Artemis 1: maiden flight of spacecraft set to take humans back to the Moon – here’s what needs to go right

Header image: Artemis-1 on the launch pad at Kennedy Space Centre. NASA

Gareth Dorrian, University of Birmingham

A launch window – the period during which a rocket must be launched to reach its destination – opens on August 29 for the first flight to the Moon since 1972 by a spacecraft designed to carry humans there. If all goes well, the Artemis project will be on track to meet its goal of putting humans back on the Moon in 2025.

Project Artemis, the namesake of the sister of Apollo and daughter of Zeus in ancient Greek mythology, is designed to establish a long-term human presence on our nearest celestial neighbour, and to ultimately explore even further afield. Artemis 1 is the first of several missions. It consists of Nasa’s new super-heavy rocket, the Space Launch System (SLS), which has never been launched before, and the Orion Multi-Purpose Crew Vehicle (or Orion MPCV), which has only flown in space once.

Unlike the Command Service Modules of the Apollo missions, which were powered by hydrogen fuel cells, the Orion MPCV is a solar-powered craft. Its distinctive X-wing style solar arrays can be swept forward or backward to reduce stress on the probe during high-thrust manoeuvres. It is capable of carrying six astronauts for up to 21 days in space. The imminent, uncrewed Artemis 1 mission, however, may last as long as 42 days.

Also unlike Apollo, Artemis is an international project. The Orion MPCV consists of a US-built capsule for the astronauts and a European-built service module containing supplies of fuel, water, air, solar-arrays and rocket thrusters.

The reliance on the Sun for power places some restrictions on when Artemis-1 can launch as the geometry of the Earth and Moon have to be such that the Orion spacecraft