length of the extra time Apollo 13’s blackout time lasted. Some websites lists 25-30 seconds, others a minute. Again, I was unable to find an ‘official’ NASA statement on the subject and the transcript of the technical air to ground voice communications does not include time stamps for the beginning and end of blackout. Additionally, two of the definitive books about Apollo 13 – Lost Moon by Jim Lovell and Jeffrey Kluger, and A Man on the Moon by Andrew Chaikin – don’t give exact numbers on the timing of the blackout.

But Air & Space Magazine quoted Gene Kranz as saying it was 87 seconds.

“Per my mission log it started at 142:39 and ended at 142:45— a total of six minutes,” Kranz told journalist Joe Pappalardo in 2007. “Blackout was 1:27 longer than predicted … Toughest minute and a half we ever had.”

87 seconds also is confirmed by a transmission recorded on one of the ARIA, the Apollo/Advanced Range Instrumentation Aircraft, which provided tracking and telemetry information for the Apollo missions, especially at launch and reentry, when the Manned Spaceflight Network tracking could not.

ARIA 4 had the distinction of being the first to reacquire Apollo 13 after the longer-than-expected communication blackout, as it was near the predicted point of reentry. Captain David Dunn, who served as the Mission Coordinator onboard the ARIA 4 aircraft, provided a recording to historians at the Honeysuckle Creek Tracking Station, who have put together a wonderful history of their role in the Apollo missions.

Captain David Dunn served as the Mission Co-ordinator onboard ARIA 4. Image via Honeysuckle Creek Tracking Station and David Dunn.
Captain David Dunn served as the Mission Co-ordinator onboard ARIA 4. Image via Honeysuckle Creek Tracking Station and David Dunn.

Space Historian Colin Mackellar from the Honeysuckle Creek website told Universe Today that until it was recently published on the Honeysuckle Creek website, the recording had not been heard by anyone other than Dunn’s family. Mackellar explained that it contains simultaneous audio of the NASA Public Affairs commentary, audio of the Flight Director’s loop, the ARIA transmissions and a portion of the Australian Broadcast Commission radio coverage.

Again, you can hear the palpable tension in the recording, which you can listen to at this link. At 7:21 in the audio, as communications blackout nears the predicted end, one of the ARIA communicators asks ARIA 4 if they can see the spacecraft. Negative is the reply.

At 7:55 you can hear Kranz asking if there is any acquisition of signal yet. Again at 8:43, Kranz asks, “Contact yet?” The answer is negative. Finally, at 8:53 in the audio, ARIA 4 reports AOS (acquisition of signal), which is relayed to Kranz. You can hear his relieved exhalation as he replies, “Rog (roger).”

Then comes Kranz saying, “Capcom, why don’t you try giving them a call.”

Capcom: “Odyssey, Houston standing by.”
Swigert: “OK, Joe.”

When the crew splashed down, the official duration time of the mission was 142 hours, 54 minutes and 41 seconds.

Dunn wrote about his experiences for the Honeysuckle Creek history website:

The ARIA 4 Prime Mission Electronic Equipment crew and the flight crew with the ARIA 4 specially equipped C-135 aircraft. Image via Honeysuckle Creek Tracking Station and Captain David Dunn.
The ARIA 4 Prime Mission Electronic Equipment crew and the flight crew with the ARIA 4 specially equipped C-135 aircraft. Image via Honeysuckle Creek Tracking Station and Captain David Dunn.

It required no great imagination to know that back in the US, and in fact all around the world, folks were glued to their TV sets in anticipation, and that Walter Cronkite was holding forth with Wally Schirra on CBS, and at the Houston Space Center breathing had ceased.

But we were there, ground zero, with front row seats and we would be the first to know and the first ones to tell the rest of the world if the Apollo 13 crew had survived…

On all the aircraft and all the airwaves there was complete silence as well as we all listened intently for any signal from Apollo 13.

ARIA 2 had no report of contact; ARIA 3 also had no report.

Then I observed a signal and Jack Homan, the voice radio operator advised me we had contact.

From Apollo 13 came the reply “OK, Joe……” relayed again from our radios to Houston and the rest of the world. Not much, but even such a terse reply was enough to let the world know the spacecraft and its crew had survived. In an age before satellite TV, teleconferencing, and the Internet, it was easy for us in the clouds at 30,000 feet above the splashdown zone to visualize breathing resuming in Houston and around the world.

Dunn concluded, “Now, exactly why would Ron Howard leave such a dramatic moment out of his film? There’s a real mystery!”

Apollo 13 images via NASA. Montage by Judy Schmidt.
Apollo 13 images via NASA. Montage by Judy Schmidt.

Tomorrow: Isolating the Surge Tanks

Previous articles in this series:

Introduction

Part 1: The Failed Oxygen Quantity Sensor

Part 2: Simultaneous Presence of Kranz and Lunney at the Onset of the Rescue

Part 3: Detuning the Saturn V’s 3rd Stage Radio

Part 4: Early Entry into the Lander

Part 5: The CO2 Partial Pressure Sensor

Find all the original “13 Things That Saved Apollo 13″ (published in 2010) at this link.

Posted on by Nancy Atkinson

13 MORE Things That Saved Apollo 13, part 5: The CO2 Partial Pressure Sensor

Headlines from the Topeka (Kansas) Daily Capital newspaper from April 1970 told of the perils facing the crew of Apollo 13.

The Apollo 13 accident crippled the spacecraft, taking out the two main oxygen tanks in the Service Module. While the lack of oxygen caused a lack of power from the fuel cells in the Command Module, having enough oxygen to breathe in the lander rescue craft really wasn’t an issue for the crew. But having too much carbon dioxide (CO2) quickly did become a problem.

The Lunar Module, which was being used as a lifeboat for the crew, had lithium hydroxide canisters to remove the CO2 for two men for two days, but on board were three men trying to survive in the LM lifeboat for four days. After a day and a half in the LM, CO2 levels began to threaten the astronauts’ lives, ringing alarms. The CO2 came from the astronauts’ own exhalations.

Jerry Woodfill working in the Apollo Mission Evaluation Room. Credit: Jerry Woodfill.
Jerry Woodfill working in the Apollo Mission Evaluation Room. Credit: Jerry Woodfill.

NASA engineer Jerry Woodfill helped design and monitor the Apollo caution and warning systems. One of the systems which the lander’s warning system monitored was environmental control.

Like carbon monoxide, carbon dioxide can be a ‘silent killer’ – it can’t be detected by the human senses, and it can overcome a person quickly. Early on in their work in assessing the warning system for the environmental control system, Woodfill and his co-workers realized the importance of a CO2 sensor.

“The presence of that potentially lethal gas can only be detected by one thing – an instrumentation transducer,” Woodfill told Universe Today. “I had an unsettling thought, ‘If it doesn’t work, no one would be aware that the crew is suffocating on their own breath.’”

The sensor’s job was simply to convert the content of carbon dioxide into an electrical voltage, a signal transmitted to all, both the ground controllers, and the cabin gauge.

Location of Caution And Warning System lights in the Command Module. Credit: Project Apollo - NASSP.
Location of Caution And Warning System lights in the Command Module. Credit: Project Apollo – NASSP.

“My system had two categories of alarms, one, a yellow light for caution when the astronaut could invoke a backup plan to avoid a catastrophic event, and the other, an amber warning indication of imminent life-threatening failure,” Woodfill explained. “Because onboard CO2 content rises slowly, the alarm system simply served to advise and caution the crew to change filters. We’d set the threshold or “trip-level” of the alarm system electronics to do so.”

And soon after the explosion of Apollo 13’s oxygen tank, the assessment of life-support systems determined the system for removing carbon dioxide (CO2) in the lunar module was not doing so. Systems in both the Command and Lunar Modules used canisters filled with lithium hydroxide to absorb CO2. Unfortunately the plentiful canisters in the crippled Command Module could not be used in the LM, which had been designed for two men for two days, but on board were three men trying to survive in the LM lifeboat for four days: the CM had square canisters while the LM had round ones.

The fix for the lithium hydroxide canister is discussed at NASA Mission Control prior to having the astronauts implement the procedure in space. Credit: NASA
The fix for the lithium hydroxide canister is discussed at NASA Mission Control prior to having the astronauts implement the procedure in space. Credit: NASA

As was detailed so well by Jim Lovell in his book “Lost Moon,” and subsequently portrayed in detail in the movie “Apollo 13,” a group of engineers led by Ed Smylie, who developed and tested life support systems for NASA, constructed a duct-taped-jury-rigged CO2 filter, using only what was aboard the spacecraft to convert the plentiful square filters to work in the round LM system. (You can read the details of the system and its development in our previous “13 Things” series.)

Needless to say, the story had a happy ending. The Apollo 13 accident review board reported that Mission Control gave the crew further instructions for attaching additional cartridges when needed, and the carbon dioxide partial pressure remained below 2mm Hg for the remainder of the Earth-return trip.

But the story of Jerry Woodfill and the CO2 sensor can also serve as an inspiration to anyone who feels disappointed in their career, especially in STEM (science, technology, engineering and math) fields, feeling that perhaps what you are doing doesn’t really matter.

“I think almost everyone who came to NASA wanted to be an astronaut or a flight director, and I always felt my career was diminished by the fact that I wasn’t a flight controller or astronaut or even a guidance and navigation engineer,” Woodfill said. “I was what was called an instrumentation engineer. Others had said this is the kind of job that was superfluous.”

Woodfill worked on the spacecraft metal panels which housed the switches and gauges. “Likely, a mechanical engineer might not find such a job exciting,” he said, “and to think, I had once studied field theory, quantum electronics and other heady disciplines as a Rice electrical engineering candidate.”

NASA engineer Jerry Woodfill with Chris Kraft, former NASA flight director and manager, in early 2015. Image courtesy Jerry Woodfill.
NASA engineer Jerry Woodfill with Chris Kraft, former NASA flight director and manager, in early 2015. Image courtesy Jerry Woodfill.

Later, to add to the discouragement was a conversation with another engineer. “His comment was, ‘No one wants to be an instrumentation engineer,” Woodfill recalled, “thinking it is a dead-end assignment, best avoided if one wants to be promoted. It seemed that instrumentation was looked upon as a sort of ‘menial servant’ whose lowly job was servicing end users such as radar, communications, electrical power even guidance computers. In fact, the users could just as readily incorporate instrumentation in their devices. Then, there would be no need for an autonomous group of instrumentation guys.”

But after some changes in management and workforce, Woodfill became the lead Command Module Caution and Warning Project Engineer, as well as the Lunar Lander Caution and Warning lead – a job he thought no one else really wanted.

But he took on the job with gusto.

“I visited with a dozen or more managers of items which the warning system monitored for failure,” Woodfill said. He convened a NASA-Grumman team to consider how best to warn of CO2 and other threats. “We needed to determine at what threshold level should the warning system ring an alarm. All the components must work, starting with the CO2 sensor. The signal must pass from there through the transmitting electronics, wiring, ultimately reaching my warning system “brain” known as the Caution and Warning Electronics Assembly (CWEA).”

And so, just hours after the explosion on Apollo 13, the Mission Engineering Manager summoned Woodfill to his office.

“He wanted to discuss my warning system ringing carbon dioxide alarms,” Woodfill said. “I explained the story, placing before him the calibration curves of the CO2 Partial Pressure Transducer, showing him what this instrumentation device is telling us about the threat to the crew.”

Now, what Woodfill had once had deemed trivial was altogether essential for saving the lives of an Apollo 13 astronaut crew. Yes, instrumentation was just as important as any advanced system aboard the command ship or the lunar lander.

“And, I thought, without it, likely, no one would have known the crew was in grave danger,” said Woodfill, “let alone how to save them. Instrumentation engineering wasn’t a bad career choice after all!”

The Apollo 13 fix -- complete with duct tape -- of making a square canister fit into a round hole. Credit: NASA
The Apollo 13 fix — complete with duct tape — of making a square canister fit into a round hole. Credit: NASA
This is an example of the team effort that saved Apollo 13: that the person who was working on the transducer years prior was just as significant as the person who came up with the ingenious duct tape solution.

And it was one of the additional things that saved Apollo 13.

Apollo 13 images via NASA. Montage by Judy Schmidt.
Apollo 13 images via NASA. Montage by Judy Schmidt.

Additional articles in this series:

Introduction

Part 1: The Failed Oxygen Quantity Sensor

Part 2: Simultaneous Presence of Kranz and Lunney at the Onset of the Rescue

Part 3: Detuning the Saturn V’s 3rd Stage Radio

Part 4: Early Entry into the Lander

Part 5: The CO2 Partial Pressure Sensor

Part 6: The Mysterious Longer-Than-Expected Communications Blackout

Part 7: Isolating the Surge Tank

Part 8: The Indestructible S-Band/Hi-Gain Antenna

Part 9: Avoiding Gimbal Lock

Part 10: ‘MacGyvering’ with Everyday Items

Part 11: The Caution and Warning System

Part 12: The Trench Band of Brothers

Find all the original “13 Things That Saved Apollo 13″ (published in 2010) at this link.

Posted on by Nancy Atkinson

13 MORE Things That Saved Apollo 13, part 4: Early Entry into the Lander

Apollo 13 images via NASA. Montage by Judy Schmidt.

To celebrate the 45th anniversary of the Apollo 13 mission, Universe Today is featuring “13 MORE Things That Saved Apollo 13,” discussing different turning points of the mission with NASA engineer Jerry Woodfill.

During the first two days of the Apollo 13 mission, it was looking like this was going to be the smoothest flight of the program. As Capcom Joe Kerwin commented at 46:43 Mission Elapsed Time (MET), “The spacecraft is in real good shape as far as we are concerned. We’re bored to tears down here.”

Everything was going well, and in fact the crew was ahead of the timeline. Commander Jim Lovell and Lunar Module Pilot Fred Haise had entered the Aquarius Lunar Module 3 hours earlier than the flight plan had scheduled, wanting to check out the pressure in the helium tank – which had given some erroneous readings in ground tests before the launch. Everything checked out OK.

Opening up Aquarius early may have been one more thing that saved Apollo 13, says NASA engineer Jerry Woodfill.

“The first time the hatches between both vehicles are opened is a time consuming process,” Woodfill told Universe Today. “It’s as though a bank teller is requested to provide a customer access to a safety deposit box behind two locked vault doors.”

The removable hatch in the Odyssey Command Module had to be tied down and stowed before entering the tunnel for access to the second door, the lander’s entry hatch. Time was required for pressure equalization process so that the tunnel, command ship and lander were at one uniform pressure.

Often, there was a putrid, burnt insulation odor when the hatch to the LM was first opened, as previous crews described, so normally time was allowed for the smell to dissipate. All of these tasks were dealt with by about 55 hours MET, much earlier than originally planned. For some reason, the LM Pilot even brought the lander’s activation check list back into the command ship for study, though activation was scheduled hours away.

“Perhaps, this would be Fred Haise’s bedtime book to read preparing himself for sleep,” Woodfill said.

Flight Director Gene Kranz (closest to the camera) watches Fred Haise on a screen in Mission Control during a broadcast back to Earth, just 17 minutes and 42 seconds before the explosion. Credit: NASA.
Flight Director Gene Kranz (closest to the camera) watches Fred Haise on a screen in Mission Control during a broadcast back to Earth, just 17 minutes and 42 seconds before the explosion. Credit: NASA.

But first, the crew provided a 49-minute TV broadcast showing how easily they moved about in weightlessness in the cramped spacecraft.

Then, it happened. Nine minutes later, at 55:54:56 MET, came the explosion of the oxygen tank in the Service Module. Despite ground and crew efforts to understand the problem, confusion reigned.

13 minutes after the explosion, Lovell looked out one of Odyssey’s windows and reported, “We are venting something out into space,” and quickly the crew and ground controllers knew they were losing oxygen. Without oxygen, the fuel cells that provided all the power to the CM would die. Tank 2, of course, was gone with the explosion and the plumbing on Tank 1 was severed, so the oxygen was bleeding off from that tank, as well.

Capcom Jack Lousma speaks to the crew of Apollo 13 from Mission Control. Credit: NASA.
Capcom Jack Lousma speaks to the crew of Apollo 13 from Mission Control. Credit: NASA.
At one hour, 29 seconds after the explosion, the new Capcom Jack Lousma said after instructions from Flight Director Glynn Lunney, “[The oxygen] is slowly going to zero, and we are starting to think about the LM lifeboat.” From space, astronaut Jack Swigert replied, “That’s what we have been thinking about too.”

At that point, only fifteen minutes of power remained in the Command Module.

“Fifteen minutes more and the entire assemblage might have been a corpse with no radio, no guidance, no oxygen flowing into the cabin to keep Lovell, Haise and Swigert alive,” said Woodfill. “Certainly, it was fortuitous circumstances that led to opening the LM early. Simply consider how much time it would have taken to remove both hatches, stabilize and inspect the tunnel and lander interior. Add to this the time required to power up the lander’s life support systems. As it was, they had an open pathway into a safe haven, a lifeboat, called the lunar lander, crucial to survival.”

If the LM had not been opened, the crew would have likely run out of time before the Command Module’s batteries died, which would have created several problems.

As we discussed five years ago in one of the original “13 Things” articles, all the guidance parameters which would help direct the ailing ship back to Earth were in Odyssey’s computers, and needed to be transferred over to Aquarius. Without power from the fuel cells, they kept the Odyssey alive by using the reentry batteries as an emergency measure. These batteries were designed to be used during reentry when the crew returned to Earth, and were good for limited number of hours during the time the crew would jettison the Service Module and reenter with only the tiny Command Module capsule.

“Those batteries were not ever supposed to be used until they got ready to reenter the Earth’s atmosphere,” said Woodfill. “If those batteries had been depleted, that would have been one of the worst things that could have happened. The crew worked as quickly as they could to transfer the guidance parameters, but any extra time or problem, and we could have been without those batteries. Those batteries were the only way the crew could have survived reentry. This is my take on it, but the time saved by not having to open up the Lunar Module helped those emergency batteries have just enough power in them so they could recharge them and reenter.”

By 58:40 MET, the guidance information from the Command Module computer had been transferred to the LM guidance system, the LM was fully activated and the Command and Service Module systems were turned off.

Mission Control and the crew had successfully managed the first of many “seat of the pant” procedures they would need to do in order to bring the crew of Apollo 13 back home.

Additional articles in this series:

Introduction

Part 1: The Failed Oxygen Quantity Sensor

Part 2: Simultaneous Presence of Kranz and Lunney at the Onset of the Rescue

Part 3: Detuning the Saturn V’s 3rd Stage Radio

Part 4: Early Entry into the Lander

Part 5: The CO2 Partial Pressure Sensor

Part 6: The Mysterious Longer-Than-Expected Communications Blackout

Part 7: Isolating the Surge Tank

Part 8: The Indestructible S-Band/Hi-Gain Antenna

Part 9: Avoiding Gimbal Lock

Part 10: ‘MacGyvering’ with Everyday Items

Part 11: The Caution and Warning System

Part 12: The Trench Band of Brothers

Find all the original “13 Things That Saved Apollo 13″ (published in 2010) at this link.

Posted on by Nancy Atkinson

13 MORE Things That Saved Apollo 13, part 3: Detuning the Saturn V’s 3rd Stage Radio

Apollo 13 images via NASA. Montage by Judy Schmidt.

To celebrate the 45th anniversary of the Apollo 13 mission, Universe Today is featuring “13 MORE Things That Saved Apollo 13,” discussing different turning points of the mission with NASA engineer Jerry Woodfill.

Very quickly after the explosion of Oxygen Tank 2 in Apollo 13’s service module, it became apparent the Odyssey command module was dying. The fuel cells that created power for the Command Module were not working without the oxygen. But over in the Aquarius lunar lander, all the systems were working perfectly. It didn’t take long for Mission Control and the crew to realize the Lunar Module could be used as a lifeboat.

The crew quickly powered up the LM and transferred computer information from Odyssey to Aquarius. But as soon as they brought the LM communications system on line another problem developed.

The Apollo 13 crew couldn’t hear Mission Control.

Screenshot from Apollo footage of Jim Lovell and Jack Swigert. Credit: NASA
Screenshot from Apollo footage of Jim Lovell and Jack Swigert. Credit: NASA

The crew radioed they were getting lots of background static, and at times, they reported communications from the ground were “unreadable.”
Additionally, the Manned Space Flight Network (MSFN) tracking stations around the world were having trouble “hearing” the Apollo 13 spacecraft’s radio broadcasting the tracking data.

“Without reliable knowledge of where the vehicle was or was going might result in disaster,” said NASA engineer Jerry Woodfill.

What was going on?

The dilemma was that two radio systems were using the same frequency. One was the transmitter from the LM’s S-band antenna. The other was the broadcast from the spent third stage of the Saturn V, known as the S-IVB.

The seismic station at the Apollo 12 site. The seismometer monitors the level of ground motion to detect arriving seismic waves. The instrument (left) is protected by metal foil against the varying temperatures on the lunar surface that produce large thermal stresses . Credit: NASA
The seismic station at the Apollo 12 site. The seismometer monitors the level of ground motion to detect arriving seismic waves. The instrument (left) is protected by metal foil against the varying temperatures on the lunar surface that produce large thermal stresses . Credit: NASA

As part of a science experiment, NASA had planned for crashing Apollo 13’s S-IVB into the Moon’s surface. The Apollo 12 mission had left a seismometer on the Moon, and an impact could produce seismic waves that could be registered for hours on these seismometers. This would help scientist to better understand the structure of the Moon’s deep interior.

In Apollo 13’s nominal flight plan, the lander’s communications system would only be turned on once the crew began preparing for the lunar landing. This would have occurred well after the S-IVB had crashed into the Moon. But after the explosion, the flight plan changed dramatically.

The flight profile of an Apollo mission to the Moon, distances not to scale. Note the Saturn V 3rd stage flight path. Credit: NASA.
The flight profile of an Apollo mission to the Moon, distances not to scale. Note the Saturn V 3rd stage flight path. Credit: NASA.

But with both the Saturn IVB and the LM’s transmitters on the same frequency, it was like having two radio stations on the same spot on the dial. Communications systems on both ends were having trouble locking onto the correct signal, and instead were getting static or no signal at all.

The Manned Space Flight Network (MSFN) for the Apollo missions had three 85 foot (26 meter) antennas equally spaced around the world at Goldstone, California, Honeysuckle Creek, Australia and Fresnedillas (near Madrid), Spain.

According to historian Hamish Lindsay at Honeysuckle Creek, there was initial confusion. The technicians at the tracking sites immediately knew what the problem was and how they could fix it, but Mission Control wanted them to try something else.

“The Flight Controllers at Houston wanted us to move the signal from the Lunar Module across to the other side of the Saturn IVB signal to allow for expected doppler changes,” Hamish quoted Bill Wood at the Goldstone Tracking Station. ”Tom Jonas, our receiver-exciter engineer, yelled at me, ‘that’s not going to work! We will end up locking both spacecraft to one up-link and wipe out the telemetry and voice contact with the crew.’”

At that point, without the correct action, Houston lost telemetry with the Saturn IVB and voice contact with the spacecraft crew.

But luckily, the big 64 meter Mars antenna at Goldstone was already being switched over to help with the Apollo emergency and “their narrower beam width managed to discriminate between the two signals and the telemetry and voice links were restored,” said Wood.

That stabilized the communications. But then it was soon time to switch to the tracking station at Honeysuckle Creek.

The Honeysuckle antenna by night. Photo by Hamish Lindsay.
The Honeysuckle antenna by night.
Photo by Hamish Lindsay.

There, Honeysuckle Creek Deputy Director Mike Dinn and John Mitchell, Honeysuckle Shift Supervisor were ready. Both had foreseen a potential problem with the two overlapping frequency systems and before the mission had discussed it with technicians at Goddard Spaceflight Center about what they should do if there was a communication problem of this sort.

When Dinn had been looking for emergency procedures, Mitchell had proposed the theory of getting the LM to switch off and then back on again. Although nothing had been written down, when the emergency arose, Dinn knew what they had to do.

“I advised Houston that the only way out of this mess was to ask the astronauts in the LM to turn off its signal so we could lock on to the Saturn IVB, then turn the LM back on and pull it away from the Saturn signal,” said Dinn.

It took an hour for Mission Control in Houston to agree to the procedure.

“They came back in an hour and told us to go ahead,” said Mitchell, “and Houston transmitted the instructions up to the astronauts ‘in the blind’ hoping the astronauts could hear, as we couldn’t hear them at that moment. The downlink from the spacecraft suddenly disappeared, so we knew they got the message. When we could see the Saturn IV downlink go way out to the prescribed frequency, we put the second uplink on, acquired the LM, put the sidebands on, locked up and tuned away from the Saturn IVB. Then everything worked fine.”

Dinn said they were able to “pull” the frequencies apart by tuning the station transmitters appropriately.

Technicians at the Honeysuckle Creek tracking station near Canberra, Australia work to maintain communications with Apollo 13. Credit: Hamish Lindsay.
Technicians at the Honeysuckle Creek tracking station near Canberra, Australia work to maintain communications with Apollo 13. Credit: Hamish Lindsay.

This action, said Jerry Woodfill, was just one more thing that saved Apollo 13.

“The booster stage’s radio was de-turned sufficiently from the frequency of the LM S-Band so that the NASA Earth Stations recognized the signal required to monitor Apollo 13’s orbit at lunar distances,” explained Woodfill. “This was altogether essential for navigating and monitoring the crucial mid-course correction burn which restored the free-return trajectory as well as the set-up of the subsequent PC+2 burn to speed the trip home needed to conserve water, oxygen and water stores to sustain the crew.”

You can hear some of the garbled communications and Mission Control issuing instructions how to potentially deal with the problem at this link from Honeysuckle Creek’s website.

As for the S-IVB science experiment, the 3rd stage crashed successfully on the Moon, providing some of the first data for understanding the Moon’s interior.

Later, on hearing that the stage had hit the Moon, Apollo 13 Commander Jim Lovell said, “Well, at least one thing worked on this mission!”

(Actually, in spite of the Apollo 13 accident, a total of four science experiments were successfully conducted on Apollo 13.)

In early 2010, NASA’s Lunar Reconnaissance Orbiter spacecraft imaged the crater left by the Apollo 13 S-IVB impact.

On April 14th 1970, the Apollo 13 Saturn IVB upper stage impacted the moon north of Mare Cognitum, at -2.55° latitude, -27.88° East longitude. The impact crater, which is roughly 30 meters in diameter, is clearly visible in the Lunar Reconnaissance Orbiter Camera's (LROC) Narrow Angle Camera image. Credit: NASA/Goddard/Arizona State University.
On April 14th 1970, the Apollo 13 Saturn IVB upper stage impacted the moon north of Mare Cognitum, at -2.55° latitude, -27.88° East longitude. The impact crater, which is roughly 30 meters in diameter, is clearly visible in the Lunar Reconnaissance Orbiter Camera’s (LROC) Narrow Angle Camera image. Credit: NASA/Goddard/Arizona State University.

Thanks to space historian Colin Mackellar from the Honeysuckle Creek website, along with technician Hamish Lindsay and his excellent account of the Honeysuckle Creek Tracking station and their role in the Apollo 13 mission.

You can read a previous article we wrote about Honeysuckle Creek: How We *Really* Watched Television from the Moon.

Additional articles in this series:

Introduction

Part 1: The Failed Oxygen Quantity Sensor

Part 2: Simultaneous Presence of Kranz and Lunney at the Onset of the Rescue

Part 3: Detuning the Saturn V’s 3rd Stage Radio

Part 4: Early Entry into the Lander

Part 5: The CO2 Partial Pressure Sensor

Part 6: The Mysterious Longer-Than-Expected Communications Blackout

Part 7: Isolating the Surge Tank

Part 8: The Indestructible S-Band/Hi-Gain Antenna

Part 9: Avoiding Gimbal Lock

Part 10: ‘MacGyvering’ with Everyday Items

Part 11: The Caution and Warning System

Part 12: The Trench Band of Brothers

Find all the original “13 Things That Saved Apollo 13″ (published in 2010) at this link.

Posted on by Nancy Atkinson

13 MORE Things That Saved Apollo 13, part 2: Simultaneous Presence of Kranz and Lunney at the Onset of the Rescue

Apollo 13 images via NASA. Montage by Judy Schmidt.

To celebrate the 45th anniversary of the Apollo 13 mission, Universe Today is featuring “13 MORE Things That Saved Apollo 13,” discussing different turning points of the mission with NASA engineer Jerry Woodfill.

Understandably, it was chaotic in both Mission Control and in the spacecraft immediately after the oxygen tank exploded in Apollo 13’s Service Module on April 13, 1970.

No one knew what had happened.

“The Apollo 13 failure had occurred so suddenly, so completely with little warning, and affected so many spacecraft systems, that I was overwhelmed,” wrote Sy Liebergot in his book, Apollo EECOM: Journey of a Lifetime. “As I looked at my data and listened to the voice report, nothing seemed to make sense.”

But somehow, within 53 minutes of the explosion, the ship was stabilized and an emergency plan began to evolve.

“Of all of the things that rank at the top of how we got the crew home,” said astronaut Ken Mattingly, who was sidelined from the mission because he might have the measles, “was sound management and leadership.”

Gerry Griffin, Gene Kranz, and Glynn Lunney celebrate the Apollo 13 recovery. Credit: NASA.
Gerry Griffin, Gene Kranz, and Glynn Lunney celebrate the Apollo 13 recovery. Credit: NASA.

By chance, at the time of the explosion, two Flight Directors — Gene Kranz and Glynn Lunney — were present in Mission Control. NASA engineer Jerry Woodfill feels having these two experienced veterans together at the helm at that critical moment was one of the things that helped save the Apollo 13 crew.

“The scenario resulted from the timing,” Woodfill told Universe Today, “with the explosion occurring at 9:08 PM, and Kranz as Flight Director, but with Lunney present to assume the “hand-off” around 10:00 PM. That assured that the expertise of years of flight control leadership was conferring and assessing the situation. The presence of these colleagues, simultaneously, had to be one of the additional thirteen things that saved Apollo 13. With Lunney looking on, the transition was as seamless as a co-pilot taking the helm from a pilot of a 747 passenger jet.”

Woodfill made an additional comparison: “Having the two Flight Directors on hand at that critical moment is like having Michael Jordan and Magic Johnson on a six-man basketball squad and the referee ignoring any fouls their team might make.”

Lunney described the time of the explosion in an oral history project at Johnson Space Center:

“Gene was on the team before me and he had had a long day in terms of hours. …And shortly before his shift was scheduled to end is when the “Houston, we’ve got a problem” report came in. And at first, it was not terribly clear how bad this problem was. And one of the lessons that we had learned was, “Don’t go solving something that you don’t know exists.” You’ve got to be sure … So, it was generally a go slow, let’s not jump to a conclusion, and get going down the wrong path…. We had a number of situations to deal with.”
The “not jumping to conclusions” was equally expressed by Kranz when he told his team, “Let’s solve the problem, but let’s not make it any worse by guessing.”

The presence of Kranz and Lunney, simultaneously, is especially obvious reading Gene Kranz’s book, Failure Is Not an Option.

“Kranz captures the wealth of “brain power” present at the moment of the explosion,” said Woodfill. “Besides both Kranz and Lunney, their entire teams overlapped. Yes, there were two squads on the floor competing with the dire opponents who threatened the crew’s survival.”

The crew’s survival was foremost in the minds of the Flight Directors. “We will never surrender, we will never give up a crew,” Kranz said later.

Apollo astronauts at Mission Control during Apollo 13. Credit: NASA.
Apollo astronauts at Mission Control during Apollo 13. Credit: NASA.

Perhaps, the most obvious evidence of how fortuitous the presence of both Kranz and Lunney was, Kranz recorded on page 316-317 of his book. The pair refuses to accept the more popular but potentially fatal decision (a direct abort) to speed the crew’s return to Earth using the damaged command ship’s engine. The direct abort would have been to jettison the lander and fire the compromised command ship’s engine to potentially quicken the return to Earth by 50 hours.

Mattingly recalled those early minutes in Mission Control after the explosion.

Ken Mattingly in Mission Control. Credit: NASA.
Ken Mattingly in Mission Control. Credit: NASA.

“The philosophy was ‘never get in the way of success,’” said Mattingly, speaking at a 2010 event at the Smithsonian Air and Space Museum. “We had choices, we debated about turning immediately around and coming home or going around the moon. In listening to all of those discussions, we never closed the door about any option of getting home. We didn’t know yet how we were going to get there, but you always make sure you don’t take a step that would jeopardize it.”

And so, with the help of their teams, the two Flight Directors quickly ran through all the options, the pros and cons, and – again – within 53 minutes after the accident they made the decision to have the crew continue their trajectory around the Moon.

Damage to the Apollo 13 spacecraft from the oxygen tank explosion. Credit: NASA
Damage to the Apollo 13 spacecraft from the oxygen tank explosion. Credit: NASA

Later, when Jim Lovell commented on viewing the damaged Service Module when it was jettisoned before the crew re-entered Earth’s atmosphere — “There’s one whole side of that spacecraft missing. Right by the high gain antenna, the whole panel is blown out, almost from the base to the engine,” — it was indeed an ominous look at what might have ensued using it for a quick return to Earth.

Read more about the decision to use the LM for propulsion in an article from the original “13 Things” series here.

By the end of the Lunney team’s shift about ten hours after the explosion, Mission Control had put the vehicle back on an Earth return trajectory, the inertial guidance platform had been transferred to the Lunar Module, and the Lunar Module was stable and powered up for the burn planned the would occur after the crew went around the Moon. “We had a plan for what that maneuver would be, and we had a consumable profile that really left us with reasonable margins at the end,” Lunney said.

Apollo 13's view from Aquarius as it rounds the Moon, with the Command Module at right. Credit: NASA/Johnson Space Center.
Apollo 13’s view from Aquarius as it rounds the Moon, with the Command Module at right. Credit: NASA/Johnson Space Center.

Kranz described the scene in an interview with historians at the Honeysuckle Creek Tracking Station in Australia:

“We had many problems here – we had a variety of survival problems, we had electrical management, water management, and we had to figure out how to navigate because the stars were occluded by the debris cloud surrounding the spacecraft. Basically we had to turn a two day spacecraft into a four and a half day spacecraft with an extra crewmember to get the crew back home. We were literally working outside the design and test boundaries of the spacecraft so we had to invent everything as we went along.”

A look at the transcripts of the conversations between Flight Controllers, Flight Directors and support engineers in the Mission Evaluation Room reveals the methodical working of the problems by the various teams. Additionally, you can see how seamlessly the teams worked together, and when one shift handed off to another, everything was communicated.

Lunney explains:

“The other thing I would say about it is, and we talked about Flight Directors and teams, equally important was the fact that, during those flights, we had this Operations team that you have seen in the Control Center in the back rooms around it and we sort of had our own way of doing things in our own team, and we were fully prepared to decide whatever had to be decided. But in addition to that, we had the engineering design teams that would follow the flight along and look at various problems that occurred and put their own disposition on them. …That was part of this network of support. People had their certain jobs to do. They knew what it was. They knew how they fit in. And they were anticipating and off doing it.”

Without the leadership of the Flight Directors, keeping the teams focused and on-task, the outcome of the Apollo 13 mission may have been much different.

“It is the experience of these two, Kranz and Lunney, working together which likely saved the crew from what might have been certain death,” said Woodfill.

Additional articles in this series:

Introduction

Part 1: The Failed Oxygen Quantity Sensor

Part 2: Simultaneous Presence of Kranz and Lunney at the Onset of the Rescue

Part 3: Detuning the Saturn V’s 3rd Stage Radio

Part 4: Early Entry into the Lander

Part 5: The CO2 Partial Pressure Sensor

Part 6: The Mysterious Longer-Than-Expected Communications Blackout

Part 7: Isolating the Surge Tank

Part 8: The Indestructible S-Band/Hi-Gain Antenna

Part 9: Avoiding Gimbal Lock

Part 10: ‘MacGyvering’ with Everyday Items

Part 11: The Caution and Warning System

Part 12: The Trench Band of Brothers

Find all the original “13 Things That Saved Apollo 13″ (published in 2010) at this link.

Posted on by Nancy Atkinson

13 MORE Things That Saved Apollo 13, part 1: The Failed Oxygen Quantity Sensor

Apollo 13 images via NASA. Montage by Judy Schmidt.

In our original series 5 years ago on the “13 Things That Saved Apollo 13,” the first item we discussed was the timing of the explosion. As NASA engineer Jerry Woodfill told us, if the tank was going to rupture and the crew was going to survive the ordeal, the explosion couldn’t have happened at a better time.

An explosion earlier in the mission (assuming it would have occurred after Apollo 13 left Earth orbit) would have meant the distance and time to get back to Earth would have been so great that there wouldn’t have been sufficient power, water and oxygen for the crew to survive. An explosion later, perhaps after astronauts Jim Lovell and Fred Haise had already descended to the lunar surface, and all three crew members wouldn’t have been able to use the lunar lander as a lifeboat. Additionally, the two spacecraft likely couldn’t have docked back together, and without the descent stage’s consumables left on the Moon (batteries, oxygen, etc.) that would have been a fruitless endeavor.

Now, for our first article in our subsequent series “13 MORE Things That Saved Apollo 13,” we’re going to revisit that timing, but look more in detail as to WHY the explosion happened when it did, and how it affected the rescue of the crew. The answer lies with the failure of a pressure sensor in Oxygen Tank 2, an issue unrelated to the uninsulated wires in the tank that caused the explosion.

Apollo 13 crew: Jim Lovell, Jack Swigert and Fred Haise. Credit: NASA
Apollo 13 crew: Jim Lovell, Jack Swigert and Fred Haise. Credit: NASA

Most who are familiar with the story of Apollo 13 are acquainted with the cause of the explosion, later determined by an accident investigation committee led by Edgar Cortright, Director of the Langley Research Center.

The tank had been dropped five years before the flight of Apollo 13, and no one realized the vent tube on the oxygen tank was jarred out of alignment. After a Count Down Demonstration Test (CDDT) conducted on March 16, 1970 when all systems were tested while the Apollo 13 spacecraft sat atop the Saturn V rocket on the launch-pad, the cold liquid oxygen would not empty out of Oxygen Tank 2 through that flawed vent pipe.

The normal approach was to use gaseous oxygen to push the liquid oxygen out of the tank through the vent pipe. Since that wasn’t working, technicians decided the easiest and quickest way to empty the liquid oxygen would be to boil it off using the heaters in the tank.

A graphic depicting the details of oxygen tank number 2 and the heater and thermostat unit. Credit: NASA.
A graphic depicting the details of oxygen tank number 2 and the heater and thermostat unit. Credit: NASA.

“In each oxygen tank were heaters and a paddle wheel fan,” Woodfill explained. “The heater and fan (stirrer) device encouraged a portion of the cold liquid 02 to turn into a higher pressure 02 gas and flow into the fuel cells. A fan also known as the cryo-stirrer was powered each time the heater was powered. The fan served to stir the liquid 02 to assure it was uniformly consistent in density.”

To protect the heater from being overly hot, a switch-like device called a relay turned off heater power anytime the temperature exceeded 80 degrees F. Also, there was a temperature gauge which technicians on the ground could monitor if temperature exceeded 80 degree F.

The original Apollo spacecraft worked on 28 volts of electricity, but after the 1967 fire on the Launchpad for Apollo 1, the Apollo spacecraft’s electrical systems had been modified to handle 65 volts from the external ground test equipment. Unfortunately Beech, the tank’s manufacturer failed to change out this tank, and the heater safety switch was still set for 28 volt operation.

“When the heater was powered up to vent the tank, the higher voltage “fused” the relay contacts so that the switch could not turn off power when the temperature of the tank exceeded 80 degrees F (27 C),” said Woodfill.

Additionally, the temperature gauge on the ground test panel only went to 88 degrees F (29.5 C), so no one was aware of this excessive heat.

A graphic of the interior of the Apollo 13 Service Module and the location of the oxygen tanks relative to the other systems. Credit: NASA.
A graphic of the interior of the Apollo 13 Service Module and the location of the oxygen tanks relative to the other systems. Credit: NASA.

“As a result,” said Woodfill, “the heater and the wires which powered it reached estimated temperatures of around 1000 degrees F. (538°C), hot enough to melt the Teflon insulation on the heater wires and leave portions of them bare. Bare wires meant the potential for a short-circuit and an explosion since these wires were immersed in the liquid oxygen.”

Because the tank had been dropped, and because its heater design had not been updated for 65 volt operation, the tank was a virtual bomb, Woodfill said. Anytime power was applied to those heaters to stir the tank’s liquid oxygen, an explosion was possible.

At 55:54:53 Mission Elapsed Time (MET), the crew was asked to conduct a stir of the oxygen tanks. It was then that the damaged wires in Oxygen Tank 2 shorted out and the insulation ignited. The resulting fire rapidly increased pressure beyond its nominal 1,000 psi (7 MPa) limit and either the tank or the tank dome failed.

But back to the quantity sensor on Oxygen Tank 2. For a reason yet to be understood, during the early part of the Apollo 13 flight, the sensor failed. Prior to launch, that Tank 2 quantity sensor was being monitored by the onboard telemetry system, and it apparently worked perfectly.

“The failure of that probe in space is, perhaps, the most important reason Apollo 13’s crew lived,” said Woodfill.

Here’s the explanation of why Woodfill makes that claim.

Cover to the Apollo 13 flight plan. Credit: NASA.
Cover to the Apollo 13 flight plan. Credit: NASA.

Woodfill’s research of Apollo 13 indicated that standard operating procedure (SOP) had Mission Control request a stirring of the cryos approximately every 24 hours. For the Apollo 13 mission, the first stir came about 24 hours into the mission (23:20:23 MET). Ordinarily, the next cryo stir would not be called for until 24 hours later. The heater-cryo stir procedure was done to assure accuracy of the quantity gauge and proper operation of the system through the elimination of O2 stratification. The sensor read more accurately because the stir made the liquid oxygen more uniform and less stratified. After the first stir, 87 % remaining oxygen quantity was indicated, a bit ahead of expectations. The next stir came about a day later, about 46:40 MET.

At the time of this second heater-cryo-stir, Oxygen Tank 2’s quantity sensor failed. Post mission analysis by the investigation committee indicated the failure was not related to the bare heater wires.

The loss of ability to monitor Oxygen Tank 2’s quantity caused mission control to radio to the crew: “(Because the quantity sensor failed,) we’re going to be requesting you stir the cryos every six hours to help gage how much 02 is in tank 2.”

However, Mission Control chose to perform some analysis of the situation in Tank 2 by calling for another stir, not at 53 hours MET but at 47:54:50 MET and still another at 51:07:41 . Because the other oxygen tank, Tank 1, indicated a low pressure, both tanks were stirred at 55:53.

“Count the number of stirs since launch,” Woodfill said. “1. at 23:20:23, 2. at 46:40, 3. at 47:54:50, 4. at 51:07:44 and 5. at 55:53. There were five applications of current to those bare heater wires. The last three occurred over a period of only 8 hours rather than 72 hours. Had it not been for the non-threatening failure of Tank 2’s quantity probe and the low pressure in O2 Tank 1, this would not have been the case.”

Woodfill explained that anyone who has analyzed hardware failures understands that the more frequent and shorter the period between operations of a flawed component hastens ultimate failure. NASA performs stress testing on hundreds of electrical systems using this approach. More frequent power-ups at shorter intervals encourages flawed systems to fail sooner.

The short circuit in Oxygen Tank 2 after the fifth heater-cryo-stir resulted in the explosion of Apollo 13’s Oxygen Tank 2. Had the normal sequence of stirs been performed at 24 hour intervals, and the failure came after the fifth stirring, the explosion would have occurred after the lunar module, the life boat, was no longer available.

“I contend that the quantity sensor malfunction was fortuitous and assured the lander would be present and fully fueled at the time of the disaster,” Woodfill said.

5 heater actuations at 24 hours periods amounts to a MET of 120 hours.

“The lunar lander would have departed for the Moon at 103.5 hours into the mission,” Woodfill said. “At 120 hours into the mission, the crew of Lovell and Haise would have been awakened from their sleep period, having completed their first moon walk eight hours before. They would receive an urgent call from Jack Swigert and/or Mission Control that something was amiss with the Mother ship orbiting the Moon.”

Furthermore, Woodfill surmised, analysis of Swigert’s ship’s problems would likely be clouded by the absence of his two crewmates on the lunar surface. Added problems for Mission Control would have been the interruption of communications each time the command ship went behind the Moon, interrupting the telemetry so crucial to analyzing the failure. When it became evident, the cryogenic system would no longer produce oxygen, water, and electrical power, those command module emergency batteries would have been activated. Likely, Mission Control would have ordered an abort of the lunar lander earlier, but, of course, that would have been futile. Had the tiny lander’s ascent stage rendezvoused and docked with the depleted CM, all the life supporting descent stage consumables would remain on the Moon.

“The nightmare would have the Apollo 13 crew saying their last farewells to their families and friends,” said Woodfill. “One can only speculate how the end might have come.”

And there likely would not have been Apollo 14, 15, 16 and 17 — at least not for a very long time.

Apollo 13 launch. Credit: NASA
Apollo 13 launch. Credit: NASA

Another aspect of the timing of the explosion that Woodfill has considered is, why didn’t the tank explode on the Launchpad?

Following the March 16 CDDT, no additional “power-up” or tests were planned. However, it is not uncommon for pre-launch re-verification to be performed.

“One such re-check might easily have been these heater circuits since they had been used in a non-standard way to empty the oxygen from the cryo tanks after the Countdown Demonstration Test (CDDT) weeks earlier,” Woodfill said. “Such re-do’s often occur for myriad reasons. For Apollo 13, despite the compromised system, none occurred until the craft was safely on its way to the Moon.”

However, such a routine re-test involving cryo stirring would have unknowingly jeopardized the launch vehicle, support persons, or astronaut crew.

Or, if the quantity sensor had failed on the ground, likely the same kind of trouble shooting that was done by Mission Control and the Apollo 13 crew, would have been performed by the KSC ground team.

Had the sensor failed at that time, a series of heater actuations/stirrings would have been executed to trouble-shoot the device.

“Of course, the result would have been the same kind of explosion nearly 55 hours 55 minutes after launch,” Woodfill said. “On the ground, the Apollo 13 explosion could have taken the lives of Lovell and crew if trouble-shooting had been done while the crew awaited launch.”

If the trouble-shooting had been done earlier, with several heater actuations/stirrings during the days before the launch, Woodfill said, “a terrible loss of life would have ensued with, potentially, scores of dedicated Kennedy Space Center aerospace workers bravely attempting to fix the problem. And the towering thirty-six story Saturn 5 would have collapsed earthward in a ball of fire reminiscent of that December 1957 demise of America’s Vanguard rocket.”

“Yes, the fact that the Oxygen Tank 2 quantity sensor did not fail on the launch pad, but failed early in the flight was one of the additional things that saved Apollo 13.”

Read our introduction to this series here.

Additional articles in this series that have now been published:

Introduction

Part 1: The Failed Oxygen Quantity Sensor

Part 2: Simultaneous Presence of Kranz and Lunney at the Onset of the Rescue

Part 3: Detuning the Saturn V’s 3rd Stage Radio

Part 4: Early Entry into the Lander

Part 5: The CO2 Partial Pressure Sensor

Part 6: The Mysterious Longer-Than-Expected Communications Blackout

Part 7: Isolating the Surge Tank

Part 8: The Indestructible S-Band/Hi-Gain Antenna

Part 9: Avoiding Gimbal Lock

Part 10: ‘MacGyvering’ with Everyday Items

Part 11: The Caution and Warning System

Part 12: The Trench Band of Brothers

Find all the original “13 Things That Saved Apollo 13″ (published in 2010) at this link.

Posted on by Nancy Atkinson

13 MORE Things That Saved Apollo 13

Apollo 13 images via NASA. Montage by Judy Schmidt.

“Things had gone real well up to at that point of 55 hours, 54 minutes and 53 seconds (mission elapsed time),” said Apollo 13 astronaut Fred Haise as he recounted the evening of April 13, 1970, the night the Apollo 13’s command module’s oxygen tank exploded, crippling the spacecraft and endangering the three astronauts on board.

“Mission Control had asked for a cryo-stir in the oxygen tank …and Jack threw the switches,” Haise continued. “There was a very loud bang that echoed through the metal hull, and I could hear and see metal popping in the tunnel [between the command module and the lunar lander]… There was a lot of confusion initially because the array of warning lights that were on didn’t resemble anything we have ever thought would represent a credible failure. It wasn’t like anything we were exposed to in the simulations.”

What followed was a four-day ordeal as Haise, Jim Lovell and Jack Swigert struggled to get back to Earth, as thousands of people back on Earth worked around the clock to ensure the astronauts’ safe return.

Jerry Woodfill and Fred Haise at the 40th anniversary celebration of Apollo 13 at JSC. Image courtesy Jerry Woodfill.
Jerry Woodfill and Fred Haise at the 40th anniversary celebration of Apollo 13 at JSC. Image courtesy Jerry Woodfill.

Haise described the moment of the explosion during an event in 2010 at the Smithsonian Air and Space Museum commemorating the 40th anniversary of the mission that’s been called a successful failure.

In 2010, Universe Today also commemorated the Apollo 13 anniversary with a series of articles titled “13 Things That Saved Apollo 13.” We looked at 13 different items and events that helped turn the failure into success, overcoming the odds to get the crew back home. We interviewed NASA engineer Jerry Woodfill, who helped design the alarm and warning light system for the Apollo program, which Haise described above.

Now, five years later on the 45th anniversary of Apollo 13, Woodfill returns with “13 MORE Things That Saved Apollo 13.” Over the next few weeks, we’ll look at 13 additional things that helped bring the crew home safely.

Jerry Woodfill working in the Apollo Mission Evaluation Room. Credit: Jerry Woodfill.
Jerry Woodfill working in the Apollo Mission Evaluation Room. Credit: Jerry Woodfill.

Woodfill has worked for NASA for almost 50 years as an engineer, and is one of 27 people still remaining at Johnson Space Center who were also there for the Apollo program. In the early days of Apollo, Woodfill was the project engineer for the spacecraft switches, gauges, and display and control panels, including the command ship’s warning system.

On that night in April 1970 when the oxygen tank in Apollo 13’s command module exploded, 27-year-old Woodfill sat at his console in the Mission Evaluation Room (MER) at Johnson Space Center, monitoring the caution and warning system.

“It was 9:08 pm, and I looked at the console because it flickered a few times and then I saw a master alarm come on,” Woodfill said. “Initially I thought something was wrong with the alarm system or the instrumentation, but then I heard Jack Swigert in my headset: “Houston, we’ve had a problem,” and then a few moments later, Jim Lovell said the same thing.”

Listen to the audio of communications between the crew and Mission Control at the time of the explosion:

Located in an auxiliary building, the MER housed the engineers who were experts in the spacecrafts’ systems. Should an inexplicable glitch occur, the MER team could be consulted. And when alarms starting ringing, the MER team WAS consulted.

Woodfill has written a webpage detailing the difference between the MER and Misson Control (Mission Operations Control Room, or MOCR).

The Mission Evaluation Room. Credit: Jerry Woodfill.
The Mission Evaluation Room. Credit: Jerry Woodfill.

The ebullient and endearing Woodfill brings a wealth of knowledge — as well as his love for public outreach for NASA — to everything he does. But also, for the past 45 years he has studied the Apollo 13 mission in intricate detail, examining all the various facets of the rescue by going through flight transcripts, debriefs, and other documents, plus he’s talked to many other people who worked during the mission. Fascinated by the turn of events and individuals involved who turned failure into success, Woodfill has come up with 13 MORE things that saved Apollo 13, in addition to the original 13 he shared with us in 2010.

Woodfill tends to downplay both his role in Apollo 13 and the significance of the MER.

“In the MER, I was never involved or central to the main events which rescued Apollo 13,” Woodfill told Universe Today. “Our group was available for mission support. We weren’t flight controllers, but we were experts. For other missions that were routine we didn’t play that big of a role, but for the Apollo 13 mission, we did play a role.”

But Apollo Flight Director Gene Kranz, also speaking at the 2010 event at the Smithsonian Air and Space Museum, has never forgotten the important role the MER team played.

“The thing that was almost miraculous here [for the rescue], was I think to a great extent, the young controllers, particularly the systems guys who basically invented the discipline of what we now call systems engineering,” Kranz said. “The way these guys all learned their business, … got to know the designs, the people and the spacecraft … and they had to translate all that into useful materials that they could use on console in real time.”

Apollo 13 astronauts Fred Haise, Jim Lovell and Jack Swigert after they splashed down safely. Credit: NASA.
Apollo 13 astronauts Fred Haise, Jim Lovell and Jack Swigert after they splashed down safely. Credit: NASA.

Join Universe Today in celebrating the 45th anniversary of Apollo 13 with Woodfill’s insights as we discuss each of the 13 additional turning points in the mission. And here’s a look back at the original “13 Things That Saved Apollo 13:

Part 1: Timing

Part 2: The Hatch That Wouldn’t Close

Part 3: Charlie Duke’s Measles

Part 4: Using the LM for Propulsion

Part 5: Unexplained Shutdown of the Saturn V Center Engine

Part 6: Navigating by Earth’s Terminator

Part 7: The Apollo 1 Fire

Part 8: The Command Module Wasn’t Severed

Part 9: Position of the Tanks

Part 10: Duct Tape

Part 11: A Hollywood Movie

Part 12: Lunar Orbit Rendezvous

Part 13: The Mission Operations Team

Also:

Your Questions about Apollo 13 Answered by Jerry Woodfill (Part 1)

More Reader Questions about Apollo 13 Answered by Jerry Woodfill (part 2)

Final Round of Apollo 13 Questions Answered by Jerry Woodfill (part 3)

Never Before Published Images of Apollo 13’s Recovery

Posted on by David Dickinson

The Number of Asteroids We Could Visit and Explore Has Just Doubled

NASA

There’s a famous line from Shakespeare’s Hamlet that says “There are more things in heaven and Earth, Horatio, than are dreamt of in your philosophy,” and the same now holds true for brave new worlds for humans to explore.

This result was published earlier this week courtesy of the NASA/JPL Near-Earth Program Office. The study found that the number of possible asteroid targets for human exploration has now doubled from the 666 known in the first study, completed in late 2010.

Credit:
NHATS NEO asteroid discoveries by year. Credit: NASA/GFSC/Brent Barbee

This information comes from NHATS, which stands for the Near Earth Object Human Spaceflight Accessible Targets Study. Yes, it’s an acronym containing acronyms. NHATS is an automated system based out of Greenbelt, Maryland which monitors and periodically updates its list of potential target candidates for accessibility. The NHATS system data is readily accessible to the public online, and as of February 11th 2015, 1346 NHATS compliant asteroids are known.

NEO orbit types.
NEA orbit types. Credit: Brent Barbee/NASA/GSFC

This is the Holy Grail for the future of manned spaceflight, and will represent a good stepping stone (bad pun intended) for future crewed missions to Mars. Several hundred NHATS asteroids require less time and energy to reach than the Red Planet, and a few dozen even require less energy to reach than it does to enter lunar orbit.

Relative delta-V and return velocity is crucial. Apollo astronauts were subject to a blistering 11 kilometre per second reentry velocity on their return from the Moon, and future asteroid missions would be subject to the same style of trajectory on return to Earth from a solar orbit.

Mission to an NEO: a typical orbital profile. credit:
Mission to an NEO: a typical orbital profile. Credit: Brent Barbee/NASA/GSFC

The test of the Orion heat shield on reentry during last year’s EFT-1 flight was a step in this direction, and the next test will be an uncrewed launch atop an SLS rocket in September 2018. If all goes according to schedule — and NASA can successfully weather the ever-shifting political winds of multiple future changes of administration — expect to see astronauts exploring an NHATS asteroid placed in lunar orbit sometime around late 2023.

I know. “When I was a kid back in the 70’s…” we expected to be vacationing on Callisto by 2015, as well.

Brent Barbee at NASA’s Goddard Space Flight Center designed the automated NHATS system. It pulls data from a source that many comet and asteroid hunters are familiar with: JPL’s Small Bodies Database. The NHATS system then makes trajectory calculations and patches in conical solutions for possible spacecraft trajectories and actually gives potential launch window dates for future missions. Seriously, its fun to play with… you can even tailor and filter these by target dates versus maximum velocity constraints and the length of stays.

NASA/JPL
The orbit of asteroid 1943 Anteros. Credit: NASA/JPL.

The first discovered NHATS-compliant NEO was 2.3 kilometre 1943 Anteros way back in 1973, and famous alumni on the NHATS list also include 10 metre asteroid 2011 MD, which passed 12,000 kilometres from the Earth on June 27th, 2011. 2011 MD is on NASA’s short list of asteroids ideal for human exploration. Another famous asteroid on the NHATS list is 99942 Apophis which — triskaidekaphobics take note — will safely miss the Earth by 31,300 kilometres on Friday the 13th, April 2029.  More are added every day, and the growing curve of discoveries also closely mirrors the rise of automated all-sky surveys such as LINEAR, PanSTARRS and the Catalina Sky Survey, though dedicated amateurs do get in on the act occasionally as well.

To date, over 12,000 NEA asteroids are now known, and you can expect future surveys such as the Large Synoptic Survey Telescope set to see first light in 2021 to add to their ranks. The Sentinel space telescope set to launch in 2017 will also boost the known number of NEOs as it covers our sunward blind spot from an orbit interior to the Earth’s. Remember Chelyabinsk? That could actually be a great rallying cry for Sentinel’s cause, as the asteroid came at the Earth from a sunward direction and avoided the sky sweeping robotic eyes of astronomers.

Sometimes, NEOs turn out to be returning space junk from the early Space Age (a low relative velocity and low orbital inclination is often a dead giveaway). Earth has also been known to capture an NEO as an occasional temporary second Moon, as occurred in 2006 in the case of asteroid 2006 RH120.

The LSST mirror in the Tuscon Mirror Lab. Photo by author.
The LSST mirror in the Tuscon Mirror Lab. Photo by author.

But beyond just creating a database, the NHATS system also presents key opportunities for astronomers to perform follow-up observations of NEO asteroids, which is vital for precisely characterizing their orbits. Two future missions are also planned to return samples from NHATS asteroids: Hayabusa 2, which launched on December 3rd 2014 headed for asteroid 1999 JU3 in July 2018, and the OSIRIS-REx mission, set to launch in late 2016 headed for asteroid 101955 Bennu in 2018.

NHATS is providing a crucial target list for that day when first human footfall on an asteroid occurs… or should we say docking?

Posted on by Ken Kremer

Remembrance Week Pays Tribute to NASA’s Three Fallen Astronaut Crews

NASA pays tribute to the crews of Apollo 1 and space shuttles Challenger and Columbia

Today, Feb. 1, concludes the most somber week in NASA history as we remember the fallen astronauts who gave their lives exploring space so that others could reach to the stars – venturing further than ever before!

In the span of a week and many years apart three crews of American astronauts made the ultimate sacrifice and have perished since 1967. Heroes all ! – They believed that the exploration of space was worth risking their lives for the benefit of all mankind.

Apollo 1 memorial 1/27/2015. We start a week of remembrances on the 'Space Coast', years apart but so close together. Credit: Julian Leek
Apollo 1 memorial 1/27/2015. We start a week of remembrances on the ‘Space Coast’, years apart but so close together. Words/Credit: Julian Leek

On Jan. 28, NASA paid tribute to the crews of Apollo 1 and space shuttles Challenger and Columbia, as well as other NASA colleagues, during the agency’s annual Day of Remembrance. Over the past week, additional remembrance ceremonies were held in many venues across the country.

“NASA’s Day of Remembrance honors members of the NASA family who lost their lives while furthering the cause of exploration and discovery,” said a NASA statement.

NASA Administrator Charles Bolden and other agency senior officials held an observance and wreath-laying at Arlington National Cemetery in Virginia on Jan. 28.

NASA Administrator Charles Bolden and his wife Alexis lay a wreath at the Tomb of the Unknowns as part of NASA’s Day of Remembrance, Wednesday, Jan. 28, 2015, at Arlington National Cemetery in Arlington, Va. The wreaths were laid in memory of those men and women who lost their lives in the quest for space exploration. Photo Credit: NASA/Joel Kowsky
NASA Administrator Charles Bolden and his wife Alexis lay a wreath at the Tomb of the Unknowns as part of NASA’s Day of Remembrance, Wednesday, Jan. 28, 2015, at Arlington National Cemetery in Arlington, Va. The wreaths were laid in memory of those men and women who lost their lives in the quest for space exploration. Photo Credit: NASA/Joel Kowsky

“Today we remember and give thanks for the lives and contributions of those who gave all trying to push the boundaries of human achievement. On the solemn occasion, we pause in our normal routines and remember the STS-107 Columbia crew; the STS-51L Challenger crew; the Apollo 1 crew; Mike Adams, the first in-flight fatality of the space program as he piloted the X-15 No. 3 on a research flight; and those lost in test flights and aeronautics research throughout our history,” said Bolden.

“Let us join together … in paying our respects, and honoring the memories of our dear friends. They will never be forgotten. Godspeed to every one of them.”

12 years ago today on Saturday, Feb. 1, 2003, Space Shuttle Columbia suddenly and unexpectedly disintegrated over the skies of Texas during the fiery reentry into the Earth’s atmosphere at the conclusion of the STS-107 science mission. All aboard were lost: Rick Husband, William McCool, David Brown, Laurel Clark, Kalpana Chawla, Michael Anderson, and Ilan Ramon.

STS-107 crew of Space Shuttle Columbia
STS-107 crew of Space Shuttle Columbia

Jan. 28 marked the 29th anniversary of the Challenger disaster on the STS-51L mission when it suddenly broke apart 73 seconds after liftoff in 1986. The entire seven person crew were killed; including Dick Scobee, Michael Smith, Ronald McNair, Judy Resnik, Gregory Jarvis, Ellison Onizuka, and the first “Teacher in Space” Christa McAuliffe.

STS-51L crew of Space Shuttle Challenger
STS-51L crew of Space Shuttle Challenger

Jan. 27 marks the 48th anniversary of the first of the three disasters when a horrendous cockpit fire at Launch Complex 34 in 1967 killed the Apollo 1 crew of Gus Grissom, Ed White II and Roger Chaffee during a training exercise in the capsule.

Apollo 1 Crew
Apollo 1 Crew

Launch Complex 34 on Cape Canaveral Air Force Station in Florida was never used again for a launch and the ruins stand as a stark memorial to the crew of Apollo 1.

An observance was also held on Jan. 28 at the Space Mirror Memorial at NASA’s Kennedy Space Center Visitor Complex.

The Space Mirror Memorial at NASA’s Kennedy Space Center honors all astronauts who perished during their service to the agency. Photo Credit: Talia Landman/AmericaSpace
The Space Mirror Memorial at NASA’s Kennedy Space Center honors all astronauts who perished during their service to the agency. Photo Credit: Talia Landman/AmericaSpace
Deeply humbled to put a rose on Christa McAuliffe's plaque at the Astronaut Memorial Ceremony today 1/28/15. A little something extra...from one educator to another. Words/Credit: Sarah McNulty
Deeply humbled to put a rose on Christa McAuliffe’s plaque at the Astronaut Memorial Ceremony today 1/28/15. A little something extra…from one educator to another. Words/Credit: Sarah McNulty

Today the fallen astronauts legacy of human spaceflight lives on at NASA with the International Space Station (ISS), the development of Commercial Crew manned capsules for low Earth orbit, and the development of the Orion deep space crew exploration vehicle and SLS rocket for NASA’s ambitious plans to send ‘Human to Mars’ in the 2030s.

There are numerous memorials to the fallen crews. Among them are the tribute plaques to all five space shuttle orbiters that were the brainchild of the Space Shuttle Launch Director Mike Leinbach.

The five orbiter plaques were mounted inside the Space Shuttle Firing Room #4, above the Shuttle countdown clock at the Launch Control Center of NASA’s Kennedy Space Center.

The plaques for Columbia and Challenger, the first two shuttles built, include the crew portraits from STS-107 and STS-51L.

Memorial displays to all five Space Shuttle Orbiters mounted inside the Space Shuttle Firing Room #4 - above the Shuttle countdown clock. These tribute displays highlight and honor the significant achievements from the actual space voyages of the individual Orbiters launched from the Kennedy Space Center over three decades –starting with STS-1 in 1981. Shuttle mission patches since the return to flight in 2005 are mounted below the tribute displays. Click to enlarge. Credit: Ken Kremer/kenkremer.com.
Memorial displays to all five Space Shuttle Orbiters mounted inside the Space Shuttle Firing Room #4 – above the Shuttle countdown clock. These tribute displays highlight and honor the significant achievements from the actual space voyages of the individual Orbiters launched from the Kennedy Space Center over three decades –starting with STS-1 in 1981. Shuttle mission patches since the return to flight in 2005 are mounted below the tribute displays. Click to enlarge. Credit: Ken Kremer/kenkremer.com.

Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.

Ken Kremer

The Dignity Memorial to fallen astronauts at the Kennedy Space Center Visitor Complex. Credit: Ken Kremer/kenkremer.com
The Dignity Memorial to fallen astronauts at the Kennedy Space Center Visitor Complex. Credit: Ken Kremer/kenkremer.com
Statement from NASA Administrator Charles Bolden
Statement from NASA Administrator Charles Bolden
Posted on by Tim Reyes

Elon Musk and the SpaceX Odyssey: the Path from Falcon 9 to Mars Colonization Transporter

ILLUSTRATION IS RESERVED - DO NOT USE. Are we seeing the convergence of a century of space science and science fiction before our eyes? Will Musk and SpaceX make 2001 Space Odyssey a reality? (Photo Credit: NASA, Apple, SpaceX, Tesla Motors, MGM, Paramount Pictures, Illustration – Judy Schmidt)

In Kubrick’s and Clark’s 2001 Space Odyssey, there was no question of “Boots or Bots”[ref]. The monolith had been left for humanity as a mileage and direction marker on Route 66 to the stars. So we went to Jupiter and Dave Bowman overcame a sentient machine, shut it down cold and went forth to discover the greatest story yet to be told.

Now Elon Musk, born three years after the great science fiction movie and one year before the last Apollo mission to the Moon has set his goals, is achieving milestones to lift humans beyond low-Earth orbit, beyond the bonds of Earth’s gravity and take us to the first stop in the final frontier – Mars – the destination of the SpaceX odyssey.

Marvel claims Musk as the inspiration for Tony Stark in Ironman but for countless space advocates around the World he is the embodiment of Dave Bowman, the astronaut in 2001 Space Odyssey destined to travel to the edge of the Universe and retire an old man on Mars. (Photo Credit: NASA, MGM, Paramount Pictures, Illustration – Judy Schmidt)
Marvel claims Musk as the inspiration for Tony Stark in Ironman but for countless space advocates around the World he is the embodiment of Dave Bowman, the astronaut in 2001 Space Odyssey destined to travel to the edge of the Universe and retire an old man on Mars. (Photo Credit: NASA, MGM, Paramount Pictures, Illustration – Judy Schmidt)

Ask him what’s next and nowhere on his bucket list does he have Disneyland or Disney World. You will find Falcon 9R, Falcon Heavy, Dragon Crew, Raptor Engine and Mars Colonization Transporter (MCT).

At the top of his working list is the continued clean launch record of the Falcon 9 and beside that must-have is the milestone of a soft landing of a Falcon 9 core. To reach this milestone, Elon Musk has an impressive array of successes and also failures – necessary, to-be-expected and effectively of equal value. His plans for tomorrow are keeping us on the edge of our seats.

The Dragn Crew capsule is more than a modernized Apollo capsule. It will land softly and at least on Earth will be reusable while Musk and SpaceX dream of landing Falcon Crew on Mars. (Photo Credits: SpaceX)
The Dragon Crew capsule is more than a modernized Apollo capsule. It will land softly and at least on Earth will be reusable while Musk and SpaceX dream of landing Falcon Crew on Mars. (Photo Credits: SpaceX)

CRS-5, the Cargo Resupply mission number 5, was an unadulterated success and to make it even better, Elon’s crew took another step towards the first soft  landing of a Falcon core, even though it wasn’t entirely successful. Elon explained that they ran out of hydaulic fluid. Additionally, there is a slew of telemetry that his engineers are analyzing to optimize the control software. Could it have been just a shortage of fluid? Yes, it’s possible they could extrapolate the performance that was cut short and recognize the landing Musk and crew dreamed of.

A successful failure of a soft landing had no baring on the successful launch of the CRS-5, the cargo resupply mission to ISS. (Image Credits: SpaceX)
A successful failure of a soft landing had no baring on the successful launch of the CRS-5, the cargo resupply mission to ISS. (Image Credits: SpaceX)

The addition of the new grid fins to improve control both assured the observed level of success and also assured failure. Anytime one adds something unproven to a test vehicle, the risk of failure is raised. This was a fantastic failure that provided a treasure trove of new telemetry and the possibilities to optimize software. More hydraulic fluid is a must but improvements to SpaceX software is what will bring a repeatable string of Falcon core soft landings.

“Failure is not an option,” are the famous words spoken by Eugene Kranz as he’s depicted in the movie Apollo 13. Failure to Elon Musk and to all of us is an essential part of living. However, from Newton to Einstein to Hawking, the equations to describe and define how the Universe functions cannot show failure otherwise they are imperfect and must be replaced. Every moment of a human life is an intertwined array of success and failure. Referring only to the final frontier, in the worse cases, teams fall out of balance and ships fall out of the sky. Just one individual can make a difference between his or a team’s success. Failure, trial and error is a part of Elon’s and SpaceX’s success.

Only the ULA Delta IV Heavy image is real. TBC - to be completed - is the status of Delta Heavy. To be launch on its maiden flight in 2015, Falcon Heavy will become the most powerful American-made launch vehicle since Von Braun's Saturn rocket of the d1960s. (Credits: SpaceX, ULA)
Only the ULA Delta IV Heavy image is real. TBC – to be completed – is the status of Falcon Heavy. To be launch on its maiden flight in 2015, Falcon Heavy will become the most powerful American-made launch vehicle since Von Braun’s Saturn rocket of the d1960s. (Credits: SpaceX, ULA)

He doesn’t quote or refer to Steve Jobs but Elon Musk is his American successor. From Hyperloops, to the next generation of Tesla electric vehicles, Musk is wasting no time unloading ideas and making his dreams reality. Achieving his goals, making milestones depends also on bottom line – price and performance into profits. The Falcon rockets are under-cutting ULA EELVs (Atlas & Delta) by more than half in price per pound of payload and even more with future reuse. With Falcon Heavy he will also stake claim to the most powerful American-made rocket.

In both cost and performance the Falcon 9 and Heavy outperform the Delta IV. The Falcon vehicle is disruptive technology. (Illustration: T.Reyes)
In both cost and performance the Falcon 9 and Heavy outperform the Delta IV. The Falcon vehicle is disruptive technology. (Illustration: T.Reyes)

Musk’s success will depend on demand for his product. News in the last week of his investments in worldwide space-based internet service also shows his intent to promote products that will utilize his low-cost launch solutions. The next generation of space industry could falter without investors and from the likes of Musk, re-investing to build demand for launch and sustaining young companies through their start-up phases. Build it and they will come but take for granted, not recognize the fragility of the industry, is at your own peril.

So what is next in the SpaceX Odyssey? Elon’s sights remain firmly on the Falcon 9R (Reuse) and the Falcon Heavy. Nothing revolutionary on first appearance, the Falcon Heavy will look like a Delta IV Heavy on steroids. Price and performance will determine its success – there is no comparison. It is unclear what will become of the Delta IV Heavy once the Falcon Heavy is ready for service. There may be configurations of the Delta IV with an upper stage that SpaceX cannot match for a time but either way, the US government is likely to effectively provide welfare for the Delta and even Atlas vehicles until ULA (Lockheed Martin and Boeing’s developed corporation) can develop a competitive solution. The only advantage remaining for ULA is that Falcon Heavy hasn’t launched yet. Falcon Heavy, based on Falcon 9, does carry a likelihood of success based on Falcon 9’s 13 of 13 successful launches over the last 5 years. Delta IV Heavy has had 7 of 8 successful launches over a span of 11 years.

The legacy that Elon and SpaceX stand upon is a century old. William Gerstenmaier, a native of the state of Ohio - First in Flight, associate administrator for NASA Human Spaceflight and past program manager of ISS has been a prime executor of NASA human spaceflight for two decades. Elon Musk shares in common a long-time enthusiasm for space exploration with Gerstenmaier. From top left, clockwise, Eugene Kranz, Michael Collins, Neil Armstron, Edwin (Buzz) Aldrin, W. Gerstenmaier, Michael Griffin, NASA Administrator Charles Bolden shaking hands with Elon Musk. (Photo Credits: NASA, SpaceX, Illustration, J.Schmidt/T.Reyes)
The legacy that Elon and SpaceX stand upon is a century old. The Ohio native, William Gerstenmaier, associate administrator for NASA Human Spaceflight and past program manager of ISS, like Musk and so many others, dreamed of space exploration from an early age. From top left, clockwise, Eugene Kranz, Michael Collins, Neil Armstrong, Edwin (Buzz) Aldrin, W. Gerstenmaier, Michael Griffin, NASA Administrator Charles Bolden shaking hands with Elon Musk, the Apollo 11 crew embarking on their famous voyage(center). (Photo Credits: NASA, SpaceX, Illustration, J.Schmidt/T.Reyes)

The convergence of space science and technology and science fiction in the form of Musk’s visions for SpaceX is linked to the NASA legacy beginning with NASA in 1958, accelerated by JFK in 1962 and landing upon the Moon in 1969. The legacy spans backward in time to Konstantin Tsiolkovsky, Robert Goddard, Werner Von Braun and countless engineers and forward through the Space Shuttle and Space Station era.

A snapshot from the SpaceX webpage describing their successful first flight of the Dragon Cargo vessel on Falcon 9. Musk's SpaceX could not have achieved so much so quickly without the knowledge and support of NASA. (Credit: SpaceX)
A snapshot from the SpaceX webpage describing their successful first flight of the Dragon Cargo vessel on Falcon 9. Musk’s SpaceX could not have achieved so much so quickly without the knowledge and support of NASA. (Credit: SpaceX)

The legacy of Shuttle is that NASA remained Earth-bound for 30-plus years during a time that Elon Musk grew up in South Africa and Canada and finally brought his visions to the United States. With a more daring path by NASA, the story to tell today would have been Moon bases or Mars missions completed in the 1990s and commercial space development that might have outpaced or pale in comparison to today’s. Whether Musk would be present in commercial space under this alternate reality is very uncertain. But Shuttle retirement, under-funding its successor, the Ares I & V and Orion, cancelling the whole Constellation program, then creating Commercial Crew program, led to SpaceX winning a contract and accelerated development of Falcon 9 and the Dragon capsule.

Mars as it might look to the human eye of colonists on final approach to the red planet. To Elon Musk, this is the big prize and a place to retire and relish his accomplishments if only for a brief moment. (Credit: NASA)
Mars as it might look to the human eye of colonists on final approach to the red planet. To Elon Musk, this is the big prize and a place to retire and relish his accomplishments if only for a brief moment. (Credit: NASA)

SpaceX is not meant to just make widgets and profit. Mars is the objective and whether by SpaceX or otherwise, it is the first stop in humankind’s journey into the final frontier. Mars is why Musk developed SpaceX. To that end, the first focal point for SpaceX has been the development of the Merlin engine.

Now, SpaceX’s plans for Mars are focusing on a new engine – Raptor and not a Merlin 2 – which will operate on liquified methane and liquid oxygen. The advantage of methane is its cleaner combustion leaving less exhaust deposits within the reusable engines. Furthermore, the Raptor will spearhead development of an engine that will land on Mar and be refueled with Methane produced from Martian natural resources.

The Raptor remains a few years off and the design is changing. A test stand has been developed for testing Raptor engine components at NASA’s Stennis Space Center. In a January Reddit chat session[ref] with enthusiasts, Elon replied that rather than being a Saturn F-1 class engine, that is, thrust of about 1.5 million lbf (foot-lbs force), his engineers are dialing down the size to optimize performance and reliability. Musk stated that plans call for Raptor engines to produce 500,000 lbf (2.2 million newtons) of thrust. While smaller, this represents a future engine that is 3 times as powerful as the present Merlin engine (700k newtons/157 klbf). It is 1/3rd the power of an F-1. Musk and company will continue to cluster engines to make big rockets.

The future line-up of Falcon rockets is compared to the famous NASA Saturn V. The first Falcon Heavy launch is planned for 2015. Raptor engines may replace and upgrade Heavy then lead to Falcon X, Falcon X Heavy and Falcon XX. The Falcon X 1st stage would have half the thrust of a Saturn V, Falcon X Heavy and XX would exceed a Saturn V's thrust by nearly 50%. (Illustration Credit: SpaceX, 2010)
The future line-up of Falcon rockets is compared to the famous NASA Saturn V. The first Falcon Heavy launch is planned for 2015. Raptor engines may replace and upgrade Heavy then lead to Falcon X, Falcon X Heavy and Falcon XX. The Falcon X 1st stage would have half the thrust of a Saturn V, Falcon X Heavy and XX would exceed a Saturn V’s thrust by nearly 50%. (Illustration Credit: SpaceX, 2010)

To achieve their ultimate goal – Mars colonization, SpaceX will require a big rocket. Elon Musk has repeatedly stated that a delivery of 100 colonists per trip is the present vision. The vision calls for the Mars Colonization Transporter (MCT). This spaceship has no publicly shared SpaceX concept illustrations as yet but more information is planned soon. A few enthusiasts on the web have shared their visions of MCT. What we can imagine is that MCT will become a interplanetary ferry.

The large vehicle is likely to be constructed in low-Earth orbit and remain in space, ferrying colonists between Earth orbit and Mars orbit. Raptor methane/LOX engines will drive it to Mars and back. Possibly, aerobraking will be employed at both ends to reduce costs. Raptor engines will be used to lift a score of passengers at a time and fill the living quarters of the waiting MCT vehicle. Once orbiting Mars, how does one deliver 100 colonists to the surface? With atmospheric pressure at its surface equivalent to Earth’s at 100,000 feet, Mars does not provide an Earth-like aerodynamics to land a large vehicle.

In between launching V-2s in New Mexico and developing rockets at Redstone Arsenal, Von Braun had time to write Mars Projekt (1952) in which he outlined a mission to Mars delivering 70 explorers. Much has changed since that early vision but some of his concepts may still become a reality and solve the problem of sending SpaceX colonists to Mars. (Credit: Mars Project, Von Braun)
In between launching V-2s in New Mexico and developing rockets at Redstone Arsenal, Von Braun had time to write Mars Projekt (1952) in which he outlined a mission to Mars delivering 70 explorers. Much has changed since that early vision but some of his concepts may still become a reality and solve the problem of sending SpaceX colonists to Mars. (Credit: Mars Project, Von Braun)

In 1952, Werner Von Braun in his book “Mars Projekt” envisioned an armada of ships, each depending on launch vehicles much larger than the Saturn V he designed a decade later. Like the invading Martians of War of the Worlds, the armada would rather converge on Mars and deploy dozens of winged landing vehicles that would use selected flat Martian plain to skid with passengers to a safe landing. For now, Elon and SpaceX illustrate the landing of Dragon capsules on Mars but it will clearly require a much larger lander. Perhaps, it will use future Raptors to land softly or possibly employ winged landers such as Von Braun’s after robotic Earth-movers on Mars have constructed ten or twenty mile long runways.

We wait and see what is next for Elon Musk’s SpaceX vision, his SpaceX Odyssey. For Elon Musk and his crew, there are no “wives” – Penelope and families awaiting their arrival on Mars. Their mission is more than a five year journey such as Star Trek. The trip to Mars will take the common 7 months of a Hohmann transfer orbit but the mission is really measured in decades. In the short-term, Falcon 9 is poised to launch again in early February and will again attempt a soft landing on a barge at sea. And later, hopefully, in 2015, the Falcon Heavy will make its maiden flight from Cape Canaveral’s rebuilt launch pad 39A where the Saturn V lifted Apollo 11 to the Moon and the first, last and many Space Shuttles were launched.

References:

National Aeronatics and Space Administration

Space Exploration Web Pages

Happy Birthday to my sister Sylvia who brought home posters, literature and interest from North American-Rockwell in Downey during the Apollo era and sparked my interest.