STS-51-G

Infobox Space mission
mission_name = STS-51-G
insignia = Sts-51-g-patch.png shuttle = Discovery
launch_pad = 39-A
launch = June 17, 1985, 11:33:00 UTC
landing = June 24, 1985, 13:11:52 UTC
Runway 23, Edwards AFB
duration = 7d/01:38:52
altitude = 387 km
inclination = 28.45°
orbits = 112
distance = 4,693,051 km
crew_photo = Sts-51-g-crew.gif
crew_caption = Back L-R: Nagel, Lucid, Baudry, Al-Saud Front L-R: Creighton, Brandenstein, Fabian
previous = STS-51-B
next = STS-51-F

STS 51-G was the eighteenth flight of a space shuttle, and the fifth flight of "Discovery". The mission launched from Kennedy Space Center, Florida, on June 17, 1985. It is probably best remembered for having Sultan Salman Al Saud of Saudi Arabia on board as a payload specialist.

Crew

Number in parentheses indicates number of spaceflights by each individual prior to and including this mission.

*Daniel C. Brandenstein (2) - Commander
*John O. Creighton (1) - Pilot
*Shannon W. Lucid (1) - Mission Specialist
*John M. Fabian (2) - Mission Specialist
*Steven R. Nagel (1) - Mission Specialist
*Patrick Baudry (1) - Payload Specialist - CNES
*Sultan Salman Al Saud (Saudi Arabia) (1) - Payload Specialist

Backup crew

*Jean-Loup Chrétien - Payload Specialist - CNES
*Abdulmohsen Al-Bassam (Saudi Arabia) - Payload Specialist

Mission parameters

*Mass:
**"Orbiter Liftoff:" 116,310 kg
**"Orbiter Landing:" 92,607 kg
**"Payload:" 20,174 kg
*Perigee: 358 km
*Apogee: 369 km
*Inclination: 28.5°
*Period: 91.8 min

Mission highlights

The Orbiter "Discovery" lifted off from Pad A, Launch Complex 39, KSC, at 7:33 a.m. EDT on June 17, 1985. The launch came 67 days after the previous launch of "Discovery" on flight STS-51-D on April 12. That stands as the record for flying a mission with a California landing, transcontinental ferry, refurbishing an orbiter for flight and launching on its next mission. The largest items of cargo were three communications satellites. Also flown were the deployable/retrievable Spartan 1, six Getaway Special canisters, a High Precision Tracking Experiment (HPTE) for the Strategic Defense Initiative ("Star Wars"), a materials processing furnace, and French biomedical experiments. All three communications satellites were successfully deployed and turned over to their owner-operators. Their PAM-D perigee booster motors fired and all three reached geosynchronous orbit, where they entered checkout operations. Spartan 1 was deployed and recovered. All the experiments were successfully accomplished. "Discovery" landed at Edwards AFB at 9:12 a.m. EDT on June 24, 1985, after a mission duration of 7 days, one hour and 39 minutes.

The crew members were Daniel C. Brandenstein, commander; John O. Creighton, pilot; Shannon W. Lucid, Steven R. Nagel, and John M. Fabian, mission specialists; and Patrick Baudry, France, and Prince Sultan Salman Al Saud, Saudi Arabia, payload specialists. deployed were the Arabsat 1-B (Arab Satellite Communications Organization); Morelos 1 (Mexico); and Telstar 3-D (AT&T). All three utilized PAM-D booster stages to achieve geosynchronous transfer orbits after deployment from the Discovery. The latter two spacecraft are variants of the Hughes-built HS-376 series of spin-stabilized satellites. Both use the Morton Thiokol Star 48 motor to circularize the orbit and align it with the equator at apogee. Morelos 1 provides 12 channels operating in the C-band and 6 channels operating in the K_u band. It can provide educational and commercial television programs, telephone and facsimile services, and data and business transmission services to even the most remote parts of Mexico. Telstar 3-D operates in the C-band only, and has 24 working channels. Using single sideband technology, a Telstar can relay up to 86,400 two-way telephone calls. Both spacecraft are about 22 ft (6.7 m) high and 7 ft (2.1 m) wide when deployed, and have a mass of around 1,450 lb (660 kg) when operational.

Arabsat 1 satellites are built by an international team led by Aerospatiale of France. It is a three-axis stabilized spacecraft with two deployable solar array wings, making it almost 68 ft (20.7 m) long and over 18 ft (5.5 m) wide when deployed in orbit. It weighs about 2,800 lb (1,270 kg) in its initial orbit, but some 1,490 lb (675 kg) of this is propellant. It has an onboard low-thrust motor that utilizes hydrazine and nitrogen tetroxide, and transfers from an initial elliptical to geosynchronous orbit by firing this motor. The remaining propellant is then used for station-keeping or moving over the life of the satellite.

Spartan 1 measured 126 by 42 by 48 inches (3.2 by 1.1 by 1.2 m), and weighed 2,223 lb (1,008 kg). The Spartan is a carrier, designed to be deployed from the orbiter and fly free in space before being retrieved. Spartan 1 included 300 lb (136 kg) of experiments in the field of astronomy. It was deployed and operated successfully, independent of the orbiter, before being retrieved.

The materials furnace, French biomedical experiments, and six Getaway Special experiments were all successfully performed, although the GO34 Getaway Special shut down prematurely. The Strategic Defense Initiative failed during its first try on orbit 37 because the orbiter was not at the correct attitude. It was successfully completed on orbit 64.

Three communications satellites, all attached to Payload Assist Module-D (PAM-D) motors, were deployed: MORE LOS-A, for Mexico; ARABSAT-A, for Arab Satellite Communications Organization; and TELSTAR-3D, for AT&T. Also flown: deployable/retrievable Shuttle Pointed Autonomous Research Tool for Astronomy (SPARTAN-1); six Get Away Special canisters; Strategic Defense Initiative experiment called the High Precision Tracking Experiment (HPTE); a materials processing furnace called Automated Directional Solidification Furnace (ADSF); and two French biomedical experiments.

Gallery

ee also

* Space science
* Space shuttle
* List of space shuttle missions
* List of human spaceflights chronologically

External links

* [http://science.ksc.nasa.gov/shuttle/missions/51-g/mission-51-g.html NASA mission summary]
* [http://www.nss.org/resources/library/shuttlevideos/shuttle18.htm STS-51G Video Highlights]