Artemis is not NASA’s first attempt to return to the moon after the Apollo program: in 2005, the Constellation program began, which aimed to send astronauts to the moon by 2020.

Only 4 years later, with a change of administration in the White House, the program was canceled, believing that it was not on a sustainable trajectory, due to numerous overruns of the originally estimated budget (as if it was the first program of NASA). in this situation). But only one vehicle survived the cancellation of the Constellation program: the Orion capsule that would be used by astronauts to reach lunar orbit.

However, the problem with the Orion capsule is that it can only transport astronauts into lunar orbit, not the surface of the moon. Initially, in the Constellation program, NASA believed that two rockets were needed to land the satellite: Ares I was supposed to launch the Orion capsule into orbit, and a separate Ares V rocket was supposed to launch a vehicle called Altair, which would be docked to it. the Orion capsule in Earth orbit would reach the Moon’s orbit together, and from there the astronauts would transfer to the Altair and descend with it to the Moon’s surface.

After the mission, Altair docked with Orion in lunar orbit, and the astronauts returned to Earth aboard Orion. It was essentially an architecture similar to that of the Apollo program, but it was to use two rockets (Ares I and Ares V) instead of one (Saturn V).

After the cancellation of the Constellation program, NASA abandoned any new Ares rockets or Altair spacecraft, but development of the Orion capsule continued: the plan was to use Orion to launch astronauts to the ISS, but that was obvious. fast enough that it would be prohibitively expensive, and NASA scrapped the idea. But not a capsule. The rescue of the Orion capsule coincided with the new Artemis program, in which it will be used for its original role: transporting astronauts to the Moon.

Orion can carry 2 to 6 astronauts for 20-day missions and consists of three parts. The Rapid Launch Termination System, consisting of a solid propellant engine, is located on top of the capsule and we hope to never see it in action as it will quickly remove the Orion capsule if the rocket explodes. Next is the capsule itself in the shape of a truncated cone, where the astronauts will live on the way to the moon and back.

Between this barrel cone and the upper stage of the SLS rocket is a third part, the capsule service module, manufactured by the European Space Agency (ESA), a module that provides propulsion (1 main engine, 8 auxiliary engines and 24 orientation control engines), oxygen, nitrogen, water and electricity (produced by 4 solar panels) required during flight.

Unlike other space capsules, Orion is designed to also be able to handle re-entry into Earth’s atmosphere from interplanetary orbit (where speeds are higher than re-entry from lunar orbit), meaning NASA will be able to use this capsule and for future missions to and from Mars.

So far everything is clear: we have the SLS rocket, we have the Orion capsule, which we will see in operation in the coming days: it will be launched to the moon and, if all goes well, will be recovered at the end of the Artemis 1 mission from the waters of the Pacific Ocean. But for the landing on the moon to take place, NASA needs a device that will allow astronauts to get from lunar orbit to the surface of the moon, the so-called lunar lander. A machine that will not be launched with an SLS rocket, but with a commercial partner’s rocket. And from here everything starts to get complicated.

Encouraged by the success of commercial programs to supply the International Space Station, NASA turned to the private sector and held a competition to select a company to design and operate a new lunar lander. The first round of this competition was won by the company SpaceX, which promised to use the Starship ship to transfer astronauts from the orbit of the moon to its surface.

NASA’s decision was challenged in court by an unsuccessful consortium led by Jeff Bezos’ company Blue Origin, but justice sided with NASA and SpaceX. However, NASA will soon organize a new round (in which SpaceX will no longer be able to participate) to select a second lunar lander, which, however, will not previously be used by the Artemis-4 mission. So for the first landing under the Artemis program, SpaceX will need to test and provide NASA with a Starship capable of docking with the Orion capsule and delivering astronauts to the surface of the Moon.

Artemis-3 is scheduled for 2025, by which time SpaceX must demonstrate that Starship can get from lunar orbit to the lunar surface in a test mission without a crew on board. In order for Starship to enter lunar orbit, the vehicle must first be launched into Earth orbit, where it will need to be refueled by other Starship vehicles before heading to the moon. It’s August 2022, and SpaceX has yet to launch a Starship rocket into Earth orbit, let alone refuel in space or perform space trials around the moon. So, if the Artemis-1 mission is to be successful, the hard work is just beginning.