How NASA’s 2022 lunar mission paves the way for humans’ return to the Moon

On December 19 1972, astronauts Eugene Cernan, Harrison Schmitt, and Ronald Evans splashed down safely in the Pacific Ocean, ending the Apollo 17 lunar mission. They were the last people to travel beyond low-Earth orbit – typically defined as less than 1,000km above the Earth’s surface.

Some 49 years later, we are approaching the launch of NASA’s Artemis 1 lunar mission. Artemis is the latest in a long series of projects over many decades to attempt a human return to the Moon. It’s by far the closest one to being realized, with the earliest launch attempts currently scheduled for March 2022.

Artemis 1 will not carry astronauts, but it will launch the first spacecraft capable of doing so on a return journey to lunar orbit in nearly 50 years. With the ultimate aim to establish a long-term human presence on and around the Moon, Artemis is the first in a series of increasingly complex deep space crewed missions slated for the coming years.

Artemis 1 consists of an Orion spacecraft which will be launched by the new space launch system – currently the world’s most powerful operational rocket. Orion comprises the crew module, a conical capsule which can accommodate up to six astronauts for 21 days in deep space, and the European Service Module, containing Orion’s main rocket engine.

The European Service Module generates electrical power with distinctive “x-wing” solar panels and carries stores of water, breathable air and fuel. It also controls the thermal environment inside the crew module, keeping astronauts, and electrical systems within safe temperature limits.

Two critical challenges

The two most difficult parts of any space mission are launch and landing. Let’s look first at how Artemis 1 will launch.

The space launch system consists of an enormous liquid-fuelled core stage, powered by engines from the Space Shuttle era, and two powerful side-mounted solid-fuelled booster rockets, which together produce nearly nine million pounds of thrust at launch.

Atop the core stage is the interim cryogenic propulsion stage, a smaller liquid-fuelled engine which will push Orion out of Earth orbit and towards the Moon.

The Orion spacecraft is now attached to the space launch system at the Kennedy Space Centre in Florida for a series of pre-launch tests and rehearsals. This includes fuelling the space launch system and practicing rolling all the elements of the rocket out to the launch pad.