Launch from Cape Canaveral (
KSC); landing on Cape
Canaveral (
KSC). The
launch was originally scheduled for March 9, 1991, but during processing work
at Pad A, significant cracks were found on all four lug hinges on the two
external tank umbilical door drive mechanisms. The shuttle was rolled back to
the
VAB for
repair work.
Dedicated Department of Defense mission, but first time not
secret.
STS-39 was a dedicated Department of Defense mission.
Unclassified payload included Air Force Program-675 (AFP-675); 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 Equipment III (RME III) and Cloud Logic to
Optimize Use of Defense Systems-IA (CLOUDS-I).
SDI experiments
including AFP-675-payload and research complex
IBSS
(included deploying and retrieval of
SPAS-II and
deploying of three
CRO-satellites);
also deploying
SDI satellite
MPEC.
The
high orbital inclination of the mission, 57 degrees with respect to the
equator, allowed the crew to fly over most of Earth's large land masses and
observe and record environmental resources and problem areas.
Landing
was diverted to the
KSC, Florida, because
of unacceptably high winds at the planned landing site, Edwards
AFB.