July 26, 2005

Shuttle’s Return Could Mean Hubble’s Survival

CAPE CANAVERAL, Fla. -- The space shuttle's return to flight could mean survival -- or at least extended life -- for the popular but aging Hubble Space Telescope.

Beloved for its unparalleled views of distant galaxies, infant stars and collisions in our own solar system, Hubble needs new batteries for power and new gyroscopes to keep it steady and let it point at specific celestial features.

While it might be possible, with infinite resources, to design robots to go and fix it, NASA chief Michael Griffin has indicated that shuttle astronauts are better suited to the job. But he has also said there can be no assessment of a Hubble servicing mission until two shuttles have flown successfully.

Astronauts have made four service calls to the orbiting observatory since its 1990 launch, and a fifth was in prospect when shuttle Columbia disintegrated over Texas on Feb. 1, 2003.

The Columbia accident prompted the grounding of the remaining three shuttles and a shift in NASA's priorities.

As investigators probed the causes of the tragedy, President Bush announced a new "Vision for Space Exploration" on Jan. 14, 2004 -- a vision to return Americans to the Moon and eventually to Mars, with no guarantee to keep Hubble going.

When NASA announced, two days later, that the scheduled shuttle servicing mission to Hubble was being canceled, the telescope's many fans, including those in Congress, launched a campaign to save it. A robotic solution was considered and discarded and a shuttle mission was seen as the best plan.


A human repair call to Hubble is no cinch, according to former shuttle pilot Scott Horowitz, who flew Discovery on a 1997 Hubble maintenance mission.

"Anytime you service Hubble, one of the biggest challenges is sort of like the Hippocratic Oath: do no harm," Horowitz told Reuters in an interview. "You sure want to leave it better than you found it. So there's a lot of pressure because you only have so much time."

Getting there is part of the challenge, since Hubble orbits at about 380 miles above Earth. This is the highest altitude mission for the shuttle, 130 miles above the International Space Station's orbit.

The actual repair can be tough, Horowitz said.

"You don't go in there with a big hammer and wrench; these are very delicate instruments," he said. "They're huge, about the size of refrigerators ... and you want them installed perfectly."

The installation is done by astronauts wearing the equivalent of "kitchen mitts" on their hands, Horowitz said.

Horowitz, now director of space transportation and exploration at aerospace and weapons firm ATK, enthusiastically endorsed the repair, despite possible risks.

Is it worth upgrading and fixing Hubble? "Absolutely. It's amazing," he said.

The Hubble telescope, named for astronomer Edwin Hubble, was designed to orbit above the distorting effects of Earth's atmosphere, enabling clearer views of astronomical objects.

When first launched, a slight imperfection in its main mirror blurred its vision. The first of four service calls corrected the problem in 1993. Other missions were in 1997, 1999 and 2002.

Another mission could keep Hubble productive through 2010. Without maintenance, its capabilities could fade by 2007 or 2008. Eventually, it is to be brought down to Earth in what NASA calls a controlled de-orbit.


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