Tim Furniss/LONDON

NASA asked Russia on 26 April to delay the launch of Soyuz TM32 to the International Space Station (ISS) by at least two days from 28 April as the Space Shuttle Endeavour crew worked to solve major computer software malfunctions aboard the US-built Destiny laboratory module.

All three Destiny command and control (C&C) computers went out of action due to a software glitch on 24 April.

With Endeavour docked to the station for at least two days more than planned, it was considered too dangerous to attempt a Soyuz docking so close to the docked Shuttle. The Soyuz craft is due to carry space tourist Dennis Tito to the ISS. Russian approval for the delay was pending as Flight International closed for press.

Destiny, which was launched on 7 February, carried unvalidated pressure control assembly and vacuum system computer software, although it is not known whether this was a contributory factor in the malfunctions.

The C&C computers automatically control ISS functions, including pointing the solar arrays at the sun. By 27 April, one of the three computers, C&C 2, was back in operation, but two computers in the Unity Node 1 were experiencing synchronisation problems.

The primary C&C 1 and extra back-up C&C 3 computers were not functioning and the station's S-band communications link needed to be re-established to allow them to be re-programmed. In the meantime, Endeavour is providing S-band communications to the ISS, plus additional life support and power.

If the computer problems are resolved, the Endeavour crew will try out the Space Station Remote Manipulator System and unberth the Raffaello Multi-Purpose Logistics Module from the station and install it in Endeavour's payload bay for a return to Earth in early May.

After criticising Russia's Mir space station so often, it is ironic that NASA is in this position so early in the station's life. NASA said the situation was "humbling".

Source: Flight International