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Lost and Found: Spy Satellite

Rutjuga

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Jun 18, 2010
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LOST AND FOUND: XSS-11 SPYSAT

On Sept. 20, 2010, amateur satellite watcher Kevin Fetter was monitoring the traffic over his home in Brockville, Canada, when a bright flash attracted his attention. "It can be seen at the beginning of this video," says Fetter. "At first I had no idea what it was." A rough orbit calculated by Fetter with refinements added by sat-tracking expert Ted Molczan suggested an intriguing possibility: Could it be long-lost military satellite XSS-11? Indeed it was. Follow-up sightings by Alberto Rango (Sept. 29) and Russell Eberst (Sept. 30) confirmed the recovery, and on Oct. 3rd Fetter video recorded the XSS-11 again.

The washing-machine-sized spacecraft was launched by the US Air Force in April 2005 to demonstrate "autonomous rendezvous and proximity maneuvers." In other words, it would approach, investigate, and photograph other spacecraft in Earth orbit. The mission was controversial because it aimed to prove technologies that could potentially be used for anti-satellite weapons.

For some 18 months in 2005 and 2006, amateur satellite watchers kept track of the XSS-11 as it visited at least two other orbiting objects: the body of the Minotaur rocket that launched it and a military DMSP weather satellite. "XSS-11 soon completed its mission, and in December 2006, it was manoeuvred into a disposal orbit, i.e. one with a sufficiently low perigee to reduce the time to decay from centuries to decades," recalls Molczan. "The dimensions and inclination of the new orbit were made public, but without complete orbital elements, it would have been difficult to find. I expected that eventually, it would be spotted as an unknown object, which is what happened on 2010 Sep 20 UTC, when Kevin Fetter noticed something make a brief, bright flash on his monitor."

"Except for the ISS (International Space Station) toolbag (which an astronaut inadvertently let go during a spacewalk), this is the smallest satellite I have ever recorded," says Fetter. "I might not have found it except for that flash. At maximum, it was about 4th magnitude, visible to the naked eye in a good dark sky." Presumably, some flat surface on the XSS-11 is glinting in sunlight, attracting a degree of attention that belies the satellite's modest dimensions.
 
Hi,

A very interesting find----even the old and seemingly dead satelites have worked wonders for the u s---no satelite is dead unless it is dead---back on the ground.


Thanks for the posting.
 
The US Air Force's X-37B space plane has gone missing. Amateur satellite watchers who routinely monitor the secret mini-shuttle failed to sight it at expected times on Oct. 7th and 9th. It's possible that the X-37B has landed. More likely, the space plane has maneuvered into a new orbit and will be recovered again in the nights ahead.

What is the X-37B for? (link)
 
The X-37B has been found again. Satellite watcher Greg Roberts sighted the secret mini-shuttle flying over Cape Town, South Africa, on Oct 12th. An analysis of the sighting by satellite expert Ted Molczan suggests that the X-37B has maneuvered into an orbit 54 km lower than before.
 
What technology are these guys using? I assume a giant database of known objects, and maybe a pair of binoculars? When they see an object that is not predicted by the orbital database, it is something "lost." But how can they tell what the object is, given that there are probably dozens of lost objects?
 
What technology are these guys using? I assume a giant database of known objects, and maybe a pair of binoculars? When they see an object that is not predicted by the orbital database, it is something "lost." But how can they tell what the object is, given that there are probably dozens of lost objects?

Interesting question. I've always assumed that amateur astronomers make discoveries via telescopes. Satellites are tricky since I've read from an astronomy book that they are only visible late in the afternoon when the sun light could glint off the solar panels.

I assume that they could compare the orbit of the "lost" object with the original object and compute the deviation. I think we have to keep note that while we've got a lot of "garbage" circling the earth the debris field is pretty sparse. Having dozens of lost objects travelling along the same orbit is highly unlikely.
 
What technology are these guys using? I assume a giant database of known objects, and maybe a pair of binoculars? When they see an object that is not predicted by the orbital database, it is something "lost." But how can they tell what the object is, given that there are probably dozens of lost objects?
Ordinary astronomical telescopes with computerized ("Goto") drives. Binoculars can be used for sighting satellites, but usually not for identifying them because you cannot record the satellite's path as a series of co-ordinates. Yes, there are databases of artificial satellites available, such as Heavens-Above Home Page.

When a satellite is located, it can be tracked and its orbital elements (ephemeris) calculated. Then various methods can be used to identify it.

Here, for instance, is the discovery report of the X-35B.

The ground track repeats almost exactly after 61 revs, which takes about 4 days. Ground tracks that repeat at 2, 3 or 4 day intervals have been a common feature of U.S. imaging reconnaissance satellites, so this finding could be a clue as to the mission. As a wild guess, another possibility may be to create a fixed set of re-entry ground tracks, that repeat fairly frequently, set up to simplify the eventual return to Earth.
When they hypothesized that the newly found satellite was the space plane, they determined its mass to surface area ratio as a final step in assuring themselves that it is a payload as opposed to a rocket body.
 
Interesting question. I've always assumed that amateur astronomers make discoveries via telescopes.
Other than identifying satellites, amateur discoveries are made with all sort of equipment, from telescopes to binoculars to off-the-shelf digital cameras.

Satellites are tricky since I've read from an astronomy book that they are only visible late in the afternoon when the sun light could glint off the solar panels.
. . .
No dear, almost all satellites are visible around dawn or dusk. Very few, such as the ISS, are large and therefore much brighter and can be sighted in broad daylight.
 

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