NASA engineers will try to fix Hubble today

NASA engineers say they know how to fix the broken Hubble Space Telescope: They have to wake up computer parts that have been sleeping in space for more than 18 years.

Today, NASA will start a complicated remote-control fix of a major glitch that stopped the telescope from capturing and beaming down pictures. Hubble should be able to send photos back to Earth by Friday, officials said.

The abrupt failure more than two weeks ago caused NASA to postpone its Hubble upgrade mission from October to next February or so. The delay is costing NASA about $10 million a month, officials said Tuesday.

Key to the repair is activating a backup data-handling system that hasn't been turned on since the telescope launched in 1990. Science data will be rerouted to that system, the equivalent of driving a new route that hasn't been used before.

Early today, a team of about 40 engineers at NASA's Goddard Space Flight Center in suburban Maryland will send hundreds of lines of complicated code up to Hubble. The entire observatory will be put into safe mode for the sixth time in its 18-year history as computer codes are rerouted. There is a risk that it will not come out of safe mode, but it is unlikely that the repairs will worsen Hubble's conditions, said Art Whipple, manager of the Hubble systems management office.

The rest of Hubble is working well, but only a little science can be done with this glitch.