Richard Fredrick <firstname.lastname@example.org> said: >I haven't observed ERBS that many times, but when I did it evoked a >strange feeling because of the shuttle from which it was released - >Challenger. Actually I found it more interesting because ERBS was released from Challenger. Before the accident Challenger was the most productive of the shuttle fleet, and most versatile - flying satellite deployment, pure science, and applied technology payloads on its nine successful missions. Its firsts in the shuttle program include the first lightweight external tank, the first IUS/TDRS, the first time a satellite was deployed and retrieved (which was also the first shuttle rendezvous), the first rendezvous with a satellite already in orbit, first solar pointing mission, first satellite repair in orbit, etc. etc. There are many Challenger-launched satellites in orbit which can be viewed (OBJ Seesat comment), including three commercial comsats in GEO (no longer functional AFAIK), the TDRS-A satellite, all of their associated PAM and IUS upper stages, and ERBS. Another Challenger-launched satellite, LDEF, was one of the brightest visible satellites from the time it was deployed in 1984 until it was retrieved in 1990. Thursday marks the anniversary of the Challenger accident. But in addition to the loss of the shuttle, its payloads and its crew, I also think about the nine successful missions which preceeded it. Philip Chien, KC4YER Earth News world (in)famous writer, science fiction fan, ham radio operator, all-around nice guy, etc.