When the space shuttle Atlantis docks with the Hubble Space Telescope for a final repair mission in October, astronauts will face a unusually high risk of a catastrophic collision with orbital debris, NASA officials say. The amount of space junk in the environment around the Hubble adds another element of danger to the already challenging mission, which aims to keep NASA's premier telescope in service until at least 2013.
The environment where Hubble flies, about 350 miles (560 km) above the planet, is more littered with shards of exploded spacecraft and rockets than the area around the International Space Station, which orbits about 210 miles above Earth. The odds of catastrophic damage from an orbital debris strike are 1 in 185 for the Hubble crew, compared with 1 in 300 for missions to the space station, John Shannon, the shuttle program manager, told reporters. "It's our biggest risk," he said [Reuters].
NASA officials say the space environment has gotten more perilous in recent years.
Two incidents in 2007 led to the biggest jump in space debris in decades: China shot an aging satellite out of orbit, creating a vast field of fragments [and an] old Russian rocket circling the Earth exploded in what a NASA space-debris newsletter called a "very serious" accident [USA Today].
Even small fragments from such break-ups can pose a hazard, as they hurtle around the Earth at speeds of thousands of miles per hour; NASA officials worry that a piece of this shrapnel could hit the brittle heat shields that protect the shuttle on reentry into Earth's atmosphere.
But senior managers say the astronauts in a worst case would be able to inspect their ship, make repairs or wait in orbit until another shuttle on standby could be launched on a rescue mission [Florida Today].
The Atlantis carries repair materials and a long boom that will be used to check the shuttle's condition before returning to Earth, and the shuttle Endeavor will be on the launch pad at Cape Canaveral, in case more drastic measures are called for. For an insider look at preparations for the Hubble repair mission, check out the photos in DISCOVER's gallery, "The Race to Save the Hubble Telescope." Image: NASA