NASA’s Artemis program has been navigating a period of significant restructuring, with Administrator Jared Isaacman recently announcing changes designed to accelerate the pace of lunar missions and refocus priorities toward surface operations. Now, a technical question is moving to the center of that planning: where, exactly, will the lunar landers meet the Orion spacecraft?
The Orbit Problem Nobody Was Talking About
The original plan called for landers to rendezvous with Orion at the Near-Rectilinear Halo Orbit, or NRHO — an elliptical orbit reaching as close as 3,000 km from the lunar surface and as far as 70,000 km out. That orbit was chosen because it would also host the Lunar Gateway space station. With Gateway now likely to be canceled, the rationale for NRHO weakens considerably. The orbit also imposed an energy penalty on landers, requiring them to expend more propellant stopping there before descending to the surface.
The obvious alternative — low-lunar orbit, the approach used during Apollo — is not available to Orion. According to the report, the Orion service module, developed by Lockheed Martin with a European service module supplied by Airbus, lacks the propulsive performance to reach low-lunar orbit and still return safely to Earth. That limitation is the direct result of decisions made over the past 15 years of the program’s development.
A middle path has emerged from a 2022 research paper by NASA engineers at Johnson Space Center. Published in July of that year, the paper analyzed multiple circular and elliptical orbits compatible with Orion’s existing capabilities. One candidate orbit stands out: the Elliptical Polar Orbit with Coplanar Line of Apsides, referred to as EPO/CoLA. Its closest approach to the Moon sits at just 1,000 km — significantly nearer than the NRHO’s closest point — which reduces the propellant burden on landers making the trip down to the surface and back up.
Reducing the Friction Between Partners
NASA has contracted both SpaceX and Blue Origin to develop human landing systems — Starship and Blue Moon MK2, respectively. Docking either vehicle with Orion is not a simple handshake. Every decision point in the process requires sign-off from the lander company, NASA, Lockheed Martin, and Airbus. Engineers have also spent considerable time managing Orion’s sensitive elements — thruster plumes, cabin pressure compatibility — all of which compound the coordination challenge.
Isaacman’s stated approach is direct. After meeting with engineers from both companies on January 13, he said the agency would “challenge every requirement, clear every obstacle, delete every blocker and empower the team to deliver… and we will do it with time to spare.” Shifting away from the NRHO requirement is one concrete expression of that approach, removing a logistical and energetic burden from the lander developers without requiring changes to the Orion vehicle itself.
The timeline the administrator has described calls for an Artemis III launch next year — used to test one or both landers near Earth — followed by one or possibly two lunar landings in 2028. The next step, according to the announcement, is for SpaceX and Blue Origin to accelerate their development programs under the looser operational framework NASA is working to establish.
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