The Explorers' Club, № MCII

Operation AXIOM: The Space Age—The 40th Anniversary of S.T.S.-51-F (№ 19), Part I
29 July 1985: Spacelab 2—The Space Shuttle Challenger OV-099 lifted off from Florida's K.S.C. with CDR Gordon Fullerton, Pilot Roy Bridges Jr., M.S.1 Karl Henize, M.S.2/F.E. Story Musgrave, M.S.3 Tony England, P.S.1 Loren Acton, & P.S.2 John Bartoe; the center S.S.M.E. rocket shut down during ascent due to sensor failures, resulting in an "Abort to Orbit," a lower-than-intended orbital altitude.

Commentary: S.T.S.-51-F was the eighth flight of the Challenger OV-099.

S.T.S.-51-F suffered a launch abort on 12 July, when the countdown was halted at T-minus three seconds (T-0:03) due to a malfunctioning coolant value on a different Space Shuttle Main Engine.

Your eyes do not deceive you, attentive reader, Spacelab 3 (S.T.S.-51-B) flew before Spacelab 2. Spacelab 2 flew in a different configuration than Spacelabs 1 & 3, with no pressurized module in the Challenger's Payload Bay, but rather the Spacelab Infrared Telescope mounted on the Instrument Pointing System, with control equipment in a smaller pressurized cylinder known as the "Igloo."

Bonus! Space Age Song o' the Day: S.T.S.-51-F
Fountains of Wayne, "Troubled Times" from Utopia Parkway (Space Cadet Mike Papa Whiskey)

Semper exploro.