Spaceflight's Sherpa-ES is a version of its existinh Sherpa tugs with larger propellant tanks to support a lunar flyby mission. Credit: Spaceflight

WASHINGTON — Launch services provider Spaceflight sees a lunar flyby mission opportunity next year as a pathfinder for future opportunities to support customers going to both geostationary orbit and the moon.

Spaceflight announced Sept. 14 that it reached an agreement with Intuitive Machines to fly as a secondary payload on that company’s IM-2 lunar lander mission, launching on a SpaceX Falcon 9 in the fourth quarter of 2022.

The mission will carry a new version of Spaceflight’s Sherpa line of tugs, called Sherpa-ES. It will swing around the moon and return to geostationary orbit, delivering a payload for Orbit Fab, a company developing tankers to support refueling of spacecraft in orbit. The lunar swingby requires about 25% less propellant than a traditional orbit-raising maneuver to GEO and allows the payload to reach GEO in just 15 days.

The Sherpa-ES is based on the Sherpa-LTC, a version of Sherpa with a chemical propulsion system. The biggest change is larger propellant tanks, said Phil Bracken, vice president of engineering at Spaceflight, in an interview. “We’re incrementally building on the design, not throwing the LTC design out the window and building a brand-new thing.”

There are some other changes, such as in communications, where he said Spaceflight will have to use a different set of ground stations to enable communications at lunar distances. “You have to fly this vehicle much more like a rocket stage,” he said, with a midcourse correction and changes in how the vehicle knows its position.

Orbit Fab is the only announced customer for that mission so far, arranged through a new smallsat rideshare company, GeoJump. Bracken said Spaceflight is in discussions with several other potential customers for the mission, including those looking for opportunities to deliver payloads around the moon, with on the order of hundreds of kilograms of capacity available.

“We’ve watched a steady increase in interest” in lunar missions, he said, tied to government lunar exploration activities. Spaceflight hopes to demonstrate with this Sherpa-ES mission that rideshare opportunities should be included in future lunar missions, such as through NASA’s Commercial Lunar Payload Services (CLPS) program, of which IM-2 is one such mission.

“Part of the reason we’re interested in doing this mission is that we believe there’s going to be a future wealth of lunar missions, whether it’s through CLPS from NASA or some other set of private or government missions,” he said. “The intent is to prove that you should put rideshare on these things.”

The agreement with Intuitive Machines only covers the IM-2 mission, which Bracken said was something of an “opportunistic” case to take advantage of the excess capacity on that mission while Spaceflight looks at ways to support customers seeking to go to geostationary orbits and the moon.

“There is a strong future in non-low Earth orbit smallsat missions,” he said. “We’re opening up future orbits for small satellite and private customers that want to go do interesting things.”

Jeff Foust writes about space policy, commercial space, and related topics for SpaceNews. He earned a Ph.D. in planetary sciences from the Massachusetts Institute of Technology and a bachelor’s degree with honors in geophysics and planetary science...