Astronauts aboard NASA's shuttle Discovery are gearing up for their planned Saturday landing after Mission Control found that a lost metal clip poses no threat to their spacecraft's return.
Shuttle commander Mark Kelly and pilot Keneth Ham test fired Discovery's maneuvering thrusters and power up systems to flex the shuttle's flight control surfaces. But after those tests, they reported spotting a shiny, rectangular bit of debris drifting away shuttle to the aft of its starboard wing.
"We've got a pretty reasonable image of it," Kelly said, later adding it appeared to move away from Discovery at about 1 foot (0.3 meters) per second.
It's not uncommon for loose items or debris to drift free from a shuttle's payload bay during its pre-landing thruster and flight systems checks, NASA officials said.
Mission controllers swiftly studied the 1- to- 1 1/2-foot long (0.3-0.4 meter) object in short video of and still images captured by the shuttle crew, finding it to pose no threat to the orbiter's planned landing.
"We're confident that this is going to be no impact for entry," NASA astronaut Terry Virts radioed the crew from Mission Control in Houston, adding that similar clips have been lost on previous shuttle missions all the way back to the first flight, STS-1, in 1981.
The clip is one of three used to protect Discovery's tail-mounted rudder speed brake against heat during launch, and not required for landing, he said.
A small bump thought to be loose insulation on the shuttle's tail was actually just an artifact of lighting, Virts added
Discovery's crew is spending the day stowing last bits of cargo to prepare for tomorrow's planned 11:15 a.m. EDT (1515 GMT) landing here at NASA's Kennedy Space Center. Kelly and Ham are also rehearsing landing activities via a computer simulation.
"Overall, it's a get ready for entry day," NASA's deputy shuttle program manager LeRoy Cain said Thursday, adding that the orbiter's heat shield appeared to be in good health for landing.
Saturday homecoming ahead
Discovery's six-man, one-woman crew is returning to Earth after successfully delivering Japan's massive, billion-dollar Kibo laboratory to the International Space Station (ISS). The astronauts also performed three spacewalks during what is slated to be a 14-day mission to outfit the new tour bus-sized lab and swapped out one member of the space station's three-man crew.
"That was pretty much solid work," Ham said Thursday. "We're all pretty much tired at this point and getting ready to come home."
Japan's 37-foot (11-meter) laboratory is the second segment of the Kibo research facility to reach orbit and followed its small storage room, which astronauts delivered during an earlier mission in March.
The new room, the largest ever launched to the space station, includes two windows, a robotic arm and a small airlock for passing new experiments to a planned porch-like platform due to launch to the space station next year. A smaller robotic arm for fine movements is also slated to fly.
"It was just amazing," said Discovery mission specialist Akihiko Hoshide, who helped install Kibo, of the view of his country's new space lab during undocking Wednesday. "I can't really explain it."
Returning to Earth with Kelly, Ham and Hoshide are mission specialists Karen Nyberg, Ronald Garan, Michael Fossum and returning station crewmember Garrett Reisman, who said he was awed at the sheer size of the now nearly three-quarters complete space station when Discovery undocked.
"It started out as just a single, little module, and now it's enormous," said Reisman, who is wrapping up a three-month spaceflight aboard the station and has compared its interior to the inside of a jumbo jet. "With the addition of Kibo, it looks like a real space station, and that's exciting."
Reisman, a NASA astronaut, joined the station's crew in March and was replaced by fellow U.S. spaceflyer Gregory Chamitoff, who arrived aboard Discovery last week to begin his own six-month mission.
"He was picking things up very quickly, I think he is going to do great up there," Reisman said, adding that he reminded Chamitoff to squeeze in some time for himself amid his daily work aboard the station.
Discovery astronauts will set up a special recumbent seat for Reisman today on the shuttle's middeck that will allow the returning long-duration spaceflyer to return to Earth's gravity in a reclining position, rather than the upright seats of the shuttle's short-term flyers.
"The truth is, adjusting back to gravity is not so easy," Reisman said during the mission. "Just like adjusting to weightlessness takes some time, adjusting back to gravity takes some time too."
All seven of the shuttle astronauts are expected to discuss their mission with reporters today as well.
Discovery has two chances to land Saturday with NASA's Spaceflight Meteorology Group at the Johnson Space Center in Houston forecasting relatively fair conditions on landing day. Some clouds are expected during the shuttle's first landing window, with a slight chance of rain showers within 30 miles (48 km) during a second opportunity at 12:50 p.m. EDT (1650 GMT).
Mission Control roused Discovery's crew early Friday with the song "Baby Won't You Please Come Home" by Louis Prima and Keely Smith, a tune chosen for Reisman by his wife Simone.
"Good morning to you Houston and a special good morning to Simone, my favorite Earthling," Reisman said. "Get ready doll face, Discovery's coming home."
NASA is broadcasting the Discovery's STS-124 mission live on NASA TV. Click here for SPACE.com's shuttle mission updates and NASA TV feed.
SPACE.com -- Space Shuttle Crew Prepares for Saturday Landing
