A NASA-sponsored study has been released which outlines a plan to return to the Moon with people and set-up an outpost at one of the poles to mine water for propellant. This report has drawn both attention and puzzlement within the space community, as the agency continues to make clear that they have no interest in human lunar missions. This disconnect is covered because NASA will not do these activities – instead, the agency will pay commercial companies to develop and implement the plan. The propellant produced at the outpost from lunar polar water will then be sold to NASA for use in future human missions to Mars.
I find both positive and negative aspects in this report. I am gratified that another study recognizes the great leveraging power for spaceflight offered by the development of lunar resources. Most NASA lunar mission studies have invariably incorporated resource utilization only in the form of small-scale demonstrations or flight experiments. In contrast, this effort makes the production of water from the Moon’s polar deposits the principal mission objective – a definite step forward. The architecture also makes significant use of robotic machines on the Moon for most of the mining and processing activities, another positive development. Because of the Moon’s proximity, controlling robots on the lunar surface in near real time permits the early establishment of processing facilities using operators on Earth, rather than on the Moon. In these ways, I find a lot of similarity with this plan and the architecture designed in 2011 by Tony Lavoie and myself.
On the other hand, there are some strange aspects to the report that warrant attention. Early stages of the program call for human crews to be sent on equatorial surface sortie missions prior to the establishment of the polar outpost. Presumably, these missions will test and prove the equipment and vehicles needed for routine lunar surface access later. But sortie missions to equatorial or mid-latitude sites offer no real benefit to the ultimate aim of the architecture: the establishment of propellant production facilities at the pole. There is no good reason for not sending the first human missions directly to the locations where our future activities will happen. There is also no rush to do so – much can be accomplished in advance of human arrival with robotic machines under the control of operators on Earth.
The architecture calls for a series of robotic missions to reconnoiter, prospect and survey potential mining sites prior to human arrival. This approach is an absolute necessity, as much is still unknown about the nature and composition of the polar ice deposits. Apparently, there has been little to no scientific input to this report regarding the consideration of actual prospecting and mining activities, a significant shortcoming. Although the study acknowledges that the unknowns of polar ice mining constitute a “major risk” to the program, that risk can be at least partly mitigated now through the incorporation of results from current research. Known facts are misstated (e.g., water concentrations) and unattributed, a general shortcoming of this effort. It is critical to demonstrate ISRU (in situ resource utilization) with robotic precursors prior to outpost commitment, but the report does not indicate what levels of production constitute success or failure of this milestone. Insufficient detail for the robotic missions likely indicates that these aspects have not been designed or imagined, e.g., the need of power and communications for polar robotic spacecraft requires a significant supporting infrastructure that is not described.
The principal object of the lunar outpost in this plan is the production of water to be converted into cryogenic hydrogen and oxygen for use as rocket propellant. The report envisions this lunar propellant (about 200 metric tons per year at the end of outpost emplacement) as enabling human missions to Mars by reducing the total number of required SLS heavy lift vehicle launches required for such a mission from 12 to 3. But 