The Orion spacecraft made its first close flyby of the Moon on Monday 21 November, coming as close as 81 statute miles (130 kilometers) from the lunar surface.
As the Artemis 1 mission’s uncrewed spacecraft flew past the far side of the Moon, Orion’s orbital maneuvering system engine fired for 2 minutes and 30 seconds to successfully put the capsule into the desired orbit for the mission, called a distant retrograde orbit around the Moon.
“This burn is setting Orion up to orbit the Moon, and is largest propulsive event so far, as Artemis is hunting the Moon,” said Mike Sarafin, Artemis Mission Manager at a briefing on Monday.
The engine burn, called an outbound powered flyby burn, is the first of two maneuvers required to enter the so-called distant retrograde orbit around the Moon.
The next burn comes on Friday 25 November, using the engines on the European Service Module. Orion will remain in this orbit for about a week to test spacecraft systems.
The distant retrograde will take Orion 40,000 miles past the Moon. Orion’s greatest distance from the Earth will be Monday 28 November at 3:05 p.m. CST (0905 UTC) at more than 268,500 miles.
Orion’s greatest distance from the Moon will be on Friday 25 November at 3:53 p.m. CST (2153 UTC) at more than 57,250 miles. This is the farthest any human-rated spacecraft has flown beyond the Moon.
Here’s a good depiction of Orion’s unusual orbit throughout the mission:
I’ve never come close to understanding orbital mechanics
What a fascinating trip home for Orion
— Chris Combs (@DrChrisCombs) November 22, 2022
Sarafin said the mission teams has had a chance to review the performance of the SLS rocket, the spacecraft and the ground systems for the Artemis I mission.
The results, he said, were “eye watering,” meaning everything has met or exceeded expectations.
“We haven’t seen a single thing on the rocket or spacecraft that would cause us to question any portion of the mission,” Sarafin said.
“This is largely a greenlight flight. The vehicle systems are very clean, but we are working a few ‘funnies’ – nothing that puts any constraints on the mission, just that some things were operating differently than expected. Overall, the mission continues to proceed as planned.”
During the flyby, cameras on board the spacecraft sent back stunning imagery of the Moon, with Earth in the distant background.
Earthset. 🌎@NASA_Orion captured this shot of Earth “setting” while the spacecraft passed close to the Moon. Nearly 270,000 miles (430,000 km) away, #Artemis I will soon surpass Apollo 13’s record-setting distance from Earth in a spacecraft designed to carry astronauts. pic.twitter.com/lvDS7nGPRo
— NASA (@NASA) November 21, 2022
“An Earthrise of our pale blue dot and its 8 billion human inhabitants now coming into view,” Mission Control commentator Sandra Jones said on NASA TV as footage was received from Orion.
“We didn’t expect to get live-stream video like we did,” said Judd Frieling, the Ascent and Entry Flight Director for Artemis 1, “but as part of testing the system, we were seeing how far we can press the bandwidth limitations. From this point forward, when we have the bandwidth available, we will broadcast the livestream from the mission.”
The Artemis 1 flight launched on November 16 and is the first mission in 50 years where a human-capable spacecraft is at the Moon. NASA hopes to use Orion, SLS, and other yet-to-be-built hardware, such as a Moon lander built by SpaceX – to send astronauts back to the lunar surface.
That first lunar landing could launch as soon as 2025. Artemis 1 is testing out much of the technology that will be needed for future flights.
Frieling also said Orion will be flying past the Moon again on December 5, and the lighting should be good enough for the cameras on Orion to capture imagery of the Apollo landing sites.
While an exciting proposition, don’t expect to see good views of the hardware left behind. Orion won’t be as close as the Lunar Reconnaissance Orbiter – which has already taken high-resolution views of the Apollo sites – nor are Orion’s cameras as good as LRO’s.
Orion will return to Earth about 25 days after launch, and splashdown of Orion is currently slated for December 11.
Using the cameras on the European Service Module’s solar arrays, engineers have been able to assess the exterior of Orion and have deemed it to be in great shape. Therefore, Orion has already been cleared for re-entry.
Sarafin said that on December 5, teams will meet to decide when and where to deploy the recovery forces, a joint effort between the US Navy and NASA.
The recovery zone will be in the Pacific Ocean, but the exact landing site will be decided based on a whole host of factors, most importantly the weather.