During the last of their mission’s five spacewalks, astronauts Andrew Feustel and John Grunsfeld replaced the second of two 460-pound (209-kilogram) battery modules, which provide power to the telescope when its solar arrays aren’t exposed to the sun.
They also swapped out one of Hubble’s three Fine Guidance Sensors, used to aim the telescope and measure the position and location of stars, and installed a new thermal protection blanket on the observatory.
Atlantis’ Hubble service trip, the first for a shuttle since 2002, is the last scheduled repair mission for the telescope, a joint venture of the National Aeronautics and Space Administration and the European Space Agency. Hubble, launched in 1990, provides data used by astronomers worldwide.
“This is a really tremendous adventure that we’ve been on, a very challenging mission,” Grunsfeld, a former chief scientist for NASA, said near the end of today’s seven-hour spacewalk, broadcast live on NASA Television. “Hubble isn’t just a satellite, it’s about humanity’s quest for knowledge.”
Extending Hubble’s Life
NASA says the upgrades will extend Hubble’s life to 2014 and help it peer deeper into the universe and capture images closer to the time of the Big Bang. A replacement, the James Webb Space Telescope, is scheduled for launch in 2014.
The school-bus-sized Hubble has become a symbol of U.S. technological achievement during its 19 years in space. On average, 14 scientific articles are published every week from information it provided.
One exposure revealed 10,000 galaxies formed shortly after the Big Bang, the cosmic explosion that scientists say marked the origin of the universe. The telescope also has viewed the evaporating atmosphere of a planet and shot high-resolution, ultraviolet images being used to detect oxygen-rich moon minerals.
During four previous spacewalks of the Atlantis mission, astronauts replaced a camera, the first set of batteries, the gyroscopes that help control Hubble and a computer that sends commands to instruments and formats data for transmission. They also installed a new scientific instrument and repaired two others.
Tools and Ingenuity
Grunsfeld called the servicing mission a “tour de force of tools and human ingenuity.”
“The only way of finding the limits of the possible is by going beyond them into the impossible,” Grunsfeld said. “On this mission, we tried some things that some people said were impossible. We’ve achieved that and we wish Hubble the very best.”
Atlantis, which lifted off on May 11, is scheduled to release the telescope tomorrow and land on Earth on May 22. NASA engineers have cleared the shuttle for return even though astronauts discovered small dents in the heat shield on a wing as it headed for its rendezvous with Hubble.
Hubble’s observations are expected to resume three weeks after the shuttle leaves.
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