NASA TV UFOs:
STS-75 UFO Over Mexico

The footage was apparently filmed on 5 March 1996:

http://www.youtube.com/watch?v=nSQnO-naMHA

I’ve previously reported about two other STS-75 UFO videos:

nasa-tv-ufos-ufo-cluster-filmed-during.html

nasa-tv-ufos-nasa-sts-75-unknown-object.html

The NASA STS-75 Columbia mission:

Launch date: 22 February 1996 -
Landing date: 9 March 1996.