Mission Complete, Almost:
Space Station Crew Prepare For An Unusual Homecoming
The astronauts of the Expedition 6 International Space Station crew are preparing for a first in NASA's history of human space flight. They're scheduled to return to Earth aboard a Russian Soyuz capsule.
While the Russians have been using the Soyuz for decades and American astronauts have flown into space twice before on the craft, NASA has never before put one of its own on a Soyuz for a landing.
The Expedition 6 astronauts, Ken Bowersox and Don Pettit, with their cosmonaut counterpart Nikolai Budarin at the controls, are scheduled to touch down May 4 (10:03 p.m. EDT May 3) in northern Kazakhstan. The crew is leaving the Station after a successful, but emotional, five months in orbit. During that time, the Space Shuttle Columbia was lost and the Shuttle fleet was temporarily grounded.
From undocking to landing, the crew's Soyuz trip is expected to last about three hours and 23 minutes. Just about everything that happens is automated; the crew has little to do but hold on tight.
About 15 minutes before the Soyuz lands, it begins to deploy a series of parachutes to slow its descent. Then, a mere two seconds before landing -- less than three feet above the ground -- six engines on the spacecraft fire toward the Earth to cushion the touchdown.
A landing in a Soyuz is generally bumpier than on a Shuttle, so Bowersox, Pettit and Budarin will ride home in custom-built reclining seats formed to fit their bodies. The seats help cushion the landing and distribute the shock; the impact measures about four times the force of gravity, or four Gs.
In the past, cosmonauts have suffered some minor injuries -- bumps and bruises -- during a Soyuz landing, NASA flight surgeon Dr. Terrance Taddeo, says. But "nothing we're medically concerned about," he says.
The Expedition 6 crew will also be wearing what Dr. Taddeo calls "anti-G" garments, which help to prevent blood from pooling in their legs when gravity kicks in.
Of course, after more than five months in space, any gravity will be a shock to the crew. Within minutes of landing, Russian space officials will set up a portable medical tent and carefully take the Soyuz crew members to it, one-by-one. Bowersox, Pettit and Budarin will spend their first moments back on Earth in special recliners, readapting to gravity's pull. About two hours later, they'll begin a trip to Star City, Russia -- outside Moscow -- where they'll spend at least 16 days undergoing medical tests and physical therapy.
Back on orbit, another first: the typical three-person Space Station crew scaled down to two. NASA and its International Partners have determined a smaller crew will be able to maintain the Station and the scientific experiments on board, while reducing the need for water and other supplies aboard the Station.
For now, Russian Progress and Soyuz spacecraft will be the only means of ferrying supplies to the Station, and those vehicles have far less cargo room than the Shuttle. Once the Shuttle is back to flying, it will be able to carry enough supplies to support a three-person Station crew again.
The grounding of the Shuttle fleet affects the Space Station in another way; construction is on hold for now. Before the Columbia accident, the Shuttles were scheduled this year and next winter for a series of missions to complete America's portion of the International Space Station, known as Node 2.
That construction plan will kick back into gear as a first priority, once the Shuttles return to flight.
Read Expedition Six NASA ISS Science Officer Don Pettit's latest Space Chronicle, "Homeward Bound", from aboard the International Space Station:
View the Expedition Six Gallery: http://www.spaceflight.nasa.gov/gallery/video/station/expedition6/ndxpage1.html
An interactive feature of the Expedition 6 and 7 Launch and Transfer:
+ View this interactive feature
An interactive feature of the Soyuz assembly:
+ View this interactive feature
For more information on the mission, visit:http://spaceflight.nasa.gov/station
Reporting from the Nation's Capitol in Washington D.C.