NASA’s Artemis II mission hasn’t returned to Earth yet (it will do so Friday night and crash into the Pacific Ocean off the coast of San Diego), but the agency is already getting closer to some key decisions about the next Artemis mission.
The American space agency announced six weeks ago that it was modifying its Artemis schedule to insert a mission before beginning the planned lunar landings. This new mission, called Artemis III and intended to fly in Earth orbit rather than to the Moon, would attempt to “reduce” the risk to give the lunar landing mission (now Artemis IV) a greater chance of success.
NASA Administrator Jared Isaacman said Tuesday afternoon that the space agency is debating which orbit to fly Artemis III in before setting a blueprint, noting that the first discussion on the design of the “higher-level” Artemis III mission had taken place earlier in the day.
Where will it happen?
“One of the questions is what the initial orbit of Artemis III will be,” Isaacman said during a press conference. “Will it be LEO or HEO? There are pros and cons to each of them, for sure.”
Low Earth orbit, or LEO, is designated as a distance of approximately 160 km to 2,000 km above the Earth’s surface. High Earth orbit is considered to be more than 36,000 km from the Earth’s surface, above geosynchronous orbit.
During Artemis III, the Orion spacecraft will launch (presumably with four astronauts) on a Space Launch System rocket from Florida. In Earth orbit, they will encounter one or both of NASA’s human landing systems. It is the upper stage of the Starship vehicle being developed by SpaceX and a modified Blue Moon lander being built by Blue Origin.
A low-Earth orbit rendezvous would potentially allow NASA to fly the SLS rocket without using an interim cryogenic propulsion stage, or ICPS. This is valuable because it could save this last remaining ICPS stage for the Artemis IV mission (for future SLS missions, NASA would use a Centaur V upper stage, also provided by United Launch Alliance). However, for an Artemis III mission into a higher orbit, NASA would need the ICPS to push Orion there.
