NASA engineers believe they know what caused the Hubble Space Telescope to unexpectedly shut down two weeks ago, and have started to fix the problem.

If the repair goes according to plan, the aging space telescope could be fully operational on Friday.  

A computer glitch forced NASA to postpone a scheduled shuttle launch to help upgrade and repair Hubble for the last time before it is decommissioned.  The Side-A of Hubble's Science Data Formatter had technical problems; the unit was responsible for collecting data, analyzing it and sending it back to Earth, helping scientists view amazing astronomy photos.

The backup data system must now be turned on, but it has been more than 18 years since it has been last activated.  All collected data will now be sent to Side-B, and although there is a possibility the remote-control repair will not work, engineers expect the repair to move along smoothly.

Assuming the fix is successful; NASA will continue to rely on the backup system to collect data even though astronauts are scheduled to bring up a new system next year.

Since space has a "benign storage environment," electronics won't rust or corrode the same way they would if left on Earth, researchers said.

The manned shuttle launch to make other repairs and upgrades to Hubble will not take place until February, NASA previously said.  It will be the fifth and final repair mission for the space telescope.  NASA hopes it will remain in operation until 2013, which is when the James Webb Space Telescope would launch into space.

The current Hubble launch delay costs NASA around $10 million per month.