Tracking MiTEx 1

MiTEx 1, 18 May 2015 (click to enlarge)

Over the years, the USA has been experimenting with satellites intended for close-range inspection of other satellites at geostationary altitudes.

The first one was the highly secret Prowler (1990-097E), clandestinely launched on Space Shuttle mission STS-38 in 1990. Two other ones were launched less covertly, though their orbits were and are classified: the experimental MiTEx satellites, MiTEx 1 and MiTEx 2 (2006-024A and B), brainchilds of DARPA, launched from Cape Canaveral in June 2006.

Speculation on the reason for their development can be found here. What we do know is that early 2009, two-and-a-half years after their launch, both MiTEx satellites were used to inspect the malfunctioned DSP-23 satellite. This was actually observed by amateur trackers Greg Roberts and Peter Wakelin.

MiTEx is an acronym that stands for Micro-satellite Technology Experiment.They are small objects, each weighing about 225 kg. While some sources (similar statements also here) have tauted that "ground-based detection via visual observation or radar is extremely difficult if not impossible" for these small objects at such a large distance, matter of fact is that amateurs (including me) actually track these objects, albeit infrequently.

The image in the top of this post shows MiTEx 1 (2006-024A) imaged on May 18, 2015, using the 0.51-m telescope of Warrumbungle Obs. in Australia. The satellite was at a low sky elevation.

I also imaged it two days earlier, on May 16, and captured it briefly flaring at that time (the trail is leaving the FOV of the CCD camera at left in this image):

MiTEx 1 is currently located in a disposal orbit at an orbital altitude just above that of operational geostationary satellites. It is drifting Westwards at a rate of about 5-6 degrees per day. During my May 16 and May 18 observations, it was moving westwards over the mid-Pacific south of Hawaii, as shown on the map below. The map also shows the drift path over the next two weeks, until the satellite's approximate position for June 1. The "wobble" in the path is the daily analema it makes due to the slight inclination of its orbit. Footprint shown is for May 18.

(click map to enlarge)

Where the MiTEx 1 sistership  MiTEx 2 (2006-024B) currently is, is less certain: my attempts to recover it near its expected position on May 16 and May 18 based on a 20-day old elset failed so far.

Imaging MiTEx 2

In 2006, the USA launched two experimental geosynchronous satellites, MiTEx 1 and MiTEx 2 (2006-024A and 2006-024B). MiTEx is an acronym that stands for Micro-satellite Technology Experiment. These small satellites were reportedly a technology demonstration and a project of DARPA, the US Air Force and US Navy. Being small (225 kg each) and hence difficult to detect, they explored the possibility of covertly sneaking up on and inspecting other satellites. In this sense, they appear to be part of the Prowler legacy.

In 2009, both the MiTEx satellites were used to inspect the classified US military DSP-23 satellite which had malfunctioned on-orbit in 2008 and had started to drift, physically endangering other satellites and interfering with their radio communications. This inspection was actually observed by amateur trackers in the UK and South Africa.

click image to enlarge

Since both satellites are small, they are faint and difficult to image. It requires large instruments. On 11 August 2012, I imaged MiTEx 2 using the 61-cm telescope of Sierra Stars Observatory. It is the faint trail in the image above (which is a 30-second CCD exposure guided on the stars).

This is not the first time though that I have imaged one of the MiTEx-es  (for example, the image of MiTEx 1 here, which happens to be the last positive observation before we lost that object, perhaps due to a manoeuvre: in fact, it was already slightly off its predicted position that March 15).