NASA Artemis Moon Landing Plans

Here, from a NASA conference presentation [PDF], is the “concept of operations” for the Artemis III return to the Moon mission.

No, you’re not hallucinating. Whereas Apollo required one launch of a Saturn V to land two people on the Moon, Artemis III will require:

  • SpaceX launch of Earth orbit Starship propellant depot
  • Four (or so) SpaceX launches of Starship tankers which will rendezvous, dock, and transfer propellant to the depot
  • SpaceX launch of the Human Landing System (HLS) Starship which docks with the propellant depot, refuels, and then departs to pre-position itself in lunar orbit
  • NASA launch of SLS/Orion with four astronauts, which delivers them to lunar orbit to rendezvous with the HLS
  • Two astronauts transfer to HLS and land on the Moon
  • After the flags and footprints, HLS returns to dock with Orion in lunar orbit
  • Orion returns to Earth

So, to land two people on the Moon, Artemis will require around six launches of Starship (which has never flown to orbit), orbital operations with a Starship propellant depot, multiple Starship tankers (with orbital propellant transfer which has never been demonstrated), and the Starship HLS, none of which has yet been built or flown, and a launch of the entirely expendable (with the exception of the crew capsule) SLS/Orion. And this is supposed to happen “no earlier than” 2025. I’d call that a safe bet.

This is described as the path to sustainable lunar exploration.


Given what it takes now, maybe the first one was faked.


As Rand Simberg has said, “In the 1960s, we didn’t have the technology to fake a Moon landing, but we had the will to do it. Today, we have the technology to fake a Moon landing, but not the will to actually do it.”


I can imagine a future diplomatic squabble as Russian & Chinese astronauts stationed on the Moon argue about which of them should get the honor of welcoming the NASA astronauts as they come down the ladder from the HLS.


Marcus House does make a good point about the differences between the scope of NASA’s 1960/70s single short exploratory trips to the Moon and the Artemis planned effectively-continuous presence on the lunar surface. The NASA plan does look very odd as a way of putting two people on the Moon, but not so odd as a way of making the Moon the new Antarctica.

The weak spot seems to be the reliance on NASA’s Senate Launch System, which will be required until Spacex’s Starship is a proven safe reliable vehicle and can receive bureaucratic approval to carry human beings. And there’s the rub … and the interminable delays.


Once upon a time, in the early and mid parts of the industrial revolution, our effects upon the environment were deemed negligible - expelling waste products into the air, rivers, the ocean. We know how that turned out. Now, House mentions various gravity assists required for efficient (but slow) deep space probes. Consider that each time we use a solar system body for this purpose, we ‘steal’ a small but calculable (I think) portion of its angular momentum. Questions: Does this constitute an ethical and/or eventually a practical issue? Or, is it actually so de minimis as to forever remain theoretical for all size solar system bodies? Recall that efforts are already being made to prevent probes designed to contact other planets from inoculating those surfaces with Earth microbes, so the practical and ethical issues of that particular possibility are already being taken into account to some extent (The probes are scrupulously clean; I don’t know if they are actually sterile).

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The effect on the planet’s orbit is completely negligible. A gravity assist is an exchange of momentum between the spacecraft and the planet. If the spacecraft speeds up, the planet slows down and vice versa. So when an Earth gravity assist is used to boost a probe to, say, Jupiter, the Earth slows down in its orbit by a tiny amount, and when an assist is used to drop a probe down toward Venus, Mercury, or the vicinity of the Sun, the Earth speeds up. In a mature interplanetary society, there would be commerce in both directions and only the net effect in one direction would matter.

But in any case, it wouldn’t make the slightest difference. Consider a typical gravity assist using a swing-by the Earth to increase the velocity of a 5 tonne spacecraft bound for Jupiter by 2.5 km/sec. (These are realistic figures based upon actual gravity assists.) Since momentum is conserved, and is simply the product of mass and velocity, \stackrel{\rightarrow}{p}=m\stackrel{\rightarrow}{v}, then the ratio of velocities will be the inverse of the ratio of masses.

The mass of the Earth is around 6\times10^{21} tonnes, so the orbital velocity “stolen” from the Earth is:

\frac{5\ \rm tonne}{6\times10^{21}\ \rm tonne}\times 2.5\frac{\rm km}{\sec}\approx 2\times{10^{-18}}\frac {\rm metre}{\sec}

This is a change in velocity which would require a year and a half to displace the position of the Earth by one angstrom. The effect on the Earth’s orbit due to accretion of cosmic dust and meteorites (around 100 tonnes a day) is much greater, and the gravitational radiation of the Earth’s orbit around the Sun (about 200 watts) reduces the Earth’s orbital velocity as much as the fly-by every two and half years.


It is a big planet – as you know from recently spending hours flying across the smaller of the planet’s main oceans. And when we fly across land areas, the main thing we see from 32,000 feet is … fields. Human factories, mines, even cities generally are not so obvious.

The beautiful people get very concerned about some of the smaller effects of human activities on the planet. They get really excited about carbon dioxide – a gas which has to be measured in Parts Per Million using incredibly sensitive modern technology. For scale, 1 ppm in the population of Switzerland would be 8 people.

Meanwhile, we humans are having very large impacts on the planet. There are estimates that human beings have already appropriated about 25% of the total Net Primary (photosynthetic) Production of the biosphere for food, fuel, and fiber. We have changed river channels and diverted rivers, with consequences of which the former Aral Sea is merely the prime example. We have fished out formerly massively productive areas of the seas.

Arguably, what our Betters do worry about and what they should worry about are two very different things.


Rube Goldberg is looking down and smiling!

And SpaceX is looking up as it prepares to leapfrog NASA to near earth asteroids, Mars, and beyond – and reduce complexity and cost !!!


Looks a lot like the planning for Apollo before they adopted Lunar Orbit Rendezvous. Makes sense if you plan to be going there regularly. May even give space station crews something useful to do.