SPACE.com learned that the Soyuz crew will actually go to the International Space Station bearing a safety measure to prevent future station computer problems in the form of a computer disc drive full of command-and-control software.

NASA officials confirmed that the Soyuz launch will take place at 3:37 a.m. EDT Saturday as planned by the Russians. In turn the Space Shuttle Endeavour mission will only be extended one day, setting up undocking on Sunday and landing back at the Kennedy Space Center on Wednesday.

"We have flown a command-and-control computer unit hard drive over to Baikonur to be included on the taxi flight," said Johnson Space Center spokesman Greg Lange. A NASA engineer traveled with the hardware to Baikonur to oversee the drive's handling and loading onto the Soyuz, Lange said.

Now being rushed to Moscow via jet is a Boeing-provided hard drive that was built by Honeywell. The hard drive was shipped to Baikonur as part of a massive troubleshooting effort being coordinated by ground engineers and flight controllers at NASAs Johnson Space Center in Houston.

On Wednesday, the International Space Station (ISS) became plagued by computer problems, throwing the Soyuz launch timetable into flux.

Pre-existing agreements between both U.S. and Russian space agencies as well as the respective governments allow last-minute gear to be flown to the ISS. In the past, Russian equipment has been expressed routed to the Mir on the U.S. space shuttle.

All three of the stations main U.S. command and control computers crashed Wednesday, stalling work being carried out at the outpost by its three resident tenants and the visiting crew of shuttle Endeavour. Exactly what caused the other two computers to shut down remains a mystery.

Only one of those computers since has been brought back on line. A bid to power up a second computer failed Friday after a new load of software was installed into the machine and the station crew attempted to reboot it.

"That failed to bring it back on line so flight controllers now are analyzing the next step with that computer," NASA spokesman James Hartsfield said.

Engineers think the third computer suffered a hard drive failure. The station crew, consequently, was told to replace the failed hard drive with one scavenged from a computer normally used to control research equipment in the outposts U.S. Destiny science lab.

The so-called mass storage unit on its way to Baikonur will be launched to the station aboard the Soyuz and serve as a permanent replacement for the failed hard drive.

"We need another hard drive flown up, and this was the fastest way to get one up," NASA spokesman Rob Navias said.

The Soyuz crew includes Tito, Commander Talgat Musabayev and engineer Yuri Baturin. The Soyuz TM-32 is scheduled to dock at the International Space Station (ISS) on April 30 at 5:10 a.m. Moscow time.

Though Dennis Tito is on the Soyuz taxi flight, his presence will have nothing to do with the transfer of hardware, according to NASA sources.

He will not play a role in the transfer of the vital piece of hardware. This replacement hard drive is for the number one computer whose hard drive is locked down completely.

The Commerce Departments Bureau of Export Administration quickly resolved an emergency request from NASAs Johnson Space Center for authority to export to Russia a critical computer component for the ISS.

The backup computer drive is not meant to solve the current spate of computer problems, but rather as a hedge against further difficulties, said Lange. "It's in case we have more problems," Lange said. NASA controllers have determined that one of the three command and control computers aboard the station suffered a failure of its hard drive. Another of the three is now running again, using basic software.