|Names||Space Transportation System-21|
|Mission type||Satellite deployment|
|Operator||NASA / U.S. DoD|
|Mission duration||4 days, 1 hour, 44 minutes, 38 seconds (achieved)|
|Distance travelled||2,707,948 km (1,682,641 mi)|
|Spacecraft||Space Shuttle Atlantis|
|Landing mass||86,400 kg (190,500 lb)|
|Payload mass||19,968 kg (44,022 lb)|
|Start of mission|
|Launch date||October 3, 1985, 15:15:30 UTC|
|Rocket||Space Shuttle Atlantis|
|Launch site||Kennedy Space Center, LC-39A|
|End of mission|
|Landing date||October 7, 1985, 17:00:08 UTC|
|Landing site||Edwards Air Force Base,|
|Reference system||Geocentric orbit|
|Regime||Low Earth orbit|
|Perigee altitude||475 km (295 mi)|
|Apogee altitude||484 km (301 mi)|
STS-51-J mission patch
Back row: David C. Hilmers, William A. Pailes
Seated: Robert L. Stewart, Karol J. Bobko, Ronald J. Grabe
STS-51-J was NASA's 21st Space Shuttle mission and the first flight of Space Shuttle Atlantis. It launched from Kennedy Space Center, Florida, on October 3, 1985, carrying a payload for the U.S. Department of Defense (DoD), and landed at Edwards Air Force Base, California, on October 7, 1985.
|Commander||Karol J. Bobko|
Third and last spaceflight
|Pilot||Ronald J. Grabe|
|Mission Specialist 1||David C. Hilmers|
|Mission Specialist 2||Robert L. Stewart|
Second and last spaceflight
|Payload Specialist 1||William A. Pailes, MSE|
|Payload Specialist 1||Michael W. Booen, MSE|
All five astronauts on the secret mission were active-duty military officers. Before William A. Pailes was assigned to the STS-51-J flight, Mike Mullane was rumored to have been assigned as mission specialist 3 on his second trip to space.
STS-51-J launched on October 3, 1985, at 15:15:30 UTC (11:15:30 a.m. EDT), from Launch Pad 39A at the Kennedy Space Center. The launch was delayed by 22 minutes and 30 seconds due to a problem with a main engine liquid hydrogen prevalve close remote power controller; the controller was showing a faulty "on" indication.
The mission was the second shuttle flight totally dedicated to deploying a United States Department of Defense payload, after STS-51-C. Its cargo was classified, but it was reported that two (USA-11 and USA-12) DSCS-III (Defense Satellite Communications System) satellites were launched into geostationary orbits by an Inertial Upper Stage (IUS). The DSCS satellites used X-band frequencies (8/7 GHz). Each DSCS-III satellite had a design life of ten years, although several of the DSCS satellites have far exceeded their design life expectancy.
The mission was deemed successful. After a flight lasting 4 days, 1 hour, 44 minutes and 38 seconds, Atlantis landed on Runway 23 at Edwards Air Force Base at 17:00:08 UTC (13:00:08 EDT) on October 7, 1985. During STS-51-J, mission commander Bobko became the first astronaut to fly on three different shuttle orbiters, and the only astronaut to fly on the maiden voyages of two different orbiters.
|Attempt||Planned||Result||Turnaround||Reason||Decision point||Weather go (%)||Notes|
|1||3 Oct 1985, 2:53:00 pm||delayed||—||technical||faulty indication from main engine liquid hydrogen prevalve close remote power controller|
|2||3 Oct 1985, 3:15:30 pm||success||0 days, 0 hours, 23 minutes|
The 51-J mission insignia, designed by Atlantis's first crew, pays tribute to the Statue of Liberty and the ideas it symbolizes, but also as not to emphasize the "classified" nature of the mission like the first one did. The historical gateway figure bears additional significance for astronauts Karol J. Bobko, mission commander; and Ronald J. Grabe, pilot, both New York City natives.
Atlantis lifting off the pad.
Space Shuttle Atlantis lands on the dry desert lakebed of Edwards Air Force Base at the end of the STS-51-J mission.
- Blakeslee, Sandra (October 8, 1985). "ASTRONAUTS RETURN FROM SECRET [sic]". The New York Times. p. C3. ISSN 0362-4331. Retrieved June 18, 2021.
- Day, Dwayne (January 4, 2010). "A lighter shade of black: the (non) mystery of STS-51J". The Space Review. Retrieved February 5, 2022.