13 MORE Things That Saved Apollo 13, part 7: Isolating the Surge Tank

Schematics of the Apollo command module interior. The surge tank was located in the left hand intermediate equipment bay. 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.

Within minutes of the accident during the Apollo 13 mission, it became clear that Oxygen Tank 2 in the Service Module had failed. Then Mission Control radioed up procedures and several attempts were made to try to save the remaining oxygen in Tank 1. But the pressure readings continued to fall, and it soon became obvious that Tank 1 was going to fail as well. At that point, both the crew and those in Houston realized the extreme seriousness of the situation.

No oxygen meant the fuel cells would be inoperative, and the fuel cells produced electrical power, water and oxygen – three things vital to the lives of the crew and the life of the spacecraft.

For power in the Command Module, all that was left were the batteries, but they were to be the sole source of power available for reentry. Besides the ambient air in the CM, the only oxygen remaining was contained in a so called ‘surge tank’ and three reserve one pound O2 tanks. These, too, were also mainly reserved for reentry, but they were automatically tapped in emergencies if there any oxygen fluctuations in the system.

In Chris Kraft’s autobiography Flight: My Life in Mission Control, the former flight director and former director of Johnson Space Center cited Gene Kranz’ decision to immediately isolate or seal off the surge tank as being one of the things that made rescuing the crew possible.

Why was it so essential to assure that the spare oxygen surge tank in the CM was protected?

“With the luxury of nearly a half century to review each decision made during those April days in 1970,” said NASA engineer Jerry Woodfill, “we can look back and see that those in Mission Control indeed made the right decisions, but at the time, many of those decisions had to be made without knowing the full extent of the problem. But more importantly, they had the presence of mind to look beyond their immediate problem and see the big picture of how to save Apollo 13.”

Shortly after the accident, electrical output readings for fuel cells 1 and 3 were at zero. Fuel cell 2 was still working, but without oxygen from the main tanks, it began to pull oxygen from the reserve surge tank. The 3.7 lb capacity tank was called a ‘surge tank’ because one of its functions was to absorb pressure fluctuations in the oxygen system. Due to the depletion of the two main oxygen tanks, the remaining fuel cell 2 began to automatically pull from the surge tank’s small supply of oxygen.

However, the surge tank also served as the reserve tank of oxygen that the crew would use to breathe during reentry to Earth after the Service Module (with -– during a normal mission — its two large full and functioning oxygen tanks) had been jettisoned. But with those tanks damaged and empty, the remaining fuel cell was starting to draw on the surge tank’s small supply in order to keep power flowing.

Kranz’ decision to isolate the tank was important, but of course, he didn’t make that decision alone. In an article in IEEE Spectrum, the EECOM (Electrical Environmental and Consumables) officer for Apollo 13 Sy Liebergot, recalled the moment he realized the Service Module was running out of power and oxygen — permanently. He, too, didn’t make that realization alone.

Sy Liebergot, EECOM in Mission Control on Apollo 13. Image courtesy Sy Liebergot.
Sy Liebergot, EECOM in Mission Control on Apollo 13. Image courtesy Sy Liebergot.

As writer Stephen Cass explained in IEEE Spectrum, “Each flight controller in mission control was connected via so-called voice loops–pre-established audio-conferencing channels–to a number of supporting specialists in back rooms who watched over one subsystem or another and who sat at similar consoles to those in mission control.” (This includes the Mission Evaluation Room where Jerry Woodfill monitored the Caution and Warning System.)

Liebergot was in communications with a team down the hall from Mission Control in Building 30, consisting of Dick Brown, a power-systems specialist, and George Bliss and Larry Sheaks, both life support specialists. When they confirmed the surge tank was being tapped, they realized they had to revise their priorities, from stabilizing Odyssey to preserving the command module’s re-entry reserves so that the crew could eventually return to Earth.

Liebergot said his call to isolate the surge tank initially took Kranz off guard, as it was exactly opposite of what was needed to keep the last fuel cell operating.

But Liebergot and his team were looking ahead. “We want to save the surge tank which we will need for entry,” writer Cass quoted Liebergot, and Kranz almost immediately understood. “Okay, I’m with you. I’m with you,” said Kranz resignedly, and he ordered the crew to isolate the surge tank.

Chris Kraft with his new flight directors before the Gemini 4 mission.  (Clockwise from lower right: Kraft, Gene Kranz, Glynn Lunney and John Hodge.) Credit: NASA.
Chris Kraft with his new flight directors before the Gemini 4 mission.
(Clockwise from lower right: Kraft, Gene Kranz, Glynn Lunney and John Hodge.) Credit: NASA.

“Because Gene was Flight Director at the time of the determination,” explained Woodfill, “his decisions result from inputs from a team of experts. He, like all the lead flight directors, is, ultimately, responsible for determining and weighing inputs from the chief system controllers who likewise receive instructions and information from a support team. To this end, ‘Flight’ is responsible for the final decision which is passed to the CapCom who, in turn, instructs the astronaut crew to act. Based on the process, often, an unknown expert might have been the original source of the instruction.”

This demonstrates how it was a team effort to save Apollo 13, and decisions that may have initially seemed incomprehensible ended up being the right ones.

“Loss of either Command Module capability — entry battery power or oxygen — threatened to be a fatal situation during the capsule’s entry return to Earth,” said Woodfill. Fortunately, as stated in one of our articles the first series of “13 Things,” a ‘jumper-charge technique dealt with the recharging the reentry batteries in the CM.

But while the LM had ample oxygen – in the form of oxygen tanks for repressurization after moon walks, tanks in the lander’s descent and ascent stages, and in the Portable Life Support System (PLSS) in the spacesuits that would have been used during moonwalks — apparently, there was no such similar way to replace oxygen in the CM from the lander’s oxygen stores.

Woodfill noted that had the surge tank been expended by the failed service module O2 tanks, there likely could have been a backup reentry plan of the crew wearing their launch suits and some type of jury-rigged system of using the oxygen from the PLSS system’s oxygen.

“A ‘shirt-sleeve’ entry would not have been the case,” said Woodfill. “This could have entailed a process similar to three scuba divers breathing from a pair of aqua lungs following the failure of one of the three.”

Woodfill noted one interesting fact. “Both Mission Control and the crew of Apollo 13 were so certain of the availability of surge tank oxygen that everyone agreed reentry would be space-suit-less.”

You can read more from Sy Liebergot in his book, Apollo EECOM, Journey of a Lifetime, and Chris Kraft in his book Flight: My Life in Mission Control.

Tomorrow: The Indestructible S-Band/Hi-Gain Antenna

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

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

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

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.

High Resolution Video Reveals Dramatic SpaceX Falcon Rocket Barge Landing and Launch

View of Falcon 9 first stage landing burn and touchdown on ‘Just Read the Instructions’ landing barge. Credit SpaceX

Video caption: High resolution and color corrected SpaceX Falcon 9 first stage landing video of CRS-6 first stage landing following launch on April 14, 2015. Credit: SpaceX

KENNEDY SPACE CENTER, FL – A new high resolution video from SpaceX shows just how close the landing attempt of their Falcon 9 first stage on an ocean floating barge came to succeeding following the rockets launch on Tuesday afternoon, April 14, from Cape Canaveral, Florida, on a resupply run for NASA to the International Space Station (ISS).

Newly added video shows video taken from the barge:

The SpaceX Falcon 9 carrying the Dragon cargo vessel blasted off from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida on April 14, 2015 at 4:10 p.m. EDT (2010:41 GMT) on the CRS-6 mission bound for the space station.

The flawless Falcon 9 liftoff came a day late following a postponement from Monday, April 13, due to threatening clouds rolling towards the launch pad in the final minutes of the countdown. See an up close video view of the launch from a pad camera, below.

Video caption: SpaceX CRS-6 Falcon 9 Launch to the International Space Station on April 14, 2015. Credit: Alex Polimeni

The dramatic hi res landing video was released by SpaceX CEO Elon Musk. It clearly reveals the deployment of the four landing legs at the base of the booster as planned in the final moments of the landing attempt, aimed at recovering the first stage booster.

By about three minutes after launch, the spent fourteen story tall first stage had separated from the second stage and reached an altitude of some 125 kilometers (77 miles) following a northeastwards trajectory along the U.S. east coast.

SpaceX engineers relit a first stage Merlin 1D engine some 200 miles distant from the Cape Canaveral launch pad to start the process of a precision guided descent towards the barge, known as the ‘autonomous spaceport drone ship’ (ASDS).

It had been pre-positioned offshore of the Carolina coast in the Atlantic Ocean.

SpaceX initially released a lower resolution view taken from a chase plane captured dramatic footage of the landing.

“Looks like Falcon landed fine, but excess lateral velocity caused it to tip over post landing,” tweeted SpaceX CEO Elon Musk.

The Falcon successfully reached the tiny ocean floating barge in the Atlantic Ocean, but tilted over somewhat over in the final moments of the approach, and tipped over after landing and exploded in a fireball.

“Either not enough thrust to stabilize or a leg was damaged. Data review needed.”

“Looks like the issue was stiction in the biprop throttle valve, resulting in control system phase lag,” Musk elaborated. “Should be easy to fix.”

The next landing attempt is set for the SpaceX CRS-7 launch, currently slated for mid- June, said Hans Koenigsmann, SpaceX Director of Mission assurance, at a media briefing at KSC.

SpaceX Falcon 9 and Dragon blastoff from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida on April 14, 2015 at 4:10 p.m. EDT  on the CRS-6 mission to the International Space Station. Credit: Ken Kremer/kenkremer.com
SpaceX Falcon 9 and Dragon blastoff from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida on April 14, 2015 at 4:10 p.m. EDT on the CRS-6 mission to the International Space Station. Credit: Ken Kremer/kenkremer.com

Overall CRS-6 is the sixth SpaceX commercial resupply services mission and the seventh trip by a Dragon spacecraft to the station since 2012.

The 20 story tall Falcon 9 hurled Dragon on a three day chase of the ISS where it will rendezvous with the orbiting outpost on Friday, April 17. Astronauts will grapple and berth Dragon at the station using the robotic arm.

Up close view of the SpaceX Falcon 9 rocket landing legs prior to launch on April 14, 2015 on the CRS-6 mission to the International Space Station. Credit: Ken Kremer/kenkremer.com
Up close view of the SpaceX Falcon 9 rocket landing legs prior to launch on April 14, 2015 on the CRS-6 mission to the International Space Station. Credit: Ken Kremer/kenkremer.com

Read Ken’s earlier onsite coverage of the CRS-6 launch from the Kennedy Space Center and Cape Canaveral Air Force Station.

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

Ken Kremer
………….

Learn more about SpaceX, Mars rovers, Orion, Antares, MMS, NASA missions and more at Ken’s upcoming outreach events:

Apr 18/19: “Curiosity explores Mars” and “NASA Human Spaceflight programs” – NEAF (NorthEast Astronomy Forum), 9 AM to 5 PM, Suffern, NY, Rockland Community College and Rockland Astronomy Club

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.

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.

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.

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.

SpaceX Resets CRS-6 Space Station Launch to April 13 with Booster Landing Attempt

Falcon 9 and Dragon undergoing preparation in Florida in advance of April 13 launch to the International Space Station on the CRS-6 mission. Credit: SpaceX

The clock is ticking towards the next launch of a SpaceX cargo vessel to the International Space Station (ISS) hauling critical supplies to the six astronauts and cosmonauts serving aboard, that now includes the first ever ‘One-Year Mission’ station crew comprising NASA’s Scott Kelly and Russia’s Mikhail Kornienko.

The mission, dubbed SpaceX CRS-6 (Commercial Resupply Services-6) will also feature the next daring attempt by SpaceX to recover the Falcon 9 booster rocket through a precision guided soft landing onto an ocean-going barge.

SpaceX and NASA are now targeting blastoff of the Falcon 9 rocket and Dragon spacecraft for Monday, April 13, just over a week from now, at approximately 4:33 p.m. EDT from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida.

NASA Television plans live launch coverage starting at 3:30 p.m.

The launch window is instantaneous, meaning that the rocket must liftoff at the precisely appointed time. Any delays due to weather or technical factors will force a scrub.

The backup launch day in case of a 24 hour scrub is Tuesday, April 14, at approximately 4:10 p.m.

Falcon 9 launches have been delayed due to issues with the rockets helium pressurization bottles that required investigation.

A SpaceX Falcon 9 rocket and Dragon cargo ship are set to liftoff on a resupply mission to the International Space Station (ISS) from launch pad 40 at Cape Canaveral, Florida on Jan. 6, 2015. File photo.  Credit: Ken Kremer – kenkremer.com
A SpaceX Falcon 9 rocket and Dragon cargo ship are set to liftoff on a resupply mission to the International Space Station (ISS) from launch pad 40 at Cape Canaveral, Florida. File photo. Credit: Ken Kremer – kenkremer.com

The Falcon 9 first stage is outfitted with four landing legs and grid fins to enable the landing attempt, which is a secondary objective of SpaceX. Cargo delivery to the station is the overriding primary objective and the entire reason for the mission.

An on time launch on April 13 will result in the Dragon spacecraft rendezvousing with the Earth orbiting outpost Wednesday, April 15 after a two day orbital chase.

After SpaceX engineers on the ground maneuver the Dragon close enough to the station, European Space Agency (ESA) astronaut Samantha Cristoforetti will use the station’s 57.7-foot-long (17-meter-long) robotic arm to reach out and capture Dragon at approximately 7:14 a.m. EDT on April 15.

Cristoforetti will be assisted by fellow Expedition 43 crew member and NASA astronaut Terry Virts, as they work inside the stations seven windowed domed cupola to berth Dragon at the Earth-facing port of the Harmony module.

SpaceX Dragon cargo ship approaches ISS, ready for grappling by astronauts. Credit: NASA
SpaceX Dragon cargo ship approaches ISS, ready for grappling by astronauts. Credit: NASA

Overall CRS-6 is the sixth SpaceX commercial resupply services mission and the seventh trip by a Dragon spacecraft to the station since 2012.

CRS-6 marks the company’s sixth operational resupply mission to the ISS under a $1.6 Billion contract with NASA to deliver 20,000 kg (44,000 pounds) of cargo to the station during a dozen Dragon cargo spacecraft flights through 2016 under NASA’s original Commercial Resupply Services (CRS) contract.

Dragon is packed with more than 4,300 pounds (1915 kilograms) of scientific experiments, technology demonstrations, crew supplies, spare parts, food, water, clothing and assorted research gear for the six person Expedition 43 and 44 crews serving aboard the ISS.

The ship will remain berthed at the ISS for about five weeks.

The ISS cannot function without regular deliveries of fresh cargo by station partners from Earth.

The prior resupply mission, CRS-5, concluded in February with a successful Pacific Ocean splashdown and capsule recovery.

Introducing Landing Complex 1, formerly Launch Complex 13, at Cape Canaveral in Florida.  Credit: SpaceX
Introducing Landing Complex 1, formerly Launch Complex 13, at Cape Canaveral in Florida. Credit: SpaceX

The CRS-5 mission also featured SpaceX’s history making attempt at recovering the Falcon 9 first stage as a first of its kind experiment to accomplish a pinpoint soft landing of a rocket onto a tiny platform in the middle of a vast ocean using a rocket assisted descent.

As I wrote earlier at Universe Today, despite making a ‘hard landing’ on the vessel dubbed the ‘autonomous spaceport drone ship,’ the 14 story tall Falcon 9 first stage did make it to the drone ship, positioned some 200 miles offshore of the Florida-Carolina coast, northeast of the launch site in the Atlantic Ocean. The rocket broke into pieces upon hitting the barge.

Listen to my live radio interview with BBC 5LIVE conducted in January 2015, discussing SpaceX’s first attempt to land and return their Falcon-9 booster.

Watch for Ken’s onsite coverage of the CRS-6 launch from the Kennedy Space Center and Cape Canaveral Air Force Station.

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

Ken Kremer

The Orion’s Heat Shield Gets a Scorching on Re-entry

Larry Gagliano, Orion project manager at NASA's Marshall Space Flight Center, photographed in front of the spaceship's heat shield. Credit: Lee Roop

Yes, she’s a little worse for wear, isn’t she? But then again, that’s what atmospheric re-entry and 2200 °Celsius (4000 °Fahrenheit) worth of heat will do to you! Such was the state of the heat shield that protected NASA’s Orion Spaceship after it re-entered the atmosphere on Dec. 5th, 2014. Having successfully protected the craft during it’s test flight, the shield was removed and transported to the Marshall Space Flight Center in Huntsville, Alabama, where it arrived on March. 9th.

Since that time, a steady stream of NASA employees have been coming by the facility to get a look at it while engineers collect data and work to repair it. In addition to being part of a mission that took human-rated equipment farther out into space than anything since the Apollo missions, the heat shield is also living proof that NASA is restoring indigenous space capability to the US.

First unveiled by NASA in May of 2011, the Orion Multi-Purpose Crew Vehicle (MPCV) was intrinsic to the Obama administration’s plan to send astronauts to a nearby asteroid by 2025 and going to Mars by the mid-2030’s. In addition to facilitating these long-range missions, the Orion spacecraft would also handle some of the routine tasks of spaceflight, such as providing a means of delivering and retrieving crew and supplies from the ISS.

NASA Orion spacecraft blasts off atop 1st  Space Launch System rocket in 2017 - attached to European provided service module – on an enhanced m mission to Deep Space where an asteroid could be relocated as early as 2021.   Credit: NASA
Artist’s concept of the Orion spacecraft being sent into orbit atop the first Space Launch System (SLS) rocket in 2017. Credit: NASA

The uncrewed test flight that took place on December 5, 2014, known as Exploration Flight Test 1 (EFT-1), was intended to test various Orion systems, including separation events, avionics, heat shielding, parachutes, and recovery operations prior to its debut launch aboard the Space Launch System,

This design of this mission corresponded to the Apollo 4 mission of 1967, which demonstrated the effectiveness of the Apollo flight control systems and the heat shields ability to withstand re-entry conditions, as part of the spacecraft’s return from lunar missions.

After being retrieved, the heat shield was transported by land to the Marshall Space Flight Center, where it was offloaded and transferred to a large support structure so engineers could perform studies on it for the next three months.

This will consist of collecting samples from the shield to measure their char layers and degree of erosion and ablation, as well as extracting the various instruments embedded in the heat shield to assess their performance during re-entry.

The heat shield arrived March 9 at Marshall, where experts from the Center and NASA’s Ames Research Center will extract samples of the ablative material, or Avcoat. Image Credit:  NASA/MSFC/Emmett Given
The heat shield arriving at Marshall on March 9th, where experts from the Center and NASA’s Ames Research Center. Credit: NASA/MSFC/Emmett Given

After the analysis is complete, technicians will load the shield into the 7-axis milling machine and machining center, where it will be grind down to remove the remaining material covering. Known as Avcoat, this heat-retardant substance is similar to what the Apollo missions used, with the exception of toxic materials like asbestos.

This material is used to fill the 320,000 honeycomb-like cells that make up the outer layer of the shield. When heated, the material burns away (aka. ablates) in order to prevent heat being transferred into the crew module. This shield is placed over the craft’s titanium skeleton and carbon-fiber skin, providing both protection and insulation for the interior.

Once all the Avcoat is removed and only the skeletal frame remains, it will be shipped to the Langley Research Center in Hampton, Virginia, for more tests. Since the Orion was returning from a greater distance in space than anything since Apollo, it experienced far greater heat levels than anything in recent decades, reaching as high as 2200 °C (4000 °F).

During Orion's test flight the heat shield reached temperatures of about 4,000 degrees Fahrenheit. Instrumentation in the heat shield measured the rise of the surface and internal temperatures during re-entry as well as heating levels and pressures. Image Credit:  NASA/MSFC/Emmett Given
Instrumentation in the Orion heat shield (visible here) measured the rise of the surface and internal temperatures during re-entry. Credit: NASA/MSFC/Emmett Given

Instrumentation in the shield measured the rise of the surface and internal temperatures during re-entry as well as the ablation rate of the shield’s coating. Over the next few months, NASA experts will be pouring over this data to see just how well the Orion shield held up under extreme heat. But so far, the results look positive – with only 20% of the Avcoat burning away on the test-flight re-entry.

In the future, the Orion spacecraft will be launched on Space Launch System on missions that will take it to nearby asteroids and eventually Mars. The first mission to carry astronauts is not expected to take place until 2021 at the earliest.

Further Reading: NASA

Year in Space Flight for Russian/American Crew Starts With Spectacular Night Launch and Station Docking

The Soyuz TMA-16M spacecraft is seen as it launches to the International Space Station with Expedition 43's NASA Astronaut Scott Kelly and Russian cosmonauts Mikhail Kornienko and Gennady Padalka of the Russian Federal Space Agency (Roscosmos) onboard Friday, March 27 (Saturday, March 28 Kazakh time) from the Baikonur Cosmodrome in Kazakhstan. Credit: NASA/Bill Ingalls

The first ever ‘One-Year Mission’ to the International Space Station (ISS) started with a bang today, March 27, with the spectacular night time launch of the Russian/American crew from the Baikonur Cosmodrome in Kazakhstan at 3:42 p.m. EDT Friday (1:42 a.m., March 28 in Baikonur and culminated with a flawless docking this evening.

NASA astronaut Scott Kelly and Russian cosmonauts Mikhail Kornienko and Gennady Padalka launched aboard a Soyuz TMA-16M spacecraft to the International Space Station precisely on time today on the Expedition 43 mission.

The crew rocketed to orbit from the same pad as Russia’s Yuri Gagarin, the first human in space.

Kelly and Kornienko will spend about a year living and working aboard the space station on the marathon mission. Padalka will remain on board for six months.

Streak shot of Expedition 43 Launch to the ISS on March 27 Eastern time, (March 28, 2015, Kazakh time)  from the Baikonur Cosmodrome in Kazakhstan with Scott Kelly, Mikhail Kornienko, and Gennady Padalka to start one-year ISS mission. Credit: NASA/Bill Ingalls
Streak shot of Expedition 43 Launch to the ISS on March 27 Eastern time, (March 28, 2015, Kazakh time) from the Baikonur Cosmodrome in Kazakhstan with Scott Kelly, Mikhail Kornienko, and Gennady Padalka to start one-year ISS mission. Credit: NASA/Bill Ingalls

The goal is to use the massive orbiting outpost to provide critical knowledge to NASA and researchers hoping to better understand how the human body reacts and adapts to long-duration spaceflight and the harsh environment of space.

The pathfinding mission is about double the normal time of most expeditions to the Earth orbiting space station, which normally last four to six months.

The one-year mission is among the first concrete steps to start fulfilling NASA’s “Journey to Mars” objective of sending “Humans to Mars” in the 2030s.

“Scott Kelly’s mission is critical to advancing the administration’s plan to send humans on a journey to Mars,” said NASA Administrator Charles Bolden, in a statement.

“We’ll gain new, detailed insights on the ways long-duration spaceflight affects the human body.”

Year in Space Begins With Soyuz Launch.  Media photograph the Soyuz TMA-16M spacecraft as it launches to the ISS with Expedition 43 NASA astronaut Scott Kelly, Russian cosmonauts Mikhail Kornienko and Gennady Padalka of the Russian Federal Space Agency (Roscosmos) onboard at 3:42 p.m. EDT Friday, March 27, 2015 (March 28 Kazakh time) from the Baikonur Cosmodrome in Kazakhstan. Credit: NASA/Bill Ingalls
Year in Space Begins With Soyuz Launch. Media photograph the Soyuz TMA-16M spacecraft as it launches to the ISS with Expedition 43 NASA astronaut Scott Kelly, Russian cosmonauts Mikhail Kornienko and Gennady Padalka of the Russian Federal Space Agency (Roscosmos) onboard at 3:42 p.m. EDT Friday, March 27, 2015 (March 28 Kazakh time) from the Baikonur Cosmodrome in Kazakhstan. Credit: NASA/Bill Ingalls

This evening the three man international crew successfully rendezvous and docked at the ISS at the Poisk module at 9:33 p.m. EDT – just four orbits and six hours after liftoff.

‘Contact and capture confirmed, 1 year crew has arrived,’ said the NASA launch commentator Don Huot. “The one-year crew has arrived.”

“Soyuz is firmly attached to the ISS.”

Soyuz spacecraft on final approach to dock with the ISS for #YearInSpace mission. Credit: NASA
Soyuz spacecraft on final approach to dock with the ISS for #YearInSpace mission. Credit: NASA

Docking took place about 253 kilometers off the western coast of Colombia, South America approximately 5 hours and 51 minutes after today’s flawless launch from Baikonur.

The crews are scheduled to open the hatches between the Soyuz and ISS at about 11:15 p.m. EDT/315 GMT this evening after conducting pressure, leak and safety checks.

NASA astronaut Scott Kelly gives a thumbs-up from inside the Soyuz TMA-16M taking him and Expedition 43 crewmates Mikhail Kornienko, and Gennady Padalka of the Russian Federal Space Agency (Roscosmos) to the International Space Station after a successful launch from the Baikonur Cosmodrome in Kazakhstan.  Credit:  NASA
NASA astronaut Scott Kelly gives a thumbs-up from inside the Soyuz TMA-16M taking him and Expedition 43 crewmates Mikhail Kornienko, and Gennady Padalka of the Russian Federal Space Agency (Roscosmos) to the International Space Station after a successful launch from the Baikonur Cosmodrome in Kazakhstan. Credit: NASA

The arrival of Kelly, Kornienko and Padalka returns the massive orbiting outpost to its full six person crew complement.

The trio joins the current three person station crew comprising Expedition 43 commander Terry Virts of NASA, as well as flight engineers Samantha Cristoforetti of ESA (European Space Agency) and Anton Shkaplerov of Roscosmos, who have been aboard the complex since November 2014.

“Welcome aboard #Soyuz TMA-16M with Genna, Scott, and Misha- we just had a succesful docking,” tweeted Virts this evening post docking.

The 1 Year mission will provide baseline knowledge to NASA and its station partners – Roscosmos, ESA, CSA, JAXA – on how to prepare to send humans on lengthy deep space missions to Mars and other destinations in our Solar System.

A round-trip journey to Mars is likely to last three years or more! So we must determine how humans and their interactions can withstand the rigors of very long trips in space, completely independent of Earth.

Astronaut Scott Kelly will become the first American to live and work aboard the orbiting laboratory for a year-long mission and set a new American duration record.

Scott Kelly and Russian Cosmonauts Kornienko and Padalka are all veteran space fliers.

They have been in training for over two years since being selected in Nov. 2012.

No American has ever spent anywhere near a year in space. Four Russian cosmonauts – Valery Polyakov, Sergei Avdeyev, Vladimir Titov and Musa Manarov – conducted long duration stays of about a year or more in space aboard the Mir Space Station in the 1980s and 1990s.

Kelly and Kornienko will stay aboard the ISS until March 3, 2016, when they return to Earth on the Soyuz TMA-18M after 342 days in space. Kelly’s combined total of 522 days in space, will enable him to surpass current U.S. record holder Mike Fincke’s mark of 382 days.

Padalka will return in September after a six month stint, making him the world’s most experienced spaceflyer with a combined five mission total of 878 days in space.

NASA Astronaut Scott Kelly and Russian Cosmonaut Mikhail Kornienko comprise  the first ever ISS 1 Year Crew
NASA Astronaut Scott Kelly and Russian Cosmonaut Mikhail Kornienko comprise the first ever ISS 1 Year Crew

They will conduct hundreds of science experiments focusing on at least 7 broad areas of investigation including medical, psychological and biomedical challenges faced by astronauts during long-duration space flight, as well as the long term effects of weightlessness and space radiation on the human body.

Another very unique science aspect of the mission involves comparative medical studies with Kelly’s identical twin brother, former NASA astronaut and shuttle commander Mark Kelly.

“They will participate in a number of comparative genetic studies, including the collection of blood samples as well as psychological and physical tests. This research will compare data from the genetically identical Kelly brothers to identify any subtle changes caused by spaceflight,” says NASA.

Scott Kelly is a veteran NASA Space Shuttle commander who has previously flown to space three times aboard both the Shuttle and Soyuz. He also served as a space station commander during a previous six-month stay onboard.

Good luck and Godspeed to Kelly, Kornienko and Padalka – starting humanity on the road to Mars !!

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

Ken Kremer

Expedition 43 crew members Mikhail Kornienko of the Russian Federal Space Agency (Roscosmos), top, NASA astronaut Scott Kelly, center, and Gennady Padalka of Roscosmos wave farewell as they board the Soyuz TMA-16M spacecraft ahead of their launch to the International Space Station.  Credit:  NASA/Bill Ingalls
Expedition 43 crew members Mikhail Kornienko of the Russian Federal Space Agency (Roscosmos), top, NASA astronaut Scott Kelly, center, and Gennady Padalka of Roscosmos wave farewell as they board the Soyuz TMA-16M spacecraft ahead of their launch to the International Space Station. Credit: NASA/Bill Ingalls