Seven astronauts were heading to the international space station aboard space shuttle Discovery today, while Nasa debated whether the orbiting outpost will need to move aside to dodge a piece of space junk.
There was one probable victim of yesterday's launch: a fruit bat found hiding next to a fuel tank. Although its fate is unknown, scientists believe it probably perished.
The launch director Mike Leinbach told a a post-launch news conference: "We're characterizing him as unexpected debris and he's probably still unexpected debris somewhere."
The launch followed five delays that caused Discovery's mission to be shortened by a day and cancelled a planned spacewalk.
And more substantial debris is keeping the control centre occupied: Space station astronauts had a close call last week with a piece of orbiting junk that passed nearby, and Nasa said today that a piece of a Russian satellite could come within about half a mile (8 kilometers) of the station early tomorrow.
Nasa will decide later today whether to fire the space station's engines to nudge the complex out of the path of the debris.
The three space station residents had to move into their emergency getaway capsule last week for about 10 minutes because another piece of space junk came too close for comfort.
A Nasa spokesman said if the space station has to move, the shuttle will have to adjust its course slightly to be in position for docking on Tuesday.
Mission managers said yesterday that despite shortening Discovery's stay by a day, they would still be able to complete 80 per cent to 90 per cent of the tasks they had planned. The canceled spacewalk chores will be tackled by the space station crew after Discovery leaves.
"It's not a major setback to us," said Bill Gerstenmaier, Nasa's associate administrator for space operations. "We're able to accomplish everything we want."
That includes dropping off the space station's newest crew member: Japanese astronaut Koichi Wakata, who is replacing U.S. astronaut Sandra Magnus. From Tokyo, Japan's Chief Cabinet Secretary Takeo Kawamura said he was relieved by the successful launch after the delays.
Other tasks during the 13-day mission include installing the station's last pair of solar wings so the orbiting outpost can operate at full power. The solar wings will join six already in place. The crew will also deliver supplies and hardware, most notably replacing a broken machine that turns urine into drinking water and a flusher and iodine solution to get rid of bacteria that is lurking in the water dispenser.
Nasa managers faced a tight schedule to get Discovery off the ground because of a Russian Soyuz rocket launch March 26. Discovery needs to be gone from the space station by the time the Russian spacecraft flies. The Soyuz will carry up a fresh crew for the space station. Nasa had until Tuesday to get Discovery flying or else the launch would have been bumped to April.
Problems with hydrogen valves kept the shuttle grounded for weeks in February and then a hydrogen leak during fueling prevented launch Wednesday. The valves worked as they should have and there were no leaks during fueling Sunday.
Discovery's crew also included pilot Tony Antonelli and astronauts Joseph Acaba, Steve Swanson, Richard Arnold and John Philips. Acaba and Arnold are former teachers.
Gerstenmaier said there was no apparent debris that came off the external fuel tank after a "first, quick look." Debris has been a concern for Nasa since a piece flew off the fuel tank and caused a breach in the wing of Columbia in 2003, dooming the shuttle and its seven crew members.
As insurance, Discovery's crew were spending a good part of today examining the shuttle's thermal protection system with cameras and sensors attached to a boom which is hooked to the shuttle's robotic arm.