[Via Satellite 06-02-2015] The United States Defense Advanced Research Projects Agency (DARPA) has revamped its Phoenix satellite program for a geostationary satellite-servicing vehicle, changing the goals of the initial mission and future potential missions to better align with the needs of the U.S. Air Force. The agency is now planning a demonstration launch of a robotic servicing vehicle in the 2020 time frame, plus or minus one year, and will seek to commercialize the vehicle through a commercial operator. According to Gordon Roesler, program manager at DARPA’s Tactical Technology Office, the Air Force was not overly enthusiastic with DARPA’s previously proposed mission, so the agency took two major steps to turn the program around about a year ago, changing the inaugural mission and the goals of the vehicle to better support the U.S. Department of Defense (DOD).
“The first was to shift the focus from a demonstration on a decommissioned object to being able to work on operational spacecraft, to do things that are of value for both commercial and military. The second was to select some missions that had economic and resiliency value: inspection, repositioning and correction of deployment. Not only would those have value to the taxpayer if we did them for military spacecraft, but they could represent an income stream for a commercial operator of the robot,” Roesler told Via Satellite. “This increases the affordability for the military because then instead of having to own and operate this robotic servicer, they could just pay a commercial operator for the service. All of those things together have turned this around and we now have a great deal of interest in this program.”
The new mission would start with an initial six to nine month demonstration to prove the vehicle can work safely around a satellite, and then will move on to actively service and repair other spacecraft. Roesler said the vehicle would have enough propellant to conduct multiple missions over the course of an eight-year lifetime.
DARPA has worked extensively on the Phoenix program robotic servicer, drawing from more than a decade of background that stretches back to the Spacecraft for the Unmanned Modification of Orbits (SUMO) and the Front End Robotic Enabling Near-Term Demonstration (FREND) missions. The agency has also partnered with commercial companies on building hardware and software for in-space robotics. Now DARPA is actively contemplating greater commercial input on how to use the vehicle, which would service both commercial and military satellites. Roesler said there are approximately 10 times as many commercial spacecraft in Geostationary Earth Orbit (GEO) than there are military, which heavily influenced DARPA’s goal of placing the robotic servicer in the hands of a commercial entity.
“We are considering a national space robotics partnership, a consortium if you will, with multiple members from U.S. satellite industry and also multiple government entities, all focused on building and operating this first robotic servicer. The consortium, in addition to owning and operating the servicer, would also have the function of asking ‘what are the safety standards, what are the operational standards, when do we have to communicate, what kind of redundancies, what kind of automation do we need?’”
The first missions that the Phoenix program robotic servicer would conduct are repairs, such as fixing a satellite component that failed to deploy or changing an antenna pattern. Roesler said DARPA’s medium term goal is to perform upgrades on orbit, and long-term is the construction of satellite hardware on orbit.
“I don’t think of it as just a demonstration mission. It is a prototype … but we really want it to do real servicing, real inspection and real repositioning missions. They do have a demonstration quality to them but they also have a real economic value,” he said.
Roesler added that the demonstration would help show how to conduct servicing missions efficiently. DARPA does not want missions to take arduous amounts of planning time, which would limit the number of missions that could be done in a year. He said the goal is to plan and execute a mission within a couple of weeks.
“Any one of these missions would start by establishing cooperative communications with the operators of the client satellite. The next thing to do is a fly around to build a full 3-D model of the client spacecraft. Yes, of course we’d have the manufacturer’s prints, but we want to establish our own model that helps us avoid collisions (especially if the client spacecraft has experienced a deployment anomaly) and also helps us to plan the rest of the mission,” he said.
From the FREND program, DARPA has a robotic arm measuring about 2.5 meters long that can attach to another satellite, holding it in place for repair or relocation along the GEO-arc. Roesler described the arm as a “Swiss army knife in space,” because it can switch tools, enabling a variety of different functions.
DARPA has also vetted many of the technological challenges associated with operating in space. Among them, situational awareness was a top concern — leading to cameras on the servicer’s arms — and making sure the quality of parts was durable enough for the environment. Roesler said DARPA has put to rest concerns that were only barely hyperbolic about “giant lightning bolts” arcing from one spacecraft to another due to differences in the buildup of static electricity. The agency tested a technique in a space environment chamber to make sure this does not occur when the spacecraft are in close proximity to each other.
Roesler said the agency also wants to find partners outside of the U.S. interested in servicing so that standards could become international. DARPA is eager to see the Phoenix program mature into a commercially viable asset that both defense and the commercial sector can benefit from. Ultimately, the DOD would become one of many customers of a company with ownership of the robotic servicer.
“If this servicer is owned by a commercial company and the government wants to upgrade or service one of its satellites, really it’s just a fee for service arrangement,” he said. “The Federal Acquisition Regulations (FAR) have provisions for that in them. Even servicing the government satellites represents a commercial opportunity.”