A fractionated satellite concept that replaces large satellites with clusters of wirelessly-linked modular spacecraft flying in loose formation has the potential to drive cultural change and reinvigorate a "mature" U.S. space industry, proponents say.

Design work is starting on phase 2 of the Defense Advanced Research Projects Agency's (DARPA) System F6 program to demonstrate a satellite architecture based on fractionated modules. The work, being undertaken by Orbital Sciences, will lead to a planned flight demonstration in 2013, says DARPA tactical technology office program manager Paul Eremenko. "We just passed preliminary design review and are about to embark on detailed design, with critical design review about a year from now," he says.

However the ramifications of the concept, which divides responsibility for various satellite functions between modules, could be as far-reaching to the industry on the ground as it might be to methods for operating in space, supporters say. "It could potentially revolutionize the entire way we operate and build spacecraft," DARPA program manager Owen Brown says.

Fractionating satellites may even drive a grass-roots revival throughout the U.S. industry which could be viewed as otherwise drifting into relative stagnation, according to Pierre Chao, managing partner of Renaissance Strategic Advisors. Fractionating offers "the intriguing possibility of re-establishing multiple parts of competition, and developing a broader industrial base," he says. The effect would "work its way down the whole food chain," he says.

The concept has its critics and faces tough technical challenges, Brown acknowledges. "This violates the fundamental tenets of space engineering. You're not minimizing mass, and that's the real hang-up for many. But we find these systems provide more value at a lower cost. It also deals with uncertainty, and that's the real essence of fractionating. It acknowledges uncertainty and provides flexibility to cope with it."

Development of myriad small modules could also drive a new wave of growth in the launch business, according to Chao, who spoke at the American Institute of Aeronautics and Astronautics Space 2009 conference in Pasadena, Calif. "We haven't worked out what is the chicken and what is the egg yet. The Orville and Wilbur Wrights of the 21st century are in the launch industry."

Phase 2 includes detail design of the spacecraft modules and ground station, a hardware-in-the-loop ground demonstration, a developer's kit for third-party design of fractionated modules, and a plan to flight-test the concept.

"We want to promulgate this as a way of doing things," Eremenko says. "It's a way of life, not a ‘thing.' We want to be able to take any monolith and upgrade and sustain it on-orbit. That requires an open set of interfaces, standards and operating source software." Algorithms will also be developed to command the modules to scatter if threatened, and to later regroup in space.

Photo: USAF