STS-51-E

STS-51-E

Then it happened: the long-planned STS-51-E mission, which was supposed to loft the TDRS-B/2 satellite atop an IUS booster stage (you may know why it was cancelled). The crew was the same as STS-41-F, except there was one Payload Specialist and his backup: Patrick Baudry and Jean-Loup Chretien. The crew was selected after the cancellation of STS-41-F in August of 1984. There was, however, an additional Payload Specialist to make 7 crew members all together: Jake Garn, who was a US senator for the Republican Party in Utah and also the Congress Observer for this flight. He was selected to fly in January of 1985.

Challenger aka OV-099 was rolled out to Pad 39A in February 1985 ahead of time for a March 1985 blastoff. Then, as you saw in the previous cancelled DoD flights, it happened: IUS failures, and the mission was cancelled. That meant that Challenger had to be rolled back into the VAB on March 5, 1985, destacked from its SRBs and EFT, and moved into its OPF to have the Spacelab-3 payloads installed in its payload bay and the TDRS-B/2 satellite atop the IUS booster stage removed and shelved until further notice. Meanwhile, the crew had to wait another month for STS-51-D, which meant they had to redesign their patch and replace Baudry with veteran Payload Specialist Charlie Walker. The original STS-51-D crew, led by Dan Brandenstein, were also waiting for a March 1985 liftoff, and they too had to be transferred to another mission: STS-51-G.