WASHINGTON — A robotic arm developed by the Defense Advanced Research Projects Agency has completed key tests and is on track to be integrated with a Northrop Grumman spacecraft next year and launch to geosynchronous Earth orbit in 2024, the agency said Nov. 8.

“The program anticipates on-orbit satellite servicing activities will begin in 2025,” DARPA said in a news release. 

Meeting that goal would mark a major victory for DARPA’s Robotic Servicing of Geosynchronous Satellites (RSGS), a program the agency started in 2017 building on a decade of research and lessons from a 2007 experiment.

DARPA wanted to take advantage of emerging commercial space technology to be able to inspect and repair aging satellites in GEO. “Currently, no options exist for visual diagnosis, upgrades, or repairs of a malfunctioning satellite’s components,” the agency said. 

The plan was to team up with a commercial satellite provider that would build the spacecraft to carry the payload. DARPA 2017 selected SSL as its commercial partner. But in 2019 SSL’s parent company Maxar Technologies bowed out of the partnership for financial reasons. DARPA solicited new bids and in 2020 selected Northrop Grumman’s subsidiary SpaceLogistics as its partner. 

The platform for the RSGS payload is SpaceLogistics’ Mission Robotic Vehicle, a 3,000-kilogram spacecraft. DARPA completed testing of robotic payload elements, not the entire spacecraft. 

Still to be completed is testing of the flight robotic hardware and software. Integration of the robotic payload with the spacecraft bus will begin in 2023, followed by testing and verification of the combined system. 

After launch in 2024, the vehicle will use its electric propulsion to climb to GEO. 

“We are seeking to create a persistent operational dexterous robotic capability in geosynchronous Earth orbit,” said Ana Saplan, DARPA’s RSGS program manager. The robotic arm was designed by the U.S. Naval Research Laboratory with DARPA funding.

“Instead of relegating satellites to space junk because of a broken part or lack of propellant, our robot mechanic will be making repair ‘service calls’ in space,” Saplan said.

The hardware that DARPA will provide to SpaceLogistics includes two robotic arms, multiple robotic tools, on-orbit checkout and calibration equipment, equipment stowage ports, cameras and lighting, and avionics boxes.

DARPA said the first assembled arm has successfully completed functional, vibration and electromagnetic testing, and is preparing to begin thermal vacuum testing. The second arm is completing integration and will begin environmental testing this fall at NRL.

SpaceLogistics announced earlier this year that its first customer for the Mission Robotic Vehicle is Optus, Australia’s largest satellite operator. The plan is to install propulsion jet packs that would  extend the service life of a 2,000 kilogram satellite by six years. 

The MRV and three propulsion jet packs — known as Mission Extension Pods — are being assembled at Northrop Grumman’s facility in Dulles, Virginia. Three pods will launch in 2024 with the MRV — one will be installed on an Optus satellite and the other two are for other customers that have not yet been announced.

Sandra Erwin writes about military space programs, policy, technology and the industry that supports this sector. She has covered the military, the Pentagon, Congress and the defense industry for nearly two decades as editor of NDIA’s National Defense...