Discovery astronauts prepare to bottle outer space during spacewalk

Shuttle astronauts aboard the International Space Station are preparing to leave the hatch today for the first of two spacewalks aimed at putting some finishing touches on the International Space Station.

With all of the station's major structural components in place, spacewalking mission specialists Alvin Drew and Navy Capt. Stephen Bowen have a to-do list that ranges from preparing the station to receive one final module, that will be attached Tuesday, to capturing a sample of space in a metal "bottle" for the Japan Aerospace Exploration Agency (JAXA).

Back on the ground, the bottle – which will remain sealed – will hit the museum circuit to provide what JAXA dubs "a conduit between humans and space."

The spacewalks represent an interesting test of the interchangeability of astronauts. Captain Bowen joined the crew in mid January, replacing Tim Kopra, who was injured in a bicycle mishap a few days earlier.

Typically, crews train for more than a year to prepare for a shuttle mission. The last-minute substitution put Bowen, a veteran of five spacewalks, on a training fast-track for the spacewalk tasks that Mr. Kopra was to perform.

Bowen's most recent trip to the space station – and his most recent spacewalks – came last May, on the shuttle Atlantis. But during an orbiting press event Sunday, Bowen acknowledged that he's still catching up on many aspects of the mission.

"There's still a lot of things I don't know" about some of the specifics of the mission, Bowen said. But the rest of the crew "has been training together so well that they've been able to pick up the slack that I've brought on board."

For support during spacewalks, he'll have Kopra at the capsule-communicator console in mission control, said David Korth, a flight director for the International Space Station, during a mission-update briefing Sunday afternoon.