Academy physics payload conducts experiments in low-Earth orbit

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U.S. AIR FORCE ACADEMY, Colo. --  An Academy physics experiment recently went to work in space aboard a Navy microsatellite. 

The experiment was created by the Space Physics and Atmospheric Research Center, better known as SPARC, in the Academy's Department of Physics. It went into space Aug. 6 aboard the Naval Research Laboratory's Atmospheric Neutral Density Experiment 2, better known as ANDESat. 

ANDESat is actually a pair of satellites and was launched from the Space Shuttle Endeavour during the STS-127 mission. The satellites are named Castor and Pollux and are identical sized spheres with different masses. 

The objective of the mission is to study the satellite orbits and make measurements on the heavier Castor satellite to allow the Department of Defense to better understand how drag from the thin neutral atmosphere effects satellite orbits. 

The payload provided by SPARC is called the Integrated Miniaturized Electrostatic Analyzer, or iMESA. The instrument, which SPARC faculty and cadets built, tested and installed, is designed to measure the effects of the plasma density and temperature on ANDESat. SPARC faculty, along with cadets in the Academy small satellite program and the Academy's ham radio club, hope to serve as a ground station for ANDESat. Both satellites operate in the two meter amateur radio brand. 

The iMESA experiment is a leap forward in data-starved field of space weather data collection, providing greater capability than previous devices of this nature, at a fraction of the size and cost, said SPARC director Dr. Geoff McHarg. Working in an environment with finite capabilities to accommodate mass, power and size, iMESA weighs in at 0.15 kilograms, needs only a half-watt of power and is smaller than most cellular phones. The size, mass and power advantages allow iMESA to easily be deployed on all military and civilian low-Earth orbit spacecraft. 

"We have an iMESA on the International Space Station right now. It comes back in November timeframe, and we replace it with another," Dr. McHarg said. "We also have three iMESAs promised to Naval Research Laboratory as part of a cubesat program. We delivered two iMESAs to the Air Force Research Laboratory for inclusion on the AFRL Plug and Play satellite, but that program's goals changed, and they never launched." 

Having several copies of iMESA on multiple spacecraft allows them to gather more data, and also mitigates the impact if any one spacecraft carrying iMESA were to fail. The Naval Research Laboratory announced Sept. 16 that Pollux stopped operating. According to NRL, the batteries apparently drained. 

For more information on the ANDESat mission, go to https://goby.nrl.navy.mil/ANDE/Main.html.