Why SpaceX Prize the Moon

Practical reasons behind lunar land-rush

In 2021 SpaceX won a hard fought contest for the first Human Landing System (HLS) contract, to develop a crew lander for NASA’s Artemis Program. The award process was relatively straightforward, SpaceX bid $2.9bn to adapt their Starship design into a lunar lander, with capabilities that far outshone their competitors, the Blue Origin led National Team and Dynetics. However, this prompted a legal challenge from both competitors and when this case was dismissed, Blue Origin appealed the decision to a federal court. This delayed contract payments for almost a year before the appeals court dismissed the case due to lack of substance. At the time SpaceX COO Gwynne Shotwell revealed they were receiving some kind of court action or regulatory challenge from a Bezos owned company every week, so things were really heated. Previously there had been an unspoken accord that Musk would aim for Mars while Bezos owned the moon – at least commercially. Now the gloves were off and the ferocity of these attacks suggested there was more in play than a tech titan’s bruised ego. Subsequently strings were pulled at congress, who suggested NASA produce a second Human Landing System; and Blue Origin were duly awarded the development contract, after SpaceX were banned from bidding…

In the past Elon Musk has been relatively dismissive about the moon, insisting Mars has far better prospects, at least for colonization purposes. Then his views abruptly changed and quite characteristically he went all in on the moon, much to Jeff Bezos’ chagrin. The development money for HLS is unlikely to be Elon’s sole motivation as he has vast financial resources; added to which he thinks strategically which suggests there’s some greater benefit to be had from the moon (for SpaceX specifically and humanity generally).

Starship delivers Space Exploration Vehicles to the moon ~ credit NASA.gov

The long view

Since the 1950s NASA has sought a practical reason to establish a lunar outpost, be it scientific, technical or even commercial. Fortunately, around the turn of the millennia, significant amounts of water were discovered, deposited on the floors of lunar polar craters. Some estimates suggest quantities of 600 million tonnes, likely in easy to access deposits just beneath the surface. As an added inducement, some methane, carbon dioxide and monoxide deposits were found at the same location, all deep frozen as these craters lie in permanent shadow hence maintained at deep cryogenic temperatures (≥ 25 Kelvin). In one swoop NASA discovered the perfect reason to base on the moon, considering these raw materials constitute all that’s needed to synthesize hydrolox and methalox propellant, in sufficient quantities to support sustained cislunar operations.

At present the cost is prohibitive to operate anywhere except in Low Earth Orbit (LEO) because all the propellant needed to go farther must be lifted out of Earth’s deep gravity well. In real terms, ~70 tonnes of propellant is expended to place a single tonne in LEO, to fuel any Beyond Earth Orbit (BEO) mission. In addition if the propellant is stored at cryogenic temperatures, normally it has to be used in less than an hour to avoid losses due to boil-off. Until recently that wasn’t a serious problem as staged vehicles could launch to LEO then promptly expend all their upper stage propellant to send their payload to BEO. However, this makes sustained operations in cislunar space almost impossible, because around 10 tanker flights would be required to refuel each tanker sent to BEO to refuel any deep space mission, assuming the boil-off problem can be solved. Hence the moon seems an ideal place to source propellant as its one sixth gravity makes launch surprisingly easy compared to Earth. To illustrate: boost stages are completely unnecessary for heavy lift launches from the moon, assuming the launch vehicle employs high efficiency hydrolox or methalox engines. As an additional bonus any lunar processing facilities could be located inside lunar polar craters which are maintained at cryogenic temperatures hence an ideal environment for propellant production and storage. The potential setup is almost too good to be true, all that’s needed is some pressing reason to operate in cislunar space…

Geopolitics and Commerce

China, Russia and an assortment of allied countries have agreed to establish an International Lunar Research Station, and China’s Chang’e 6 rover should return samples from the South Pole region this year, as a precursor to sending taikonauts in the 2030s. This strongly suggests another space race is brewing, except this time between the US and China. The original space race fizzled, mainly due to inherently high cost, but if cheap propellant can be produced on the moon that changes everything, making sustained lunar operation far more feasible. NASA intend to build an outpost in the southern polar region, to investigate propellant production along with lunar science and exploration. No doubt many commercial companies will become involved in this effort, for example: Collins Aerospace and Axiom Space have been contracted to develop space suits for the lunar surface, which they intend to lease to NASA. SpaceX are heavily invested into In Situ Resource Utilization (ISRU), with a focus on producing propellant from raw materials common to other worlds, something they have pursued for over a decade to support Mars missions.

“Mars ISRU was what I worked on for my last 5 years [2013-2018] at SpaceX” ~ Tom Mueller, former CTO of Propulsion Development

Given SpaceX’s commitment to this work and prior experience, they could mount a pretty compelling bid for propellant production on the moon, and in the process establish methalox (the propellant system used for Starship) as the standard for cislunar operations.

Asteroid mining has long been heralded as the next big space application, considering a single asteroid could contain $trillions of rare earths and metals. However, asteroids have rained onto the surface of the moon for billions of years, which suggests any raw materials they contain have been deposited on the surface, essentially there for the taking. It should be possible to refine these raw materials on the moon, helped by its one sixth gravity, to further increase their value. Some materials are clearly better targets for lunar mining, for example: two hundred tons of lanthanum (a rare earth element) is only worth $1m, while the same quantity of rhodium (a platinum group metal) could net $3bn! And we shouldn’t discount the discovery of even more exotic materials on the moon, which are currently unavailable on Earth, that could make rhodium prices seem like pocket change. Overall there seems good reason for geopolitical interest in the moon, not to mention its strategic importance as the fuel stop for cislunar operations. No doubt if Chinese and American corporations compete for resources in this region, the US Space Force might need to patrol the area to help maintain the peace.

“But as nations move out, and as the economy grows between here and the lunar surface, and as you look at key terrain for the defense of our nation, I think it’s an area that will be significant as we move forward… I do see that there may be a role for Guardians that will be in space. So I think that will happen in the... career timeframe of the Guardians that are coming into service right now.” ~ Chief of Space Operations Gen. John W. “Jay” Raymond

SpaceX Prize

Given the breakout potential for lunar commerce, SpaceX should be in pole position to benefit given their unparalleled prowess as a space transport company. Certainly they have big plans for the moon, beyond launching hundreds if not thousands of passengers to NASA’s moon base. Elon suggests a complete propellant production plant could fit inside Starship, capable of manufacturing thousands of tons of propellant, if landed close to surface deposits of the raw materials. However, such large scale production would need significant power, likely ~1MW of electricity would be consumed for continuous operation.

“To get one ship back, you need about eight football fields worth of solar cells on Mars… It’s much better to use nuclear fission reactor… We’re working with NASA on that, and hopefully they’ll get funding to develop that. They’ve got a program called Kilopower going that’s like, ten thousand watts, a 10 kilowatt reactor. We need a megawatt, but you know, you need to start somewhere.” ~ Tom Mueller, former CTO of Propulsion Development

Fortunately Starship can carry up to 200 tons, which suggests it could be equipped with one or more nuclear reactors, similar to those used on nuclear submarines. Miniature reactors are normally unobtainable by commercial companies, so it would represent a major win for SpaceX if they gain access to this technology, given the strategic importance of in situ propellant production. Of course, once they are familiar with their construction and operation, SpaceX could manufacture their own nuclear reactors, perhaps sourcing fissile materials locally on the moon and Mars – an even bigger win for the company. Probably important to note: SpaceX have a longstanding interest in developing nuclear propulsion because it offers an order of magnitude higher efficiency (Isp) than convention chemical engines. Such high Isp engines would enable far more capable transport vehicles than Starship, with potentially enormous tonnage to accelerate the colonization process. Hence gaining access to nuclear reactors could be seen as the gateway to acquiring nuclear propulsion, a significant step towards solidifying the company’s dearest ambitions.

In addition, SpaceX plan to operate legions of autonomous equipment on Mars: Optimus robots, pressurized Cybertrucks, water excavation equipment, propellant plants even Starship itself will be flown by AI. They’ll need vast amounts of data to train these AIs, something they could acquire under realistic conditions from their propellant production operation on the moon. Technically conditions inside lunar polar craters are far tougher than Mars, e.g. colder temperatures, lower gravity and more abrasive dust, but this could actually assist SpaceX in the long run. Any equipment developed on the moon would be far more durable, likely a godsend for Mars considering it could take 2 years to deliver spares or suitable replacements from Earth.

In conclusion

Competition for lunar exploration and exploitation is hotting up between US and China – and already red hot between SpaceX and Blue Origin. Currently there’s billions at stake for government contracts with trillions more for whoever discovers a mountain of noble metals on the moon – a real El-Dorado.

Whatever happens on the moon SpaceX should benefit directly, through providing a reliable transport service with Starship. Arguably the indirect benefits accrued could be far greater, such as gaining access to nuclear power, which then leads to nuclear propulsion – releasing the genie from the bottle. Sure SpaceX will have great fun testing all their new tech in cislunar – and show China how it’s done...

Chris Prophet