Recently the Canadian government announced the passage of a Space Launch Act to facilitate launch from it’s territory. As a Brit I have little stake in Canadian politics, and I only found out about this when my X feed filled up with invective being fired at this act on the basis that it was either not possible, or extremely difficult, or commercially infeasible, to launch from anywhere in Canada due to it being too far north. As one commentator put it:

Does anyone in Ottawa understand basic physics?

It's significantly easier (ie, cheaper) to launch to space from near the equator.

That's why Europe's space port is in French Guiana.

Anyone launching from Canada is either an idiot or expecting massive government subsidies.

This may sound like a knock down argument to a non-expert. And indeed it received many appreciative responses who were happy to see through the physics-defying “scam” and feel smart. But it really is clinging on to one small factoid and drawing very wrong conclusions from it.

Getting to Orbit

To get to orbit a rocket needs to achieve a velocity horizontal to the ground of about 7.8 kilometres/second. Rockets launch vertically to get out of the thick part of the Earth’s atmosphere before gaining much speed, and to reach the target altitude - but horizontal velocity is the name of the game. Air resistance and gravity losses add to the cost of getting to orbit - so ultimately you need a bit over 9 km/s of Δv in total. But most of that is horizontal velocity.

If you are on the equator, you are moving eastwards at 465 metres/second already. At French Guiana, the closest space port to the equator at only 5 degrees north, the eastwards velocity is 463m/s. At Kennedy Space Centre, 28.5 degrees north, it is 410 m/s and at Baikonur, 46 degrees north, it is only 324m/s.

The argument goes that, while this is only a small fraction of the total speed required, the tyranny of the rocket equation kicks in and it means that the equatorial site has a huge advantage in putting material into orbit - so much so that only an idiot will build a northerly launch site.

But the truth is quite different.

It is rare for a rocket to launch due east. The only condition where you can do this is if the inclination of the target orbit is exactly equal to the latitude of the launch site. Once your launch azimuth deviates from due east, the already small advantage you get from rotational velocity is reduced. By the time you are flying due north, into a polar orbit, the boost is actually a penalty to your Δv because it needs to be cancelled out to reach your target orbit, which has zero eastward velocity. It is a small one, and not significant at all in practice, but it undermines the assertion that eastward velocity is always good. Beyond a 90 degree angle, when orbits become retrograde (such as a sun synchronous orbit, typically about 98 degrees inclined) the penalty imposed by eastward motion gets greater. So technically, it is easier to launch as far north as possible.

Nobody is clamoring for launch sites in the arctic circle though - the most northerly major spaceport is Plesetsk, near to Archangelsk in Russia. At 63 degrees north it is just sub-arctic. This is because the impact of eastward velocity is not really that great whereas the cost of operating in polar regions is.

But then why does it go the other way around? Why does ESA go to all the trouble of operating a near equatorial launch site far from it’s workforce and industrial base, with all the logistic headaches that brings?

Plane Changes

The key insight in how launch sites relate to orbits has nothing to do with the rotation of the Earth. It is all about inclination.

ArianeSpace carved out it’s commercial niche by launching satellites to geostationary orbit - a high altitude 0 degree inclination orbit. They also got costs down by pioneering dual manifesting of satellites. Prior to Falcon 9 taking the industry by storm, Ariane 5 was the market leader in the most lucrative part of the launch sector.

The near equatorial launch site was helpful to getting to this profitable equatorial orbit. To get to a geostationary orbit from Kennedy Space Centre would require about 400m/s extra Δv relative to Kourou, while getting there from Baikonur would require an extra 900m/s (although some clever Russia orbital dynamics can shave about 100m/s off that, but it is beyond the scope of this argument). However, the difference in eastward velocity only accounts for 50m/s and 140m/s respectively of the total difference. What causes the rest?

To get to a geostationary orbit (GEO) you start in a geostationary transfer orbit (GTO). This is an elliptical orbit with the perigee in LEO, or where your booster injected you into orbit, and the apogee at the altitude of GEO. Crucially, this transfer orbit is not equatorial - it is whatever plane is convenient to reach from your launch site. When you reach apogee, you perform a burn which simultaneously circularises your orbit and also changes it’s plane to 0 degrees. Almost the entire difference in difficulty getting to GEO is in this plane change.

This might seem like splitting hairs - because an equatorial site still comes out on top, even if it is for a very different reason than claimed. But in reality there are many other valuable orbits out there. GEO is not even commercially dominant any more - LEO constellations are the new thing, and they use significantly higher inclination orbits to get good coverage:

There is also a substantial market for sun-synchronous orbits, which are good for Earth observations and are also attractive for the proposed on-orbit data centres, due to being able to align them such that they almost never go into eclipse and thus have constant reliable solar power.

So the utility of a launch site for flying these commercial missions is not it’s latitude - it is whether or not the azimuth needed to reach the target orbit is available from that site. If the latitude is higher than the inclination a “dogleg” launch is required which does add Δv, but given there are profitable target orbits all the way up to sun-synchronous orbits at 98 degrees, there is no site that can be excluded on these grounds. Having a clear range in a set of useful azimuths is a lot more critical for site selection than mindlessly minimising latitude - as are many other factors, such as logistics and weather.

Why This Matters

I have been campaigning for some time for an indigenous launch capability in the UK, from the UK mainland. We do possess an overseas territory, Ascension Island, which lies almost exactly on the equator, but it is small, remote and operating there would impose significant costs. So I prefer launch from the British Isles. The government agrees, and has thus put money into Saxavord spaceport. This will host a launch by a German company RFA later this year, but I want to see British launch vehicles, and much larger vehicles, to pursue a more robust British space program.

When I raise this, I sometimes get asked a question about latitude, and if it is asked nicely I explain why it is not a problem as best as I can. Other times though, including one especially egregious opinion piece in one of our tabloid papers, I get called a “moron” for even suggesting it - by someone ignorant of all the actual physics I outlined above. Someone writing in a paper has a wider audience than my mere newsletter, and thus may be able to convince the public. There is a risk that public policy might be steered by people too stupid to understand how little they understand about spaceflight, to the detriment of the nation. Some quick snark about how only stupid people don’t understand the need for low latitude launch sites is a lot quicker to write than the explanations I offer above.

This has been summarised in Brandolini’s Law - “The amount of energy needed to refute bullshit is an order of magnitude bigger than that needed to produce it”. This unfortunate fact is a boon for cranks, hack journalists, self-described skeptics and con artists. All I can do is put in the work here, and hope that the truth can slowly make it’s way through the public consciousness and disarm the blowhards.

And yet, I heard a substantial amount of negative commentary on the matter. Was this just all noise and clickbait? Who actually opposes space exploration and colonisation, and is it really a popular position? One place to look was in my own home country of Great Britain, where polling had ostensibly not been as positive. Aside from a small contribution to ESA, this was not a British mission and British taxpayers were not on the hook for its costs, but that doesn’t usually stop us having opinions on things, and I thought it might be useful to understand why we aren’t as positive about it as Americans in order to understand more general opposition.

As Artemis II blasted off, the polling company YouGov published a survey of Britons asking if they would consider visiting the Moon. The response, as reported, were fairly negative. One part that got much attention was respondents reasons for not wanting to visit the Moon, even if safety was assured.

I have, however, looked at the tables for this survey and the picture is more complex than first appears. But it does raise the issue of if there is enough popular support to sustain current programs - or to start new ones in countries like the UK, which lag behind in space capabilities.

I’m going to be discussing opposition to the mission itself here - some opposed Artemis II on valid technical and programmatic grounds whilst generally being in favour of human spaceflight to the Moon and beyond. Nor am I going to address the crazy people who think its fake. Here we are strictly talking about those who think we should not go to the Moon for moral, political or economic reasons.

Snark

To get something out of the way, some people are against spaceflight for bad reasons - they have got “Musk Derangement Syndrome”, or they just like dunking on something others enjoy, or because they know hostility and snark get clicks. Vice offers a prime example here:

This writer has simply jumped on the word “colonialism” without considering how it’s negatives do not apply to an uninhabited solar system. This lets him just regurgitate rehearsed talking points about this in order to pass something off as criticism, and get online engagement.

This wasn’t the worst example though. On Sky News, a Guardian columnist just dismissed the entire thing out of hand, whilst utterly failing to understand what the mission was about - nobody expects to find life on the Moon:

Zoe Williams is generally an unpleasant and not very bright commentator; her previous contributions include the assertion that democracies don’t use nuclear weapons, which may come as a shock to the residents of Hiroshima and Nagasaki, and a lazy three paragraph opinion piece on Katy Perry going to space, in which two of the paragraphs were criticism of her appearance. I’ll not waste any more time and energy on her, and move on to some actual substantive criticisms

Criticism

In terms of genuine intellectual criticism, there is the old trope that humans are pointless in space and it is better to send robots. In this case, it is the Astronomer Royal Martin Rees making this argument in The Guardian.

This argument has been made consistently since the dawn of the space age - but it was especially intense in the aftermath of the Moon landing. The Soviet answer to the Saturn V, the N-1, failed before first stage separation on every attempt to launch it. They use the smaller Proton rocket to launch some advanced (for the time) robotic probes, including two nuclear powered rovers and three automated sample return missions. In their propaganda they denied ever having been attempting to send humans to the Moon, and insisted their robotic program was better.

The argument is flawed in two ways; first, it assumes that science is the only reason to send humans to other planets. It is not - colonisation and economic development are the main aims, and this encompasses all aspects of human activity, including science. Secondly, the notion that robots are better at science than humans is only ever argued in a situation where humans are not present at all to compete - e.g. on the surface of Mars. It is notable that science on Earth still involves humans in fieldwork, and will do for the foreseeable future.

In a separate editorial, as well as reiterating the above, the paper made this argument:

Rather than serving to remind us of Earth’s preciousness, there is a risk that the £100bn Artemis programme is a dangerous distraction from the urgency of finding ways to live within the ecological limits of the world we already have

First lets flag the cost figure used here - this is the total programme cost since its inception. The cost of this particular mission on its own is around $4 billion. Aggregating the entire cost since 2012 is done purely to make it sound as expensive as possible. If we were to, for instance, aggregate the spending of the NHS over that period and convert it to dollars, the figure would be around $2,700 billion.

Part of this intentional inflation of costs is to justify the use of the word “distraction” - as if there is a huge opportunity cost to Artemis. There is not - the flight of Artemis II cost each American taxpayer about $12. The cost to the UK readers of the Guardian is basically zero. What this editorial is worried about distracting from is an apparently Malthusian crisis they are convinced is real - but that they provide no evidence or argument for, let alone justify as “urgent”. This whole paragraph is written with a set of very dubious assumptions about the world that the authors are not used to being challenged. Define ecological limits? How close are we actually to them, to make it urgent? And why is this not in fact an argument for space colonisation, so we can move population and industry off Earth and reduce the trade-off between human needs and our desires to maintain ecosystems? This lazy sort of argument exemplifies why people must familiarise themselves with disagreement before staking out their position in this manner.

The coverage from the Guardian isn’t all negative of course; there is this piece which contrasts the touching tributes of the mission to dead friends and colleagues with the violence currently going on on Earth, and describes Artemis as “the best of humanity”.

The Artemis Generation

Looking at the tables for the YouGov poll, it’s clear that the younger generations are consistently more supportive of space in all questions than older ones. Part of this might be timeline realism - many questions ask if some milestone will happen “in your lifetime” which obviously means something quite different to a 70 year old than a 20 year old. The largest gap in opinion is between men and women though. The first question about interest in space is perfectly reversed; for men 62% interested versus 37% uninterested, and for women 37% interested versus 62% uninterested. The pattern repeats throughout the survey. This is something that the space colonisation movement has to address - a colony without women is by definition not able to sustain itself.

In terms of socioeconomic class, the survey divides respondents into “Higher”, “Intermediate” and “Routine”. What is interesting here is that when asked about the importance of various activities in space, the most negative responses came from the “Intermediate” class in the majority of the questions, especially pronounced where the overall opinion was most negative:

Breaking down by question, there was a positive responses came across almost all groups on the importance of maintaining a physical presence of space of some kind (the question gives the example of the ISS), with majority support across all social classes and both sexes. This may indicate a status quo bias; if someone is neither strong pro- nor anti- space, they might think there is no need to do more or less than we currently do.

Two very categories with very positive responses were “Maintains the system of communications satellites orbiting the Earth” at 82-10 important vs not important, and “Explores space for scientific purposes” at 73-21. They both maintained positive ratios across all groups asked.

What this suggests, to me, is that ordinary people are happy to see money spend on space activities that are purposeful. It hasn’t been widely explained to them what exactly the point of going to the Moon or Mars is - except perhaps in the most abstract terms.

I think that YouGov presented their results with a needlessly negative spin; looking at this alongside some of the articles mentioned above it seems to me that the anti-space movement is very much top down; some loud voices purporting to speak for the ordinary, common sense person but in fact not being especially representative. It should also be noted that journalists as a profession tend to draw from the “Intermediate” group above, so are likely to some extent to report the bias of that group.

I assume those reading this far are mostly in agreement with me; and so what we should all be doing is bypassing the Malthusians, blowhards and the haters, speaking directly to as many people as possible, and letting them know your reasons for going to the Moon and beyond. The surveys mentioned here indicate to me this is an easily winnable debate.

If you know anybody who would still like to catch up with this mission, please share this with them.

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Given the issues that were discovered after the reentry of Artemis I, this mission was delayed substantially and a new reentry trajectory was planned. The decision was taken not to change the heat shield, as this would delay the mission even further. A modified heat shield will fly on Artemis III, and NASA believes Artemis II can still be successful with the older design if it flies a different trajectory.

Before I get on to that, one last update on the trajectory of Integrity as it accelerates towards Earth:

During the mission NASA have been publishing updated ephemris data - the position and velocity of the spacecraft at each point in time - as corrective burns and the lunar gravity have altered it.

These changes are very small, and I chose not to show them on the main trajectory plot and just use the latest one, as the differences would be substantially less than the with of the line. Even zooming in on the entry interface portion at Earth, it looks as if the initial trans-lunar burn was very good.

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During the Apollo missions, keeping the crew safe from solar flares mostly relied on forecasting - thankfully no major even occurred during a mission, but a large one did occur in August 1972 between Apollo 16 and Apollo 17. There was a procedure to move to the part of the Command and Service Module where the spacecraft structure would provide most shielding, but this would not have been a full mitigation. Things work differently for Artemis though.

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At the same time, NASA have downloaded and released images taken during the flyby. One of the ones which has captivated the public most is the “Earthset” image. My favourite version of this is the wider shot:

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What they saw was not quite the same as what the crew of Apollo 8 saw - Integrity passed the Moon at a significantly higher altitude, and the Earth was in a different phase at the time. There was also not the tension in this blackout that there was the first time Apollo 8 passed behind the Moon, because on that mission they had to perform a rocket burn during the blackout to place themselves into a low Lunar orbit, and mission control had no way of knowing if it had succeeded until they reestablished contact.

I have some thoughts on the messages for Earth that the crew transmitted before and after blackout, but first I’ll drill down on some details about the flyby itself.

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The Moon is now quite large in the window, and the crew have already begun visual observations of it.

At the current distance of the spacecraft, around 366,000 km at the time of writing, there is notable lag in radio communications due to the speed of light. Another way to write their distance would be as 1.2 light seconds, so a round trip signal to them takes 2.4 seconds. You may notice in live conversations with the crew this delay in their response.

Approaching the Moon

I’ve now plotted the Moon on the orbit diagram; it will pass through the centre of the loop when Artemis II is at the very bottom of the orbit as shown. It might not seem as if the two objects will intersect, but bear in mind that Integrity is slowing down significantly at this point.

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The life support system of the capsule ultimately responds to the presence of humans; for example, someone has to be breathing out carbon dioxide for the scrubbers to remove. So the crew can be thought of as part of the system themselves, and part of the process of testing it.

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There had been complaints about both the temperature and humidity in the capsule being too low, both of which were resolved. The lower humidity in particular makes the performance of the carbon dioxide scrubbers worse. Somewhat more concerning, there was another anomaly with the on board toilet. In a worst case scenario the crew is able to relieve themselves into special bags, but fortunately the problem was fixed.

Aside from debugging issues with the life support systems, the crew exercised using a flywheel system to provide resistance, while mission control monitored any vibrations this caused in the spacecraft.

The Halfway Point

Integrity passed the halfway point to the Moon, in terms of distance, early today. At the time of writing it is even closer according to the most current tracking data:

The Moon has not yet entered this plot; it will appear tomorrow.

So far the trajectory is excellent; the trans-lunar injection burn was accurate enough that the error was only 0.8 metres/second, small enough that mission control decided to cancel today’s course correction.

The spacecraft slows as it gets further from Earth, so the closest approach will still not be for another three days. The crew are already preparing for this though, and spend some time testing how the spacecraft will be configured at the time of flyby, in terms of arrangement of cameras and orientation.

Space in Space

There was a conversation between Mission Specialist Christina Koch and mission control today about where to store some waste bags. The capsule is packed with supplies, and aside from the venting overboard of urine and excess CO2, all of the waste the crew produces must remain inside. So generally, waste has to be placed into the lockers that contained the supplies being used up.

As can be seen above, it is fairly cramped inside, but not that much by space capsule standards. The habitable volume of the spacecraft is about 9.3 cubic metres, shared between 4 astronauts. In comparison, an Apollo capsule had about 5.8 cubic metres shared between 3 astronauts. That means 2.2 cubic metres per crew in Orion compared to 1.9 cubic metres per crew in Apollo - the extra room being what allows facilities such as the dedicated toilet, exercise machine etc.

However, this is a lot less roomy than the Space Shuttle, which provided 8.9 cubic metres per crew, or as much as 14.7 cubic metres when flying with its Spacelab or Spacehab modules[1]. If Orion is going to be involved in deep space missions longer than this one, it will have to dock with something larger.

Yesterday I previewed some discussion of the broader Artemis plan; that will be in tomorrows update, as I ended up having more to discuss here than I thought. If you haven’t already, please consider subscribing to follow along with the mission.

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[1] Cohen, M., Testing the Celentano Curve: An Empirical Survey of Predictions for Human Spacecraft Pressurized Volume

Today I’ll be summarising some mission events, and discussing the details of trans-lunar injection (TLI). If you haven’t already, please consider subscribing so that we can follow along with this mission together.

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I had been planning to discuss some of the activities on board today, but one particular moment stood out - shortly after the TLI burn, Commander Reid Wiseman took this photograph of the Earth

We had of course expected such photos to come from this mission, having all seen the famous “Blue Marble” taken on Apollo 17. But I was surprised what a striking image this is. It is actually the night side of Earth, illuminated by the full Moon (a giveaway for this is the city lights which can be seen across Spain and North Africa, in the bottom left). The brightness of the Earth is achieved by a longer camera exposure, not post-processing.

Both the northern and southern aurora can be seen in this photo, marking the magnetic poles of the planet. On the lower right there is bright zodiacal light from the limb of the Earth nearest to the Sun (which is behind the Earth here). The exposure also allows stars to be seen. The planet Venus is also clearly visible. There is a good chance this is the most memorable image of the mission.

There isn’t much for the crew to do before they reach the Moon in terms of direct mission objectives; so en route they will continue to test the spacecraft and its life support systems. Today then, I’m going to go into some slightly technical details of exactly how they got to the Moon.

The Orbital Battery

Travelling to the Moon is a matter of energy. The spacecraft is moving at a certain speed in an Earth orbit, and then accelerates, and is now on a more elongated and thus higher energy orbit passing through the same point - an orbit large enough to reach the Moon.

The chemical energy of the rocket propellant is the source of this orbital energy. But you don’t necessarily want to use it all at once. On this mission, and on the Apollo missions, it is considered wise to spend a short time in Earth orbit to check that the spacecraft is working correctly before committing to a lunar journey. The downside of this is, because both Apollo and Artemis missions use deeply cryogenic propellants on their upper stages, they lose some to boil off whilst waiting for the TLI burn.

During the Apollo 8 mission, the combined Apollo CSM and S-IVB upper stage (no lunar module was carried) spent 2 hours 44 minutes[1] in Earth orbit before departure. During this time, the liquid oxygen supply reduced by 110 kilograms, which was only a negligible fraction of the remaining supply. But the more volatile liquid hydrogen supply reduced by 1,050 kilograms - and this was almost 10% of what remained, due to the fact that this combination has an oxidiser-to-fuel ratio of almost 5 . These materials were not simply dumped overboard as they boiled; they were vented rearward to create a small thrust which kept the propellants settled in the back of the tanks.

Orion is a vehicle with fewer test flights than Apollo, and being launched by an agency that is more cautious, so they want to spend longer in Earth orbit before departure. Managing the cryogenic propellants with minimal boil-off over 24 hours would be tricky and is not something the ICPS is capable of. So in this instance, they have opted to consume the chemical energy of the propellants soon after launch, and store the energy in another form - orbital energy. By sending Integrity into a highly elliptical orbit around Earth, which has most of the energy needed for TLI but still remains close to the planet for a quick return if needed, the Artemis II mission planners were able to use this orbit to “store” energy for later use.

The Oberth Effect

When it was time for the Orion capsule to complete lunar injection, the manoeuvre was performed at the lowest point of the orbit, approximately 185km. This is considered a very low orbital altitude - the ISS orbits at above 400km for comparison. It had just come down from an apogee of 70,000km, almost twice the altitude of geostationary satellites.

This has an advantage that is not intuitively obvious; I’ll try to explain it here without too much maths.

The equation for kinetic energy is

if we move the mass term m to the right side, so we are talking about energy per unit mass (sometimes called specific energy) we end up with the equation for the area of a triangle with base v and height v. The area of that triangle is the energy:

Rocket engines add a velocity to the spacecraft we call Δv. What does the triangle look like if we add that velocity increment? Here is the case for two different starting velocities:

The light blue triangle is what you might naively think is the added energy if you hadn’t seen this plot - its how much energy would be added if starting from zero velocity. But there is also a ‘bonus’ energy, in the dark blue rectangle. The critical thing is that the same velocity increment yields more energy if applied to a larger starting velocity.

I haven’t accounted here for potential energy; but that doesn’t change the overall picture. During an elliptical orbit, there is a constant exchange between gravitational potential energy, just as there is with a pendulum. At the highest point, the balance is maximally towards potential energy and the velocity is slowest, and the lowest point with the least potential energy the velocity is highest. Thus, for a TLI burn like the one Artemis II performed, being at the low point of an elongated orbit maximises the velocity, and thus maximises how much overall energy the same rocket burn can add.

Tomorrow, with the crew safely underway, I will discuss more about how this mission fits into the broader Artemis plan. If you haven’t already, please consider subscribing to follow along with the mission.

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[1] All figures here for the Apollo mission are from “Apollo by the Numbers” by Richard Orloff

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Numerous issues that occurred during testing of the rocket caused its launch date to be put back several times from the original target of February, but the launch day itself went quite smoothly. There were a few minor glitches during the countdown - trouble closing the hatch, a faulty reading on one of the batteries for the launch abort system - but these were resolved in a timely fashion and the rocket lifted off only 11 minutes into a 2 hour launch window.

The ascent proceeded without issue, and inserted the capsule, named Integrity, into a low altitude elliptical orbit around the Earth, with the lowest point being inside the atmosphere and its apogee being at an altitude of around 2,200km. At the first apogee, the Interim Cryogenic Propulsion Stage (ICPS) performed a burn to raise the perigee out of the Earth’s atmosphere. The core stage remained on the original insertion orbit, reentered and burned up.

After another half orbit, the ICPS fired for a final time to raise the apogee of the orbit, placing it in a high altitude Earth orbit with an apogee of around 70,000km above the surface. At this point, the capsule separated from the upper stage, and used it as a target for a practice of rendezvous and docking that will be needed on future missions. The high Earth orbit has a period of around 24 hours, meaning the crew has ample time to check out the spacecraft and ensure it is good for the lunar voyage, whilst still remaining close to Earth for a quick return if anything is off. When the Orion capsule reached the apogee of this orbit, it performed its first burn to raise the perigee in preparation for trans-lunar injection

The only problem that seems to have arisen during this period is with the toilet, which is not a critical system anyway as the crew have backup facilities (essentially going in bags, as the Apollo crew did). The problem was fixed though, and the crew are now at the time of writing preparing for Trans-Lunar Injection (TLI), where the engine on the capsule’s service module will perform the final burn to send the crew on a free return trajectory around the Moon.

The Purpose of the Mission

This mission has drawn much attention in the media, and the first question many have on learning of it for the first time is “what’s the objective?”.

The simplest answer is that it is a test flight. This mission itself will not achieve any of the ultimate objectives of the Artemis program, which are all now occurring on the surface of the Moon, but it will demonstrate the capsule that will be used to achieve those objectives, buy down risk, and practice procedures. As Apollo 8 was a necessary step towards achieving the Moon landing with Apollo 11, Artemis II is a necessary step in achieving a Moon base beginning with Artemis IV.

If this is accepted, the obvious next question is on the purpose of Artemis itself. This has always been that the US should return to the Moon to stay, and not just visit, but until the recent refocusing of the lunar effort by the new NASA Administrator Jared Isaacman, the details on this were unclear. Now there is more of a firm plan.

A Moon base will be established which will serve as both a proving ground for Mars - where technology can be demonstrated with the safety net of being able to return to Earth at any point in 3 days, rather than having to wait 6 months - and also as a site for commercial exploitation of the resources of the Moon. The critical difference between a Moon base and an orbiting station such as the ISS (or the Lunar Gateway that was part of the original Artemis plan, but is now cancelled) is that a surface base has a supply of raw materials at hand. By developing technology to turn these raw materials into useful items, such a base can turn 1kg of Earth cargo into 10, 100 or 1000kg of actual payload.

Mass is the fundamental constraint in space, and so this kind of leverage is critical for the ambitious projects to build huge data centres, solar power satellites, giant space telescopes and human habitats in space. The Moon base will be an amplifier for every space ambition, both from the public and private sector.

Tomorrow, assuming all goes to plan with the trans-lunar injection burn, I will be discussing the trajectory design of this part of the mission, and why it differs from the Apollo program. If you haven’t already, please consider subscribing to follow along with the mission.

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This is against the background of an acceleration in the race to return humans to the Moon. This month, NASA Administrator Jared Isaacman led an event called “Ignition”, which laid out the full plan that has been teased for some weeks now. America is going to build a Moon base, and we now have some details on precisely how and when this is going to happen.

Not only does this plan include the already announced SLS/Orion missions - Artemis III as an Earth orbit mission in 2027, and Artemis IV and V as landings in 2028 - but the agency also announced an intensification of CLPS (Commercial Lunar Payload Services - pronounced “clips”).

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Upcoming Features

Here are some things I’ve got planned in the near future:

• When Artemis II launches, currently set to be on the 1st April, I will be providing regular updates throughout the mission. I haven’t decided how many yet - I am wondering if there will be enough interesting happenings to do it daily.

• A big historical deep dive on the V-2 rocket. This is a bit off the beaten track for what I normally do here, but its a critical part of space history and I think many people get it wrong.

• Coverage of a number of new startups developing In Situ Resource Utilisation (ISRU) technologies. This may lead to regular updates on those companies in the Mass Value Reports

• Potentially open sourcing some of the code I have written to produce plots and analysis here.

A Logo

I’m not much of an artist, but I have had a go at designing a logo for the top of the page. It features the orbits of the first four planets in our solar system and a definition of the title, as a shorter version of the explanation I keep on the front page.

I’m not settled on it yet, and I’ve had some feedback already so the final form will not look quite like that. I’d like to get some comments on it below.

Reader Feedback

I am currently just under 3,000 subscribers in total, and most of those I never hear from. I’d like to know what you would like to read more of, or what you think I ought to be doing differently. I’m hoping a lot of you will add a comment to this post.

Next week I’ll be posting the Mass Value Report for March - I’m going to be making an effort to be more timely with these and hopefully they should be more reliably landing on the last day of the month.

Finally, if you are reading for free, please consider becoming a paid subscriber to support my work:

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Compared to the book, the film speeds through some of the science, and this is probably for the best. Were everything on the page to be included the film would be perhaps 4 hours long and terrible. The film correctly places the relationship between the scientist Grace and his alien friend Rocky at the centre of the story, and its more about how they work together to save their respective planets than on precisely how they do it.

Arguably, even mentioning Rocky is a spoiler - but he is heavily featured in the trailers and promotional materials, and the puppet has even made public appearances. Some fans questioned this choice; but having seen the film I think that they realised they had an iconic character on their hands and understandably wanted to make the most of it. He is created with practical effects and is hugely expressive despite lacking any kind of face.

The Ship

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The reason for doing this, aside from for comfort, is that microgravity has serious health effects on humans; we lose muscle and bone mass, the heart weakens, flows of fluid to the head can impact eyesight and even cause neurological issues. Some of these effects can be mitigated by a very intense workout regimen, but it is ultimately a losing battle. For most people a few months of exposure requires extensive recovery when back on Earth, and some effects can persist long after returning. If we want to make living and working in space widespread and routine, and allow long term stays, we cannot subject people to these conditions.

There are barriers to doing this. If a spacecraft spins too fast, or if the radius of rotation is so small that there is a significant difference in the force felt between the head and the feet, people inside can become nauseous.

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Everyone has understood for a long time that the slow flight rate of the Space Launch System is a problem - as Isaacman himself put it, skills atrophy and teams need to develop “muscle memory” for the processes of launching a rocket.

I’ll get into the details below; but first lets revisit New Glenn. Blue Origin is one of the lander providers for Artemis, and the new schedule puts pressure on them to get that lander flying soon.

Blue Origin

The third flight of New Glenn, and the first reflight of a recovered booster, is now scheduled to happen in March. This will launch a cellular satellite for AST SpaceMobile. Below I have plotted the launch campaigns of the first four New Glenn launches, in order to estimate how many flights they will achieve this year.

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Hanks is not just a random celebrity voice here - he has been keeping the spirit of the Apollo era alive for years, and includes here a lot of his own personal recollections of seeing the first Moon landing when he was 13. He is a very effective public advocate for space exploration, and able to make it relevant to ordinary people in a way that us nerds sometimes struggle with.

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When you arrive at Lightroom, you enter a bar area where you can get some refreshments before going down to the room itself. Once it is time for your show, you proceed downstairs through a somewhat maze like series of corridors, before arriving at the venue itself. The place is larger than I had imagined based on seeing photos online, and despite this showing being very busy, it did not feel overcrowded. We were able to get a seat, but some children ended up sitting on the floor (which didn’t seem to dampen their enjoyment). The show lasts for about 50 minutes, and is engaging all the way through. There are multiple elements projected on different walls, so I found myself turning around a fair bit to make sure I took everything in. If that is uncomfortable you can get plenty out of it focusing on the front screen.

Both me and my 12 year old son especially enjoyed the parts when the projection was used to place the audience on the lunar surface with the Apollo astronauts. Much of this part focused on later Moon missions, which is good because it is quite common among the general public to forget that there were 5 more landings after Apollo 11.

Quillette’s Substack

The Artemis Project

Next month, four astronauts will blast off from Kennedy Space Center on the Artemis II mission to the Moon. This is the first time anybody has travelled beyond low-Earth orbit since 1972. The spacecraft, an Orion capsule named Integrity, will fly on a free-return trajectory, looping around the far side of the Moon before returning directly to Earth…

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2 months ago · 1 like · Peter Hague

The Artemis Generation

One especially notable thing was how the show directly linked the Apollo missions to the upcoming Artemis missions to the Moon, including accounts from all four crew members about what Apollo and space exploration in general means to them.

I’d be interested to find out if this show raises general interest in the Artemis missions among the public. As I said above, it seemed pretty popular. I also wonder if this show will be updated and re-released in anticipation of the Artemis III mission in a few years. If you are in the UK (or one of the cities this show tours to) and want to get a friend or family member excited about space exploration, then taking them to Lightroom is a good idea.

To many, this is vindication of their belief that Mars was always a “scam”, that anybody who believed it was happening was stupid, and that they were clever enough to see The Truth. Its a conspiratorial mindset, and unsurprisingly people holding it will consider almost anything to validate their belief that the entire SpaceX enterprise is a house of cards ready to collapse at any moment.

The reality, of course, is a little different.

The New Mars Timeline

Its clearly stated in this post that large scale Mars missions will begin in the 2031 or 2033 windows - which is what most people paying attention had already assumed. The setbacks of last year had made the 2026 window essentially unattainable, and the mission has always called for sending an unmanned flotilla in the synod before the human mission (that would be the 2029 window). I suspect it would take two synods to build full confidence to send humans - the first would be a data gathering mission, to test that the vehicles really can land safely, and the second would be vehicles refined based on this data delivering large amounts of cargo for the initial human missions. So I thought it would probably be 2033 for people, but Musk still publicly aims for 2031:

Slips in the development in Starship have pushed the Mars mission back many times - the initial pitch, back when it was a very different vehicle made out of carbon fibre, mentioned initial cargo missions in 2022. That the best case for these flights is now 2029 is often seized upon as proof that the entire proposal is a fraud meant to boost the stock price (of a company that is not yet publicly traded) by promising to spend perhaps a trillion dollars in the future with little chance of return. These critics don’t seem to understand how business and investment works very well.

The more mundane explanation is of course that Starship is a big, complex project and has suffered delays and setbacks, as these things often do. It would be naive to assume that delays will continue to grow at this stage, as many of the problems of the program are now behind it. Citing past delays to claim the program will keep getting delayed indefinitely, without any technical insight into the actual progress made, is silly.

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The AI Data Centre Rush

The reason Falcon 9 has been able to achieve such high flight rates, high levels of reuse, and amazing economics is Starlink. There was not enough external demand in the launch industry to drive the cadence ramp SpaceX wanted, so they generated demand internally. Not only did Starlink turn out to be very profitable in itself, it also helped reduce costs of launch itself.

The possibilities of space based data centres offer a chance to do this again for Starship, at a much larger scale, hence the company absorbing xAI. The concept is that there will be huge ongoing demand for compute in space, so much so that it will not even be possible to meet it through Earth launched equipment, and a Lunar base with a mass driver will be needed to continue the exponential increase. If it pans out, this will provide a commercial rationale for thousands of Starship launches, paying for the acceleration of the program, and this high cadence vehicle will then be available for Mars missions when a window arrives.

Now the viability of this assumption is up for debate - not so much due to the possibility that we are in an AI stock bubble, because that just means particular companies are overvalued and prices will correct, but because there are differing views on whether or not current AI approaches will slam into some kind of hard barrier causing advances in intelligence to slow. The vibe I get from experts on this is that the answer is “no”, but your mileage may vary. Musk is betting the company somewhat on continued rapid advances in the field requiring ever more compute to train meaningfully more capable models.

If this bet pays off, and although I am no expert in AI I think it has a better chance than not, then it means the demand for Starship flights is practically unlimited and SpaceX can profitably launch them as fast as it is physically capable of doing so. And that same armada of reusable rockets will feed directly into the Mars effort.

Solving the Mass Problem

Elon Musk understands, as many do and as I myself have written about here, that the fundamental problem in space is payload mass. Almost everything is downstream of it. You want to go further or get their faster? You need more propellant mass, and more massive tanks to store it, and more massive engines to provide sufficient thrust. You want to keep astronauts alive for long duration space voyages? They require a lot of mass in terms of food, water and oxygen. Radiation a problem? You need more mass for shielding.

Solving the mass problem is the necessary but not sufficient condition for solving all problems in spaceflight, and in pretty much every case there is a sufficient solution that involves throwing more mass at the problem. This mass doesn’t have to come from Earth, although for the moment it almost always does. It can be provided by recycling waste, as is done on the ISS to some extent, or from in space resources.

The critical thing here is that a good solution to the mass problem (such as a high Starship cadence, or a lunar mass driver) is applicable to pretty much every mission you could want. It will help satellite companies, habitat builders - and Mars colonists. So long as SpaceX remains focused on this problem, they will continue to be successful.