ISS Computer Problems Force NASA to Leave Endeavour Docked for Two More Days

Computer problems continue to hamper operations on the International Space Station. This has caused NASA to decide to keep Space Shuttle Endeavour docked to the ISS for another two days. NASA has also asked Russia to delay the launch of Soyuz TM-32 carrying Dennis Tito. Since Soyuz launches begin some irreversible operations 24 hours before launch, NASA needed to send formal notification to Russia today.

Earlier today, Expedition 2 crewmember Susan Helms was able to establish a link with one of three command computers this morning. Helms performed a series of troubleshooting steps that restored mission control’s ability to monitor and send commands to U.S. systems on the ISS. While mission control was able to download data, some of it was lost. The retrieved data is now being analyzed to determine the problem.

However, while some systems have been fixed problems continue to occur. The most recent problem is the loss of half of the lights in the Destiny lab. “Tiger teams” (troubleshooters) at NASA are working the problem which they believe is most likely software related.

The space station was given commands this morning to put the complex’s systems in a better configuration in the event computer problems happen again. The “handshake” between the Canadarm and Canadarm2 (passing of the pallet that carried Candarm2 into orbit to the Shuttle’s arm for stowage prior to return to Earth) was delayed again until Friday.

Today the shuttle crew will reload the Italian Raffaello logistics module with unneeded equipment and supplies from the space station. There will also be reboost of the space station by the shuttle later today.

Here is how NASA described the situation this morning (Source: ISS MER Daily Report 26 Apr 2001)

Upon crew wake up today, the FCT was successful in recovering C&C 2. All I/O was inhibited to preclude unnecessary communications with the C&C. Communication with the OIU was re-established and data dumps were performed of C&C 2. Communication with the INT-2 MDM was reestablished. The FCT has performed a data dump of the N1-1 MDM and as of 10 am was not able to dump N1-2. Both NCS MDMs were in diagnostics, which may have caused by an ADA Exception set off by the C&C 2 time stamp (1992) when the C&C 2 was brought back up. C&C 2 is still on line and functioning nominally.

NCS MDM N1-1 MDM data dump performed. N1-2 data dump has not been perfomed. ODIN has attempted the dump several times. MER is has given the go power cycling the MDMs to recover them. N1-1 has been recovered. MER gave the go to power cycle N1-2. N1-2 is now in Standby.

Still looking at bringing up a second C&C MDM. Primary objective is to ensure the NCS is operating nominally prior to continuing with C&C backup MDM recovery.