Stock Photo - 11/05/1999 __ At Launch Pad 39B, the payload canister for Space Shuttle Discovery, for mission STS_103, is lifted up the Rotating Service Structure. The hoses attached to the canister provide airconditioning until the canister is mated to the environmentally controlled Payload Changeout Room and the payload bay doors are open. Installation of the payload into Discovery is slated for Friday, Nov. 12. The mission is a call_up due to the need to replace portions of the pointing system, the gyros, which have begun to fail on the Hubble Space Telescope. Although Hubble is operating normally and conducting its scientific observations, only three of its six gyroscopes are working properly. The gyroscopes allow the telescope to point at stars, galaxies and planets. The STS_103 crew will also be replacing a Fine Guidance Sensor and an older computer with a new enhanced model, an older data tape recorder with a solid_state digital recorder, a failed spare transmitter with a new one, and degraded insulation on the telescope with new thermal insulation. The crew will also install a Battery Voltage/Temperature Improvement Kit to protect the spacecraft batteries from overcharging and overheating when the telescope goes into a safe mode