NASA officials decided to move up part of the servicing mission that had been scheduled for June 2000 after three of the telescope's six gyroscopes failed.

The Hubble team believed they understood the cause of the failures, although they could not be certain until the gyros were returned from space.

Having fewer than three working gyroscopes would have precluded science observations, although the telescope would have remained safely in orbit until a servicing crew arrived.

It is believed that oxygen in the pressurized air used during the assembly process caused the wires to corrode and break.

The VIK modifies the charge cutoff voltage to a lower level to prevent battery overcharging and associated overheating.

A spare solid state recorder was also installed to allow efficient handling of high-volume data.

The New Outer Blanket Layer (NOBL) and Shell/Shield Replacement Fabric (SSRF) help protect Hubble from the harsh environment of space.

It protects the telescope from the severe and rapid temperature changes it experiences during each 90 minute orbit as it moves from sunlight to darkness.

The unique project provided elementary schools (selected on a rotating basis) with special posters to be autographed by students, then scanned onto disks and carried aboard a NASA Space Shuttle mission.

NASA began a tradition of playing music to astronauts during the Gemini program, which was first used to wake up a flight crew during Apollo 15.