Category: Hubble

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Not surprisingly, former astronaut Jeff Hoffman has been watching the current Hubble servicing mission with interest. After all, he was a member of the first repair crew that visited the telescope in December 1993, part of the team which essentially rescued the Hubble program from what could have been a disaster. But, now Hoffman is impressed with this current crew and what they’ve accomplished, saying they are part of a “brotherhood of Hubble warriors.”

And Hoffman is feeling a little nostalgic, too.

“It certainly brought me back 15 years to when I was doing that job,” he told Universe Today. “I look at them floating around Hubble, seeing images from their helmet cameras and watching them work with all those tools, and I feel a little heart tug. But also, I feel tremendous excitement because every time we go up there we just make Hubble better and better. It’s just a phenomenal story.”

One of Hoffman’s tasks on the first Hubble repair mission, STS-61, was to install the Wide Field Planetary Camera 2. Later nicknamed “The Camera that Saved Hubble,” WFPC2 replaced the original optical camera on Hubble, and was constructed to work with the corrective optics instrument (COSTAR) – basically a set of eyeglasses to overcome the spherical aberration in Hubble’s primary mirror.

“I put the Wide Field Planetary Camera 2 in Hubble in 1993,” Hoffman reminisced, “and that is the camera that has taken the majority of the spectacular pictures by which the whole world has come to know Hubble. This crew has removed it now and replaced it with an even more powerful camera. So I had kind of a bittersweet moment when I saw “my camera” leaving the telescope!”

But he said he is looking forward to seeing even more spectacular images from WFPC3. Plus, Hoffman has been invited to Goddard Space Flight Center to see his old camera when it returns from space. “I’ll get to put my hands on it once again after fifteen years.”

For Hoffman, what is most remarkable about the current mission was the type of work the astronauts were able to do, and the panoply of tools they had at their disposal. “One of the fantastic developments is the ability for astronauts to do complex servicing, and the tools are really what make these tasks possible,” he said. “Wearing astronaut gloves, you are really pretty clumsy. It’s like wearing welder’s gloves or ski mittens and trying to do brain surgery. But the engineers have now developed a whole suite of tools optimized for the individual tasks, allowing what would otherwise be impossible to come within the realm of what an astronaut dressed in a spacesuit can accomplish.”

The electronics on two of Hubble’s instruments had failed, — the Space Telescope Imaging Spectrograph (STIS) and the Advanced Camera for Surveys (ACS) — and the STS-125 crew basically went into the electronic guts of both instruments, pulled out circuit boards and replaced them.

Seeing the astronauts make repairs at that level was a marvel, Hoffman said. “That is something which we never imagined doing with Hubble. But it just shows how with every mission we’ve gotten more and more willing to push the envelope.”

Hoffman retired from NASA in 1997 and is now a professor of aeronautics and astronautics at MIT. He believes Hubble’s greatest legacy is how the observatory has impacted society.

“People all over the world have developed a love for Hubble,” he said, “and from Hubble we have the knowledge that the Universe is a stranger and more beautiful place that any of us had ever imagined. That’s what Hubble has done for people, giving us breathtaking images that are in some cases more beautiful than any abstract artist could come up with.”

But it’s not just the beautiful pictures. “The power of Hubble to show us what the Universe is like just one or two billion years after the Big Bang, where we can actually see the birth of the first few galaxies that were forming in our universe — this is mind boggling stuff. Hubble has re-written astronomy textbooks over the years and with the new set of instruments having even more sensitivity, it’s going to happen all over again.”

Now that the current crew has released Hubble, Hoffman recalled watching the telescope float away after the completion of his own mission. “They were probably looking at it with the same feeling of nostalgia as we did as we watched it slowly drift away,” he said. “It’s kind of a fraternity of Hubble, all the people in the six crews who have been involved with the Hubble Space Telescope. Every time I see someone from the crews that have worked on Hubble or the thousands of people on the ground who have been involved with it over the years, it’s like a brotherhood/sisterhood of Hubble warriors, so to speak. It’s been just an incredible adventure and it is nowhere near the end yet. I look forward to another 5, 10, maybe 15 years of incredible discoveries coming down from the Hubble Space Telescope.”

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Almost like Benjamin Button, the Hubble Space Telescope is now more vigorous and capable than with its original complement of instruments. “This is a tremendous adventure we’ve been on,” said astronaut John Grunsfeld at the end of Monday’s very successful EVA to repair and refurbish the famous space telescope. “This has been a very challenging mission. Hubble isn’t just a satellite, but it’s about humanity’s quest for knowledge.”

Grunsfeld and Drew Feustel installed a set of the observatory’s batteries, replaced a fine-guidance sensor that helps keep the telescope’s gaze precisely fixed on astronomical targets, and also replaced three thermal blankets protecting Hubble’s electronics.

“With today’s EVA Hubble is returned to flagship status with a full complement of instrument and tools for astronomers to use for the next several years,” saidJon Morse, Astrophyscis Division Director as NASA. “It is bittersweet to know this is our last visit to Hubble, but we have a saying in the science mission directorate: science never sleeps. So our work is just beginning. We have literally thousands of astronomers waiting to use Hubble, chomping at the bit to get their data.”

Monday’s 7 hour and 2 minute-long spacewalk marked the end of the five scheduled spacewalks for the STS-125 servicing mission. However the spacewalking team of Mike Massimino and Mike Good will be ready to go outside if any issues crop up Tuesday morning when all the systems are checked out before Hubble is released by the shuttle crew. Mission managers hope to have Atlantis back on the ground by Friday.
Earlier spacewalks overcame stubborn bolts and problematic tools, but all the mission objectives were achieved, much to the delight of everyone at NASA.

“This must be what it’s like to win the superbowl,” said Preston Burch, Hubble Program Manager. “As those of you who have followed us the past five days, working in space is challenging and there is a fine line between things that look easy and things that are impossible. The crew just never gave up.”

Lead flight director, Tony Ceccacci reminded everyone at a press conference following the EVA that Monday’s spacewalk was the last planned EVA out of the shuttle airlock. “It was both a very happy day and a sad day. We looked at each other and knew that was the last planned EVA out of the shuttle airlock. We’ve been working on this for over 2 ½ years, and we looked at each other and said, ‘wow this is really over.'”

The only glitch in the otherwise smooth EVA came at the very end when Grunsfeld – a self-proclaimed “Hubble Hugger” inadvertently bumped into one of the observatory’s two low-gain antennas with his foot, breaking off a small end cap. Grunsfeld felt terrible about the accident. “OK. I’m sick,” he said. However, the antenna still worked normally, mission control radioed up to him.

Grusnfeld and Feustel placed a protective cover over the cone-shaped device for added insulation before ending the spacewalk.

“Sorry, Mr. Hubble,” Grunsfeld said as he headed back to Atlantis’ airlock. “Have a good voyage.”

“Consider it a goodbye kiss, John,” Massimino radioed from inside the shuttle.

As Grunsfeld prepared to head back inside the shuttle he asked to say a few words.

“On this mission, we tried some things that some people said were impossible,” Grunsfeld said later. “We’ve achieved that, and we wish Hubble the very best.”

A replay of highlights from the 5th spacewalk is available.

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Astronauts from the STS-125 mission have now successfully completed all the EVAs for the Hubble Servicing Mission, accomplishing all the mission goals. Undoubtedly, the special tools the astronauts were essential to the success of the mission. In fact, at the end of today’s fifth spacewalk, astronaut John Grunsfeld called the mission “a tour de force of tools and human ingenuity.” To have any chance of completing the wide variety of tasks for this mission, NASA had to develop more than 100 new tools for removing, installing and repairing components on Hubble. “The biggest challenge for us in designing and developing tools for astronauts is to make it easy for them to use in their suit,” said Jill McGuire, manger of the CATs team (Crew Aids and Tools) for the HST mission. “EVA time is at a premium. So, any tool that we develop we develop it in order to optimize the time we have up there and make it as easy and simple for the astronauts to use.” The team built a variety of tools, from power tools to different hand tools that the astronauts used. Here’s a look at some of these super-tools:

“I like all the tools, but the one I’ll probably be using the most is the Mini-Power Tool,” said STS-125 astronaut Mike Massimino before the flight. “It’s a little drill and is a unique tool that I think is going to be used in space for a long time. So, I’m very glad we’re going to be the first ones to use it and I bet you’re going to see a lot of space crews using it for many years on new space ships. This is going to be a pretty cool tool.”

NASA has long used a cordless drill called the Pistol Grip Tool, but needed a faster tool with less torque than the PGT, and Cassisdy likened the mini power tool to what Indy pit crews used to rapidly change bolts.

The mini power tool spins at 210 revolutions per minute, as opposed to the PGT’s 15.

During the spacewalks, however, the astronauts did have to re-set the power tool’s torque settings to loosen some extremely tight bolts.

Some of these components, like the Space Telescope Imaging Spectrograph (STIS) were never designed for astronauts to fix on orbit. The instrument failed in 2004, and the problem was traced to the power supply. Justin Cassidy, the lead systems engineer for CATS team, compared the work astronauts would have to do on orbit to opening up a computer and replacing a board while wearing thick gloves on their hands and a fishbowl on their head.

“To actually open up an instrument and pull a board had never been thought of nor conceived that we would want to do that and therefore the interfaces were not very friendly to an astronaut,” said Cassidy.

In fact, there were 111 tiny screws that needed to be removed from the instrument in order to gain access to the board. Mike Massimino completed the STIS repair with the ingenious “fastener capture plate.”

“The beauty of the fastener capture plate is, it does capture all the fasteners but it’s got a clear window,” said Cassidy. “And that clear window enables the astronaut, when he takes that power tool, he can actually see the little tiny bit going into the little tiny fastener. So, we have not blocked any of his visibility, yet when he takes that fastener out it won’t come out the little hole that the tool past through.”

It took 4-5 years to develop the mini power tool and the capture plate.

In today’s spacewalk, John Grunsfeld used a special tool to remove old insulation from the telescope so that new protective thermal insulation could be installed. The insulation protects the equipment bays on HST.

In order to replace the gyroscopes, or rate sensor units, which are located inside the Hubble Space Telescope and hard to reach while wearing a large spacesuit, engineers had to develop a tool that would work like an extension to an astronaut’s arm. Here is the Rate Sensing Units Changeout Tool, a crew member is able to reach inside the telescope without entering it, and capture and restrain a sensor unit by pulling a trigger. The tool is able to withstand temperatures ranging from -74 degrees F to 189 degrees F.

This Battery Extraction Tool allows an astronaut “grab” the batteries on Hubble, and exert additional force to remove it. This tool is capable of exerting several hundred pounds of exertion force.

“One could think you go to the hardware store and actually pick out a tool and use that in space,” said Cassidy. “The space environment is very harsh. It’s very hot, very cold, and it’s also in a vacuum and most tools, power tools for example that you pick up from Home Depot just would not survive in the environment of space.

Here are just a few things the CATs team has to consider when developing a new tool”

• The tight quarters the astronaut would have to work in with the tool.
• The brief amount of time an astronaut has to take out each fastener to release the board.
• Temperature swings of 500 degrees from the heat of direct sunlight to frigid shade. Either extreme can make the metal innards of a power tool seize up instantly.
• What would happen to each of the 111 fasteners in weightlessness.
• How much the tools weigh.
• Whether the tools can withstand the vibrations of launch.

Sources: NASA, Discovery Space,

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As today’s final spacewalk of the Hubble Servicing Mission begins, it seems very fitting to share a poem written by my friend Stuart Atkinson. Stuart is a poet, a blogger, a member of Unmanned Spaceflight.com (which means he is a Photoshopper extraordinaire!) and a passionate promoter of space exploration. Stuart has written many touching poems previously about the Mars rovers, the Phoenix lander, the Kepler mission and many other missions, but this verse about the final human mission to the Hubble Space Telescope is priceless. See below for “The Final Pilgrims” and check out Stu’s website Cumbrian Skies for more great poetry, images and information.

Thanks, Stu, for sharing your poem with Universe Today!