Orion Begins The Journey Home

NASA’s Orion spacecraft successfully fired its main engine today to begin the trip back home from the Moon. After six days in a Distant Retrograde Orbit, the uncrewed spacecraft will spend the next week and a half making its way back to Earth with splashdown in the Pacific Ocean on December 11.

The Lockheed Martin-built Orion spacecraft with its ESA-provided European Service Module fired the Orbital Maneuvering System engine for 1 minute and 45 seconds at 4:53:56 pm ET this afternoon. It’s the first of two burns needed to take it out of lunar orbit. The second is on Monday.

The large nozzle of Aerojet Rocketdyne’s OMS engine can be seen in the upper left corner of this image Orion took of itself on flight day 1 using a camera on one of its solar arrays. That engine flew in space 19 times on space shuttle flights.

Orion is part of the Artemis I mission, an uncrewed test flight of Orion and the Space Launch System rocket. They blasted off from Kennedy Space Center on November 16 headed for a Distant Retrograde Orbit around the Moon.

DRO is a very stable orbit that requires little fuel to maintain. The downside is that it’s far from the lunar surface. Future Orion missions will use a highly-elliptical Near Rectilinear Halo Orbit (NRHO) that brings the spacecraft close to the surface every six-and-a-half days. The longer-term plan is to put a small space station, Gateway, in NRHO. Orion will dock there and crews will either stay to conduct research or transfer to landers to go down to and back from the surface.

But this is a test flight to see how the systems perform over the 26-day mission. Orion set a new record on Monday for the furthest a human-capable spacecraft has ever flown — 268,554 miles (432,194 kilometers). Its 16 onboard cameras are sending back spectacular selfies with the Earth and Moon in the background including this one when it was at its most distant point.

A second OMS burn is needed to get Orion out of lunar orbit and on the path home. That Return Powered Flyby will happen on December 5 at 11:43 am ET setting up a splashdown in the Pacific around 12:42 pm ET on December 11.

Orion will come as close as 79.6 miles (128 km) from the lunar surface during that second burn, but it will be on the farside. During the time it’s on the near side passing over the Apollo 12 and Apollo 14 landing sites, it will be about 6,000 miles (9,650 km) high so the imagery may not be very clear.

NASA is delighted with how Artemis I — the SLS rocket and Orion spacecraft — is performing.  Shortly after launch, Artemis I Mission Manager Mike Sarafin called SLS’s performance “eye watering.” At a briefing yesterday he said Orion is “overachieving.” Deputy Chief Flight Director Zebulon Scoville added that “rather than having to work anomalies, we’re able to push the boundaries.”