Boeing is preparing to demonstrate a high-power and lightweight solar electric array developed under Darpa’s FAST (Fast Access Space Testbed) program which it says could offer unprecedented power density for future space vehicles.
Delivering up to six times the power capability per cubic inch volume than current power systems, the array consists of a louvered set of solar electric array elements that can be packaged in relatively small fairings for launch. “They look like a mini-blind” says Boeing Advanced Space Exploration director Steve Johnston. When fully deployed the “wings” extend to 23.1m on either side of the vehicle. Each wing is 2.25m in ‘chord’ and can generate up to 30kWe.
The modular concept means the wings can be scaled-up and several can be used at once. Boeing designs include configurations with up to six wings in tandem to produce up to 180 kWe, as well as double-sized versions producing up to 720 kWe. The system could eventually generate powers up to 1 mW says Johnston.
The concept could be applied to a variety of potential applications ranging from tactical response spacecraft and commercial vehicles, to self-deploying spacecraft which will travel from low earth orbit to geostationary orbit using power from the array. Boeing also believes the system would provide adequate power for in-space transfer uses such as missions to Mars as well as deeper-space exploration missions.
A sea of sails? A Mars-mission could use many solar arrays - as in this Boeing concept. (Guy Norris)
The ground test, set for September, is funded under Phase 2 of the Darpa FAST effort and could lead to an offerable system. “Any follow-on will depend on the size and scope of the vehicle to be flown, but it could be ready within three years or so. We could be ready to perform an operational demonstration (within the same time period),” he adds.
Although sized to fit in the 5m fairing of a SpaceX Falcon 1E, it could be launched first in an Orbital Sciences Minotaur or other vehicles, says Johnston. “It depends on who will take if to a flight demo,” he adds.