NOSS satellites are 3 in a group, flying in tight formation about 1 degree apart. This makes them interesting objects to observe. They are military reconnaissance satellites. The following images shows one group, NOSS 2-1, as a triangle on 2002/4/10. Although normally faint and need binoculars to see, the triple flared to magnitude 3 and was easily visible to unaided eye. Image taken with a camcorder.

NOSS triplet