Hubble was put out of service last month because of a technical problem with Side-A of its Science Data Formatter -- the unit that allowed the powerful telescope to collect data, format it and relay it back to Earth, yielding spectacular images of space.

Jon Morse, director of NASA's astrophysics department, said the space agency's Hubble team will switch the Hubble space telescope over to its Side-B for the first time since its launch 18 years ago, allowing the telescope to collect data once again.

"The process will commence Wednesday morning and it's expected to take a couple of days to bring Hubble back to its science operations," Morse told reporters Tuesday.

This technical failure prompted NASA to postpone until next February at the earliest, a long-awaited space shuttle mission to service and upgrade the orbital observatory. That flight is to be the fifth and final servicing call by space shuttle astronauts to the observatory and had been scheduled for liftoff on Tuesday.

By delaying the shuttle mission, NASA hopes to fly a spare parts to restore backup capability to the telescope. The shuttle program is scheduled to end in 2010.

Hubble managers said they should know by the first or second week of November if the spare unit is ready to be flown.

Orbiting 575 kilometers (360 miles) above Earth, Hubble launched in 1990 has enabled scientists to better measure the age and origins of the universe, observe distant supernovas, and identify and study bodies inside and outside the solar system.

Hubble is due to function at least two more years until 2013 when the space telescope James Webb Space Telescope will be launched.

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