NASA’s Orion spacecraft completes powered lunar orbit – Spaceflight Now

NASA’s unmanned Orion spacecraft fired its main engine for two and a half minutes Monday just before the capsule lifted off 81 miles from the lunar surface, completing a flyby maneuver to bend its trajectory toward a high orbit for additional tests on future lunar missions from cosmonauts.

The main engine caught fire at 7:44 a.m. EST (12:44 a.m. GMT) on Monday as the Orion spacecraft flew over the far side of the moon, forcing NASA flight controllers in Houston to wait until the capsule left the moon. , before confirming the fact of the result of the maneuver.

Monday’s launch of the Orion spacecraft’s engine, called the Outbound Powered Flyby, was the most critical moment in NASA’s Artemis 1 mission since it launched last Wednesday from the Kennedy Space Center in Florida. On its first test flight, the Space Launch System’s huge new lunar rocket launched the Orion crew capsule into its target trajectory to begin a five-day cruise to the moon.

Artemis 1 is a test flight before NASA begins flying astronauts on the SLS moon rocket and the Orion spacecraft. If the Artemis 1 mission is successful, the space agency plans to fly three American astronauts and a Canadian astronaut around the far side of the moon as part of the Artemis 2 mission in late 2024. After that, there will be missions to land on the moon. The 2020s and the construction of a mini-space station in orbit around the moon.

After launching last week from Florida, the Artemis 1 Orion lunar rover expanded solar panels from its European-built service module to generate electricity and completed a series of corrective burns as it was exposed to the moon’s gravitational pull over the weekend. The exit powered flyby, or OPF, used the Orbital Maneuvering System engine on the back of the Orion Service Module. The OMS engine is a holdover from the Space Shuttle program, when it completed 19 flights in orbit from 1984 to 2002.

The OMS engine fired to generate about 6,000 pounds of thrust as the capsule cruised about 328 miles (528 kilometers) above the lunar surface. During the two-and-a-half-minute firing, the engine accelerated the Orion spacecraft to more than 580 miles per hour (933 kilometers per hour) and burned about 2,900 pounds (1,300 kilograms) of hydrazine and nitrous oxide. fuel, according to NASA. This is approximately 20% of the entire fuel load of the Orion spacecraft.

Shortly after the burnup, the Orion crew capsule reached its closest point to the moon — 81 miles (130 kilometers) above its cratered crust — at 7:57 a.m. EST (1257 GMT). About two minutes later, at 7:59 a.m. EST, mission control reestablished communication with the Orion spacecraft as the capsule reappeared from behind the moon, establishing direct radio communication with NASA’s Deep Space Network antenna in Goldstone, California.

Live video feed from the Orion spacecraft resumed as soon as Goldstone’s antenna picked up a signal, revealing a blue marble-like Earth hanging in the dark of space. The Orion spacecraft later flew about 1,300 miles (2,100 kilometers) above the Apollo 11 landing site in the Sea of ​​Tranquility. All the maneuvers took place when Orion flew nearly a quarter of a million miles from home.

Although Artemis 1 is unmanned, the Orion spacecraft has three mannequins in its sealed cabin equipped with instruments to collect acceleration, vibration and radiation data during the flight to the Moon and back.

NASA Mission Control has received signals from the Orion spacecraft again after passing the far side of the Moon. I am waiting for a report on the results of the Outbound Powered Flyby recording. https://t.co/Ie3TWpO5mP pic.twitter.com/YeS6IQz1CM

— Spaceflight Now (@SpaceflightNow) November 21, 2022

NASA confirmed Monday’s engine burn and flyby were successful, helping the Orion spacecraft use the moon’s gravity to send it into a long retrograde orbit, or DRO, with an average distance of about 43,000 miles (70,000 kilometers) from the moon.

The Artemis 1 mission’s next major maneuver is scheduled for Friday at 4:52 p.m. EST (9:52 p.m. GMT), when Orion’s main engine will re-ignite, lasting about a minute and a half, to propel the spacecraft into a distant retrograde orbit. DRO gets its name because it is not the low-altitude orbit that the Apollo spacecraft flew to in the 1960s and 1970s, and because Orion will be orbiting the Moon in the opposite direction to that of the Moon around the Earth.

The mission organizers chose the orbit for several reasons. First, the propulsion system of the Orion spacecraft does not have the ability to direct the capsule into a low-altitude orbit around the Moon, as the Apollo missions did. And the DRO is stable because it is near the point of balance between the gravitational pull of the Earth and the Moon, reducing the fuel Orion needs to maintain its orbit after arrival.

The Orion spacecraft will spend about six days in a deep retrograde orbit performing tests and inspections. It will reach its greatest distance from Earth next Monday, November 28, at a distance of more than 268,500 miles (432,000 kilometers). On Dec. 1, after completing a half-circle around the Moon, the capsule will fire its engine again to exit the far retrograde orbit and turn back toward the Moon for another low-altitude flyby on Dec. 5 on its way back to Earth. .

The launch of the Orion capsule into the Pacific Ocean is scheduled for December 11.

Email The author.

Follow Stephen Clarke on Twitter: @StephenClark1.