NASA scientists and engineers have been working since Tuesday night to fix a computer failure on board the Hubble Space Telescope that hobbled the instrument and derailed a shuttle mission.
A spokesman for NASA said today that scientists worked overnight to switch the telescope's failed data formatter and control unit over to an onboard redundant system. He added that they expect to find out later today whether the remote switchover and reboot was a success.
Late last month, the space agency announced that the computer failure was preventing data from being sent to Earth. Michael Moore, a program executive for the Hubble Space Telescope, has said in a previous interview that the computer problem is the worst the Hubble has suffered since it went into orbit more than 18 years ago.
This is the first Hubble computer malfunction that has required the installation of a replacement system. "There's nothing young in the system," said Moore.
The Science Data Formatter is designed to take information from five onboard instruments, format it into data packets, put a header on it and then send it to Earth at speeds of up to 1Mbit/sec. Without this computer, Hubble can't take on long-planned research projects.
NASA scientists are now working to switch the Hubble over to onboard redundant systems to resume services until the space shuttle arrives with another system, which then will act as the new backup. NASA postponed the space shuttle's planned October repair mission in order to get the replacement computer system ready.
As of now, John Shannon, shuttle program manager at the Johnson Space Center, said the flight will likely be rescheduled for next February or April.
According to Moore, remotely switching over to the redundant systems should take about 10 hours. The switchover will involve shutting the telescope down then commanding it to come back up running on another set of boxes.
Ed Weiler, the associate administrator of the Science Mission Directorate at NASA, had noted in a previous interview that the switchover and subsequent installation of new redundant systems should add another five to 10 years to the Hubble's life. "Hubble has a habit of coming back from adversity, and the Hubble team, which includes the Shuttle team, works miracles. And you know, I am not too concerned about this," said Weiler. "We will find a way to get this fixed."