Final Shuttle Flight Will Be Delayed at Least Until November for AMS Switchout


A switch-out of the magnet for a much anticipated particle physics experiment on the International Space Station will force NASA to delay the final flight of the space shuttle until at least November, and change which orbiter and crew will fly the final space shuttle mission. The $2 billion Alpha Magnetic Spectrometer was scheduled to head to the ISS in July of this year, but recent thermal vacuum tests showed the superconducting magnet that was originally planned to power the experiment would have only worked 2-3 years. An ordinary magnet, which doesn’t need to be super-cooled will last for a decade or more – and given the ISS has been given a longer life, it seems to be the best option. “I don’t think it’s correct to go there for three years where there is a chance to do physics for 18 years,” said Dr. Samuel Ting, AMS Principal Investor, in an article in the New York Times.

NASA officials said today they still are evaluating the exact day in November, as they must schedule the mission to fit around other resupply and crew flights to the ISS, with the Russian Progress and Soyuz vehicles.

The AMS is designed to search for various types of unusual matter by measuring cosmic rays, and will help researchers study the formation of the universe and search for evidence of dark matter and antimatter.

Changing the magnet means the AMS won’t arrive at Kennedy Space Center before August and shuttle workers need time to get the payload ready to fly inside the shuttle’s cargo bay.

Atlantis at the pad for the STS-132 mission. Credit: Alan Walters ( for Universe Today

The upcoming flight of the shuttle Atlantis (STS-132) remains on schedule for launch no earlier than May 14. But Endeavour was scheduled for the AMS flight in July, which will now move to no earlier than November. Discovery’s STS-133 flight (bringing up the Leonardo MPLM as a permanent storage module) stays on the schedule for September 16. So while the schedule changes, numerical order is restored!

Another possible change to the shuttle schedule would be if the decision to fly what is called STS-335, the Launch On Need mission, a shuttle ready to go as a rescue ship for the last scheduled mission. Many shuttle supporters say since Atlantis would be ready to fly that it should fly. No decision has yet been made, however.

Even if the final flight or flights get delayed into 2011, funding is not a problem, as Congress anticipated possible delays and provided funds for shuttle operations into early next year.

Liquid helium would have been used cool the superconducting magnet’s temperature to near absolute zero. But tests showed the helium would dissipate withing 2-3 years, leaving the seven-ton experiment useless. The ISS has been extended to at least 2020, and possibly as long as 2028.

Sources: New York Times, Orlando Sentinel

ISS to get ‘Man Cave’ Complete with Robot Butler


There might be a new favorite hang-out for astronauts aboard the International Space Station later this year. The Multi Purpose Logistics Module (MPLM) known as Leonardo – which will be going to the ISS on the upcoming STS-131 mission carrying cargo and supplies — will be transformed after the mission into a Permanent Multipurpose Module (PMM), and brought up to stay on the station on STS-133 as a storeroom for supplies. But it might also become a haven to get away from it all.

“The thought is, the PMM might become sort of a ‘man cave’,” said Mike Kinslow, the Boeing payload manager out at Kennedy Space Center. “It won’t have all the background noise of fans, computers and other equipment running like in the laboratories, so it will be a quieter atmosphere that might appeal to the astronauts during their off-duty hours.”

No plans for a big screen TV Kinslow said, but there will be ports for computers, and since internet is now available on the ISS, Leonardo could be the location of choice to compose emails to loved ones back home, or do a little Twittering.

Another interesting piece of hardware scheduled to fly on the PMM is the Robonaut 2, NASA’s second generation of dexterous robots with a human-like torso that can work with tools and one day are envisioned to be able to do EVA work outside the ISS. But for now, R2 will be tested inside the station in zero-g. “It will be used on orbit for routine maintenance indoors only.” said Kinslow, “This is not an external unit.”

It has a “head” with a vision system, with hands that can do work, controlled by virtual-reality-like operation. Any chance R2 could be programmed to serve drinks or bring food into the man cave?

See our article on how General Motors is going to use R2 for manufacturing cars.

Turning Leonardo into a permanent module will take some work, said NASA Payload Manager Joe Delai. “Once it returns from this flight we will beef up the external shield and change things internally to become a permanent module. It will be about a four month process to get it ready.”

Leonard being attached to the ISS on a previous mission. Credit: NASA TV

The MPLMs were built in Italy, but are owned by the U.S. and provided in exchange for Italian access to U.S. research time on the Station. Four modules were built; three flew to the ISS. STS-131 will be Leonardo’s seventh trip to space.

Kinslow said shields for an MPLM are lighter weight because they are only meant to be on orbit for 2 weeks at a time. “Leonardo will be plated with a multilevel Kevlar blanket, the same type of exterior shielding other modules have, which is similar to armor plating, to protect against meteorite or debris impact. Internally, not a lot of changes will be made,” he said. “It already has a ventilation system like a normal module, but will need a computer system and a few other additions.”

Leonardo won’t be outfitted with a sleep station or crew quarters because it might be in a more vulnerable position for radiation or debris hits. “They don’t really want crew to get in and sleep because of the shielding,” Kinslow said. “It will be a storage module, and we’re discussing putting exercise equipment in there.”

The PMM will be berthed on the Node 1 nadir, or Earth-facing port. Leonardo measures about 6.5 meters (21 feet) long and 4.5 meters (15 feet) in diameter.

STS-131 is currently scheduled for an April 5 launch, and STS-133 is shooting for a September 2010 launch.

Just a note on the ISS internet: T.J. Creamer, who is on board the station now told Universe Today that they aren’t able to have streaming video or download large files. “In terms of download speeds – you know, back in the old days, it kind of compares to 9.6 and the 14.4 kilobyte modems, so it’s not really fast enough to do large file exchange or videos, but it certainly lets us to do browsing and the fun reading we want to do, or get caught up on current events on that day. It’s a nice outreach for us, and of course you’ve heard about the Twittering which is a nice feature that we can partake in also.”

Peggy Whitson: A Heroine of Science and Technology


This post is part of Ada Lovelace Day, which is a worldwide effort to get as many people as possible to blog about a heroine of science or technology. Ada was a mathematician who lived in the 1800’s who created the first computer program. Yep — you read correctly — a computer in the 1800’s. It was actually a device called an analytical engine, which was an important step in the history of computers. You can read more about Ada and Ada Lovelace Day here.

The person I chose to write about is a goddess of both science AND technology. She is a biochemist and an astronaut. She was the first science officer on board the International Space Station and later become the first female commander of the ISS. She helped get some of the initial science programs going on the on the space station, and as commander oversaw a period of one of the biggest expansions for the station, coordinating the additions of European and Japanese laboratory modules. Her name is ….

Dr. Peggy Whitson

Perhaps I have always been drawn to Whitson because she grew up in a rural, agricultural environment, as I did. But I have always found Whitson to be endearing because of her easygoing and friendly personality. But yet, she must be almost a “slave-driver” and perfectionist when it comes to her work. During her expeditions on the ISS, Whitson earned a reputation for high achievement, which prompted mission planners to assign the crew extra work every day. NASA called it “The Peggy Factor.”

“We account for the fact that Peggy is going to do things more efficiently, and that she likes to work some on her time off, and so she’ll accomplish more,” said NASA deputy station project manager Kirk Shireman.

Whitson works with a science glove box on board the ISS. Credit: NASA

First some the details about Whitson: she graduated from Iowa Wesleyan College in 1981, and received her doctorate in biochemistry from Rice University in 1985. She worked as a Welch Postdoctoral Fellow before joining NASA in 1986.

From 1989 to 1993, Whitson was a research biochemist for NASA. During that time, she also served as an Adjunct Assistant Professor at the University of Texas and Rice University. In 1995, she became co-chair of a combined American and Russian working group, and a year later she was named an astronaut candidate.

Whitson flew her first space mission in 2002 as a flight engineer to the International Space Station as part of the Expedition 5 crew. While there, then NASA Administrator Sean O’Keefe gave her the title of first NASA Science Officer. Of course, she took some ribbing about being like “Spock,” the science officer on the original Star Trek, but she came to enjoy using the phrase “Live Long and Prosper.” During that mission she performed 21 experiments in human life science, microgravity sciences and commercial payloads.

During her second stint on the station, Expedition-16 in 2007-2008, she was named the commander.

I could go on about her accomplishments, but perhaps even better would be to let Whitson herself tell about her experiences in space. During her stays on the ISS, she wrote “letters home” to family and friends, answering questions and sharing details of her days in space.

Here’s what she had to say about doing science on the ISS:

I set up the first experiment inside the microgravity sciences glovebox this week. Tomorrow, I will do the powered checkouts of the glovebox and the next day start up the experiment. It is ssssoooo cool, getting to do science in space!!! This week we are also doing the urine collections for the renal stone investigation…and while I suspect this won’t be especially fun to collect the samples, I do think it’s one of the best experiments (I am biased, of course, since it is my experiment!).

In reading her letters, I found it interesting that she did amateur astronomy while on board the space station!:

One evening, I had dimmed the lights inside the module so that I could better watch the Earth/stars. I watched the sun set as we moved into the shadow of the Earth. I was pleasantly surprised a few min later to see a half-moon rise into view from behind the Earth. As the stars started popping into view, I was surprised again, as I saw a satellite pass by above us, looking so much like one of the other stars, but moving across the field of “constant” stars. I had never thought about the fact that I could, as one of those satellites, actually see another! And then I saw a second! Amazing.

Whitson during an EVA at the ISS. Credit: NASA

Whitson has conducted six spacewalks. Here’s how she described her first one:

My first look, as I poked my head out the hatch, was amazing! I previously compared the view of being in space to having lived in semidarkness for several years and having someone turn on the lights. Well, the view from my helmet, continuing the same analogy, would be like going outside on a sunny, clear day after having lived in semidarkness for years! If it gets better than this, I’m not sure my mind would be able to comprehend it!

And in this letter home, she waxes poetically about seeing Earth from space. She also talks about how people on Earth can watch for the ISS in the night sky, which is something that I love to do, and so it was interesting to read her perspective on that as well:

Although all the views of our planet are incredible and varied from our viewpoint up here on the Station, with the colors, textures, and lighting changing as we orbit…the most impressive view is the curve of the planet at the horizon. That curve is the special place where it is possible to see the layers of atmosphere extend beyond the surface to meet with the blackness of space beyond. Relative to the size of the Earth, it seems impossibly thin, less than a finger-width. The atmosphere carries all the shades of blue in that thin band, closest to the planet a glowing blue, like sunlit water over white sand, extending to the deepest blue-purple mixture that holds the blackness at bay.

As the night-side of the planet slips by beneath me, it carries on the fringes of darkness the colors of a sunset on the clouds below. The Station is still lit by the sun, despite the fact that we have already crossed the terminator between day and night below us. This is the timeframe when Station is most visible to folks on the ground, just before their dawn or after their dusk. A small bit of sunlight reflected off of our structure, illuminates us moving across their darkened sky. As the terminator approaches the horizon, the sun shows a blinding face that burns the atmosphere with molten reds and oranges before seemingly melting itself into the darkness, leaving a royal blue line that dissipates more slowly as the stars come out from hiding. Less than an hour passes before our path around the planet brings us back to the royal blue curve, signaling sunrise, as the process reverses itself. I am sure that after I return, I will again miss watching the curve of the Earth.

You can read more of Whitson’s letters home here.

Whitson’s ride home from space after Expedition 16 was more dramatic than expected. A malfunction made the Soyuz enter Earth’s atmosphere at a steeper angle than normal and the crew experienced “ballistic” descent at eight times the force of Earth-normal gravity. But, thankfully, everything turned out OK.

Whitson is currently chief of NASA’s astronaut office at Johnson Space Center.

Sources: Official NASA Astronaut bio, Orlando Sentinel

Next Shuttle Launch is Go; Universe Today Will Be There


Liftoff of space shuttle Endeavour for the STS-130 mission to the International Space Station has been been given the go-ahead, and launch is scheduled for Feb. 7 at 4:39 a.m. EST. Universe Today will be at the launch to provide on-site coverage of all the pre- and post-launch events, and we look forward to sharing the experience with you. This is likely the last night launch of the space shuttle, and it should be a beautiful sight.

STS-130 will bring the Tranquility node and a cupola, a 7-window observation portal for the ISS. Mission managers said at a press briefing today that the issue with problematic ammonia coolant hoses on the module has been resolved. The 7-member crew will carry out three spacewalks to install and outfit the Tranquility node.

Space Station Pictures


Here are some space station pictures. We’ve already done photo galleries of the International Space Station, but let’s take a look at some different stations as well:

This is a picture of the Mir Space Station, launched by Russia. This photograph was taken by the crew of STS-89 on the space shuttle Endeavour.

Space Station

Here is a recent image of the International Space Station captured by the crew of STS-129. It shows how much of the construction has now been completed.


This is a picture of Skylab, the United States’ first space station. It was in orbit from 1973 to 1979, and was visited by 3 crews of astronauts.

Stanford Torus

And maybe some day we’ll live in a futuristic space station like this. It’s called a Stanford Torus, and rotates to provide the people living inside an artificial gravity.

Bigelow station

This is an artist’s impression of a future space hotel developed by Bigelow Aerospace. The various modules are inflated and connected together. Test versions of the modules have already been sent into orbit.

We’ve written many articles about the International Space Station for Universe Today. Here’s an article about how you can track the International Space Station, and here’s an article about a how a radio operator was able to communicate with the station.

If you’d like more info on the station, check out NASA’s mission page for ISS. And here’s a link to NASA’s human spaceflight page for the station.

We’ve also recorded an episode of Astronomy Cast about the space shuttle. Listen here, Episode 127: The US Space Shuttle.

What Would NASA Do with an Added Shuttle Flight?

Space Shuttle Atlantis sits poised for the STS 129 launch from Pad 39 A on 16 November 2009. Atlantis would likely fly a proposed new flight as STS-135. Credit: Ken Kremer

The end of the Space Shuttle Era is rapidly approaching and with it some urgent questions including, “How will the US support continued use of the ISS?” and “What would NASA do if granted an additional shuttle flight?”

Currently, only 5 flights remain on the manifest and right now, the final shuttle flight is set for September 2010. This deadline and policy was decreed by the Bush Administration and simultaneously coincides with the end of ISS assembly and the end of the Fiscal 2010 budget year. Thus far the Obama Administration has not announced any policy changes despite recurring questions from Congress and the press as the retirement approaches.
ISS.  Credit: NASA

Then comes the big “gap” in US human spaceflight launch capability between the looming shuttle shutdown and the debut of the Orion capsule. Orion will not be ready until 2015 or later. So there will be a minimum 5 year “gap” when NASA cannot launch its own astronauts or even unmanned cargo supply vessels to the International Space Station which will operate until at least 2015. Hence the practical questions from the US side on “How to re-supply the ISS?”

NASA will then be utterly dependent on Russia to launch US astronauts to the ISS at a cost of some $50 million per Soyuz seat. Several companies are receiving NASA funding under the COTS program to develop cargo up-mass vehicles to the ISS and are also exploring crewed options.

For the most part, the general public is unaware of these facts. Congress has been fully aware of this quandary since 2004 when President Bush announced new NASA goals as part of the VSE or “Vision for Space Exploration” to return to the Moon and beyond to Mars. NASA’s budget has been cut in the intervening years and the “gap” has grown longer. Insufficient funding from Washington, DC directly caused a slower development pace for Orion and the Ares rocket.

One much discussed “gap” closing measure is to slightly extend the deadline for closing out the shuttle program by adding 1 or more new flights. This action requires a direct decision soon from President Obama and enabling funding from Congress.

If granted the authority to extend the Shuttle program with an additional flight, NASA officials at a very high level have already decided on paper what such a mission would entail. Bill Gerstenmaier, NASA Associate Administrator for Space Operations says that the team has done some planning for what is dubbed a ‘contingency’ flight. “It sits on the manifest as a ‘contingency’ if we need to fly it. It would be prudent to have an MPLM (pressurized Multi-purpose logistics module) in there to carry spares and restock station. We originally wanted to have a back up shuttle available in case we had a situation where we needed to do a contingency crew support to keep them in orbit for some period of time.”

At the Kennedy Space Center (KSC), I spoke with Scott Higginbotham about the details of the ‘contingency’ flight. Scott is a shuttle payload mission manager at KSC, most recently for STS-129 . He told me, “If there was to be another mission then the plan is to fly another MPLM. We have two more MPLM’s but only one is flight worthy. For the call up mission, the possible new last flight, we would fly ‘Raffaello’. But NASA needs more money and work modifications to get ‘Raffaello’ ready and up to speed”.

‘Donatello’ MPLM module inside the Space Station Processing Facility at KSC.  This module is being utilized for spare parts. Outer shielding is being removed.   Credit: Ken Kremer
‘Donatello’ MPLM module inside the Space Station Processing Facility at KSC. This module is being utilized for spare parts. Outer shielding is being removed. Credit: Ken Kremer

NASA has three MPLM’s total, named ‘Leonardo’, ‘Raffaello’ and ‘Donatello’ after significant engineers in Italian history and the Ninja turtles too. All were built by Alenia in Italy under contract to the European Space Agency (ESA). ‘Leonardo’ will be permanently attached on the current last flight, STS 133, after “beefing up the outside to provide extra micrometeoroid debris protection for the module. That will allow it to stay on orbit,” according to Gerstenmaier. ‘Leonardo’ would then be redesignated as a Permanent Multipurpose Module, or PMM. Initially it will be docked at a space facing port on the Harmony connecting node.

“Since the MPLM’s only go up on short sortie missions, their shielding is not as thick as the other station elements,” said Higgenbotham. ‘Leonardo’ flies once more in March 2010 and will then be modified to add shielding. “Donatello will never fly. It’s become our spare parts man to be raided if needed.” Alenia also constructed the Tranquility and Cupola long duration modules I observed recently at a ceremony inside the KSC Space Station Processing Facility (LINK). While inside the station facility, I inspected all three of the MPLM’s (see photos).

“Because of the limited number of shuttle missions left and budget constraints, it makes more sense financially to just fly ‘Leonardo’ over and over again. ‘Raffaello’ is being maintained just in case” added Higgenbotham. “We know that we would like to fly more supplies to the station and bring things home. But whether we actually go prepare ‘Raffaello’ for that contingency mission is being discussed. So we are doing some of the advanced exercises in case we get turned on.”

Leonardo’ MPLM module inside the Space Station Processing Facility at KSC built by Alenia under contract to ESA and the Italian Space Agency (ASI).  This module will be left attached to the ISS on the last scheduled shuttle mission, STS 133. It will be modified with additional shielding for protection against strikes by micrometeoroids. Note grapple fixture at top. Each MPLM is 21 feet long, 15 feet in diameter, weighs 4.5 tons, and can deliver up to 10 tons of cargo to the ISS.  Credit: Ken Kremer
Leonardo’ MPLM module inside the Space Station Processing Facility at KSC built by Alenia under contract to ESA and the Italian Space Agency (ASI). This module will be left attached to the ISS on the last scheduled shuttle mission, STS 133. It will be modified with additional shielding for protection against strikes by micrometeoroids. Note grapple fixture at top. Each MPLM is 21 feet long, 15 feet in diameter, weighs 4.5 tons, and can deliver up to 10 tons of cargo to the ISS. Credit: Ken Kremer

“We know the big picture of what would be included. It would include science experiments, spare parts, food, clothing, station consumables and what the crew needs to get by day to day”, he said. “So if I have the ability to launch another MPLM mission, then I can loft thousands of pounds that I don’t need to pay a commercial vendor or the Russians to do,” Higgenbotham explained. “We can save them for other items that may break down in the future.”

Large outside items would probably not go up on that mission. “The expectation is we are going to clear the house of all large external parts by the time the last mission flies. All those are planned for going up on the already manifested missions. We have analyzed what’s needed over the lifetime of the station if we extend out to 2020,” said Higgenbotham.

The station must be continually resupplied with spare parts and logistics for its remaining lifetime whether it’s 2015 or longer to 2020 which is far beyond the upcoming retirement of the Space Shuttle.

“NASA has one External Tank (ET) already built for the ‘contingency’ mission” according to Mike Moses, shuttle integration manager at KSC. Two others exist only in pieces he told me. Since it takes 3 years to build a new ET from scratch, there would be some launch delay for any further missions beyond the possible ‘contingency’ flight.

The future goals of NASA and US human and robotic spaceflight hangs in the balance awaiting critical choices by President Obama and political leaders in Washington, DC. At this point, there is no indication of when President Obama will make a decision on goals or funding. With each day’s delay, the chances to extend the shuttle program are diminished as US manufacturing production lines are shut down, more shuttle workers are layed off and their high technology skills are lost.

About 7000 shuttle workers will lose their jobs at KSC and many more across the US as the Space Shuttle program is terminated in the midst of the current recession.

A Day in the Life on Board the ISS

In this video, International Space Station commander Frank De Winne explains what a typical day on board the ISS is like. Today, however, De Winne and his crew of Robert Thirsk, Roman Romanenko, Nicole Stott, Maxim Suraev and Jeffrey Williams are busy getting ready for the arrival of the STS-129 space shuttle crew. They need to set up to take pictures of the incoming shuttle to document the condition of the shuttle’s heat shield as it makes a “back flip” or a rendezvous pitch maneuver during its approach to the station. Plus, if the crew is anything like me, they probably have some last minute tidying to do before company arrives. Docking is scheduled for 11:53 a.m. EST. Watch it live on NASA TV.

International Space Station Viewing

Now that it’s mostly complete, the International Space Station is the brightest human-built object in space. It’s easy to see with your own eyes, the trick is knowing when to step outside and look up to see the station go overhead. If you do get your timing right, you’ll see the station as a bright star moving quickly in the sky. It only take a couple of minutes to pass through the sky above your house. Want to see the station for yourself? Here are some resources for International Space Station viewing.

The best place to go is NASA’s Human Spaceflight tracking page. This shows you the current location of the International Space Station, the Hubble Space Telescope, and any space shuttles currently in orbit.

So that shows you where the space station and shuttles are right now, but how will you know when they’re going to be passing over your part of the Earth?

NASA has a page for sighting opportunities. You can either choose your location from a list of common locations around the world, or you download an application that lets you pick your specific spot on Earth. It will then tell you the exact times ISS will be passing overhead.

If you’ve got an iPhone, check out the ISS Visibility App. This tool will calculate the next times you’ll be able to see the ISS pass overhead.

You can also use a great service called Heavens Above. This will also show you the current location of satellites, as give you times when ISS will be passing overhead.

We have written many articles about the International Space Station for Universe Today. Here’s an article about how ISS is now visible in the daytime.

We have recorded an episode of Astronomy Cast about the space shuttle. Listen to it here, Episode 127: The US Space Shuttle.

ISS Tracking

The International Space Station, or ISS, is the largest object every built by humans in space. And because it’s so large, it’s also very bright; easily visible with the unaided eye. The ISS also follows an orbital track that takes over different parts of the Earth. That means if you know the right time, you can go out and watch the station pass right over. But you need to know the right time, and that requires some kind of ISS tracking tool. Let’s take a look at some ISS tracking tools you can use to tell you when you should head outside and look up.

The best place to track ISS is from NASA’s human space flight ISS tracking page. This site will tell you the current location of the International Space Station, and space shuttles currently in flight, and the Hubble Space Telescope. The problem is that this tells you where the space station is right now, and not when it’s going to be passing through your skies… at night.

A better tool for that is the ISS sightings page. You download an applet that lets you put in your place on Earth and it gives you some upcoming dates and times that the station will be passing overhead. There’s also a quick drop down box, where you can select your location from many places in the world.

Another great tool is Heavens Above. It allows you to track the current position of thousands of satellites, including ISS and the space shuttles, when they’re in orbit.

So use one of these tools for ISS tracking, and then head outside and see if you can see the station with your own eyes.

We have written many articles about the International Space Station. Here’s an article about how you can actually see ISS in the daytime; it’s just that bright. And here’s an image of ISS and the shuttle transiting the Sun.

We have recorded an episode of Astronomy Cast that talks about the Space Station’s orbit.

“Suits and Ties” Collaborate on Successful Space Station Repair


At the end of Wednesday’s successful spacewalk to change out a faulty motor on one of the International Space Station’s solar array positioning devices, the astronauts outside the ISS and flight controllers in Houston were congratulating each other on the group effort it took to pull off this particularly tricky and potentially dangerous repair job.

“You guys looked really good to us. Thanks for making it look so easy,” Mission Control in Houston radioed up to the spacewalkers after their seven-hour and 10 minutes EVA.

“Yeah,” said ISS astronaut Dan Tani. “And we did’t even have to put on a tie.”

This spacewalk really was a collaboration between the “suits and ties” at NASA. The suits — spacesuits, that is — were worn by astronauts Tani and Peggy Whitson. The ties were sported by the engineers and astronauts in Mission Control who planned the repair and guided the spacewalkers during the entire EVA.

Tani and Whitson were thanking one tie-wearing astronaut in particular. Tom Marshburn had practiced the choreography of the spacewalk in the Neutral Buoyancy Lab in Houston, and shared his insights with the spacewalkers. Usually astronauts get to practice their own EVA’s in the enormous pool that contains a mock-up of the ISS. But the Bearing Motor Roll Ring Module on the starboard solar array quit working in December when Whitson and Tani were already on board the station. So the plan and nuances of the EVA were tested in the pool by Marshburn and former ISS resident Suni Williams and relayed up to Tani and Whitson.

The spacewalk was especially hazardous because of the risk of electrical shock from 160 volts of electricity that flows through the arrays. For safety, Whitson and Tani waited until the International Space Station was on the dark side of Earth, giving them only 33 minute increments to complete their tasks. Whitson had to squeeze inside the station’s truss girder to swap out the 250 pound (113 kilograms) garbage can-sized motor.

The new motor successfully performed a 360-degree test spin during the spacewalk. It’s power-generating capabilities were tested successfully as well.

“Yay, it works!” exclaimed Whitson as she and Tani watched the solar wing turn. “Excellent, outstanding…isn’t that cool?”

The successful repair means the station should be able to generate enough power to support the new modules that will be brought on the next shuttle missions, the European Columbus science lab, and the Japanese Kibo labratory.

“Given the complexity of this spacewalk and the risks that we had to manage … we are exceptionally pleased with how things went,” flight director Kwatsi Alibaruho said after the EVA.

In addition to the motor repair, Whitson and Tani also performed another inspection of the station’s starboard Solar Alpha Rotary Joint, a 10-ft wide gear that keeps the solar wings pointing toward the sun The SARJ is not working and is contaminated with metal shavings. The spacewalkers evaluated damage from the debris and collected samples from areas previously unseen.

Alibaruho said the new debris samples will help determine what repairs will be done, perhaps later this year. NASA hopes to launch up to five shuttle flights to the ISS this year.

Wednesday’s EVA was the final planned spacewalk of the Expedition 16 mission and the 101st dedicated to space station assembly and maintenance. The spacewalk also marked the sixth career EVA’s for both Whitson and Tani.

So, there’s just one question for Dan Tani: Which is harder — donning a 280 lb spacesuit or tying a Windsor Knot?

Original News Source: NASA TV