STS-6/TDRS-1

(TW: Lag on weaker devices) STS-6 was the 1st mission of the orbiter Challenger. It was also the 1st Shuttle Mission to have a spacewalk. It has the 1st Inertial Upper Stage (then called Interim Upper Stage) on a Shuttle. The Inertial Upper Stage was a 2-stage upper stage that can deliver payloads to Geostationary Orbit and also to an interplanetary trajectory to some planets. For Geostationary Orbit, the 1st stage (Perigee Kick Motor Stage) would carry the payload to a Geostationary Transfer Orbit then the 2nd stage (Apogee Kick Motor Stage) would circulize the orbit to make a Geostationary Orbit. Then the payload is deployed. For Interplanetary ones, the 1st stage carries the payload to an elliptical orbit then the 2nd stage would take it to deep space. The payload on the upper stage was a TDRS Satellite called TDRS-A. A TDRS satellite relays data of satellites to ground stations. It can only relay, so it can't process the data it recieved. Also the letter changes to a number when in it's proper orbit (Example: TDRS-A to TDRS-1). The mission also had the 1st spacewalk in a shuttle but the 1st spacewalk was supposed to be in the previous mission, STS-5 but due to suit problems, the spacewalk was cancelled so this mission had the 1st spacewalk in a shuttle. This orbiter would explode 3 years after this mission at STS-51-L due to a problem with the O-rings of one of the boosters. It will also have an abort at STS-51-F.
Antenna credit to user called 2511827356