Hubble trouble: Delay until 2009 possible

The failure of a critical system on the Hubble Space Telescope over the weekend potentially could delay a planned Oct. 14 launch of NASA's last Hubble servicing mission until early next year.

A key component within the telescope's prime Science Instrument Control and Data Handling system forced flight controllers to shut down science observations until a back-up system can be pressed into service.

The Control Unit/Science Data Formatter -- which is considered the "heart" of the system -- formats and sends all commands and data to designated destinations such as the telescope's flight computer and its data management unit. A primer on Hubble systems is here: HSTSYSTEMS. See Section5.5 for details on the Control Unit/Science Data Formatter.

NASA officials say a spare unit that has been used for testing is available at Goddard Space Flight Center in Greenbelt, Md., but it's unclear how long it would take to certify the device for flight.

NASA managers are meeting today to put together a course of action, and a decision to repair or replace the failed unit could trigger a mission delay until early next year. The near-term plan is to switch to a back-up unit that has not be used since the telescope was launched in 1990.

That would enable Hubble to restart science observations, but the telescope then would be vulnerable.

If the back-up unit failed, the telescope would be permenantly disabled. A move to repair or replace the failed unit would result in additional crew training, and that likely prompt NASA to delay the Hubble servicing flight and focus on launching a time-critical mission to the International Space Station.

Endeavour is slated to launch Nov. 16 on a mission to outfit the station for an expansion of its crew -- to six from three. The mission, however, must be launched by Nov. 25 or it too would be delayed until next year.

The sun angle on the station between Nov. 26 and Dec. 17 will be such that the station could not generate enough electricity or dispel enough heat to accomodate a docked shuttle orbiter. The agency also would opt not to launch during the holidays, so the mission in that case would be pushed back to early January.

NASA managers are mulling their options and will hold a media teleconference later today. The time now is No Earlier Than 6 p.m.

NOTE ON IMAGES: Click to enlarge the very cool images of the Hubble Space Telescope. They were recorded by the crew of STS-103 during a servicing mission in Decmber 1999. You can also click the enlarged images to get even bigger views.