Uncertainty over shuttle launch
While Nasa reassesses plans to launch Europe's Columbus laboratory, preparations continue for the debut flight of Europe's cargo ship to the International Space Station.
Repairing the space shuttle's faulty fuel sensor system will probably postpone Columbus' arrival at the orbital outpost to late January or February.
But space station programme manager Mike Suffredini said on Thursday that Nasa would still like to see Europe's Automated Transfer Vehicle, known as the Jules Verne, lift off as planned in mid-to-late February.
Nasa had hoped to launch Atlantis and a joint US-European crew on a mission to deliver and install Columbus earlier this month.
But problems with fuel sensors forced the US space agency to cancel two launch attempts.
The sensors are part of a backup emergency system to cut off the shuttle's three main engines if they run out of hydrogen fuel before the ship reaches orbit.
Running the engines without fuel could trigger a catastrophic explosion.
Fixing what is suspected to be a faulty electrical plug in the sensor system is likely to delay Atlantis' launch by several days or weeks, the shuttle programme manager said.
Nevertheless, the Jules Verne can launch and, if necessary, remain idle in orbit for two weeks before docking at the space station.
"We can launch and loiter if we need to," Mr Suffredini said.
Programme managers are looking at docking the Jules Verne to the station between 15 and 23 March, or between 27 March and 2 April.
The capsule will haul about seven tones of cargo to the outpost.
Jules Verne's launch and docking will be integrated into the timelines of the next two planned shuttle missions - the upcoming flight of Atlantis with Columbus, and Endeavour's flight, originally targeted for 14 February, with part of Japan's Kibo laboratory complex.
Speaking about the ATV Jules Verne, European astronaut Leopold Eyharts said: "This is first time we will launch a module built in Europe, launched by Europe, that will make a rendezvous and docking in space, so this is a big challenge for all of us."
Eyharts himself is scheduled for what may be an abbreviated stay on the station between the Atlantis and Endeavour flights.
Launching with Eyharts on Atlantis will be Germany's Hans Schlegel, who will be making two spacewalks during the mission to install the Columbus laboratory. ( BBC )