The Saga of USA 53 - Found, Lost, Found Again and Lost Again
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Satellite sleuths will recall space shuttle mission STS 36, which
deployed a secret CIA/Air Force satellite named USA 53 (90019B, 20516)
on March 1, 1990.  Aviation Week reported it to be a large digital
imaging reconnaissance satellite.  Members of an observation network
which I organized, observed the satellite between the 2nd and 4th of
March.  It was deployed into a 62 deg inclination, 254 km altitude
orbit.  Early on March 3rd, it manoeuvred to a 271 km altitude.

Observers noted that the object was extremely bright, reaching a visual
magnitude of -1 under favourable conditions.  Its brightness was similar
to that of the very large KH-9 and KH-11 imaging reconnaissance
satellites.

On March 16th, the Soviet news media reported that several large pieces
of debris from the satellite had been detected in orbit on March 7th,
and suggested that it had exploded.  In response to Western media
enquiries, the Pentagon stated that "hardware elements from the
successful mission of STS 36 would decay over the next six weeks".  As
expected, the Air Force statement was vague about the status of USA 53.
The debris could have been from a break-up of the satellite, or simply
incidental debris.  Only five pieces of debris were ever catalogued.  An
intensive search by observers in late March failed to locate the
satellite.  Six months later, the mystery of USA 53 was solved, through
the efforts of three European observers.

On October 19th, 1990, I received a message from Russell Eberst, stating
that he, along with Pierre Neirinck and Daniel Karcher had found an
object in a 65 deg inclination, 811 km altitude orbit, which did not
match the orbit of any known payload, rocket body or piece of debris.
He suspected that the object could be a secret U.S. payload, and asked
me to try and identify it.

There are many secret U.S. objects in orbit, however, initial orbital
elements, released in accordance with a United Nations treaty, are
available for most of them.  Most objects could be easily ruled out on
the basis of orbital inclination.  There remained three recent high
inclination launches for which the U.N. had not yet received elements,
and three satellites in near 65 deg inc orbits which had been tracked
for a short time by observers, then lost after they manoeuvred.  I found
an excellent match with one of the latter, USA 53.  There were no close
matches with any of the other objects.

My analysis revealed that the orbital plane of the mystery object was
almost exactly coplanar with USA 53 on March 7, 1990, the same date that
the Soviets found debris from USA 53 in orbit!  This is a strong
indication that the object in question actually is USA 53, now in a new
orbit.  The debris may have been connected with the manoeuvres to the
new orbit.

USA 53 was successfully tracked by observers until early November 1990,
when it manoeuvred once more.  The orbit was raised slightly on or about
Nov 2nd, which is reflected in the most current elements.  Bad weather
prevented further observation attempts until 7 November, by which time,
the object had made a much more significant manoeuvre, and could no
longer be found.  So far, all attempts to once again locate USA 53 have
failed. The following are its last known elements:

USA 53          18.0  4.0  0.0  4.1
1 20516U 90019  B 90309.99079700 -.00002298  00000-0 -95528-3 0    03
2 20516  65.0200 194.0588 0009734 214.9671 144.9440 14.26241038    04

- Ted Molczan