With the Shuttle gone, the Expedition-15 crew was alone on ISS once more. They quickly adjusted their sleep pattern and returned to their daily routine of exercise, maintenance, and experiments. Anderson has described some of the experiments in which he would take part:
“You know, some of them are quite simple. For example, scientists on the ground want to know what I eat, how much I eat and drink, and how often I eat and drink, and they want to know my vitamin-D content. Well, vitamin-D is something we get from sunlight on Earth, primarily, but we need it for strong bones and muscles, and so folks, elderly folks that have trouble with bones and osteoporosis and those kind of problems can benefit by the scientists that are doing experiments and gathering data on how a crew member in space that doesn’t get sunlight anymore and has to supplement his vitamin-D with either drugs—or vitamin tablets—and what he eats and what he drinks, and that’s a key experiment that’s pretty simple. They just have to gather the data. Another experiment that’s quite interesting to me is I’m going to wear a special watch, for the entire increment, and it’s called an actiwatch, and it’s a sleep watch: it knows when you move, it knows when you go to sleep, it knows when the lights go on and when the lights go out, and scientists will gather that data that we’ll downlink periodically through the mission. What they’re trying to do is try to figure out ways to benefit people on Earth that do shift work or that have trouble sleeping or that sleep too much, and ways to work with your circadian rhythm and your body and try to help you not go through these periods when you can’t stay awake or when you can’t go to sleep. So that’s quite neat. And those are simple experiments. The more complex experiments include things, we’re going to look at combustion on the station through an experiment that has… several samples that just rotate through a chamber and they look at the flammability and take the data and then they’ll evaluate it on the ground. We’ll grow some plants, we’ll grow some worms, and the key there, of course, is when you go on long duration, can you grow plants, can you eat those plants, how do physical things like worms adapt to zero-g in a long-duration mission, such that we can apply that to humans.’’
As to his spare time, Anderson had plans of his own:
“From a personal standpoint, I like to write music and I’m going to try to write a song when I’m in space. Now I don’t know how much time I’ll have, I don’t know how successful I will be. The other thing I’d like to do is there’s a guitar on board and I’ve always wanted to learn to play guitar and hopefully I’ll have enough time and there’s some software on our computers that will try to guide me through the learning process to learn how to play the guitar. I think what I want to do the most, though, is I want to try to absorb as much as I can, all that I experience and see while I’m there, and try to take as much of that with me as a memory either through video media or computer e-mails or what have you, but I want to try to take as much of that away as possible so I can relate it to people back here on Earth.’’
PMA-3 had been delivered to ISS by STS-92 in October 2000 and installed on Unity’s nadir. In December of the same year, STS-97 had docked to it in that location in order to install the P-6 ITS on the Z-1 Truss. STS-98 had also docked to PMA-3, in order to install Destiny, in February 2001. During the visit of STS-102, in March 2001, PMA-3 was moved from Unity’s nadir to Unity’s port CBM, thus allowing Unity’s nadir CBM to be used for the berthing of MPLMs carried by Shuttles docked to PMA-2 on Destiny’s ram. On August 30, 2007, the Expedition-15 crew relocated PMA-3 in preparation for the arrival of STS-120. Anderson operated the SSRMS from inside Destiny, while Yurchikhin operated the relevant CBM docking mechanisms on Unity. Kotov backed up both of his colleagues. After latching the end-effector of the SSRMS onto PMA-3, Yurchikhin commanded the docking system on Unity’s port CBM to release and Anderson removed the PMA at 09: 18. During the undocking a fault alarm sounded when one of the latching bolts registered zero load. The work was stopped to study the situation before continuing. During the relocation fault, alarms sounded intermittently on three securing bolts and work was stopped a second time to further review the situation. Finally, Houston gave the command to continue. After Anderson had manoeuvred PMA-3 next to Unity’s nadir CBM, Yurchikhin commanded Unity’s docking mechanism to close, holding the PMA in place at its new location. The move was completed at 10: 07.
The relocation of PMA-3 was required so that Harmony could be temporarily docked to Unity’s port CBM. This temporary installation on Unity was necessary because the SSRMS could not reach to install a PMA on Harmony’s ram if the new module was docked directly to Destiny’s ram when it was delivered by STS-120. When STS-120 had departed, the SSRMS would be used to undock PMA-2 from Destiny’s ram and move it to Harmony’s port. Next, the SSRMS would be used to move Harmony, with PMA-2 on one end, and docking, via its exposed CBM on the other end, to Destiny’s ram, leaving PMA-2 exposed on Harmony’s ram to receive visiting Shuttles. Zvezda’s thrusters were fired on September 24, to adjust the station’s orbit in advance of the launches of Soyuz TMA-11 and STS-120, planned for October 10 and October 23, respectively.
Anderson updated the software in the American navigation systems and installed new American computer hardware, and Kotov tested and upgraded the Russian computers before the two computer systems were integrated as one system.
The station was re-oriented on September 11, to reduce drag as it passed through the upper atmosphere. It was estimated that the manoeuvre would save the equivalent of the total amount of manoeuvring propellant for Zvezda’s thrusters delivered on two Progress flights. Onboard, both loops of the Russian thermal control system suffered a single pump failure, leaving both loops operating on just one pump each. Repairs made by Kotov on October 3 returned one loop to full operation, the second loop would have to await the delivery of a new pump on Soyuz TMA-11. Both men worked to replace Russian EVA support equipment in Zvezda and Pirs on September 19-20. The original equipment had passed its use-by date.
Even as preparations for the arrival of STS-120 continued, Yurchikhin and Kotov were also preparing for the end of the stay on ISS. Progress M-60 was undocked at 19: 37, September 18, but was not commanded to re-enter immediately. Rather, it was commanded to perform six manoeuvres as part of the “Plasma – Progress” experiment. Progress M-60 finally re-entered on September 25.
As the Expedition-15 crew brought their experiment programmes to an end, they also began packing to go home. Before that could happen they had to relocate Soyuz TMA-10. On September 27, having prepared the station for unoccupied flight, all three men donned their Sokol pressure suits and sealed themselves in the Soyuz, which was docked to Zarya’s nadir. Yurchikhin undocked his spacecraft at 14: 20 and manoeuvred clear of the station before flying along its length and manoeuvring to dock at Zvezda’s wake. Docking occurred at 14: 47 and the crew returned to the station after leak checks. They then began the task of reconfiguring the station for occupation once more. The move cleared Zarya’s nadir for the docking of Soyuz TMA-11, flown by the Experdition-16 crew. That launch was planned for October 10.
The following day, September 28, Zarya’s starboard photovoltaic array was retracted. This was required to prevent impact with the starboard radiator, mounted on the ITS, that would be deployed during the visit of STS-120. Zarya’s port photovoltaic array was retracted on September 29, to prevent impact with the port radiator, which would be deployed after STS-120 had left the station. Meanwhile, on September 30, STS-120 was transferred from the VAB to LC-39A, in preparation for its launch on October 23.
In Destiny, Anderson activated the American Oxygen Generation System and measured the sound levels that the machinery produced on October 2. The new oxygen generator was set at 50% and left running, while Houston monitored its performance. When running at full power the American system would provide sufficient oxygen to fill the entire station at “Core Complete’’ plus the International Partners’ modules. It would be capable of supporting the entire station, even when operated by six Expedition crew members.
The MT/MBS combination was moved to the port side of ISS on October 3, in preparation for the arrival of STS-120 and the relocation of the P-6 ITS. Moving the P-6 ITS from the Z-1 Truss and relocating it to the far end of the port side of the ITS, and the installation of the S-6 ITS on STS-119, represented the ultimate tasks that the SSRMS would be called upon to perform during the construction of ISS. The SSRMS would be operating fully extended and at the extreme limit of its reach.
On the same day, the crew reopened the hatch to Progress M-61, which they had sealed prior to relocating Soyuz TMA-10.
October 4, 2007 was the 50th anniversary of the launch of Sputnik-1, the world’s first artificial satellite. Asked about the significance of the anniversary in a pre-launch interview, Expedition-16 crew member Yuri Malenchenko said:
“I believe we have achieved a considerable progress over such a short time period. We learned to live in space just a short 50 years ago, but didn’t live in space. We weren’t even thinking, or rather we were thinking, but weren’t sure if it is possible, to live in space constantly. Currently we have a continuous presence of humans in space, not only living in space but performing complicated activities and tasks, performing science experiments, and it has been going on for years. Of course, space exploration is unique. All steps, all achievements, regardless of where, which country and when, have been completed, are important, and each step is an important stage for subsequent steps.’’
The Expedition-15 crew marked the anniversary onboard ISS, but also had to continue with their own work as well as their preparations for the arrival of Soyuz TMA-11 and their own return to Earth. Meanwhile, Anderson worked with Kotov to use the Oxygen Uptake Measurement equipment to collect data as he exercised on the stationary bicycle. The Oxygen Generation System in Destiny continued to operate at 50%, waiting for the system’s water supply to be depleted. During the week before the launch of Soyuz TMA-11, the crew mounted the centreline camera in Unity’s port CBM, where it would be used in support of the initial docking of Harmony during the flight of STS-120. The three men also completed the medical experiments and extra exercise that all long-duration crews perform as their flight approaches its end. They also made room in Zvezda where the Soyuz TMA-11 spaceflight participant would perform his experiments during his short visit to the station.
On October 6 the TVIS treadmill in Zvezda failed during Kotov’s exercise period. The crew worked with engineers in Korolev to replace three roller bearings and return the vital unit to use. As they prepared for their return to Earth, Yurchikhin and Kotov continued to work with both Russian and American experiments.
SOYUZ TMA-11 DELIVERS THE EXPEDITION-16 CREW
When Soyuz TMA-11 launched towards ISS at 09:21, October 10, 2007, it contained an extremely experienced crew. Soyuz Commander Yuri Malenchenko served 126 days on Mir and had commanded the 185-day occupation of ISS as part of the Expedition-7 crew. He had also visited ISS during the 12-day flight of STS-106. Whitson had made two Shuttle flights, serving as Pilot. Whitson had also served on ISS for 185 days as part of the Expedition-5 crew. Following the Soyuz TMA-11 crew’s transfer from Soyuz to the station, she would become the first woman to command an ISS Expedition crew. Sheikh Muszapher Shukor was a commercial customer of the Russian Federal Space Agency on his first flight. On launch day, Russian engineers presented Whitson with a ceremonial Kazakh riding whip and suggested that she might use it to keep her male colleagues in line while on the station. Asked about how she viewed being the first female Commander of ISS, Whitson replied:
“I think being a woman doesn’t really play too much into that. I think it’s special that I get the opportunity to play that role, but I think it’s also special to have an opportunity to demonstrate how many other women also work at NASA. So I’d like to be able to do that as well.’’
In answer to a different question she explained:
“Actually it’s going to be kind of exciting. During STS-120 Pam Melroy will be commanding that Shuttle mission; my lead flight director is Holly Ridings. I also have Lead Flight Directors for two different Shuttle missions during those phases, Dana Weigel and Sally Davis. And so we have a big team, which is consistent with any mission, but it happens this time around we have a number of females in the leadership roles. So I think it’s exciting.’’
Soyuz TMA-11 lifted off from Baikonur at 09: 22, October 10, 2007. As was the standard procedure, during the launch and solo flight, Malenchenko served as Soyuz Commander. Following a standard 2-day rendezvous, Soyuz TMA-11 docked to Zarya’s nadir at 10: 50, October 12. After leak and pressure checks the hatches between the two spacecraft were opened at 12: 22 and Whitson led the Expedition – 16 crew on to ISS. After the standard safety brief, Shukor and Anderson moved their seat liners and Sokol pressure suits between the two Soyuz spacecraft, Anderson thus becoming a member of the Expedition-16 crew and Shukor preparing for his return to Earth in Soyuz TMA-10 with the Expedition-15 crew. The next 9 days were spent in joint experiment programmes while the new crew, who were both ISS veterans, also took time to re-associate themselves with the station. Shukor performed his experiment programme in Zvezda. That programme consisted of five Malaysian experiments and three ESA experiments. In a Malayan press release, he was identified as the country’s first angkasawan (astronaut). Meanwhile, Anderson replaced a failed audio terminal unit in Quest on October 11. The new unit would lock up during the Soyuz TMA-11 hand-over period. Houston began an investigation.
On October 16, China expressed an interest in getting involved with ISS. Li Xueyong, a Chinese minister of science and technology, stated:
“We hope to take part in activities related to the International Space Station. If I am not mistaken, this programme has 16 countries currently involved and we hope to be the 17th partner… The Chinese government has always pursued a foreign policy of peace and consistently worked for the peaceful use of outer space.”
In Whitson’s first in-flight press conference, the subject of Russian cosmonauts’ attitude towards their female colleagues was discussed. The new station commander remarked, “Russian cosmonauts are very professional. Having worked and trained with them for years before we got to this point makes it better.’’ Yurchikhin added, “It’s not a problem, women running operations. The problem is whether we are professional or not. We are professionals. She is our friend and colleague.’’ On the same subject, Anderson joked, “I’m a little concerned about this whip. I’m kind of waiting for her to take it out and put me in line sometimes.’’
Figure 101. Expedition-16 crew (L to R): Sheikh Muszaphar Shukor, Yuri Malenchenko, Peggy Whitson.
After a week of shared maintenance, experiments, and daily exercise, the official hand-over of command took place on October 19, at which time Whitson told Yurchikhin and Kotov, “It’s been a very impressive mission, and you guys have performed exceptionally.’’ Yurchinkhin, Kotov, and Shukor said their farewells the following day and sealed themselves in Soyuz TMA-10. They undocked from the station around 03: 14, October 21. Following the standard retrofire manoeuvre, Soyuz separated into its three parts. The descent module re-entered the atmosphere but soon deviated from its planned trajectory and followed a much steeper, ballistic trajectory. The course change had been commanded by the onboard computer. After a re-entry in which the crew pulled higher ^-forces than planned, the spacecraft’s parachutes deployed and lowered Soyuz TMA-10 to a safe landing in Kazakhstan, at 06: 37. The Expedition-15 crew had been in flight for 196 days 17 hours 5 minutes. Shukor’s flight had lasted 10 days 21 hours 14 minutes. Although the landing was 338 km south of the target, the recovery forces had tracked its descent and recovery helicopter crews had the descent module in sight as it descended on its parachute. After removal from the module by the recovery forces, the cosmonauts used the satellite phone, added to the Soyuz spacecraft after a similar re-entry trajectory switch by Soyuz TMA-1, to speak to Korolev. Talking about the re-entry afterwards, Yurchikhin stated:
“The overload was really powerful, but nobody fainted… I remember the overload going to 8.5 or 8.6 g.’’
Shukor was more descriptive, stating:
“I was not really scared, it happened so fast… It felt like an elephant pressing on my chest, but the Russians trained us very well.’’
On the subject of his flight he remained optimistic, saying:
“I hope to go back and inspire a generation of Malaysian youth… I hope other Muslims would be united, stay away from war and be peaceful.’’
STS-120 DELIVERS HARMONY, “THE PIECE THAT MAKES THE REST POSSIBLE”
Scott Parazynski, Douglas Wheelock,
Stephanie Wilson, Paolo Nespoli (ESA)
In the days leading up to the launch of STS-120, a degradation of the outer protective coating was observed on the leading edge of both of Discovery’s wings. One RCC panel on one wing and two on the other showed the degradation, which had been present for the past three of Discovery’s flights. Launch managers decided that the problem fell within the limits of acceptable risk and decided not to roll STS-120 back to the VAB and replace the panels in question. A roll-back would have caused the flight to be delayed by a minimum of two weeks.
Rain threatened on the morning of launch, but in the end the weather held back. One technical problem that had threatened to delay the launch was a build-up of ice on a propellant line under the left wing. By the time the countdown reached its final stages, the ice had melted sufficiently to offer little threat to the Shuttle.
Discovery lifted off on time at 11: 38, October 23, 2007, after what Launch Director Michael Leinbach described as, “One of the cleanest countdowns we’ve had since I’ve been a Launch Director.’’ Discovery passed through a succession of cloud layers as it sped towards orbit. Melroy reported that several pieces of ice struck the orbiter’s forward windows during launch, but did no damage. All observed ice shedding from the ET took place after the critical first 2.5 minutes of flight, by which time Discovery was beyond the thick lower atmosphere, where the supersonic slipstream might slam the ice into the orbiter, causing damage.
On NASA’s website, Commander Pam Melroy had shared her enthusiasm for the flight, saying:
“STS-120 is such a cool mission. Node-2 is the expansion of the Space Station’s capability to bring international laboratories up. It’s the expansion of our capability to carry additional people. It has additional life support equipment that will allow us to expand out beyond a three-person crew. It’s this big boost in capability which is really exciting.’’
With lift-off behind them, the crew opened the payload bay doors to deploy their vital radiators and deployed the Ku-band antenna before spending several hours configuring their spacecraft for orbital operations, before settling down to their first eat and sleep period at 17 : 30.
On ISS, Whitson and Anderson worked on the TVIS treadmill, while Malenchenko serviced the toilet in Zvezda. The following day, Malenchenko serviced the KOB-1 and KOB-2 Thermal Control Loops performing a major plumbing overhaul that returned both systems to partial operation.
Up again at 01: 30, October 24, the STS-120 crew’s first full day in space was occupied by using the OBSS on the end of the RMS to inspect Discovery’s Thermal Protection System, including the RCC panels on the leading edges of both wings. An initial review of the data showed no immediate problems for re-entry at the end of the flight. They also prepared the EMUs stored in Discovery’s airlock as well as the equipment they would use during the rendezvous and docking the following day, including installing the centreline camera and extending the docking ring. Inside the orbiter, a high-speed computer modem presented the one difficulty of the day. The modem was due to be used to download the crew’s digital photographs to MCC-
Figure 102. STS-120 crew (L to R): Scott E. Parazynski, Douglas H. Wheelock, Stephanie D. Wilson, George D. Zamka, Pamela A. Melroy, Daniel M. Tani, Paolo A. Nespoli.
Figure 103. STS-120 approaches ISS with Node 2, Harmony, in the payload bay.
Houston. On ISS, Anderson was approaching the end of his 4.5-month occupation, and was undergoing an increased daily exercise regime, in preparation for his return to Earth. Anderson and Malenchenko also prepared the cameras they would use to photograph Discovery’s underside during the now standard r-bar pitch manoeuvre prior to docking. Whitson performed pressure leaks in PMA-2 in advance of Discovery’s docking. The Shuttle crew’s day ended at 17: 38.
Awake once more at 01: 39, October 25, Melroy’s crew ate breakfast together before making the final preparations for rendezvous with the station. Melroy began the rendezvous manoeuvres just before 03: 00. Two hours from docking Anderson told Discovery’s crew, “We can’t wait to see you. We welcome you with arms open. The towels are clean and laid out.’’ At 07: 32, at a range of 200 metres below the station, Melroy had Discovery perform a nose-over-tail pitch manoeuvre so that Anderson and Malenchenko could photograph the TPS on the Shuttle’s underside. Those digital images were sent to MCC-Houston, so that specialists could search them for evidence of any damage caused by the ice or foam shed from the ET during launch.
Docking, with Melroy at the controls, occurred at 08: 40, off the coast of North Carolina, and was greeted with cheers from both crews. On ISS, Whitson rang the ship’s bell and announced, “Discovery arriving.’’
Parazynski remarked, “Everyone here is ecstatic. We are so fired up to be here.’’ As usual, docking was followed by pressure and leak checks, before the hatches between the two spacecraft were opened 2 hours later. As the hatches opened, Whitson, the first female commander of ISS, greeted Melroy, only the second female commander of a Shuttle flight. Before launch Melroy had talked about this moment, saying, “The most important thing to me is the picture we take when our hands first meet across the hatches.’’ In Russia, before her own launch, Whitson had sounded less enthusiastic about the meaning of that handshake, saying, “I look forward to their arrival… She thinks it will be a special moment.’’
In reality, Whitson embraced Melroy as she entered Destiny. The media-hyped meeting, as the female commanders in charge of two separate spacecraft, was pure coincidence, caused by the delays in past Shuttle launches. Originally, STS-120 had been scheduled to launch before Whitson took command of Expedition-16.
The remainder of Melroy’s crew were greeted with handshakes and hugs. After the formal greeting onboard the station and the standard safety brief, Discovery’s crew began moving spacewalking equipment into the Quest airlock. At 12: 12, Tani installed his couch liner and Sokol launch and re-entry suit in Soyuz TMA-11, becoming part of the Experdition-16 crew, while Anderson moved his equipment into Discovery, transferring him to STS-120. As the day ended, Melroy’s crew were told that initial inspection showed no damage to Discovery’s Thermal Protection System. Melroy replied to the news, saying, “Oh, man. That is fantastic news. Obviously, that was a question that has been on our minds.’’ Parazynski and Wheelock spent the night “camped out’’ in Quest, in preparation for the first EVA the following day.
October 26 began at 01 : 39. After breakfast, Discovery’s crew commenced preparations for their EVA. Wheelock and Parazynski exited Quest at 06 : 02, half an hour earlier than planned, at the beginning of a planned 6.5-hour excursion. Italian astronaut Nespoli choreographed the EVA from inside Discovery. As the preparations came to an end and Quest was depressurised, Whitson joked, “We’ll open the hatch so you guys can go out and play.’’
Parazynski replied, “They call it work, but there is no better job, is there?’’ As the outer hatch swung open, Parazynski was awed by the view of Earth and remarked to Wheelock, “You’re not going to believe this.’’ Their first task was to remove a malfunctioning S-band antenna from its position on the Z-1 Truss and store it in Discovery’s payload bay for return to Earth. They also disconnected the final umbilicals running between the Z-1 Truss and the P-6 ITS, in preparation of the latter’s relocation later in the flight. Parazynski was subjected to a small ammonia leak while disconnecting the umbilicals and had to undergo cleaning procedures after returning to Quest at the end of the EVA. As they passed over the Gulf Coast, Wheelock remarked enthusiastically, “Oh, boy, look at that; Hello, Houston.’’ Returning to the payload bay, they put in place a payload and data grapple fixture that could not be mounted on Harmony during launch, due to lack of room within the closed payload bay doors. Their next task was to disconnect the umbilicals supplying electrical power and cooling fluids to Harmony. Tani, Anderson, and Wilson then grappled the new module with the SSRMS, lifted it out of the payload bay, and manoeuvred it to its temporary location on Unity’s port CBM. It was the first new pressurised module to be added to ISS in six years.
As the EVA drew to a close, Parazynski remarked, “Great day in outer space.’’ The ammonia decontamination procedures were first used on STS-98 and consisted of partially pressurising Quest, venting the airlock to vacuum once more, in an attempt to remove any residue ammonia crystals, before pressurising Quest to allow the other astronauts to briefly open the internal hatch, pass in wet towels, and close the hatch once more. The two EVA astronauts then wiped down the exterior of each other’s EMUs, before bagging the towels and finally leaving the airlock to return to the station. The EVA ended at 12: 16, after 6 hours 14 minutes.
Flight Director Dereck Hassaman described Harmony in the following terms:
“It’s the gateway to the International Partners. As the station is configured today, there’s nowhere to put the International Partner modules until we deliver and activate Node-2. That’s the piece that makes the rest possible.’’
Flight Director Rick LaBode added:
“We’re going to put it on the left side of Node-1 [Unity], and then, after the mission undocks, we’ll robotically remove the port the Shuttle docks to [PMA-2] from the end of the lab [Destiny] and put it on Node-2 [Harmony]. And then we’re going to take the Node-2 [with PMA-2] and put it on the end of the lab.’’
In orbit, with the job of delivering Harmony already completed, Parazynski stated, “Now the crews that are hot on our heels have a place to come.’’
As the day continued the Mission Management team in Houston decided to add an unplanned task to the second EVA, planned for October 28. The starboard SARJ had been experiencing increased friction over the previous 6 weeks. Parazynski and Wheelock would remove the thermal covers and make a 360° inspection of the joint.
Meanwhile, October 27 began at 01: 39. After breakfast, Whitson and Nespoli worked together to prepare Unity’s port CBM, before the crew opened the hatch giving access to the interior Harmony. That happened at 08: 24, when the hatch was swung back allowing Whitson and Nespoli to become the first people to enter the new module. All crew members wore surgical masks during their first visit to the new module in case there was any loose debris floating around that might be inhaled. With Harmony only in a temporary location, their task was not to power up the module before preparing it for the arrival of Columbus and Kibo. Rather, they applied minimal electrical power and installed a temporary ventilation line to circulate air into Harmony’s interior. Later in the day the two crews used the new Node to host a press conference, during which Whitson remarked, “We think Harmony is a very good name for this module because it represents the culmination of a lot of International Partner work and will allow International Partner modules to be added on.’’ Melroy added, “This is a really special moment for the station. This kicks off the international science portion of the Space Station’s life cycle.’’ Flight Director Rick LaBrode told the media, “It’s beautiful; bright shiny. The report from the crew is that it’s as clean as can be. Perfect shape!’’ Melroy also praised the work of the other members of both crews during the previous day, saying, “I just sat around and made lunch for everyone, and watched them do a totally fantastic job.’’
During the morning Discovery’s OBSS was returned to its storage position along the orbiter’s payload bay hingeline. The second inspection of Discovery’s Thermal Protection System, planned for that morning, had been cancelled the previous day. During the remainder of the day, Tani reviewed the plan for him to inspect the SARJ during the second EVA, and he also spent time with Anderson, working on handover procedures. At 15: 23, as the crew’s day ended, Parazynski and Tani were locked inside Quest and the pressure was dropped, to allow them to “camp out’’ overnight, in preparation for their EVA the following day.
The crew’s wake-up call on October 28 came at 01 : 09. After breakfast, Parazynski and Tani donned their EMUs inside Quest, while Wilson and Wheelock manoeuvred the SSRMS to grasp the P-6 ITS, mounted on the Z-1 Truss. Exiting the airlock at 05: 32, Parazynski remarked, “It’s a beautiful day,’’ and Tani replied, “Awesome.’’ After collecting their tools they made their way to the base of the P – 6 ITS, where they disconnected the final electric cables and the bolts that held the structure in place. Wilson and Wheelock then lifted the P-6 ITS away from the Z – 1 Truss. The 15 m long P-6 was left hanging overnight on the end of the SSRMS. Meanwhile, the two EVA astronauts set about performing separate tasks. Parazynski moved to the exterior of Harmony, where he installed EVA handrails. Tani made his way to the starboard ITS, where he checked the CETA cart for sharp edges on its handrails and then moved on to the SARJ, where he removed the thermal covers and inspected the joint for friction points. He discovered the joint was covered in a black dust, which included metal shavings, and there was friction wear on the race ring, then he replaced the covers. Station managers decided to limit the amount of rotation that the joint was subjected to while the investigation into problem continued. Tani also reconfigured connections on the S-l ITS that would allow Houston to deploy the S-l cooling radiator at a later date. For their final task they worked together to install a second PDGF on the exterior of Harmony, by which it would be held during its transfer from Unity’s port side to Destiny’s ram. They also removed launch covers from the exterior of Harmony. The EVA ended at 12:05, after 6 hours 33 minutes. After the EVA, NASA’s Mike Suffredini commented to a press conference regarding the port SARJ, “I really don’t think we are in any situation we can’t recover from. It’s just a matter of time. We have an obligation to try and get our partners to orbit as quickly as we can.’’
October 29 was a day of robotic work, with astronauts inside ISS and Discovery moving the P-6 ITS around outside the station. The day began at 01: 39 and after breakfast the two crews set about their individual tasks. Parazynski and Wheelock had a relatively quiet day preparing Quest and the station’s EMUs for the third EVA, with Nespoli’s assistance. Meanwhile, the remainder of the two crews separated into their own work teams. Wilson and Zamka operated Discovery’s RMS while Anderson and Tani operated the SSRMS. At 04: 08 the RMS was manoeuvred to grapple the P-6 ITS, after which SSRMS was commanded to release it. Discovery’s RMS held on to the P-6 ITS while the MBS holding the SSRMS was commanded to travel to the far end of the port ITS, from where it would still be stretched to its limits to install the P-6 ITS in its final location. The MBS translation along the port ITS took 90 minutes.
Tani has described his activities during the 3 days of work required to relocate the P-6 ITS:
“Conceptually it’s not that difficult: It’s four bolts—very big bolts but four bolts—it’s about a dozen electrical connectors and, and some fluid connectors. During the first couple of EVAs we will disconnect the electrical connectors; on the second EVA I will help unbolt the actual element. We’ll have Doug Wheelock inside running the arm. He will initially move the P-6 out and away from the station. Now the difficulty here is that the arm is not long enough to take it from its initial position and move it out to its final position. So we have to do a juggling act. We move it out to the side of the Space Shuttle and I believe Stephanie [Wilson] or George [Zamka] will then grab the P-6 Truss so that the Space Station arm can let it go, and then we utilize the Mobile Transporter, which is this little rail car that’s on the truss, and they’ll drive this little rail car, with the Space Station arm on it, all the way out to the end of the truss as far as they can go. Then the next day, I’ll run that Space Station arm to go pick up the P-6 Truss again and hand it off from the Shuttle. On the next EVA, I’ll run the arm and we’ll do a final install during the EVA with Doug and Scott outside, to do its final install and bolt it to the end of the truss and then redo those electrical and fluid connectors… right now the P-6 solar arrays have been fully retracted. It’s a big element but at least it doesn’t have these huge wings hanging off them. It’s hard to think of an analogy, but we are adding a huge source of power to the Space Station, or we’re moving it, and the power reconfiguration to protect all the circuitry, once you hook that up, is very extreme. In fact, we’ll have to power down half the Space Station while we do this because you don’t want to do what we call a ‘hot mate’. You don’t want power in one connector and have arcing across these connectors. So we will be powering down half the Space Station while we do this. We mate the P-6 to the P-5 and then, as soon as we can, once the electrical connectors are made, the folks on the ground will start powering those channels back up and we will start attempting to deploy these solar arrays.’’
During the MBS translation, Whitson and Tani worked inside Harmony, installing avionics racks. The remaining crew members spent most of the day transferring items from Discovery to the station. During the day, Houston informed them that an additional day had been added to the flight plan, giving them a day of additional light workload between EVA-4 and EVA-5. Also plans were added to try and clean the starboard SARJ during EVA-4. As a result of the last point an inspection of the port SARJ was added to EVA-3 in order to provide data with which to compare the descriptions of the starboard SARJ obtained during EVA-2. No attempt would be made to repair the port SARJ on this flight. The changes meant that plans to test a space age caulking gun, designed to be used to repair gouges in the Shuttle’s Thermal Protection System caused by foam or ice impacts during launch would be abandoned and moved to a later Shuttle flight. As the day ended, Parazynski and Wheelock were shut inside Quest and the pressure reduced, in preparation for EVA-3 the following day. Meanwhile the Mission Management Team had studied the effect of stopping the continuous rotation of the starboard SARJ, which was a reduction in electrical power production. The reduced electricity supply would be sufficient to support the launch of Columbus, then scheduled for December 2007, but might not support the addition of Kibo, due to be launched in early 2008. Work would continue to resolve the problem.
October 30 began at 00:38. After breakfast, Parazynski and Wheelock began dressing for their EVA while the RMS and SSRMS teams began their own preparations for the hand-off of the P-6 ITS and its re-installation on the far end of the P-5 ITS. The two astronauts left Quest at 05 : 45. The P-6 ITS was offered up on the end of Discovery’s RMS towards the SSRMS, now positioned on the end of the port ITS. After the hand-off to the SSRMS, the P-6 ITS was manoeuvred and then offered up to the exposed end of the S-5 ITS. With few cameras in the area, Parazynski and Wheelock were there to give verbal instructions. Following a successful re-mounting, the two astronauts drove home the four bolts and completed the connections with the P-5 ITS and the station’s power system. This move and the similar installation of the S-6 ITS represented the design limits of the SSRMS, even so the two teams on ISS made the task look simple. As all astronauts are pleased to acknowledge, this was all down to the highly professional nature of their training and the dedication of their training teams.
Parazynski then moved to the port SARJ and removed the thermal covers. He described the joint as ‘‘pristine’’. The EVA ended at 12: 53, after 7 hours 8 minutes, but on getting out of his EMU, Parazynski discovered a small hole in the outer layer of the thumb on his right-hand glove.
As the EVA reached its final moments, controllers in Houston commanded the first SAW to deploy on the P-6 ITS. When it was fully extended, Discovery’s crew commanded the second SAW to deploy. When it had deployed to approximately 30 m, 80% of its full length, Melroy called a stop, “We’ve detected something that appears to be a wrap-around or some damage.’’ Houston replied, “We see it.’’
The live television pictures in the control room showed a tear in the SAW. Programme Manager Mike Suffredini later told a press conference, “This will take time and needs to be worked, but my personal opinion is we’ve got the time to work this issue, so we can be methodical about it, and we will.’’ The remainder of the day was spent discussing the new problem, transferring items from Discovery and talking to the press.
October 31 began at 00: 38. As breakfast ended, Parazynski and Wheelock began configuring a spare EMU to replace Parazynski’s original suit, which had suffered from cooling problems during the third EVA. Together with Nespoli, they would spend the day preparing for the fourth EVA, which was now planned for November 1, and would be dedicated to a thorough inspection of the starboard SARJ and sampling of the debris seen in the joint during the second EVA, as well as trying to identify the root cause of the friction. Meanwhile, Whitson and Tani worked inside Harmony, removing launch restraints and deploying the Zero Gravity Stowage Rack. On the subject of Harmony, Whitson explained:
“Node-2, Harmony, like Node-1 [Unity], has six different ports that we can add modules on to, to build the station. So it’s, it’s our next big connecting piece in our puzzle of putting this huge station together on orbit. Node-2 is required to power and provide the thermal heat rejection for the science laboratory modules that’ll be coming up, the one built by the European Space Agency and the one built by the Japanese Space Agency. So it’s a pretty key module for us, for the continued development of the station.’’
As the day proceeded, the priorities for STS-120 changed. Although the ripped SAW on the P-6 ITS was producing 98% of the electricity that it would if fully deployed, Houston decided to make it the priority for the remainder of Discovery’s flight. The fourth EVA would be slipped back 24 hours, to November 2, or even November 3, if more time was required for preparation, and would now concentrate on repairing the ripped P-6 ITS SAW before the damage got any worse. The Mission Management Team decided that the priority was to fully deploy the SAW and thus hopefully prevent further damage. Initial plans called for Parazynski to carry out the repair while riding the end of the OBSS mounted on the SSRMS, while Wheelock provided verbal instructions for Wilson and Tani operating the SSRMS. The repair itself would consist of threading wire through holes in the SAW blanket on either side of the tear and using an aluminium strip to support it from beneath, thus closing and supporting the tear in much the same way as a cuff-link works on a man’s shirt sleeve. Meanwhile, in Houston, Suffredini was blunt:
“I need this array. We believe over time we could tear the blanket further. If we do enough damage, we could potentially get into a configuration where we could not stabilise the array. If we can’t, we have to figure out what to do. We don’t have a lot of options, and the most likely option is that we would have to jettison it.’’
“The station is a robust vehicle. We have many options with how to deal with the problems. It’s not a situation where anyone is particularly panicked. But on the other hand, we want to get this fixed to a point where we can continue with the assembly the way we planned… This is not about style points. It doesn’t have to look good. It just has to produce power.’’
Suffredini also paid a compliment to the team of engineers who had been working on the problem since the torn SAW was first identified:
“We give this team a little time to start thinking about creative solutions, and it doesn’t take them long to blow you away with what they come up with.’’
During the afternoon press conference with the crew, the President of Italy congratulated Nespoli on his flight, but predictably the conversation returned to the damaged SAW. Melroy described what she had seen as the second SAW deployed:
“It was a tough situation. The Sun was shining directly into our camera views. At one point, we did stop because we were concerned we had lost our big picture. We can second guess ourselves, and there may have been something we could have done, but I think we certainly aborted as soon as we saw something that was not right.’’
“My initial take was the guide-wires that became frayed earlier may have been the culprit. However, it looks to our eyes, via the binoculars and photos, like the guide-wires may be intact.’’
During the day the fourth EVA was pushed back to November 3, to give ground teams more time to come up with a work schedule and to give the astronauts additional time to prepare. Even so, Whitson, Commander of ISS, remained confident stating, “If there is a way to do this, we will figure out a smart way to come up with whatever workaround we need to make it happen.’’
The crew spent the remainder of the day making the hinge stabilisers that they would install when they repaired the SAW and preparing their EMUs. At one point Ex-President George Bush Senior and his wife Barbara visited the control room in
Houston and were able to talk to the crew. Talking to Melroy, he told her, “Good luck to you. Pam, we want to wish you well and all of your team. We’re so proud of your team… Barbara and I.’’
November 2 began at 01: 38 and was another day of preparation. During the morning, controllers moved the MBS back from the far end of the P-5 ITS to the centre of the ITS. There it was used to take hold of the OBSS and remove it from Discovery’s payload bay hingeline. The OBSS was then handed to Discovery’s own RMS, where it would stay overnight, while the MBS moved back to the far end of the port ITS.
In Houston, NASA made the media aware of some of the risks involved in making repairs to a SAW that was still actively producing electricity. Astronaut David Wolf, head of the EVA branch of the Astronaut Office, said, “We are faced with a difficult situation. At some point, we have to execute the plan we’ve got, as long as it’s very safe, instead of having a perfect plan and having it be too late to execute.’’ He added, “It’s a real test of the adaptability of this team, of our baseline knowledge of how to work in space … We have some risks here.’’
The two rips, one just under 1 m long and one 0.3 m long, would be repaired using five bracing straps made from 12-gauge wire with a 10 cm long aluminium strip at each end. The aluminium strips would be fed through existing holes in the SAW to hold the damaged areas together along a 5 m length. The straps, which the team that developed them had begun calling “cuff-links’’, varied in length from 1 m to 2m. To prevent an electrical discharge and possible injury to Parazynski, Kapton tape, an insulating material, had been wrapped around each of the straps, as well as the tools that would be used and the exposed metal parts on the outside of Parazynski’s EMU. The panel was “live’’, with up to 100 volts of electricity passing through it, and could not be turned off. As a result, the two EVA astronauts had been instructed in which parts of the P-6 ITS represented shock hazards. At the end of the day, Parazynski and Wheelock “camped out’’ in Quest under reduced pressure.
November 3 began at 01 : 38 and breakfast was followed by the hand-off of the OBSS from Discovery’s RMS to the SSRMS. The EVA started at 06:03. Melroy encouraged her two crew members as they left the airlock with the call, “Go out there and fix that thing.’’ Parazynski replied, “We will.’’ Even so, Houston warned, “Time is of the essence.’’
Having mounted the OBSS, Parazynski spent 90 minutes being swept through 180° of open space, taking him from the centre of the ITS to the worksite 30 m above Quest and 50 m out to the port side of the station. As he watched Earth sweep by below him, he told Houston, “This is just indescribable. Words just can’t do it justice. At least, not mine.’’
On arrival at the damaged area, he found that the guide wires used during the SAW’s deployment were damaged, but the wires carrying electrical current were not damaged. His helmet camera showed a view of the deployment guide wires that he described, “It appears severely frayed.’’
Melroy viewed the area with binoculars from Discovery and described it as a “furball’’. She added, “I’m sure that is causing shudders on the ground somewhere.’’ Tani told Parazynski, “You are a dot to us.’’
Figure 104. STS-120: damage to the P-6 photovoltaic array was stabilised with loops of wire referred to as “cufflinks” by the crew.
Figure 105. STS-120: Scott Parazynski rides the OBSS held in the SSRMS during the fourth EVA. During the EVA he installed six wire loops to stabilise damage to the P-6 photovoltaic array (see above).
Parazynski cut one of the guide wires with an insulated tool, and Wheelock, working at the base of the SAW, used a pair of pliers to feed it into the relevant take – up reel. Parazynski then installed the five cuff-links, poking the aluminium straps through existing holes in the SAW. As the EVA ended, Parazynski sighed, “What an accomplishment?” Whitson complimented them, “Excellent work guys. Excellent.” With the repair complete, just past 11:00 controllers in Houston began commanding the SAW to complete its deployment. Fifteen minutes and 13 computer commands later the SAW was deployed to its full extent. Meanwhile, it took an hour to sweep Parazynski back through open space to the centre of the ITS, from where the two men made their way back to Quest, closing the hatch at 13: 22, after an EVA lasting 7 hours 19 minutes.
Lead Station Flight Director Derek Hassman called it, “One of the most satisfying days that I’ve ever had in Mission Control.” Suffredini was equally enthusiastic, “We are in great shape, fixing the array lets us get on with the assembly… This was just a fabulous effort. Our baby is still beautiful to us.’’
The remainder of the day was spent clearing up after the EVA and transferring equipment. While electricity from the P-6 ITS 2B SAW was integrated into the station’s main power supply, that from the repaired 4B SAW remained isolated while testing of the repaired SAW continued.
November 4 began at 02: 08, before the clocks were put back an hour for the change from edt to est. During the morning briefing, Houston told the two astronauts, “This will go down as one of the biggest successes in EVA history. Words cannot express how proud you made everyone with the execution by the entire team.’’ After breakfast the two crews completed the final transfer of items between the two spacecraft before beginning to get ready for Discovery’s undocking. 992 kg of new supplies were now on ISS, in addition to Harmony, while 916 kg of scientific samples and other items would be returned to Earth in Discovery. Anderson’s occupation of ISS was at an end, but like everyone else before him he was in two minds about how he viewed the prospect of leaving the station:
“I have a lot of blood, sweat and tears left aboard the International Space Station. What we are doing here is very important for all of human kind. It’s worth the risk. It’s worth the cost… Five months ago I was on my back preparing to launch and wondering what the heck I had gotten myself in to. Now, I’m poised to return to Earth after having served very proudly… Part of me is ready to go and part of me wants to stay.’’
After saying their formal farewells, the two crews locked arms and swayed back and forth to music, laughing together and some of them even shed a few tears. At 12: 28 Melroy led her crew, including Anderson, back to the Shuttle, closing the hatch between the two spacecraft at 12: 03. Whitson, Malenchenko, and Tani remained on the station to continue the Expedition-16 occupation.
A 02: 38 wake-up call on Discovery on November 5 was followed by a quick breakfast and final preparations for undocking. Zamka backed Discovery away from PMA-2 at 05: 32. In Destiny, Whitson rang the station’s bell to mark their departure.
Figure 106. STS-120 departs ISS. The RMS holds the OBSS, which lies across the empty payload bay.
Figure 107. STS-120: a nadir view of ISS as STS-120 completed its fly-around. Harmony is shown docked to Unity’s port CBM, opposite the Quest airlock. The P-6 ITS has been relocated from the Z-1 Truss to outboard of the P-5 ITS.
She told them simply, “Thanks, guys.” Zamka performed a full 360° fly-around of the station while the crew photographed and videoed its new configuration from all angles. Back opposite PMA-2, Zamka performed the separation burn at 07: 15. Discovery’s crew spent the day using the OBSS mounted on the end of the RMS to inspect the orbiter’s wing leading edges and nosecap for damage sustained while in flight. They found none, and Discovery’s TPS was cleared for re-entry. Anderson spent the day exercising in the mid-deck, in advance of his return to Earth.
Discovery’s last full day in space, November 6, began at the 02: 38. Melroy and Zamka undertook the standard test of the orbiter’s flight surfaces and thrusters. The remainder of the crew spent the day packing for re-entry. During the afternoon Anderson’s recumbent chair was set up on the mid-deck and the Ku-band antenna was stowed. As Discovery passed over KSC, Melroy noted, “We can see the runway from orbit. So, the weather is looking pretty good.’’ Discovery had been planned for a night landing, but Melroy had asked for the flight plan to be changed in favour of a daylight landing, due to the unintended length and complexity of the flight.
During the day, Melroy talked to the media about how she felt “extremely concerned’’ for Parazynski’s wellbeing during the EVA to repair the 4B SAW.
Parzynski recalled, “It was a phenomenal personal experience to be out on the end of the boom.’’
Anderson discussed his mental preparations for his return to Earth, “I’ve enjoyed my time up there immensely, and it’s kind of a bittersweet time for me to come home, but I’m ready.’’
The final day of STS-120 began at 02: 38 November 7. Following breakfast, preparations for re-entry began at 08 : 03. Discovery’s payload bay doors were closed at 09: 20. Melroy and Zamka began preparing for the de-orbit burn, turning Discovery to a tail-first attitude before igniting the rocket motors at 11: 59. When the burn was complete, Melroy turned the orbiter so that its flat underside faced the on-coming atmosphere. Following the standard radio blackout caused by the sheath of ionised air surrounding the vehicle, Melroy flew a series of large, sweeping S-turns in the sky to bleed off energy. Finally, approaching Florida she flew the spacecraft across the state and headed out over the ocean as Discovery turned around the heading alignment circle to line it up with the end of the Shuttle Landing Facility at KSC. Melroy put the rear undercarriage on the runway at 13 : 01, after a flight lasting 15 days 2 hours 23 minutes. Anderson had been in space for 152 days.
After the flight, Melroy described the mission emotionally, saying, “What you saw is who we are at NASA.’’ NASA’s Administrator Michael Griffin watched the landing from alongside Runway 33, KSC. He took a similar tone when he described the flight to reporters as, “NASA at its best.’’