``As you can imagine, the space station is a closed volumeand we've had a crew of three living up here for some 20 weeks,'' Mr Andrew Thomas, the astronaut in charge of packing, said on Saturday. ``And as is inevitable, a lot of trash and waste is generated.'' Possible computer problems aboard Discovery, meanwhile, had mission managers huddling last night. Computer experts at Mission Control feared the software in the shuttle's main computers may have been corrupted by the astronauts' hasty reactivation of two of the machines earlier in the day. Even though the computers appeared to be working fine, flight controllers debated whether the software should be reloaded, a lengthy and unprecedented process. The Italian-made cargo carrier, Leonardo, doubled as a garbage can during Discovery's delivery mission. It was launched aboard Discovery on March 8, attached to space station Alpha on March 12 and then emptied of 5 tonne of gear. (AP)Astronauts and cosmonauts spent the past few days filling it with more than 1 tonne of stuff for return to Earth.

Leonardo was to be detached from the space station andmounted back in Discovery's payload bay in preparation for the departure of the shuttle.