WASHINGTON — With an eye toward flying an on-orbit demonstration just a few years from now, the U.S. Defense Advanced Research Projects Agency (DARPA) is preparing a competition for another round of work on an experimental satellite servicing and salvaging project dubbed Phoenix.
The goal of Phoenix is to develop a maneuverable spacecraft equipped with a dexterous robotic arm to salvage useful components from retired communications satellites. For the first demonstration mission, tentatively scheduled for launch in 2015 or 2016 on an as yet unidentified rocket, a Phoenix spacecraft will try to remove an antenna from a satellite in a graveyard orbit and affix it to a so-called satlet: a new type of modular satellite core structure DARPA is developing.
If the salvaged antenna can be switched on by the satlet and transmit a signal to the ground, DARPA will consider the demonstration a success, David Barnhart, DARPA’s Phoenix program manager, said during a Jan. 19 teleconference with the press.
DARPA contractors have been working for six months on some of the technologies needed to pull off the demonstration. Work on additional technology, including spacecraft sensors and ground infrastructure, is the subject of the upcoming competition.
DARPA has scheduled a “proposers day” Feb. 8 at its Arlington, Va., headquarters, Barnhart said. After that meeting, in which DARPA will brief prospective bidders on its requirements, the agency will officially release the Broad Agency Announcement to which prospective contractors must respond.
Barnhart said DARPA wants ideas for sensors that will help the Phoenix spacecraft to navigate various Earth orbits; sensors for close-quarter rendezvous and proximity operations; and data about whether small robotics facilities scattered across the United States might be as capable of reducing expenses associated with testing Phoenix’s appendage as larger, more established test centers.
Barnhart would not say how much funding has been set aside for the work to be done under the Broad Agency Announcement. He did say that DARPA officially began the development phase of the first Phoenix demonstration mission in 2012 and has allocated $180 million over four years for the project.
Phoenix’s goal, Barnhart said, is to offer a dramatically cheaper way to maintain space-based communications capabilities. The U.S. military would be the first beneficiary, but DARPA would also like to see the technology passed on to private satellite operators, Barnhart said.
“The bottom line, without any equivocation, is cost,” Barnhart said.
Based on projections published in a DARPA white paper, salvaging an 18-meter reflector from a satellite in a graveyard orbit — geostationary satellites nearing the end of their service lives are often boosted to a higher orbit so as not to pose a threat to operational craft — and repurposing it for use on a satlet would be about 10 times cheaper than launching a new satellite with the same-sized antenna, Barnhart said.
DARPA has yet to identify which retired satellite Phoenix will target for its first demonstration mission. In a request for information that closed back in July, the agency invited commercial satellite operators to provide information on retired satellites that might make good candidates. Barnhart said DARPA, using NASA databases, has identified about 140 satellites with working antennas that would be good choices for the first Phoenix demonstration.
Phoenix contractors include aerospace giants and garage-based startups. Those identified so far are:
- Aerospace Group of Beltsville, Md., which is providing the spacecraft bus for the Phoenix tender craft.
- MDA Information Systems of Pasadena, Calif., which is designing the spacecraft’s servicing arm.
- Altius Space Machines, Louisville, Colo., which is building an extendable boom for the servicing spacecraft.
- General Corp. of Washington, which is studying options for a carrier pod that would ride to space as a hosted payload, then separate from its host and eject a cache of satlets to be picked up later by the Phoenix spacecraft.
- NovaWurks, which is developing the satlets.
- NASA’s Jet Propulsion Laboratory, Pasadena, which is providing an adhesive called “Gecko-Gripper.”
- Satellite manufacturer of Palo Alto, Calif., which is studying the logistics of transporting satlets to geostationary orbit as commercially hosted payloads.
Those contractors responsible for hardware have all built at least engineering models, Barnhart said. It is still not clear when the various parts of the first Phoenix tender craft will be delivered for final assembly. It is known, via public procurement notices, that the ATK-built bus for the Phoenix spacecraft is to be delivered to DARPA in October 2014.