On 23 October 2026, NASA announced work with United Launch Alliance on an “extended” Centaur V upper stage that, paired with the Space Launch System core stage, could deliver Orion to low-lunar orbit. NASA’s published concept currently depicts Orion docking with Blue Origin’s Blue Moon lander in an elliptical orbit approximately 8,500 kilometres above the lunar surface, while NASA is also studying docking in low lunar orbit.
A low orbit a few hundred kilometres above the Moon would substantially reduce Blue Moon’s propellant requirements for descent and ascent, potentially freeing mass for cargo, shielding, redundancy, or life-support hardware. It would also provide more frequent and faster crew-return opportunities during a surface emergency. The change addresses long-standing propulsion and spacecraft-integration gaps that NASA previously mitigated through the Lunar Gateway’s near-rectilinear halo orbit, but it introduces new requirements for the extended Centaur, Orion, navigation, docking, and integrated mission safety.
The Ark team should track the extended Centaur V design, Orion low-lunar-orbit demonstrations, Blue Moon performance margins, and NASA’s decision between approximately 8,500-kilometre elliptical docking and low-orbit operations. Ark habitat studies should model the recovered lander mass as additional radiation protection, consumables, spare systems, and emergency ascent capability, while treating launch-vehicle integration and multi-vehicle rendezvous as critical single-point programme risks.