Simplifying Hardware To Liberate Satellite Users

By Michael Mecham
Source: Aviation Week & Space Technology

Despite the existence of Pumpkin and others like it, customers still need to know what they are doing. They must source their own control software, antennas (EDNS uses hardware-store retractable tape measures) and source cells.

Pumpkin is geared to producing large numbers of the same design, so government agencies such as Ames, JPL and the National Reconnaissance Office (NRO), and prime contractors of the likes of Boeing and Northrop Grumman are its natural customer base. A contract for 12 3U cubesats from the NRO in 2007 provided Pumpkin's big push. Called Colony 1, the order is intended to seed innovation by providing institutional design teams with basic hardware. Users, such as the University of Southern California, take it from there. The NRO's Colony 1 Aeneas mission is an experiment for the Homeland Security Department to track cargo containers over open oceans by interrogating a 1-watt Wi-Fi-like transceiver on the container.

Ames also is using an approach of combining modular units in a Common Bus to simplify satellite manufacturing on a bigger scale. The first application, the $263 million Lunar Atmosphere and Dust Environment Explorer (Ladee), is set for launch on a Minotaur V in late August or early September. Other proposals are not yet funded but illustrate the design's flexibility: an asteroid mission and a lunar robotic lander for the Google Lunar X-Prize competition.

While not in the cubesat you-build-it mode, the Common Bus draws on the same philosophy to reduce costs, says Project Manager Butler Hine. Its stackable modules are made lighter and stronger by being comprised of carbon composite formed into a single monocoque octagonal blank with titanium frame inserts that have no ribs. Stress points are reinforced with added plies, and common bolt patterns on top and bottom allow for easy stacking.

Ladee's top two modules carry the instruments—a laser communications experiment, neutral mass spectrometer, ultraviolet/visible spectrometer and lunar dust experiment—and satellite avionics and communications equipment, while the bottom units contain the propulsion system. The body has fixed solar panels, giving it a single safe mode, and its reaction wheels and reaction thrusters are off-the-shelf commercial satellite hardware.

Ames leads NASA's small satellite programs largely because its director, Pete Worden, is an evangelist for their cause. Besides the promise of simplified design and reduced mission costs, his broader vision is that they will become disruptive technologies. The obvious analogy is to the smartphone and Internet. Their ubiquitous presence has created a web of interconnected electronics that beg users to create applications, regardless of whether they understand the hardware behind them. But for such an idea to work in space, satellites need to be cheap enough that a failure would not stop the innovation clock for a decade.

Ames will launch 22 satellites this year, most as cubesats ejected from the space station. Others, weighing in at 20 kg. (44 lb.), are engineering efforts relying on off-the-shelf avionics and costing less than $1 million. “For a few million bucks, you can do really cool stuff in space,” Worden says.

But the real revolution will come from what is done on the ground, although how it will be done is not yet clear. “The secret sauce of Silicon Valley is ferment,” Worden says. “What I really want to do is have one kid in her garage who says, 'I have an idea and I'm going to write an app.'”

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