The many questions Artemis will answer as humans look to Mars via moon

Parked near the moon, how do they eat, breathe, cope with isolation, radiation?

The last man to walk on the moon, Gene Cernan died in 2017 at the ripe age of 83. Cernan commanded the Apollo 17 Mission, which did a three-day survey of Luna in December 1972.

The entire NASA Apollo programme ran on less computing power than a modern top-end smartphone. Other 2022 technologies, such as the materials used, the rocket fuels, the power sources, have all advanced a lot as well.

Given that, it may seem counterintuitive that the NASA Artemis Missions will not even attempt to land a human being on the moon until several flybys have been accomplished. It may seem even more surprising, and definitely disappointing, that Artemis 1 launch has been postponed to sort out engine glitches, since we do understand how to build rockets.

Artemis is making haste slowly because it is actually vastly more ambitious in its scope than the Apollo Missions. The mission objectives are to not only land a person (certainly a woman, and maybe a person of colour, as Americans quaintly refer to certain races) on the moon; it is also to establish a permanent human and robotic presence on and around Earth’s satellite.

Artemis would give NASA and its partners the foundational skills for launching a vastly more ambitious mission: sending humans to Mars. Even if it doesn't work as planned, it would enable us (meaning the human species) to better understand the problems of living for prolonged periods in low-gravity, high-radiation, near-vacuum environments with massive temperature fluctuations.

Artemis is run by NASA, which is leading a coalition of space agencies of 21 nations (India, China and Russia are three space-going nations that are not part of the coalition). The mission has to develop a Space Launch System (SLS) to carry the Orion, which is a partly reusable spacecraft with a human crew.

The SLS will also place the Lunar Gateway, a habitable space station, in orbit around the moon.

Artemis also has to develop a Human Landing System (HLS), designed to carry humans to and fro from the space station (or directly from the Orion) to the moon. This HLS will serve as a habitat on the lunar surface and be capable of returning to the space station.

The design specs for the HLS were tendered out commercially, and the winner is called the Starship HLS. Apart from the components, the missions will also put cubesats (small satellites) into lunar orbit and run a host of scientific experiments of various kinds using different types of robotic techniques.  

If all this works, we will know if human beings are capable of surviving for long periods on the lunar surface. At that stage, NASA will start looking into sending a crewed vehicle to the fourth planet.

The rocket is new and larger than anything that’s been used for decades, but we do know a fair amount about rocket design (which is why the glitches are mildly surprising).

The Lunar Gateway is a new design built for new purposes and it has to tackle a somewhat different environment compared to the International Space Station (ISS). It is tiny and solar-powered and constructed to serve as a parking bay for robots, lunar rovers, etc., as well as being a science laboratory, and a human habitation. It won’t be up and running until 2024 at least, and it may take longer.

The Starship HLS is an adaption of SpaceX’s Starship design but it has been pared down because it operates near the moon, which has no atmosphere. Hence it doesn’t need a heat shield to protect it from atmospheric friction. Nor does it have wings, ailerons, rudders, etc. to steer it in the atmosphere. It would be separately boosted into lunar orbit rather than being carried on the same SLS as Orion.

The engineering and design problems are obviously formidable. But there is only one aspect in which a lunar landing mission is more complicated (actually a lot more complicated) than a Mars landing. The moon’s surface is covered by many metres of dust, and a lander may sink and become unstable since the surface terrain is invisible. Mars doesn’t have that problem.

In every other respect, a Mars mission is far more complex. A moon mission can be over and done in a few days, since the moon is only 385,000 km away. There’s 55 million km between Earth and Mars when they’re at their closest, and 400 million km between them when the two are on opposite sides of the sun. A Mars mission takes many months for one leg of the journey.

However, keeping a team on the moon or near it for long periods will give us a better understanding of the health issues. How do they eat? How do they breathe? What happens during a prolonged period of low gravity? What kind of damage can high doses of unshielded radiation cause? And finally, how likely is mental illness under conditions of such isolation? One way or another, Artemis will answer many of those questions.