It has been 40 years since NASA launched the first dedicated Department of Defense Space Shuttle mission, after which engineers spotted O-ring seal defficiencies that would doom Challenger a year later.
The five crew members launched on the three-day jaunt to space and back – aboard Space Shuttle Discovery – on January 24, 1985.
The purpose of the classified mission was to deploy a satellite to geostationary orbit using an Inertial Upper Stage (IUS).
Mattingly also flew with Henry “Hank” Hartsfield on Space Shuttle Columbia for STS-4 in 1982.
A year later, the Space Shuttle Challenger would launch under similar conditions and be lost.
Engineers discovered O-ring seal defficiencies that would end Challenger a year later, forty years after NASA launched the first Department of Defense Space Shuttle mission.
On January 24, 1985, the five crew members boarded the Space Shuttle Discovery for the three-day journey to and from space. The classified mission’s objective was to use an Inertial Upper Stage (IUS) to launch a satellite into geostationary orbit.
The mission was led by Apollo veteran Thomas “TK” Mattingly, who flew on Apollo 16 after being dropped from Apollo 13 for being exposed to German measles. Additionally, in 1982, Mattingly flew on Space Shuttle Columbia for STS-4 alongside Henry “Hank” Hartsfield.
In addition to Mattingly, the crew included pilot Loren Shriver, US Air Force payload specialist Gary Payton, and mission specialists James Buchli and Ellison Onizuka.
Confidentiality surrounded the mission. Public media coverage of the expedition quickly stopped following the successful lift-off, and the precise launch time was kept a secret until T minus nine minutes.
We should always anticipate the unexpected in space, as demonstrated by the near-miss of Shuttle Columbia.
It has been fifteen years since anyone visited the Hubble Space Telescope.
An ex-Space Shuttle commander corrects the Hubble upgrade mission record.
An astronaut first flew from the Space Shuttle forty years ago.
Even though the mission was classified, problems discovered after launch caused some engineers to pause and consider how it might have mirrored the Challenger disaster a year later. Unusually cold weather had caused managers to postpone liftoff, but their main worries were that ice on the Space Shuttle’s external tank might break off during the ascent and endanger the orbiter.
Engineers found issues with O-ring seals that stop hot gas from escaping from the Solid Rocket Boosters (SRBs) joints when they were taken out for examination, repair, and reuse. They found “significant erosion and ‘blow-by’ between the primary and secondary O-rings.”. “..”.
Due to the pad’s freezing temperatures, which made the O-rings brittle and more prone to erosion, the erosion was the most significant that the Space Shuttle program had seen to that time. Similar circumstances would lead to the launch and eventual loss of the Space Shuttle Challenger a year later.
