STS-39 (40)

Pad 39-A (40)
40th Shuttle mission
12th Flight OV-103
7th Rollback
Diverted landing
7th KSC landing


Michael L. Coats (3), Commander
L. Blaine Hammond, Jr.(1), Pilot
Guion S. Bluford Jr.(3), Mission Specialist 1
Gregory J. Harbaugh (1), Mission Specialist 2
Richard J. Hieb (1), Mission Specialist 3
Donald R. McMonagle (1), Mission Specialist 4
Charles L. Veach (1), Mission Specialist 5


Flow A:
OPF - Oct. 17,1990
VAB - Feb. 9,1991
PAD - Feb. 15, 1991
Flow B (rollback):
VAB - March 7,1991
OPF - March 15, 1991
VAB - March 25,1991
PAD - April 1, 1991



Mission Objectives:

Click here for Press Kit
Click here for Additional Info on STS-39


April 28, 1991,7:33:14 a.m. EDT. Launch originally scheduled for March 9, but during processing work at Pad A, significant cracks found on all four lug hinges on the two external tank umbilical door drive mechanisms. NASA managers opted to roll back the vehicle to the VAB on March 7, and then to OPF for repair. Hinges replaced with units taken from orbiter COLUMBIA, and reinforced. Discovery returned to pad on April 1, and launch re-set for April 23. Mission again postponed when, during prelaunch external tank loading, a transducer on high-pressure oxidizer turbopump for main engine number three showed readings out of specification. Transducer and its cable harness were replaced and tested. Launch was rescheduled for April 28. Launch Weight: 247,373 lbs


Altitude: 140nm
Inclination: 57.0 degrees
Orbits: 134
Duration: 8 days, 7 hours, 22 minutes, 23 seconds.
Distance: 3,470,000 miles


SRB: BI-043
SRM: 360L015
ET : 46/LWT-39
MLP : 2
SSME-1: SN-2026
SSME-2: SN-2030
SSME-3: SN-2029


May 6, 1991, 2:55:35 p.m. EDT, Runway 15, Kennedy Space Center, Fla. Rollout distance: 9,235 feet. Rollout time: 56 secs. Landing diverted to KSC because of unacceptably high winds at planned landing site, Edwards. Landing Weight: 211,512 lbs.

Mission Highlights:

Dedicated Department of Defense mission. Unclassified payload included Air Force Program-675 (AFP675); Infrared Background Signature Survey (IBSS) with Critical Ionization Velocity (CIV), Chemical Release Observation (CRO) and Shuttle Pallet Satellite-II (SPAS-II) experiments; and Space Test Payload-1 (STP-1). Classified payload consisted of Multi-Purpose Release Canister (MPEC). Also on board was Radiation Monitoring Equip- ment III (RME III) and Cloud Logic to Optimize Use of Defense Systems-IA (CLOUDS-I).

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Last Updated Friday June 29 11:21:02 EDT 2001
Jim Dumoulin (