A high-Earth orbit propellant depot will be launched as part of a SpaceX Falcon 9 launch that will send a commercial Moon lander on its way to the Earth’s nearest neighbor. As part of the launch, rideshare organizer Spaceflight Inc and propellant depot startup OrbitFab have revealed plans for the world’s first high-Earth orbit propellant depot.
Technically known as “Tanker-002,” the co-developed spacecraft will be the first fuel store in space, serving as a basically in-space gas station, when it reaches a geostationary orbit 36,000 kilometers (22,300 miles) above the Earth’s surface. OrbitFab’s unique GEO depot will be built around a variant of Spaceflight’s brand new Sherpa OTV space tug vehicles. While the company hasn’t disclosed the planned capacity of its unique GEO depot, the public specifications of Sherpa suggest that the company will be able to deliver a few hundred kilograms (300-800 lb) of hydrazine that will be accessible through a series of small docking ports.
Tanker-002 is not only fascinating because of its one-of-a-kind location as a tanker in GEO, but it is also intriguing for other reasons. The engineering and trajectory design feats that Spaceflight and OrbitFab will do to bring the tiny spacecraft into position will be impressive in and of itself.
We're excited to soon launch the first propellant tanker to geostationary orbit!
— Orbit Fab (@OrbitFab) September 27, 2021
Spaceflight plans to co-manifest Tanker-002 on Intuitive Machines’ IM-2 lunar lander, which is planned to fly on a SpaceX Falcon 9 rocket no sooner than (NET) late 2022 or early 2023, according to a press release. Spaceflight’s Sherpa-ES tug and Tanker-002 cargo ship will initially piggyback on the IM-2 lander’s launch into orbit, but will swiftly separate approximately four hours after liftoff. As an alternative to preparing to enter orbit around the Moon, Sherpa-ES will conduct a short burn, altering its trajectory to include a lunar flyby as well as a gravity assist maneuver.
That slingshot around the Moon will enable Sherpa-ES and Tanker-002 to reach a circular geostationary orbit much more effectively and in just a few weeks after launch, according to a first-of-its-kind trajectory designed by company GeoJump. The IM-2 lander, on the other hand, would most likely enter lunar orbit and begin a slow fall until it is ready to land — perhaps around the same time as Tanker-002 arrives in geosynchronous orbit.
Above all else, OrbitFab’s Tanker-002 depot serves as a full-fidelity proof of concept for the company’s Tanker series. The tanker (like it did with Tanker-001) will be launched before any potential clients for its propellant exist in an attempt to overcome the chicken-and-egg problem of commercial orbital propellant depots (which comes first: the refuelable spacecraft or the fuel source?). That implies that even when it reaches Geostationary Earth Orbit, there are no current spacecraft that can be refueled using it. Tanker-002 is expected to be tiny enough to refuel a class of geostationary small satellites that are a source of continuous research and development but are only marginally present in the current day, according to the information available.
OrbitFab, which has received attention and limited financing from firms like as Northrop Grumman and Lockheed Martin, will hopefully see the fruits of its “build it and they will come” leap of faith in the coming years.