Three members of the Senate Appropriations Committee (SAC) have expressed skepticism over NASA’s decision to scrap its Restore-L satellite-servicing mission.

Restore-L was slated to launch in 2020 to refuel the U.S. Geological Survey’s Landsat-7 Earth-imaging satellite. In December, NASA awarded a $127 million contract to Space Systems Loral (SSL) of Palo Alto, Calif., to build the mission’s spacecraft bus.

But Acting NASA Administrator Robert Lightfoot told the SAC’s Commerce, Justice, Science subcommittee June 29 that his agency has decided to de-fund Restore-L and instead focus on developing servicing-related technologies, which industry could then use to conduct robotic refueling or repair missions of satellites in low Earth orbit.

“We think this is a great opportunity for a public-private partnership to allow commercial folks to take our technologies that we develop and build the systems,” Lightfoot testified at a hearing on his agency’s fiscal year 2018 budget request.

That request contains $48 million for those technologies, including rendezvous and proximity operations sensors and propellant transfer systems.

However, Sen. Joe Manchin (D-W.Va.) said at the hearing that he is not convinced that industry will step in on its own due to the technical hurdles.

“I would respectfully ask you to reconsider” Restore-L’s cancellation, Manchin told Lightfoot.

Sens. Shelley Moore Capito (R-W.Va.) and Chris Van Hollen (D-Md.) both said they need more written information to justify NASA’s decision. Capito asked for details on the extent of industry’s work in satellite servicing, and Van Hollen asked NASA to show how its new approach would be more cost-effective than Restore-L.