NASA Identifies Lunar Cargo and Mobility Gaps

The development of NASA’s Moon to Mars Architecture is a continuous process, one which is always seeking to strengthen our approach to sending humans to Mars and beyond. In June, NASA released a pair of white papers that give a glimpse into this year’s analysis: Lunar Surface Cargo and Lunar Mobility Drivers and Needs. These papers tell a story of unmet demand at the Moon, and suggest that NASA will soon procure a new cargo lander and utility rover to support the early Artemis campaign. Furthermore, these documents offer an exemplary case study of how this process helps the agency efficiently meet its needs—and how the public can uncover clues about what comes next.

A Brief Architecture Recap

NASA’s architecture development process is formally known as the Strategic Analysis Cycle, a continuous workflow punctuated by annual Architecture Concept Reviews. These reviews are followed by the release of public documents to help communicate NASA’s progress, including a revised Architecture Definition Document and a number of brief “white papers” on specific topics. NASA is currently working towards the 2024 Architecture Concept Review, ACR24, and these new white papers are the first public products from this year’s cycle.

During the Strategic Analysis Cycle, NASA works backwards from its overall goals for the Moon to Mars program, breaking them down into the use cases and capabilities needed to achieve them. When a gap in these capabilities is identified, the agency has a few options. Smaller gaps may be covered by existing elements, like a spacecraft taking on an expanded role. But larger gaps may require NASA to start considering a new system, a process formalized by Element Initiation. This is how elements such as the Pressurized Rover and Surface Habitat came to be part of the Artemis Program.

This is the key context for these new white papers: each one identifies a major gap in NASA’s capabilities at the Moon, implying the agency will initiate new elements to fill these roles. Specifically, NASA finds itself lacking the means to deliver mid-sized cargo to the Moon and to transport these payloads between different sites on the lunar surface.

Lunar Surface Cargo

Sustained exploration of the Moon will require a diverse array of cargo payloads to be delivered to the surface, ranging from technology demonstrators at just a few kilograms up to rovers and habitats with masses of many tons. In particular, astronauts living for long durations on the surface will need supplies such as food, spare parts, and other items that are often lumped together as “logistics.” Just like the International Space Station needs continuous resupply from cargo vehicles, future Artemis crews may need anywhere from 1 to 6 tons of logistics to be delivered to the surface per mission, depending on how long astronauts will be staying on the Moon.

Cargo variants of the HLS, called Human-class Delivery Landers (HDL), can transport elements up to 15 tons; at the other end of the scale, commercial landers procured via CLPS are sized for payloads no larger than 500 kilograms, or half a ton. But neither of these size classes is well-suited to mid-sized payloads, which may include power generation and science equipment in addition to critical crew supplies. This disparity creates a gap in capability: no current lander can efficiently transport payloads between 0.5 and 12 tons to the Moon. Crucially, this limits logistics deliveries for long-duration missions.

Author’s note: NASA’s analysis of the cargo gap focuses on current CLPS task order capability. Future CLPS providers, such as Blue Origin’s Blue Moon Mark 1, may extend the upper limit of CLPS capabilities and help provide redundant coverage of this gap alongside a dedicated international element.

During early Artemis missions, astronauts will use logistics stored inside the Human Landing System (HLS), the spacecraft that will transport them to and from the lunar surface. However, the HLS is not equipped to carry supplies for missions longer than about a week. Smaller quantities could be split up between multiple small landers, while larger ones might hitch a ride alongside other large payloads to fill an HDL. Still, NASA has emphasized the importance of flexibility in cargo delivery options. A diverse fleet of vehicles ensures NASA can meet its needs as efficiently as possible, and provides redundancy in case any single provider becomes unavailable.

This is where Element Initiation comes in: to fill this gap in capability, NASA may soon officially incorporate a mid-sized cargo lander into the Moon to Mars Architecture. There are already a few likely candidates to fill this role. The European Space Agency has been developing its Argonaut lander concept for several years. This multipurpose lander is designed for payloads of around 2 tons, handily covering the lower end of the gap, and sufficient for logistics needs in the near term. NASA has also been working with the Japanese Aerospace Exploration Agency on another cargo lander, though its capacity has not yet been determined. This lander could be adapted to fit the higher end of the gap, perhaps overlapping with ESA’s Argonaut to provide redundant coverage of NASA’s logistics needs.

However, the size of these new landers—and the rockets needed to launch them—remains an open question. At about 10 tons, the smaller Argonaut is slated to require an Ariane 64, Europe’s heaviest lifter. Arianespace currently offers up to 8.5 tons to a lunar transfer orbit, though a planned carbon fiber upper stage called Icarus and uprated boosters may lend it a few extra tons of capacity. Meanwhile, Japan’s native H3 is limited to about 5 tons to the Moon, likely not enough for a lander much larger than Argonaut. Mitsubishi Heavy Industries, the vehicle’s manufacturer, has reportedly been considering a triple-core variant to enable more capable lunar missions, including possible lander services, though such an upgrade would be years away. Despite these challenges, both space agencies are committed to partnerships with NASA in the Artemis program, and each looks eager to serve this nascent architecture role.

Lunar Mobility Needs and Drivers

Delivering cargo to the lunar surface is only half the battle. Any lunar surface architecture must resolve a simple problem: cargo cannot always be landed exactly where it needs to end up. To avoid sandblasting each other with dust kicked up by their engines, landers may need to maintain a minimum separation of at least a kilometer from one another. Furthermore, the rugged terrain and low sun angles at the lunar South Pole cast everything into a stark contrast between light and shadow. Sunlit mountain peaks and ridges might be ideal for locating habitats and solar power, but such “islands in the dark” may be just a few hundred meters across, forcing landers to keep clear of this prime real estate. To get from points of delivery to points of use, cargo will need to travel several kilometers and negotiate steep slopes. As previously described, this includes frequent logistics packages massing around 2 to 6 tons, and the occasional larger element of up to 15 tons.

For early Artemis missions, the Lunar Terrain Vehicle (LTV) will help astronauts roam a few kilometers from their landers, carrying up to 800 kilograms of cargo along for the ride. Later on, the Pressurized Rover, a mobile home for longer journeys, may be able to saddle up to about a ton of cargo. Still, both of these rovers will be tied up serving astronauts first and foremost, and limited to carrying light payloads for field work; neither of them will be free to run odd jobs as an independent utility truck. This is the second major gap in capability: NASA needs a workhorse vehicle on the lunar surface, able to operate independently of crew and relocate the large quantities of cargo needed to support future missions.

As before, this clear identification of a well-defined architecture gap signals that NASA may soon initiate a new element for the Moon to Mars Architecture—in this case, a robotic utility rover. Besides carrying heavy cargo over long distances and rough terrain, this vehicle could also be used to unload payloads from their landers, and may need to dock or otherwise interface with other elements on the surface. The new element should be at least partially autonomous to reduce crew workload and streamline operations, and could even employ novel technologies such as collaborative swarm robotics. NASA’s white paper stressed that how these systems are used is just as important as their technical capabilities.

This role may sound familiar to those who have followed NASA’s lunar ambitions over the years. To support the defunct Constellation Program, NASA’s Jet Propulsion Laboratory developed the six-legged ATHLETE rover, which would have filled a similar niche. This vehicle leveraged precision robotics to manipulate large items like habitat modules, exhibiting flexibility and complexity in equal measure. While a modern system could look very different, much of the underlying technology and operational paradigm will likely remain quite similar.

So, what could this new element look like? LTV providers such as Lockheed Martin and Astrobotic have conceptualized utility variants of their crewed rovers, which could help buy down risk for a future cargo rover. However, there is an even closer match: the Canadian Space Agency is studying its own multi-purpose utility rover to contribute to the Artemis program through an international partnership. The concept is still in its early stages, but the functions under consideration for this vehicle closely align with those currently missing from NASA’s Moon to Mars Architecture: hauling heavy payloads and autonomous operation, as well as smaller “housekeeping” tasks to streamline crew operations in an exploration zone.

While an official arrangement with NASA has not yet been announced, Canada may seek to exchange this utility rover for Canadian boots on the Moon, much as JAXA has done with the Pressurized Rover. However, and similarly to JAXA’s vehicle, Canadian industry will need to overcome unresolved challenges with wheeled mobility on the Moon. Larger rovers struggle to generate traction in the moon’s low gravity and loose, dusty soil, called regolith, and this dust can infiltrate and erode moving parts. Delivery of the new element to the Moon will also be an item to watch. If the vehicle is comparable in mass to the LTV, it might leverage similar landers such as Intuitive Machines’ Nova-D; any larger, and it could require a more capable HDL, or perhaps the new mid-sized cargo lander.

What Comes Next

While it is possible that NASA may partially fill these gaps by expanding the capabilities of existing systems, the evidence suggests that the Moon to Mars program will initiate a new cargo lander and utility rover in the near future. A pair of NASA projects that seem to align with these roles are known to be in pre-formulation, an early phase of development. If these elements are initiated between now and ACR24 this November, they would make their first appearance next January in Revision B of the Architecture Definition Document, the annually-revised summary of NASA’s Moon to Mars Architecture. However, updates on their status could come as soon as the next meeting of NASA’s Human Exploration and Operations Committee on August 29th.

In the meantime, white papers like the ones covered in this article can be released at any time, providing new snapshots of NASA’s evolving architecture process. In fact, these two papers each alluded to additional topics which will receive white papers of their own: one on NASA’s lunar surface strategy, and another highlighting an additional gap in cargo return capability. These would likely be published no later than January of 2025 as part of the ACR24 product release, alongside many more on other Moon and Mars topics.

The early development of these new elements serves as an excellent example of how NASA’s Moon to Mars Architecture responds to its needs. Both systems serve functions and use cases that are not yet fulfilled by existing elements, and will allow NASA to close important gaps in capability during the Foundational Exploration period of the Artemis program. Furthermore, the utility rover role in particular will likely be transferable to Mars. Early missions to the Red Planet will almost certainly require multiple surface elements working together, generating a similar demand for moving large payloads from one point to another.

Though NASA’s architecture process can seem opaque on the surface, by understanding its inner workings we can keep up to date with the latest conversations happening within the Strategy and Architecture Office. White papers like these are immensely valuable in decoding the Moon to Mars Architecture as it happens, and offer clues about the next steps for this groundbreaking program.

Edited by Scarlet Dominik, Emily B and Nik Alexander