SNW #61: Artemis II Explained

 ARTEMIS II EXPLAINED:

Artemis II is NASA’s mission to the moon launching in early 2026. It will be the first time humans will visit the moon in over 50 years. It is, however, closer to a test flight—four astronauts will fly around the far side of the moon over a 10-day journey. The rocket they will fly on is nothing short of astonishing, the most powerful manned rocket to date—the SLS.

THE SPACECRAFT:

It is this rocket I want to dive a little bit deeper into, as it is a really interesting and super cool piece of machinery. The whole spacecraft the crew will be launching on is the SLS (Space Launch System) rocket and the Orion spacecraft.

The SLS consists of two solid rocket boosters and one orange core stage in the middle. The next stage is called the interim cryogenic propulsion stage (ICPS), and above that is the uppermost stage—Orion. Orion is really the star of the show, as it is the newest and most technically advanced way we have to get to outer space. The SLS is mostly made up of recycled parts from the Space Shuttle program or even Apollo. Orion is brand new, and it consists of a few parts.

The bottom part is the European Service Module (ESM), and it provides the crew with power and propels the whole spacecraft. Then there is the crew module, which is the astronaut habitat. The crew work and live inside of here; they will stay here for the whole 10-day duration of the mission. Orion is way roomier than its Apollo predecessor, giving the astronauts more space to move around (it is true, though, that Apollo had a 3-person crew and Artemis has 4, making the room per person more comparable).

The crew of Artemis II has named their capsule Integrity. Integrity will also be the only part of the whole spacecraft that will return to Earth at the end of the mission; the rest of the parts will be discarded. You can also see a long protrusion on top of Orion. This is the Launch Abort System (LAS), which, in case of malfunction of any component that could harm the crew, can pull the capsule away from the rest of the rocket, bringing the crew to safety. Then they would parachute back to the ground. But let’s hope that they won’t need to use it.

THE MISSION:

Now, let’s talk about the specific mission profile of Artemis II. Artemis I launched back in 2022 as the first test of the SLS spacecraft, and it was an immense success. However, that time, Orion was uncrewed. This time, on Artemis II, it’s time to test it with astronauts on board.

Humans will therefore be able to test more of the human-centric features like docking, radiation shielding, food, communication, sleeping, and exercise—all the life support systems that could not be tested before. This includes people going to the toilet aboard Orion, which is actually shielded from the rest of the capsule by an opening door, and it closely resembles a normal on-Earth toilet.

Artemis II will launch from Kennedy Space Center in Florida from launchpad 39B. This launchpad launched Apollo missions to the moon as well as many Space Shuttle missions. It is set to launch as early as February 2026. Two minutes into launch, the solid rocket boosters will be jettisoned, leaving just the core stage to power it to LEO. At this time, the LAS will also be jettisoned, as it wouldn’t be of much help at this stage and onward. 8 minutes in, the core stage is empty and is also left behind, while the ICPS ignites and gives the final push to get the crew to space.

*Just a fun fact, the SLS core stage is going to go from full to empty in 8 minutes. Its capacity for fuel combined is around 987,000 kg; that’s 123,375 kg of fuel burned per minute or 2056 kg PER SECOND. Two tons of fuel burned each second of flight.

After the second stage does its job, the spacecraft will be in an elliptical orbit around Earth, at which it will be 74,000 km away from Earth on its far side and 185 km on its close side. This orbit will take around a day to complete. During this time, Orion’s going to separate from the ICPS and perform a test docking maneuver. In the coming years, Orion is expected to dock with the Lunar Lander and the Gateway station, so this test will check if the autopilot works and if the thrusters perform as expected.

Once Orion passes back around the Earth, completing its orbit, it’s going to reignite its engines for the trans-lunar injection, making course for the moon. This maneuver will be carefully measured so that Orion can take a free return trajectory back to Earth. This means that the gravity of the moon and Earth will naturally bring Orion back to Earth without any additional burns. This is a really good trajectory to use on test spacecraft, as if anything went wrong, the astronauts will end up back on Earth using gravity alone. It is also the same trajectory that ended up saving the Apollo 13 astronauts.

As said before, this is a lunar flyby mission, meaning no one will step foot on the lunar surface. It will be the same kind of mission as Apollo 8 in the 1960s. During this, Orion will do all kinds of corrections on its own to ensure it ends up at the correct place on Earth at the correct time.

After another 4 days, the astronauts will be entering the Earth’s atmosphere. This happens shortly after Integrity separates from the ESM. Integrity will then prepare for splashdown back at Earth. They will splash down in the Pacific Ocean, be picked up by the U.S. Navy, and complete their 10-day mission.