The decision is in and the Hubble Space Telescope is saved.
NASA announced Tuesday that it will go ahead with one final space shuttle mission to repair and upgrade Hubble after months of debate over the risks of such an endeavor.
In the end, the decision came down to NASA chief Michael Griffin, who has long said that he would support a proposed Hubble servicing mission provided its risk did not exceed that already accepted for other shuttle flights. The mission will add years onto the Hubble’s lifetime and could help NASA prepare the space telescope for its ultimate, but controlled, plunge through the Earth’s atmosphere.
NASA TV is broadcast today's Hubble decision live. A press conference with the mission's astronaut crew is set for 12:45 p.m. EST.
“Hubble is one of the great observatories,” Griffin has said. “It has revealed fundamental things about the universe of which we had no idea.”
Griffin said the upcoming servicing mission will launch in 2008 between construction flights to complete the International Space Station (ISS), and is expected to feature no less than five spacewalks to upgrade Hubble’s optics and make other repairs.
“I think it is important to at least make the decision, because that will then tell us [what’s happening],” University of Texas astronomer J. Craig Wheeler, president of the American Astronomical Society, told SPACE.com. “It’s terribly important to make a decision.”
Astronomers hope the decision means Hubble could still be in operation by 2013 when NASA’s next great observatory — the James Webb Space Telescope — is slated to fly. Hubble’s visible and ultraviolet observations will not be duplicated by JWST, which will scan primarily in the infrared wavelengths, researchers said.
The astronauts set to perform the tricky Hubble refurbishment work — which includes repairing at least one instrument that was not designed to be modified in orbit — will discuss their duties in press conference scheduled for 12:45 p.m. EST (1745 GMT) today.
Hubble-bound shuttle astronauts have a daunting task ahead of them. Their tasks include:
The installation of Wide Field Camera-3, a new camera to amplify Hubble’s vision.
The replacement of Hubble’s batteries, some thermal insulation and a broken guidance sensor.
Refurbishment of the Hubble’s vital attitude controlling gyroscopes used to orient the space telescope. Only two of the six are in operation. Two are held as spares while two others are broken.
The installation of the Cosmic Origins Spectrograph and unprecedented repair of Hubble’s Space Telescope Imaging Spectrograph (STIS), which was never designed to be worked on in space.
Using the shuttle’s engines to boost Hubble into a slightly higher orbit.
Long road to Hubble
NASA initially cancelled the upcoming Hubble servicing flight in 2004, citing the proposed mission as unsafe following the 2003 Columbia accident that killed seven astronauts. But the agency eventually backpedaled after outspoken disapproval from the science community and public, and support by the then-newly installed Griffin.
“I don’t think that there is actually another scientific instrument that people on the street recognize other than Hubble,” said Mario Livio, a senior astronomer at the Space Telescope Science Institute (STScI) that oversees Hubble. “It has inspired generations of people from children to senior citizens.”
After first studying the potential to service Hubble robotically, NASA ultimately returned to an astronaut-based servicing mission.
Astronaut safety in orbit topped NASA’s list for a potential Hubble servicing mission.
The tragic 2003 loss of Columbia and its crew stemmed from heat shield damage that went undetected during the orbiter’s 16-day mission. NASA now trains more than 100 cameras on orbiters during liftoff, record the flight with onboard cameras, followed by a series of in-orbit heat shield inspections with a robotic arm-mounted boom.
Should serious damage prevent an orbiter’s return, most of NASA’s remaining astronaut crews can simply take refuge aboard the International Space Station, where they will already be docked there to complete the outpost’s construction by NASA’s September 2010 shuttle retirement date.
But the Hubble-bound mission will not carry that ISS safe haven plan, prompting NASA to commit to having a second shuttle nearly ready to fly before staging the servicing flight in the first place.
Griffin has conceded that devoting a NASA shuttle mission to service Hubble does interfere slightly with the ISS construction flow, but it does not disregard the obligations of NASA to its international ISS partners.
“Obviously, that’s a flight that we’re doing that’s not an assembly mission,” Griffin said, adding that Hubble has always been a joint mission between NASA and the European Space Agency. “Hubble itself has had international participation and its contributions to the advancement of knowledge have been international in nature.”
But science aside, it has always been the pictures of the universe that have been Hubble’s strength, a forte that will apparently continue for quite some time.
“Hubble has probably been the most incredible instrument ever,” Livio said. “Not just in doing the science, but bringing that science to the awareness of people all over the globe.”
Copyright © 2006 Imaginova Corp. All Rights Reserved. This material may not be published, broadcast, rewritten or redistributed.