July 1, 2011: The United States launched a cheaper, smaller (about half a ton) spy satellite on June 30th. The ORS-1 is in a 400 kilometer high orbit, circling the world every 90 minutes. The orbit brings it over the Middle East regularly, to provide support for American forces in Afghanistan. Taking only three years to develop and build, ORS-1 is another U.S. Air Force effort to build smaller satellites that can be built and put into orbit faster and cheaper. The ORS-1 was based on the sensor package used in U-2 high-altitude reconnaissance aircraft. ORS-1 was put into orbit using a 40 ton Minotaur rocket (based on a retired ICBM). While the ORS-1 can do much of what the traditional Keyhole spy satellites do, there are differences. The Keyholes weigh and cost 30 times more than the ORS-1, and are over ten times more expensive to put into orbit. But the Keyholes can change orbits, and last about five times longer up there. The Keyholes also have more sensors. But for just basic spy missions, the ORS-1 gets the job done.
For the last six years, the U.S. Air Force has been recycling retired ICBMs as satellite launchers and targets for testing anti-missile systems. So far, the Minotaur Program has used nine converted Minuteman II missiles to launch small (under half a ton) satellites. Converted Peacekeepers are also used for launching anti-missile system targets.
The Minotaur program actually uses the rocket motors from the Minuteman and Peacekeeper missiles, and adds non-military guidance system components and additional stages. A Peacekeeper based Minotaur will be able to put nearly two tons into low orbit. The air force is using Minotaur to develop satellite launch systems that can get birds in orbit quickly. The solid fuel rocket motors of ICBMs makes this possible.
For the last decade, the U.S. Air Force has been developing and launching lightweight (under half a ton) TacSat reconnaissance satellites. The first TacSat 3 went up two years ago, and was providing data to combat commanders in Afghanistan until earlier this year. Troops on the ground could communicate with the TacSat, which provided photo-reconnaissance.
TacSat and ORS-1 are not alone up there. There are a number of lightweight photo satellites in use. Two years before the 109 kg/240 pound TacSat 1 went up, Israel launched the 300 kg/660 pound Ofek-5. While TacSat 1 had only an infrared camera, regular camera, (both low rez) and a radio signals collection package, Ofek-5 had a one meter resolution digital camera, good enough to tell the difference between a tank and a car and spot a group of tanks assembling for attack.
The 400 kg/882 pound TacSat 3 had a wider array of sensors, including a hyperspectral (can detect a large range of light sources) imager, an Ocean Data Telemetry Microsatellite Link and the Space Avionics experiment. TacSat 3 sensors have a four meter resolution, but the ARTEMIS hyperspectral sensor can detect vehicles hidden in forests, as well as buried roadside bombs.