"G. Groth" wrote in message
...
I have been watching satellites for about 25 years. In the last 2 years I
have seen 3 satellites in a right triangle formation all within about a
degree of each other. I live in central Colorado and have seen them
traveling North in the winter months and just recently going South in the
summer months. I have seen them no less than 5 times in these past few
years but never before a couple years ago. Has anyone else seen these
satellites and know which sat's these are.

They are secret U.S. NOSS (Naval Ocean Surveillance System) satellites. They
determine the location of ships at sea by triangulating on their radio
transmissions.

The first experimental triad was launched in 1971. Seven first generation
triads were successfully launched between 1976 and 1987, on Atlas rockets.
They are small, and rarely visible to the unaided eye, typically requiring
the use of at least 80 mm aperture binoculars. Their orbits have become more
eccentric over time, making them somewhat easier to observe when near
perigee.

Second generation triads were launched in 1990, 1991 and 1996, on Titan IV
rockets. They are much larger than the first generation satellites. They are
reliable objects in 7x50 binoculars on favourable passes,. Occasionally,
they brighten to unaided-eye visibility, reaching magnitudes between 2 and
4. Rarely, they have been seen to "flare" to negative magnitudes.

Here are the U.S. government's SSN catalogue numbers of the 2nd generation
triad members:

NOSS 2-1 20691, 20692, 20642

NOSS 2-2 21799, 21808, 21809

NOSS 2-3 23908, 23862, 23936

The latest NOSS launch, in 2001, employed an Atlas 2AS rocket. Surprisingly,
only two satellites appeared, leading to speculation that the third failed
to deploy. Objects 26905 and 26907 are about as bright as 2nd generation
NOSS, and fly in a close formation, one behind the other. Another launch in
teh series may take place in the Fall.

The NOSS orbits are not published by the U.S. government; however, they are
routinely tracked by hobbyists who maintain accurate orbital elements,
available on Heavens Above, and elsewhere.

Ted Molczan