Science|NASA Spacecraft Finishes Its Close Encounter With the Moon
NASA’s Orion spacecraft zipped past the moon’s far side on Monday, passing within 81 miles of the surface.
The spacecraft, which has no humans on board, has been traveling toward the moon since Wednesday, when it launched as part of the Artemis I mission. Its journey will last 20 more days.
“The vehicle continues to operate exceptionally,” Howard Hu, the Orion program manager at NASA, said during a news conference on Monday evening.
One of the mission’s main purposes is to verify that the Orion spacecraft works as designed, and to allow NASA to make any necessary adjustments and fixes before astronauts board for the Artemis II mission, which will not take off until at least 2024. The third Artemis mission, involving the Orion spacecraft as well as a SpaceX vehicle, will aim to land astronauts on the moon’s surface.
A few minutes before Orion’s closest pass with the moon on Monday, the capsule fired its engine for 2.5 minutes. That accelerated its velocity as the spacecraft swung outward toward what is known as a distant retrograde orbit.
The orbit is distant — 40,000 miles above the lunar surface; retrograde means that the spacecraft is traveling around the moon in the direction opposite to the way the moon travels around the Earth.
The spacecraft will be there for six days, providing an extended period of time for mission controllers to test out Orion’s systems. NASA pointed out that it would be the farthest that any spacecraft designed to carry humans had ever been from Earth. (The previous record occurred during Apollo 13 when the crippled spacecraft had to swing around the moon for the trip back to Earth instead of entering orbit.)
Before the flyby, a camera on Orion provided sharp video of the moon growing ever larger as the spacecraft approached, capturing an earthset — the small blue marble of Earth slipping behind the big gray disk of the moon in the foreground.
With Orion behind the moon, NASA’s mission controllers lost contact with the spacecraft, as planned. Thus, they did not know that the engine firing had succeeded until Orion emerged again 34 minutes later.
The spacecraft demonstrated its ability to send live video back to Earth during the flyby, said Judd Frieling, a NASA flight director, who added it would transmit more on a NASA website when possible. The Orion also took video and images of the moon’s far side while it was out of contact behind the moon.
“It will take us a few days to get those particular images down,” Mr. Frieling said.
Artemis I lifted off on Wednesday on top of NASA’s big new Space Launch System rocket from the Kennedy Space Center in Florida.
Except for minor glitches — Mike Sarafin, the Artemis mission manager, called them “funnies” — the Artemis I flight has proceeded smoothly. The funnies included Orion’s star trackers being momentarily confused when the spacecraft’s thrusters fired.
“We are on flight day six of a 26-day mission,” Mr. Sarafin said on Monday, “so I would give it a cautiously optimistic A+.”
The flyby exercised the major piece of Artemis that is not American. The parts of the Space Launch rocket were built by Boeing, Northrop Grumman and the United Launch Alliance while the Orion capsule itself was built by Lockheed Martin.
However, the service module — the part of Orion below the capsule that houses the thrusters, solar arrays, communications equipment and other supplies — was built by Airbus, and was one of the contributions by the European Space Agency to the Artemis program. The module will not return to Earth, but instead will be jettisoned to burn up in the atmosphere shortly before the capsule splashes down.
On Friday, the thrusters on the service module will fire again to put Orion into the distant retrograde orbit. On Saturday, Orion will pass the Apollo 13 record of 248,655 miles from Earth for a spacecraft designed to carry astronauts; next Monday, Orion will reach its maximum distance from Earth: nearly 270,000 miles.