Op-Ed: Setting Up Camp, an Exploration of Artemis

Today’s feature comes from industry expert Robbie Gitten – Robbie Gitten grew up watching way too much Star Trek and now finds himself working on one of the crewed lunar lander programs. He is passionate about commercial human spaceflight, an industry he is actively helping to build, and hopes to someday put a person on Mars. Outside of work Robbie likes to write on his blog.

After decades of dreaming, We Are Going! The rockets are flying, crews are in training, and the landers are under contract. Artemis will put the first woman and first person of color on the Moon by the end of this decade… But then what? A plan is slowly coming together. NASA along with its commercial and international partners intends to do so much more than flags and footprints. That next landing will be the start of a sustained campaign on the Lunar surface, one that will open up the Moon as a new frontier for international scientific collaboration and where we learn what we need to go to Mars.

A Plan (of Sorts)

Congress has directed NASA to develop an overarching strategy for how the Artemis program will build on its initial Lunar landing focus to enable human missions to Mars. It has the delightful title of ESDMD-001 Moon-to-Mars Architecture Definition Document. We’ll call it the ADD for short.

Mars is the ultimate goal and the EDD works backwards from there, what NASA calls Architecting from the Right. The ADD outlines three major phases, or what NASA calls segments, of Lunar exploration to build the requisite skills needed for Mars. First up is the Human Lunar Return, an initial series of short duration missions to get boots back on the Moon. This will be followed by the Foundational Exploration segment, where we will actually start building up the infrastructure to enable astronauts to live and work at the Lunar South Pole for durations of at least 30 days. 

Why the South Pole? The South Pole is by far the most interesting part of the Moon. Deep craters like Shackleton may have water ice and other volatiles in their permanently shadowed regions. These volatiles could contain a crucial record of the early solar system and may also be a resource for a future Lunar economy. Why 30 days? According to the ADD, 30 days is about the minimum stay time for an initial human Mars mission. NASA wants to demonstrate that their hardware, procedures, and people can operate in a similar environment for the same amount of time.

After the Foundational Exploration is the Sustained Lunar Evolution segment. This bit is a lot less concrete than the other segments. If anything, it describes NASA’s desired end goal: they go to Mars while industry and international partners build a continuous human presence on the Moon. It is somewhat analogous to what NASA is seeking to do in low Earth orbit after the retirement of the ISS.

That’s the plan as of today. Given that our current experience with Lunar surface operation is measured in hours not weeks, I think the general sequence to build out capabilities described in the ADD makes sense. I also fully expect that large parts of it can and will change. New technology, new science, & changing politics, are part of the kludge that is human spaceflight. Even if the ADD doesn’t fully come to pass a minimum set of things will be required to do anything useful on the Moon. Let’s take a look at them.

Suits

Extravehicular Activity (EVA) really is the mission for Artemis. We are here to learn how to explore a world like Mars on foot as god and Jack Schmidt intended. Lunar EVA is going to be unlike anything we have done since Apollo. We’re going to be going out more or less every day on the Moon. Contrast this with EVAs on ISS, which are carefully planned events that only happen roughly once a month. Think about that for a second: a single thirty day Artemis mission is likely going to do more than twice as many spacewalks as the ISS does in a year! This is going to require a new type of space suit that can be used over and over again in the harsh Lunar environment. Given that the Apollo suits were struggling to keep up after only a few days of EVA, these modern moon suits are going to be an absolute leap in EVA technology.

Under their Exploration Extravehicular Activities Services (xEVAS) program NASA has selected two providers for Artemis suits: Collins and Axiom Space. Collins and their partner ILC Dover are the legacy NASA suit team, having built the suits for Apollo, Shuttle, and ISS. They build good stuff that works but have a reputation for being on the pricier side. Upstart Axiom Space is a commercial company originally founded in 2016 to develop a commercial space station. They have licensed a lot of NASA’s own internal designs for advanced suits and hired many of the key people. These are both stellar teams and I think they will make NASA proud. Outside of Artemis, SpaceX is developing their own EVA suit for Polaris Dawn and who knows what else is being worked on out there. This is a very dynamic time for suits.

The fundamental constraint on EVA is time. Time drives everything, because the suits only have so many hours of oxygen. A rule established during Apollo is that the astronauts must have enough oxygen in their tank at all times so as to safely walk back to their lander before their air runs out. The distance that the astronauts can travel is highly dependent on the levels of O2 in their tanks and is called the maximum safe walk back distance. NASA is requiring their xEVAS providers to support eight hours of nominal EVA time plus an additional hour for contingency. The 1hr contingency drives the walk back because it represents the worst case scenario. If an astronaut on EVA has an average speed of 2 km/hr (as they did on Apollo) then the maximum safe walk back distance is 2 km.

Two kilometers is not very far. If we set down at the Space Needle in Seattle, 2 km gets us most of downtown and just across the I-5 to Cap Hill. Good enough for tourists, but doesn’t give a visitor the true feel for the city. If we want to make a better use of our EVA time we need to do better than 2 km/hr. What we need is a set of wheels.

Mobility

Rovers are an obvious solution to the walk back constraint because they allow us to travel further in the limited time we have. We will get to the interesting locations sooner with more oxygen still in our tank and can make a longer walk back if the car breaks down. This is why NASA built the original Lunar roving vehicle (LRV) in the 60s. The LRV extended the range of exploration to 10 km! Now we can get to some of the more interesting neighborhoods. 

A simple rover completely transforms what can be done on the Moon, and thus NASA wants one ASAP. Dubbed the Lunar Terrain Vehicle (LTV), it will be delivered on a separate cargo lander later this decade. NASA envisions the LTV as more of a robotic platform with seats. Like one of the JPL Mars rovers, the LTV will be self-powered and capable of autonomous driving. The plan is to move the rover to different locations at the Lunar South Pole and have the crew meet it in their lander. How cool is that!

NASA plans to procure the LTV as a commercial service sometime in mid 2024. The field is stacked with everyone from legacy primes like Lockheed & Northrop to California startup Venturi Astrolab throwing their hat in the ring. 2024 is sure to be an exciting year for Lunar exploration as one of these lucky teams will be chosen to build our next Lunar rover.

LTV is an unpressurized rover. The astronauts are still relying on their space suits and their 8 hrs of oxygen. It will allow us to go far but we can’t stay for very long. Not exactly the most convenient situation for a night on the Hill. Spacesuits are cool but we can do better. Enter the pressurized rover.

Pressurized rovers are not new. Herge first depicted an adorable “moon tank” in the famous Tintin comic. During the Apollo program NASA did quite a bit of serious work on a version of this concept called MOLAB (MOBile LABoratory, get it?). The idea is pretty self-explanatory; make your rover a little mobile habitat, something with enough oxygen, water, and other resources to support the crew for days instead of a few hours.

The Japan Aerospace Exploration Agency, JAXA, has even offered to build one, and proposed such an architecture for Artemis missions. Dubbed the Lunar Cruiser, it will be built in partnership with god-tier truck manufacturer, Toyota. Lunar Cruiser would be capable of supporting 2 crew for 30 days or 4 crew for a week or two. It’s a beast of a Moon machine with its own power generation, life support, and communications back to Earth. Like the LTV, the plan for Lunar Cruiser is to be capable of autonomous driving so it can meet the crew at their landing site.

Lunar Cruiser will be a boon to Lunar exploration. Instead of only brief excursions lasting a few hours, scientists would be able to spend days in the field doing the kind of in depth surveys that they would do on Earth. In a contingency, the crew will be able to fully top off their suit tanks from the rover’s own oxygen supplies, allowing them to venture 12 km from the lander. An LTV + Lunar Cruiser working together would be even better. Instead of maximum walk-back distance, there would be a maximum drive-back distance, with the crew able to use one rover to return to their lander if either rover developed any issues. For instance, should the Lunar Cruiser break down at a remote site, the LTV could ferry the crew back to the lander. 

At this time JAXA appears committed to only building one Lunar Cruiser, which in my opinion is a bit of a shame. Two would allow the astronauts to more or less eliminate all walk-back or drive-back constraints. If something goes wrong, the crew just boards their second spaceship on wheels and drives home in comfort. A second pressurized rover would allow a single crew to explore for hundreds of km. That gets us not only Seattle but the Olympics and Cascades too. It would open up the entire Lunar South Pole to human exploration and it is my sincere hope that humanity finds the resources to build it.

Habitation

Although they’re not as mobile as pressurized rovers, dedicated surface habitats bring two major benefits to early lunar exploration. The first is by acting as a logistics depot for the pressurized rovers. A surface habitat can be a place to stash supplies and spare parts so that the rover doesn’t always have to lug that weight around. The second is that surface habs could provide dedicated laboratory space to actually do crew tended science on the Moon with more advanced equipment, everything from biomedical research in partial gravity to in-situ analysis of samples collected during rover journeys.

The current leading candidate for humanity’s first lunar habitat is the Multi-Purpose Habitat (MPH) being developed jointly by the Italian space agency, ASI, and Thales Alenia Space, TASI. It is a 3m diameter module and is of similar form factor to the HALO and I-HAB modules TASI is building for Gateway. Independent power generation and life support will enable MPH to support crews of up to 4 for around 30 days (although TASI has not specified the full capability). The project is a few years behind Lunar Cruiser, having only just completed its element initiation review with NASA in October, 2023. MPH will undergo its mission concept design review in early 2024. Should that go well, the detailed design and development would commence.

There continues to be rumblings of a potential U.S. surface habitat to complement international efforts like MPH. American Aerospace companies such as Sierra Space, Lockheed Martin, and Northrop Grumman have developed concepts under the NASA NextSTEP Appendix A program. In the original source selection document for Starship HLS, NASA cited how Starship’s large pressurized volume and ample cargo delivery mass could enable it to fulfill many of the missions envisioned for a dedicated surface hab. With MPH gaining momentum, I personally do not see a U.S. surface habitat program arising anytime soon. If international partners are stepping in, then NASA and Congress may find that their funds are better spent on things like Mars sample return or commercial LEO destinations. 

Utilization

Utilization is a NASA term for the science and research payloads that fly on a crewed mission. Artemis is very much a science forward program and NASA will by flying utilization on the very first HLS mission. In 2022, NASA published HEOMD-006 Exploration Systems Development Mission Directorate Utilization Plan, the master plan for science on the Moon. It outlines many scientific goals for lunar exploration that frankly warrant their own article. In short they can be categorized as:

• Using the Moon to learn about the Moon
• Using the Moon to learn about the Earth, the Sun, and the solar system
• Using the Moon as an astronomical platform
• Using the Moon as a technology testbed
• Using the Moon to develop procedures and training for Mars

It is very early days and NASA is only just now beginning to engage the research community on what these payloads may look like. Like ISS, most will be small instruments that are either carried by astronauts or mounted to a larger element. However, we are beginning to see interest coalesce into some larger scale efforts that are worth noting.

The first is fission surface power, FSP, an effort to operate a nuclear reactor on the Moon. FSP would be the first nuclear reactor NASA has operated in space since SNAP 10A in 1965. The project has many stakeholders at the agency. The human exploration community wants FSP because it will likely be needed to power crewed infrastructure on Mars. The science community wants FSP because it will develop the technology needed for high power missions to the dark outer planets. NASA and the Department of Energy have funded some preliminary studies and even conducted some ground tests. but it remains unclear if enough funding will be available to proceed to a flight program. Several international partners, mainly the United Kingdom, are also interested in being part of a reactor development. Although FSP is a lot less clearly defined than other surface elements I remain optimistic that it will fly one day.

The second is lunar in-situ resource utilization, ISRU. This is a broad term for a host of technologies that does everything from lunar earthmoving to make roads and landing pads to chemical extraction of oxygen and other valuable resources from the Moon. There is a lot of buzz in this space but the technology is very preliminary. NASA is developing an ISRU roadmap and I fully expect the early days to look more like a family of experiments than an operational capability. Given that China is flying a dedicated ISRU demo on Chang’e 8 I expect this to be an early priority. 

Lastly, there’s Endurance-A. This is a concept for a robotic rover that collects samples and drives them back to waiting astronauts who return them back to Earth in their lander. Why a robot rover? Even with spacesuits and multiple rovers there are still areas of the Moon we wouldn’t want to send crew for one reason or another. They could be areas that are too treacherous for crew to safely access or areas we don’t want crew to contaminate. Endurance-A has some legs behind it. It was endorsed in the 2022 National Academy Decadal Survey which is a big deal for a robotic mission. The Decadal represents the scientific community’s consensus on where funding priorities should go. Given the historic narrative on humans vs robots, it is an encouraging sign to see the scientific community propose mission like this. Endurace-A would be the first example of humans and robots exploring another world together and would hopefully be precedent for similar combinations in the future.

Logistics

The HLS landers are designed to transport the crew, their suits, some small payloads, and samples to/from the Moon. Everything else is going to require dedicated logistics. For delivering large elements like Lunar Cruiser & MPH, NASA will be working with their HLS partners to develop a cargo derivative of HLS called the Human-Class Delivery Lander, HDL. HDL is going to be a monster capable of putting multi ton modules on the Moon. Think of it as the Shuttle C to HLS’s Shuttle Orbiter. Delivering cargo with HDL is likely going to be a complex and expensive operation; requiring multiple spacecraft and launches, just like HLS. It will probably only be used for large monolithic elements that require its capacity.

For smaller payloads NASA plans to partner with their Commercial Lunar Payload Services (CLPS) providers. CLPS landers can transport several hundred to several thousand kilograms to the lunar surface. They can go up on a single launch (or better yet, as a rideshare) and are therefore likely to be significantly cheaper per flight than an HDL class lander. Smaller payloads like LTV, Endurance-A, and FSP all assume delivery via a CLPS lander. In addition, the European Space Agency, ESA, has recently announced their own CLPS sized lander, Argonaut. It will launch on Ariane 6 and is going to be part of ESA’s contribution to the surface exploration effort. 

The plan for each Artemis mission is to pre-deploy the cargo via HDL or CLPS class landers months in advance and have the crew land nearby in HLS. The number of logistics flights will depend on the mission. Early missions might just require a single CLPS or Argonaut to deliver a payload package. Later, thirty day, exploration campaigns will require literal tons of supplies for the crew alone in addition to utilization and large element deliveries. It is quite conceivable that once Artemis is running at full speed we could be sending as many logistics flights to the Moon as NASA currently does to ISS, if not more!

Cargo for crew is of a special consideration. Unlike most scientific payloads, human supplies like food, clothing, and hygiene supplies can’t just sit out on the lunar surface unprotected. The temperature extremes and UV radiation will break most macronutrients and textiles down. Cargo like this has to be delivered in a pressurized logistics container that almost acts like a miniature habitat or spacesuit. NASA has begun development of such logistics containers.

 They are looking at 3 candidate designs differentiated by means of transport into the rover or habitat. Two are intended to be hand carried by suited astronauts, the idea being that the crew would physically transfer the container into the receiving vehicle’s airlock. NASA tested this concept with real astronauts underwater and there were concerns. Chief among these that given the size of anything a single astronaut can carry with them through an airlock is small (akin to a handbag), and thus that it would require dozens of transfers in order to resupply something like Lunar Cruiser. This would be both time consuming and challenging to do with the limited mobility of a space suit. The third design is to have a larger container with a small hatch. The crew would “berth” the container to an identical hatch on the receiving vehicle allowing for the cargo to be transferred in a shirtsleeve environment. It does require some sort of mechanical aid to lower the container to the surface, but in my opinion this is clearly the way to go for lunar logistics. Early tests like this will be super useful for informing the design of elements like Lunar Cruiser and MPH.

One area where NASA is struggling is returning cargo from the Moon to Earth. As of now the only means to get a sample or a payload back to Earth would be to send it back to Gateway with the crew in HLS and then from Gateway to Earth in Orion. HLS is not intended to lift large amounts of cargo off the Moon nor does Orion have tremendous capacity for down mass. This poses several challenges for NASA and Artemis at large. The most obvious one is that it is going to limit the amount of lunar samples that can be returned to Earth. This will have all kinds of knockdown effects on the type of science that can be done on the Moon to who gets priority of these samples. The other major challenge is sustainability. On ISS, items are constantly being returned to Earth either to be reused on a subsequent mission or disposed of as trash. Without a means to get used items off the Moon, waste is going to accumulate. Unless NASA and partners carefully manage that footprint, Artemis Base might look like one of those Russian Antarctic stations where junk is just lying around everywhere. Not a good look.

Fortunately there is both interest and time in solving this problem. Some of the more popular ideas include developing an ascent vehicle for CLPS or using recurring HDL flights as garbage trucks. Maybe you will think of something!

Conclusion

So there you have it; suits, mobility, habitation, utilization, and logistics do a Moon base make. I wanted to tell you about all this because I am excited – excited not just by the coolness of the rovers, suits, and other hardware, but excited in an almost sublime way. If you think about it, Artemis is in many ways the culmination of a story, our story. Millennia ago our ancestors came down from the trees and set up our first camp on the savanna. What must those days, those most distant days, have been like? I imagine that in the very very beginning it must have felt like one group, one human tribe against the world. For whatever reason, disaster, petty rivalry, or perhaps simply the desire to see what’s beyond the horizon, the tribe split up. At some point a splinter of humanity reached the sea. What’s this? We can’t drink this or swim across it? Faced with a challenge, people as curious, smart, and motivated as any of us working on Artemis today invented boats. The tribe thus began to expand to the whole world and we have been on a 50,000 year camping trip ever since. 

How lucky we are to be part of the generation that will build the human tribe’s first camp on another world. What a monumental task this will be. It’s something that happens only once in the history of a civilization. Building out this surface infrastructure is not the task of any one nation or company but of an entire planet. Artemis Base Camp will remind us that we are one people surviving in this cosmos together. That’s what has me excited about all this and I hope you truly have come to feel the same as well.