NASA Artemis I – Flight Day 21: Orion Spacecraft Leaves Lunar Sphere of Influence, Heads for Home
On Flight Day 21 of the Artemis I mission, Orion exited the lunar sphere of gravitational influence. It occurred at 1:29 a.m. CST on Tuesday, December 6, marked the last time this will happen on the Artemis I mission. This was less than a day after completing the return powered flyby burn that put the spacecraft on course for splashdown Sunday, December 11. Earth’s force of gravity is now the primary gravitational force acting on the spacecraft.
Orion successfully performed the fourth return trajectory correction burn at 4:43 a.m. using the reaction control system thrusters. The burn lasted 5.7 seconds and changed the velocity of the spacecraft by 0.6 feet per second.
Flight controllers used Orion’s cameras to inspect the crew module thermal protection system and European Service Module, the second of three planned external spacecraft inspections. Teams conducted this survey early in the mission to provide detailed images of the spacecraft’s external surfaces after it had flown through the portion of Earth’s orbit containing the majority of space debris, and teams reported no concerns after reviewing the imagery. This second inspection during the return phase is being used to assess the overall condition of the spacecraft several days before re-entry.
During both inspections, the Integrated Communications Officer, or INCO, commanded cameras on the four solar array wings to take a series of still images. Engineers and flight controllers at NASA’s Johnson Space Center in Houston will review the imagery over the coming days. A final photographic survey will be conducted Friday as Orion continues its journey home.
Teams responsible for recovering Orion after its splashdown are continuing preparations ahead of the December 11 splashdown off the coast of California. The mission management team will determine the landing site location Thursday, December 8. Listen to NASA’s Artemis I recovery director, Melissa Jones, talk about what it takes to fetch the Orion spacecraft from the Pacific Ocean at the end of the mission on “Houston We Have a Podcast.”
Just after 5:30 p.m. on December 6, Orion was traveling 244,000 miles (393,000 km) from Earth and about 79,000 miles (127,000 lkm) from the Moon, cruising at 500 miles per hour (800 km per hour).