May 13, 2009

Atlantis Preparing To Grapple With Hubble

Crewmembers aboard space shuttle Atlantis continued their pursuit of the Hubble Telescope on Wednesday as they prepare to make contact with the observatory for the first time since March 2002.

Shuttle commander Scott Altman will guide Atlantis close enough to Hubble so that astronaut Megan McArthur can grab it with the shuttle's robotic arm and lift it to the shuttle's cargo bay where astronauts will make a series of crucial repairs in the final upgrade mission to the telescope.

Repairs and upgrades will take place over the course of five planned spacewalks. The first spacewalk is planned for Thursday at 1216 GMT.

According to NASA, the crew is expected to grapple the telescope 340 miles above the Earth at 12:54 p.m. EDT.

The crew spent Tuesday inspecting Atlantis' heat shield during a routine procedure to avoid mistakes made during the Columbia mission in 2003. Project managers noted four nicks on the shuttle, but said they do not seem to pose any risks at this time.

"Again, right now, everybody's feeling pretty good that it's not something particularly serious," Mission Control told the astronauts. "We just want to make sure we do the right thing and complete all the analysis."

But now, at its current altitude, Atlantis is in a dangerous place filled with more space junk than ever before. It doesn't take a large piece to make a huge impact because objects orbit the Earth at high speed.

According to the AP, space junk trackers have spotted about 950 pieces from this year's crash between a defunct Russian satellite and an American communications satellite. They have discovered more than 2,500 from the 2007 explosion of a satellite destroyed by China.

"It's not something to lose sleep over," said NASA chief space debris scientist Nicholas Johnson. "We do take it very, very seriously, but in the scheme of things, it's a small risk."

"Hubble is being pummeled regularly," Johnson said. "We see evidence of thousands of impacts."

"The greatest risk to space missions comes from the non-trackable debris," he said.

Shuttle Atlantis launched from Kennedy Space Center in Florida at 1401 EDT.

Atlantis is the first mission planned to Hubble since the Columbia disaster. The incident caused NASA to delay critical upgrade missions to Hubble, which has been crippled by camera issues, instrument failures, and the telescope's computer has also gone offline.

During the mission, astronauts will install the so-called Cosmic Origins Spectrograph, which will observe the light put out by extremely faint, far-away quasars and see how that light changes as it passes through the intervening gas between distant galaxies.

The mission will also see the installation of the new Wide Field Camera 3, which will equip Hubble to take massive, detailed pictures over a wide array of colors.

Hubble has received four upgrades since it was launched by shuttle Discovery in 1990, where it was put into an orbit of 304 nautical miles above the Earth.

NASA and the ESA believe the current mission will allow Hubble to continue operations for at least five years. Meanwhile, its successor, the James Webb Space Telescope is under development.


Image Caption: Commander Scott Altman sits on the flight deck of space shuttle Atlantis. Photo credit: NASA TV


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