by Jay Chladek
Initially, Russian managers guessed that perhaps the new arrays had sent a power spike through the systems or that perhaps the mass of the ISS allowed it to build up an excessive static charge, but inspection of the computers by Kotov and Yurchikhin over the next few days, plus engineering analysis on the ground, revealed the real culprit. Wires in a power monitor box, a form of surge protection for the ISS, had corroded; thanks to a short circuit, it had sent a false power-down command to the computers. The problem was corrected when the faulty power box was bypassed. The corrosion was caused by excess condensation in the Zvezda module. Bypassing the faulty box and hooking directly to the power feed made the computers potentially susceptible to a possible power surge, the same as plugging in a home computer to a wall outlet instead of a power strip. A new monitor box was sent up on the next cargo vehicle. Life aboard the ISS returned to normal for the three Expedition 15 crewmembers after the STS-117 crew wrapped up their tasks and headed for home with Sunita Williams on board.
Three Musketeers in Orbit
Fyodor Yurchikhin, Oleg Kotov, and Clay Anderson got along well together during their time in orbit. It was rather lucky, given that Clay had spent more time training with Expedition 16 crewmembers Peggy Whitson and Yuri Malenchenko on the ground. But Anderson and Kotov had at least known one another as they conducted Soyuz survival training together. The Russian-language training for Anderson paid off, as he could speak pretty good Russian to his crewmates. Oleg Kotov could also speak very good English, and Fyodor Yurchikhin was not far behind. The crewmembers called themselves the “three mushkatiery en orbitya” (“three musketeers in orbit”).
When the time came for Anderson and Yurchikhin to perform their space walk, they did it professionally with no problems. Anderson was particularly proud to wear the red stripes on his suit, meaning that he was designated the lead spacewalker on the EVA, even though Yurchikhin was the Expedition 15 commander. After completing other tasks, which included installation of a television camera stanchion and service work to an S-band antenna, the pair unbolted the refrigerator-sized Early Ammonia Servicer tank and a second piece of related equipment. With Kotov driving Anderson on the end of the SSRMS to a launching point, the astronaut let go of both assemblies in a path opposite of the station’s direction of travel. These new satellites were dubbed Nebraska 1 and Nebraska 2, and each spent a few months in orbit before they finally reentered and burned up in the atmosphere.
STS-118 visited the station in August, carrying the S5 truss, the External Stowage Platform 3, and replacement control-moment gyros. Internal supplies were also carried inside the final Spacehab module to fly on a shuttle. This was the first flight of the space shuttle Endeavour since the Columbia accident, and it was also the first time the Station to Shuttle Power Transfer System was tried out, allowing the shuttle to power down its fuel cells in orbit for a while. Four EVAs were conducted on this flight, and Clay Anderson took part in two of them as part of his original STS-118 assignments. But the first EVA had to be cut short when Rick Mastracchio’s glove showed a possible tear to its outer covering. The pair had completed their assigned tasks already and were doing some get-ahead tasks when the EVA was abruptly concluded.
Astronaut Barbara Morgan was part of the STS-118 crew. In 1985 she was selected as Christa McAuliffe’s backup for the Teacher in Space program. After McAuliffe was lost on Challenger, Morgan returned to her teaching job in Idaho. In 1998 Morgan was selected to become a mission specialist astronaut, and she became one just prior to NASA’s creation of the title educator-astronaut, for other teachers wishing to become astronauts. As part of STS-118, she took part in a classroom lesson for schools on Earth, which demonstrated the unique aspects of weightlessness and Isaac Newton’s physics laws.
STS-118’s mission was cut short by a day due to a threat to the Houston area by Hurricane Dean. The storm was in the Gulf of Mexico when Canadian Dave Williams and Clay Anderson were conducting the fourth EVA. The pair got a very good look at the massive hurricane as it passed below them. Upon seeing it, Anderson commented, “Holy smoke!” Dave Williams had a look and replied, “Man, that’s impressive,” to which Anderson responded, “They’re only impressive when they’re not coming toward you.” The space walk was concluded two hours early with all the assigned tasks completed. The hatches between the two vehicles were closed that night.
Early the next day, Endeavour undocked and headed for home. After the two crews parted company, Anderson appeared overcome with emotion since he was good friends with the STS-118 crew. He was in regular contact with his family at home and knew about the evacuation preparations for the hurricane. NASA started preparations in case of a direct strike, and primary control of the ISS was transferred from JSC to the TsUP in Russia so that workers in Houston could assist with their own families’ storm preparations. The precautions weren’t needed, though, as Hurricane Dean ended up going south and making landfall on the Yucatán Peninsula instead of Texas. Endeavour returned to Earth safely, and ISS operations continued without interruptions.
Ballistic Reentry, Part 1
Expedition 15 gave way to Expedition 16 when Soyuz TMA-11 docked with the station on 12 October 2007. This mission was a first, as astronaut Peggy Whitson was assigned as the station’s first female commander. To commemorate the event, Russian managers gave her a pair of traditional Kazakh riding whips as a sign of respect just prior to launch in order to honor her command role. For the launch, and later for the return, flight engineer Yuri Malenchenko was the commander of the Soyuz craft. Joining them on this mission was Malaysian spaceflight participant Sheikh Muszaphar Shukor, flying a short-duration mission to the ISS as Malaysia’s first astronaut.
After eight days of joint operations, Fyodor Yurchikhin, Oleg Kotov, and Sheikh Muszaphar Shukor boarded Soyuz TMA-10 to return home. Undocking and retrofire went well, but the reentry didn’t go as planned, as TMA-10 underwent a ballistic reentry instead of a controlled one and landed about 340 kilometers short. The crew landed safely, but concerns were raised about the Soyuz TMA design, as this was the second ballistic reentry to occur within a five-year period. A postflight investigation said that the problem was due to a faulty cable. The TMA-11 spacecraft was given a clean bill of health by the Russians.
Peggy Whitson had come quite a long way since her days as a project scientist representing NASA during the Shuttle-Mir Program. She conducted many experiments as Expedition 5’s science officer, and while construction was the order of the day for Expedition 16, her management skills came in handy. Her scientist husband continued research in the work she had begun when they both started working for JSC in the 1990s. Part of their research dealt with the use of a calcium citrate dietary supplement to help prevent the formation of kidney stones in astronauts due to the leaching of minerals from bones during a long stay in orbit.
Expedition 16 had a total of six astronaut members assigned to it. Clay Anderson’s increment would only last a couple of weeks before his replacement, Dan Tani, would arrive aboard STS-120. French ESA astronaut Léopold Eyharts from STS-122 would then take over for another month before being replaced by STS-123’s Garrett Reisman, whose duties would dovetail into Expedition 17 before his scheduled return home on STS-124.
Finding Yourself on NEEMO
Many ISS astronauts have taken part in a program called NEEMO, which stands for NASA Extreme Environment Mission Operations. The NEEMO missions take place aboard an underwater habitat known as Aquarius, which is located just off the Florida Keys. The lab is funded by the National Oceanic and Atmospheric Administration; scientists use it to study sea habitats in the region, since very long dives can be conducted from there.
Occupants of Aquarius stay on board and don’t return to the surface until the end of their missions. By living in the habitat for several days, astronauts (or rather aquanauts as they are called during NEEMO) learn teamwork and skills to operate in hostile environments, since the ocean floor can be just as deadly as space. It also acts as a form o
f screening for possible ISS astronaut candidates by putting them in a stressful environment. Peggy Whitson commanded NEEMO 5 with Clay Anderson and Garrett Reisman as two of her crewmates. Dan Tani took part in NEEMO 2 with Sunita Williams.
Pambo
STS-120 lifted off on 23 October 2007. In Discovery’s payload bay was ISS Node 2, a module known as Harmony. As with Unity, the new module had CBMs all around it, and its placement on the ISS would allow for the Columbus laboratory module from Europe and the Kibo laboratory from Japan to be attached at later dates. Harmony would add 20 percent to the station’s internal volume. Originally, the ISS was supposed to have a dedicated habitation module to act as the living quarters for three crewmembers among its other uses, but budget cuts in 2001 forced a revision. New sleep stations and other amenities would be provided in Node 2 instead. The node’s addition was necessary before the ISS crew could be increased from three to six crewmembers.
The mission would also move the P6 solar arrays from their central location to the end of the P5 truss, where they would once again be unfurled. The final set of S6 solar arrays were scheduled to arrive on STS-119 in a few months. With the final arrays installed, the ISS would be fully mission-capable from an electrical power standpoint.
In command of STS-120 was Pam Melroy. A veteran pilot of ISS assembly flights STS-92 and STS-112, Pam Melroy was the third female shuttle pilot selected by NASA and only the second female shuttle commander. Astronaut Susan Kilrain, a naval aviator, was the second female shuttle pilot; even though she had two missions under her belt, Kilrain retired from the astronaut corps in 2002.
Melroy was a U.S. Air Force veteran and flew KC-10 tankers after flight school. Her squadron flew in support of the F-111 bombing raids on Libya in 1986 as part of Operation El Dorado Canyon, but unfortunately Melroy was unable to participate since she was conducting air force survival, escape, and evasion training at the time. She would later fly support missions for the invasion of Panama in 1989 and the first Iraq war in 1991. Melroy attended the Air Force Test Pilots School at Edwards AFB and was involved in early testing of the C-17 cargo plane before her selection as an astronaut.
Around the astronaut office, Melroy was known as Pambo in reference to the Sylvester Stallone Rambo films. Gifted with an interesting sense of humor, Melroy was also sometimes known as Tank Girl, since one of her favorite movies was the 1995 postapocalyptic film of the same name. The main character of the film is a seemingly ditsy blonde girl who drives a tank. A copy of Tank Girl was placed in the ISS movie library by Melroy during one of her visits to the station as a house-warming gift of sorts.
In addition to the crew and the mission cargo, the space shuttle Discovery had a Star Wars lightsaber movie prop in a storage locker, flying as part of the mission’s Official Flight Kit, which contained memorabilia items selected for a trip into space. NASA has pretty strict guidelines as to what can and can’t be flown in Official Flight Kits and the astronauts’ own Personal Flight Kits. The lightsaber generated a bit of media attention on the ground, and it gave Clay Anderson an idea for some wakeup music.
During Sunita Williams’s stay, she had begun a tradition of transmitting a wakeup call from the ISS to the ground and selecting music to play for mission control. When Anderson arrived, he decided to continue that tradition, calling it “Radio Station K-ISS.” He would periodically select music that was appropriate for that day in similar fashion to the wakeup music usually transmitted to shuttle flights. So the morning after Discovery lifted off, Anderson played the song “Whip It” by Devo in honor of the two female commanders Peggy Whitson and Pam Melroy, since one had been given whips and the other was packing a lightsaber. Peggy Whitson laughed of course, but Anderson joked that he was glad she didn’t have her riding whips in orbit or she might have used them on him.
STS-120’s Apollo 13 Save
Docking day came as expected, and the combined crew got right to work. The Harmony node was berthed on a CBM on the port side of Unity for temporary stowage. After the shuttle returned home, PMA-2 on the front of Destiny would be relocated to the front of the node, and the pair would then be berthed on the front of Destiny for future shuttle dockings. Astronauts Scott Parazynski and Doug “Wheels” Wheelock performed a space walk to prepare the module’s exterior and set up an S-band antenna on it, as well as set up an external stowage platform. The Harmony node was opened for the first time on 27 October, and the crew said hello to their new living quarters.
Parazynski and Tani conducted a second space walk to prepare the P6 for its relocation a couple of days later. They also checked out the starboard truss’s Solar Alpha Rotary Joint (SARJ), as it had apparently been acting up for about a month with vibrations as it moved. The SARJ units allow the truss assemblies to rotate the arrays and track the sun. Each array also has a joint allowing side-to-side movement as well. Tani’s inspection revealed some metal shavings, indicating that the SARJ’s bearings were wearing excessively; he used a piece of tape to collect some samples for ground analysis. Controllers made plans for Parazynski and Wheelock to inspect the P4 and P5 trusses on the third space walk to see if there was a similar problem. The P6 array was then moved off the Z1 truss and parked on the SSRMS before movement to its final location.
During the next EVA, the P6 was finally relocated, and the proper electrical connections were made. The arrays were then unfurled again. The first pair opened up fine, but a big problem developed on the second one. Like a set of window blinds, the arrays also contain guide and support wires to make sure they unfurl properly. A guide wire on one of the arrays frayed and got caught on a support wire. The snag began tearing a hole in one of the solar panels and kinked up the hinges in others, producing an ugly-looking bulge in the delicate array. Things did not look good at all.
The movement was put to a stop while everyone analyzed the problem. The array could not be kept partially unfurled, and it couldn’t be fully retracted again either. In its position, it was unstable as station reboost firings could cause the structure to oscillate wildly and perhaps snap from the stress. Engineers had to come up with a fix and do it fast. To complicate matters, the ISS had not been designed to support EVAs to the arrays. There were no handholds that far out and also no provisions for a space walker to climb up the arrays themselves.
Fortunately, the ISS had all the materials it needed to perform a repair. Engineers came up with a procedure to cut away the snagged wire. Several “cuff links” were made with thick, nylon-coated wire wound together like a rope with a loop at each end. Inside these end loops were a set of flat blocks. When the array was unfurled, the cuff links would help guide the array to flatten in its proper position, giving a firm platform for the panel hinges to pivot against, at least in theory.
Don Pettit, on the ground, helped come up with the procedures for making the cuff links and a couple of tools that would be used for this repair. He helped shoot a video that was uplinked to the ISS along with written instructions. It was an interesting parallel to Apollo 13, when the crew of that mission had to assemble adapters for their carbon dioxide scrubber cartridges to work in the LM using available materials and instructions radioed up.
Both shuttle and ISS crews worked together as a combined team to get ready for the repair. There was a lot riding on this; everyone knew that if the repair wasn’t successful, the arrays might have to be jettisoned. That would cut the power-generating capability of the ISS by a significant percentage and potentially cripple the station’s mission. There was no backup set of arrays on the ground and no budget to build a replacement, let alone have a replacement available before the shuttle’s planned retirement. For the two commanders, Whitson and Melroy, the waiting that night before the repair EVA was agonizing as they ran the possible scenarios in their minds concerning what might happen.
On 3 November the repair EVA was conducted. Scott Parazynski set up a foot restraint on the OBSS and strapped himself on it. To get to the work site, the SSRMS grasped the OBSS at its midpoint gra
pple fixture, and the astronaut positioned on its end would be moved to the damaged area of the array. Since the SSRMS had never been operated in quite this manner, Doug Wheelock acted as the arm operator’s eyes at the base of the arrays while Parazynski directed the movements from his end.
The midpoint grapple fixture on the OBSS had to be used since the SSRMS wasn’t set up to attach at the base of the boom like the shuttle RMS. It couldn’t use the cameras and sensors on the OBSS either. The mission also had a time constraint, since the electronics in the OBSS could only remain unhooked from shuttle for about ninety minutes before its onboard batteries would run out of power, potentially causing the sensors to freeze from lack of heating. While no problems had been detected with Discovery’s heat shield, a final OBSS inspection is typically done after undocking to check for last minute problems, just in case. The OBSS sensors were still needed.
Scott Parazynski picks up the story:
This was an unprecedented work site. We had never planned to go [that] far away from the safety and comfort of the airlock, and we had never planned to go near a solar array that was only partially deployed like this, which is very unstable. And finally, we had never planned to go near a solar array that had sustained damage because one thing that could conceivably happen is [electrical] arcing from this energized solar array into the spacesuit, which of course is just a balloon filled with 100 percent oxygen. Thinking things through clearly and carefully, it was felt . . . correctly so . . . that the likelihood of arcing to my suit was relatively low, provided I didn’t come in direct contact with [the array]. Anything that I was going to contact the array with would be isolated.