The MiTEx Mystery: Mobile microsats make nerds nervous

Right now, a pair of mysterious, highly mobile microsatellites dubbed MiTEx are roaming about in geostationary orbit (GEO). Their mission and their capabilities are unknown; even their orbital position is classified. Lockheed Martin and Orbital Sciences each built one of the 225kg microsatellites for DARPA, and the Naval Research Lab built the propulsive upper stage.
Information on the microsatellites themselves is virtually nonexistent. Calls by this office to DARPA were quickly met with no comment, and Space News writer Jeremy Singers inquiries also went unanswered. DARPA has already run the controversial DART and XSS-11 missions, both of which tested technology with anti-satellite applications. Since these missions were conducted largely within the public eye, one has to wonder what MiTEx is up to that must remain so secret.
The MiTEx launch, on June 18, was heralded by a press release touting its upper stage as a technology demonstrator, but this is where the story gets interesting. The upper stage is equipped with lightweight, high-capacity propellant tanks and with thrusters that use a platinum/rhodium alloy, which should be able to fire tens of thousands of times. It has solar panels and lithium-ion batteries to provide electrical power, as well as a star tracker. Compared to traditional upper stages which consist of an unadorned solid-fuel rocket motor - this elaborate contraption of an upper stage is quite novel and is certainly designed to do a lot more than transfer the microsatellites from their transfer orbit to GEO.
But while such a tricked-out upper stage is unusual only one other known upper stage, the Integrated Apogee Boost Subsystem (IABS), has even carried solar panels every one of the individual technologies listed above is in itself tested and well-established. So what exactly are the technologies which this technology demonstrator is demonstrating?
The MiTEx satellites about which no information is available - are freely traversing GEO with a robust upper stage that, based on launch vehicle performance, probably has plenty of fuel to spare for significant maneuvers. What exactly will they be doing in what has become the most economically viable and strategically important locale in space?
That is the million-dollar question. The high level of secrecy surrounding the satellites themselves, as well as the unusual upper stage, suggests that MiTEx might be more than a technology demonstrator. The fact that MiTEx effectively has stealth capability (only the U.S. Space Surveillance Network has a chance of detecting it) doesnt help calm the nerves.
Close proximity operations around other satellites as demonstrated by DART and XSS-11 are certainly possible and would allow for a wide range of activities. For example, proximity operations would enable detailed reconnaissance of a satellite, identifying weaknesses, taking photographs, and collecting all the satellites incoming and outgoing radio traffic. More hostile acts, such as denying ground communications, depleting propellant reserves, and even causing permanent damage to the satellite, cannot be ruled out.
MiTEx could merely be demonstrating technologies that havent been tried before in the harsher GEO environment. Or it could indeed be operational, performing any number of possible clandestine missions. We simply do not know.
More information on MiTEx can be found at the World Security Institute's Center for Defense Information. Ryan Caron is a research assistant for the space security project at the World Security Institutes Center for Defense Information. He studies aerospace engineering at the Worcester Polytechnic Institute.