Commander's cover: An envelope's flight through space, time and eBay

The last time that Richard Truly saw it, it was on board the space shuttle Challenger 38 years ago. The small envelope, bearing a special postmark identifying it as "Space Mail Orbited Via STS-8," was then newly-signed by Truly and his STS-8 crewmates.

Source : https://www.space.com/challenger-sts8-space-mail-truly-cover