On Monday the crew of Space Shuttle Atlantis successfully carried out their fifth and final spacewalk of the difficult mission to service the Hubble Space Telescope, 350 miles above Earth’s surface. Today, they answered questions from reporters on the ground about what the job had been like. They will return to Earth on Friday, May 22nd.
Although the astronauts completed all the scheduled repairs and upgrades, including those termed “optional” if time or other constraints got in the way, the jobs didn’t always go according to plan. There was a handrail that had to be pried off by force and a stuck bolt that nearly prevented the swap-out of the 15-year-old WFPC 2 camera for its better, $135 million replacement. But the task that was supposed to be hardest, delicate repairs to the Advanced Camera for Surveys, which was not designed to allow such work, turned out to be the easiest of all.
The astronauts had rehearsed every move for years, including with robots that might have attempted the repairs if humans had not gone up. But robotic repairs proved impossible; the jobs were too complicated and likely to require too much moment-by-moment judgment. Even when things worked just as they had practiced on the ground, the astronauts praised the crew at the Goddard Space Flight Center in Maryland for help in working them through each bit of the way.
The achievement will give the Hubble not just a longer lifespan — 5 or perhaps even 10 more productive years — but increased its capabilities as well. And it will eventually have an orderly death. The astronauts added a remotely-operable spacecraft dock so that a small rocket can push Hubble back into the atmosphere for safe destruction at the end of its lifespan.
President Obama is scheduled to talk with the crew on Thursday. When asked about the meeting, astronaut’s responses were all in favor of exploration and the importance of manned missions. The space shuttle program has been NASA’s only way to get astronauts into orbit since 1980, but it will be abandoned after eight more flights. NASA’s Constellation rocket program, designed to take the shuttles’ place, won’t start flying until around 2015. Nevertheless the astronauts enthusiastically endorsed sending not just machines but people to explore the solar system. “As much as we love low earth orbit,” said John Grunsfeld, “it's time to leave orbit. Time for humans to start moving out and explore the cosmos.”
Each expressed awe at docking with Hubble, and especially at watching it float away knowing that it will never be touched again. Astronaut Megan McArthur, the only female on the flight, said she stood in "awe at the human ingenuity in creating such a thing." After completing the final repairs, colleagues John Grunsfeld and Andrew Feustel gave Hubble “one last hug.” “It lived up to all our expectations,” they said. “We did it, but I'm still impressed that we did it.”
Valerie Daum is an intern at Sky and Telescope