Mars and the moon: not an either/or proposition

The moon may be a much-needed pit stop for a very long journey to Mars.

This op-ed originally appeared in the Aug. 27, 2018 issue of SpaceNews magazine.

In planning a new venture, it is often useful to look at prior similar attempts or analogs; hindsight is always 20/20. One analogous era in American history is that of the American Western Frontier, when the nation and the unique American brand of exploration and free enterprise were developing.

Historical precedent shows successful exploration frontiers typically make use of local resources, such as water, along the exploration route.

The U.S. government under the leadership of then president Thomas Jefferson funded the 1804 Lewis and Clark Expedition to find a path to the West Coast. They navigated and surveyed the path and defined state of the art exploration.

From 1842-1860, U.S. Army forts in this new frontier enabled westward migration as waypoints and logistics resupply on a path for frontier pioneers migrating West along the Oregon Trail.

Initially many doubted the truth of gold claims in the West. It was not until President James Polk confirmed to Congress that the claims of gold deposits were accepted as accurate. This spawned the 1849 Gold Rush.

There was a surge of prospectors bound westward. Supporting them were small towns that sprouted up to outfit the prospectors and provide the products they might want to spend their newfound wealth on. There was a frenzy of economic activity in prospecting and logistic support of prospecting. Often this was a more dependable economic endeavor than the hit-or-miss gamble of prospecting.

The 1866-1869 Transcontinental Railroad united the East Coast and the West Coast. One of the benefits were surveying large swaths of land which provided data points (benchmarks/monuments) for future development. Another benefit was the relatively rapid transport of people and goods as well as cultural diffusion. The railroad accelerated the speed of travel and the amount of cargo moved.

This acceleration not only increased commerce, but changed the way we thought about time, distance and geography.

The West grew from the initial surveys of the Lewis and Clark exploration, to the prospecting of entrepreneurial settlers. Because of the infrastructure support of the federal government, the West turned from a sparsely populated wilderness into an economic engine of the 19th and 20th centuries.

From this historical analog we can draw some key takeaways:

  • Exploiting the value of new frontiers often takes vision, but you must invest in order to harvest what the value of the frontier will be.
  • Preliminary resource speculation needs to be validated by ground verification efforts to establish the credibility of the claims.
  • Providing key investments, R&D and infrastructure encourages an environment where free enterprise thrives.

It is not enough to explore. You must know where you are and where you have been and where you are going. The development of critical surveying and navigational infrastructure accelerated the development of resources.

Current Situation

Propellant is the currency of space travel. The water ice indicated to be present on the moon could provide liquid hydrogen (LH2) used as fuel and liquid oxygen (LO2) used as oxidizer. Their value as propellant is tremendous in the context of LEO and even greater on the Lunar Surface. These potential water ice deposits also have immense value as water to drink, air to breathe, water to grow plants with, and water as radiation shielding. The supply and demand equation is unclear for a cislunar economy. On the supply side, there are no proven reserves of water ice on the moon. There are strong indications of water ice in the shadowed craters of the moon’s North and South poles, but there is no ground truth proof yet.

The potential return on investment is uncertain in lunar exploration and resource development of unproven reserves of water ice. Even if water ice is confirmed, the initial costs of processing and delivering may make it challenging to make a near-term profit.

On the demand side of the equation, there is no clear demand function, that is, there are no obvious customers. Therefore, there is widespread indifference in the business community toward the prospect of mining unproven lunar ice. There is market apathy due to the nebulous nature of NASA plans for Mars (lack of urgency, clarity or plan/schedule leading to specific launch dates to Mars), as well as a sparse proposed SLS launch schedule and the likely distant date of going to Mars.

Typical business leaders like clarity of plans and predictability and guaranteed return on investment in a short period.

Proposed Pathfinder Plan

Offer commercial entities the opportunity to fuel the outbound mars spacecraft in low Earth orbit to support the Journey to Mars.

Based on publicly available sources an estimated 1.9 million kilograms of propellant is needed to fuel upper stages for outbound spacecraft assembled at 407-kilometer circular orbit (the approximate altitude of the International Space Station) to place crews on Mars.

A potential solution to the market stagnation noted above would be a well-publicized pathfinder campaign with the goal of enabling commercial partners to deliver rocket fuel and oxidizer to a logistics node as part of the Mars exploration architecture. This step would further NASA’s “Journey to Mars” effort and create demand function by providing a “gas station” for outbound spacecraft at Low Earth Orbit (LEO). Two potential scenarios are a plug-in “Drop tank” technique or an option to refuel used empty tanks. This would increase the payload capacity available for delivery to Mars surface. This is like how a KC-135 refueling a B-52 in flight on the way to a target enables the B-52 to carry as much payload to the target as possible instead of fuel.

Initial propellant for outbound spacecraft could be provided from Earth during pathfinder expeditions, like initial supplies brought to base camps for Earthly expeditions to summits. These pathfinder expeditions would rely heavily on robotic “scouts” to prospect, assess and survey.


The initial steps of this lunar exploration pathfinder would be to characterize likely locations of usable resources, principally water ice, which has been indicated to be potentially present in the permanently shadowed craters of the South Pole of the moon. As part of the prospecting process, sample collection and drilling would occur using robotic rovers, possibly driven by Astronauts on Earth. Analysis of these samples could validate composition and suitability as a resource for the Journey to Mars.


There would need to be a survey of Lunar South Pole surface contours and topology using robotic rovers. And, assisting future navigation and surface development would require the emplacement of surveying monuments at key benchmarks to document prospecting finds.

These surveying assets would be available for later surface assembly situational awareness. This would be like heritage International Space Station on-orbit robotic assembly techniques as well as current ISS robotic operations from the ground. Employing these techniques could help bridge the divide between human spaceflight and the Jet Propulsion Laboratory robotic community. This would also serve as a dress rehearsal for robotic operations in Mars orbit (if this is part of the exploration architecture). Once the surface resource concentrations are understood, these can be mapped as part of the planning process for extraction and utilization, assuming water ice exists.


Providing the large amount of propellant anticipated to be needed for the Journey to Mars from the moon gives a delta-v advantage of increased payload capacity to Mars, because that fuel would not have to be launched from within the Earth’s gravity well. The pathfinder plan outlined above would also provide system/ operational testing. If moon and Mars water ice properties are comparable, the moon may serve as a pathfinder for Mars resource utilization. This would take the form of training for Mars orbit tele-robotics (if this is part of the architecture) as well as Mars crew consumable production (water, air), as well as Mars Ascent Vehicle propellant production. Not only can operations protocols be tested, but hardware can be tested. There is an old test adage: “Test what you fly and fly what you test.” No computer simulation can provide the quality of data (hardware, software and human) that a real-world test under realistic stressful conditions can provide.

Fuel from the moon would be a more efficient propellant/consumable resource from a delta-V standpoint and thus potentially are a lower cost option.

Profit may be possible if the lunar water reserves can be proven and if the cost of extraction, processing and delivery from lunar surface to LEO turns out to be less than the cost of launch from Earth.

Build on lessons learned

The International Space Station serves as a technical integration model and lessons learned for large scale international integration efforts. It also serves as a model for managing international partner relationships, which have proven to be a major part of the ISS success story.

Successful large scale system integration must have a strong, clear, unwavering set of top-level requirements.

Commercial cargo/commercial crew for ISS can also be used as model for public-private partnership. As a result, NASA can be more focused on the proving ground mission of ISS and private enterprise can focus on transporting cargo and eventually crew to the ISS. This pathfinder proposal would let NASA focus on Earth independence and exploring Mars and let private enterprise be focused on providing fuel to get from LEO to the red planet.

The renewed exploration vigor of this sort of a pathfinder would inspire public excitement. Properly marketed, there could be increased STEAM emphasis and national pride as well as increased economic opportunity by creating demand for resources found off Earth.


The moon may be a much-needed pit stop for a very long journey to Mars. The distance to Mars (approximately 54.6 million kilometers at closest approach) makes aggregation points beyond the Earth’s gravity well vital to the sustainability of Mars exploration. By creating a demand function for propellant for future exploration and providing key investments, R&D, and infrastructure to develop the new frontier of space, the U.S. government can create an environment where free enterprise can thrive and the nation and world economy can prosper by expanding the Earth’s economic realm into space.

John Cook worked on the Space Shuttle and the International Space Station from 1995 until 2014.