Falconsat-7 Features Innovative Telescope Design

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WASHINGTON — Students at the U.S. Air Force Academy are developing a satellite that would demonstrate a revolutionary lightweight telescope design that can be folded into a tiny package for launch and deploy once on orbit.

Slated to launch around 2014, Falconsat-7 is a so-called cubesat whose payload is the Peregrine solar telescope, according to Geoff McHarg, director of the academy’s Space Physics and Atmospheric Research Center. The Peregrine optical camera would use a plastic sheet called a photon sieve to concentrate light on its detectors, he said.

The academy successfully tested the telescope’s deployment system six times Aug. 26 aboard a NASA aircraft that provides brief periods of microgravity by flying a series of parabolas, McHarg said.

One of the tests went perfectly and two others went well, but some tinkering with the hardware was required for the other three, McHarg said during an Aug. 27 interview. Students and their instructors are analyzing what went wrong in those tests, he said.

“You always learn the most actually from the ones that don’t work best,” McHarg said. “We are going to analyze those in detail, find out what went wrong and see if we have to change our design any for the mechanical deployment stuff.”

The Air Force Academy’s Falconsat program provides students an opportunity to design, test and operate small satellites. Falconsat-7 was designed to observe the sun, but the telescope can be used for any number of applications, McHarg said.

The Peregrine telescope, which is only about the size of a coffee cup, is designed to collect imagery at resolutions of 1.8 meters from a distance of 450 kilometers. Resolution generally refers to the size of objects that can be detected by a telescope.

Instead of a traditional optical lens, the Peregrine telescope  utilizes a photon sieve, a thin plastic sheet with millions of tiny holes through which light passes and is focused on detectors. The technology could enable the U.S. Defense Department and others to launch telescopes in much smaller packages than is possible today, thereby saving on launch costs.

A cubesat, for example, is a standard, cube-shaped satellite that measures 10 centimeters on a side. Cubesats typically are launched as secondary payloads aboard rockets carrying larger |satellites.

The Aug. 26 demonstration was funded by the Defense Department’s Space Test Program, a long-running activity used to find rides to space for promising technologies and applications. The Pentagon has marked the Space Test Program for termination next year, but it is unclear whether Congress will go along with that plan.

“I’m very happy that we were as successful as we were,” McHarg said. “It is the first time we have actually done mechanical deployments anywhere other than our laboratory. We were all very excited as a team to have it work out as well as it did.”

The U.S. Defense Advanced Research Projects Agency is providing $1.7 million for the Falconsat-7 mission, McHarg said. Officials received funding for it for the first time this year, he said. The critical design review for Falconsat-7 will take place in November, McHarg said.