Discovery
Orbiter OV-103
See also Space Transportation System and space shuttle
This orbiter is currently active.

Entered service August 30, 1984.

Flights:
    STS-41D    08/30/84
    STS-51A    11/08/84
    STS-51C    01/24/85
    STS-51D    04/12/85
    STS-51G    06/17/85
    STS-51I    08/27/85
    STS-26    09/29/88
    STS-29    03/13/89
    STS-33    11/22/89
    STS-31    04/24/90
    STS-41    10/06/90
    STS-39    04/28/91
    STS-48    09/12/91
    STS-42    01/22/92
    STS-53    12/02/92
    STS-56    04/08/93
    STS-51    09/12/93
    STS-60    02/03/94
    STS-64    09/09/94
    STS-63    02/03/95
    STS-70    07/13/95
    STS-82    02/11/97
    STS-85    08/07/97
    STS-91    06/02/98
    STS-95    10/29/98
    STS-96    05/27/99
    STS-103    12/19/99
    STS-92    10/11/00
    STS-102    03/08/01

Discovery was the third active orbiter in the fleet.

Discovery was also the first orbiter built with design enhancements learned from previous vehicles. Enterprise was a test vehicle, and so had no predecessors, Columbia was the first active orbiter, and Challenger was built from a modified static test article. Discovery, however, was built completely new after these initial vessels, and was able to take advantage of several design improvements. One of the results of this is that Discovery weighed in at 6,870 pounds less than Columbia at rollout.

Discovery was one of two orbiters to be modified to carry a Centaur launch vehicle upper stage in its payload bay. This involved adding extra fuel piping into the bay, since the Centaur upper stage has a liquid-fuel rocket engine, as well as controls in the aft deck to control and monitor the rocket. Challenger was the other orbiter with this modification. This has since been deemed to risky and there are no plans to use this functionality.

At the time of this writing, Discovery is awaiting launch STS-105, scheduled for August 9, 2001.

The rest of the orbiter fleet:
Enterprise * Columbia * Challenger * Atlantis * Endeavour