WASHINGTON — A Sherpa tug launched a month ago is still undergoing commissioning and has yet to start maneuvers as its orbit gradually decays.

Spaceflight planned to use a chemical propulsion system on the Sherpa, provided by Benchmark Space Systems, to raise the orbit of the vehicle to an altitude of 1,000 kilometers.

Sherpa-LTC2 is the first of Spaceflight’s line of Sherpa tugs to launch with this high-performance chemical propulsion system.

Another Sherpa vehicle, Sherpa-ES, will carry a chemical propulsion system with high delta-V, or change in velocity, performance, for a mission that will take payloads on a “lunar slingshot” mission around the moon to geostationary orbit in 2023.