Artemis I – What did we learn?

September 13, 2023

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On December 11th, the NASA-led Artemis I mission came to a successful end after a 25-day journey to the Moon and back. The Orion capsule, which is designed to transport the crew of future Artemis missions, splashed down in the Pacific Ocean off the coast of Mexico. It is now being transported back to the Kennedy Space Centre in Florida so that NASA scientists can assess how well it performed throughout the mission.

Rocket Launch

Artemis I is being hailed as a series of successes. The Space Launch System (or SLS) rocket which launched the Orion capsule – together with its European-designed and built service module – into space performed exactly as intended. Considering that Artemis I was the first integrated flight of the SLS and the Orion capsule, this is no mean feat.


The spacecraft travelled over 1.4 million miles, completing two lunar flybys and coming within 80 miles of the lunar surface. At its farthest distance during the mission, Orion travelled nearly 270,000 miles from our home planet, more than 1,000 times further than where the International Space Station orbits the Earth. And during that time, numerous systems were checked and tested to ensure that the spacecraft can safely transport humans around the Moon – the intention of Artemis II, which is due to launch within the next two years.

Orion Approaches Moon Before Return Flyby.
Orion Approaches Moon Before Return Flyby. Image credit: NASA

Testing systems

Among the tests conducted was a modal survey, where NASA scientists conducted small ignitions of Orion’s thrusters in order to ensure this didn’t unduly flex the solar panel wings attached to the European service module.

Another test ensured the proper functioning of Orion’s guidance, navigation and control system. The optical navigation camera which guides the system can help Orion autonomously return home if it were to lose communication with Earth. Meanwhile, scientists also tested cameras designed to check for micro-meteoroid or space debris strikes during the mission.

Moonkin Campos

More experiments and tests came courtesy of a life-sized mannequin, nicknamed Commander Moonikin Campos, who was in the Orion capsule. One experiment concerns the levels of radiation future astronauts will be exposed to. Exposure will occur as the spacecraft travels through the Van Allen Belts (which contain radiation trapped around the Earth by its magnetic field), as well as from solar flares and cosmic rays.

Moonikin Campos is equipped with two radiation sensors, to see how protective an environment the capsule provides. Another key experiment concerns the acceleration and vibration forces future astronauts will experience. Crews are expected to experience up to four times the force of gravity during Artemis missions, so it’s vital to understand whether this has been the case on Artemis I.


But perhaps the most dangerous and testing part of the mission was re-entry through the Earth’s atmosphere. The Orion spacecraft separated from the service module in space. During re-entry, Orion endured temperatures about half as hot as the surface of the Sun at about 2800 degrees Celsius. Within about 20 minutes, Orion slowed from nearly 25,000 mph to about 20 mph for its parachute-assisted landing. Scientists will be carefully studying Orion’s heat shield to ensure it performed as expected.


The tests and experiments conducted during Artemis I will be keeping scientists busy for months and years ahead as they prepare for the first crewed Artemis mission in 2024. For more detail on the future of Artemis, sign up for Mission Astro today – our in-depth interviews with key mission planners will be sure to inform and fascinate!

Orion Approaches Moon Before Return Flyby
Orion Approaches Moon Before Return Flyby. Image credit: NASA

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