August 20, 2012
Credit: Credit: Frank Morring, Jr.
Frank Morring, Jr. Logan, Utah
Tight budgets and small satellites are turning out to be an attractive mix, driving industrial and academic efforts to make tiny spacecraft more attractive to customers with deeper pockets than the penurious graduate students and innovative professors who pioneered the move down the size and mass scales.
Presentations at the American Institute of Aeronautics and Astronautics/Utah State University Conference on Small Satellites here show that entrepreneurs and established companies are starting to address the limitations posed by the cubesat standard to drive more capability into the 10 X 10 X 10-cm (3.9 X 3.9 X 3.9-in.) boxes originally developed as teaching tools for engineering students. And cubesats are growing beyond the three-unit, or U, limit imposed by the Poly-PicoSatellite Orbital Deployer (P-POD) dispenser they typically ride to orbit.
“The idea of 6U gives you a little more room, a little more payload space, and a little bit more room for avionics and things like that,” says James P. Marshall, director of business development at the Space Dynamics Laboratory here, which has developed operational cubesats and other small spacecraft and boasts what may be the only cubesat qualification lab in the world. “I've always guessed that we would all find the cubesat form-factor to be too constraining, and that we would all miniaturize a bunch of stuff and then get to the point of diminishing returns,” Marshall says.
Among the hardware on display here was a 6U dispenser under development by Planetary Systems of Silver Springs, Md., “in collaboration” with the Pentagon's Office of Responsive Space (ORS), according to company founder Walter Holemans. The ORS interest in cubesats as a way to meet its military mission is one of the factors shaping the direction the industry is taking, and for the second year in a row the organization held a classified workshop to discuss its requirements with industry representatives who are cleared to learn them and potentially able to meet them.
While the largest aerospace companies were represented here, some of the most promising work was presented by small startups such as Planetary Systems, which is building on its niche in mechanical separation mechanisms with the cubesat-dispenser work. Vulcan Wireless Inc. of Carlsbad, Calif., displayed a family of software-defined radios built to fit into the cubesat form that can meet some military communications requirements.
“The small satellites are starting to get more capability, so the military's starting to look at these platforms as a kind of stop-gap measure, low-cost, rapid-deployment,” says Kevin Lynaugh, president and CEO of Vulcan. “So you need to start looking into more sophisticated communications that's more applicable to military solutions and, to some extent, commercial. And those waveforms are quite a bit more sophisticated than ham radio analog modulation.”
Most cubesats flying today use amateur-radio frequencies to communicate with the ground, a simple approach in keeping with the low-cost origins of the satellite class. But just as military applications may require larger buses to accommodate optical and other specialized payloads, they also require higher data rates and encryption capability unavailable in the ham frequencies.