NASA delays Hubble mission to 2009

NASA is delaying the planned Oct. 14 launch of a Hubble Space Telescope repair mission so astronauts can replace a critical observatory part that failed over the weekend.

That means NASA's next shuttle mission will be the Nov. 16 launch of Endeavour on a mission to the International Space Station.

NASA shut down Hubble science operations over the weekend when a key part that serves as the heart of the telescope's science instrument control and data handling unit failed.

The Control Unit/Science Data Formatter formats and sends all computer commands and data to the telescope's primary flight computer, its science instruments and other spacecraft systems.

NASA will attempt later this week to start up a back-up unit that has not been used since the observatory was launched aboard shuttle Discovery in April 1990. If that is successful, science operations will be restarted.

The telescope, however, still would be vulnerable. If the back-up failed, the telescope essentially would be out of commission. So NASA wants to qualify a spare on the ground for flight and then install it on its fifth and final trip to the observatory.

The spare unit has been used for testing and troubleshooting on the ground but still must be certified for flight in space, and that effort is expected to take months. The seven astronauts destined to fly the mission also must be trained to do the replacement work, which will be unprecedented.

The bid to start-up the back-up unit is critical to restarting science operations. If NASA is unsuccessful, then the agency will not be able to conduct science operations. The agency, however, still would be able to control the telescope a and keep it healthy until the astronauts arrive.

NASA officials say the mission will now not be launched before January or February.

Next up: Endeavour and seven astronauts on a mission to outfit the International Space Station with the gear and equipment needed to accomodate crews of six -- double the current size.

NASA is facing a Nov. 25 deadline to get the mission under way.

The sun angle on the station between Nov. 26 and Dec. 17 would be such that the station could not generate enough electricity or dispel enough heat to accomodate a docked shuttle orbiter.

NASA also would opt not to launch the mission over the holidays, so a slip beyond Nov. 25 would push both the station and Hubble missions into 2009, compromising the agency's ability to complete construction of the international outpost before a Sept. 30, 2010 deadline set by President Bush.