While testing of the overall system to support a crewed Mars mission in an integrated fashion is certainly highly recommended, a crewed base on the Moon as suggested by commasense is not likely to be the best value. I could only guesstimate the costs of a Lunar outpost which would depend not only on the scale and complexity of the effort but also the transportation and logistical systems used to support and supply it from Earth which do not currently exist in any sustainable form. The entire Apollo program cost ~US$120B in FY16 dollars, and delivered only six small two person landers to the Lunar surface, three of which were J-class extended missions of three days each. Developing a system capable of indefinite duration stays would easily be an order of magnitude more expensive, so we would be looking at budgets on the order of US$1T or more.
By comparison, it is estimated a single opposition-class Mars mission (40 days surface duration) with 4-6 crew is estimated somewhere around US$300B based on the NASA Mars Design Reference Mission (DRM) 5.0. The longer conjunction-class mission (~950-1000 days surface duration) is probably in the US$500B cost range. A lower cost “Mars Direct” opposition-class mission could be performed for ~US$200B by eliminating some of the subsystem level testing and performing “all-up” testing, as well as eliminating some testing entirely and relying on simulations, and accepting a much larger threshold of risk (~80% probability of mission success versus >95%). Bear in mind the current NASA budget for crewed space is ~US$8.5B, covering Orion and SLS development, ISS operations, and commercial crewed space development, and ground segment and training support, out of a total projected budget of ~US$19B. A crewed Lunar or Mars program would essentially be over and above that, and even if the ISS support and supply were eliminated (~US$3B) the budget would have to be increased by an average of US$20B for an opposition-class mission or US$33B for a conjunction-class mission in 2033 over the 2018 to 2033 timeframe. (Costs are not actually evenly distributed and it would likely peak at three times that number somewhere in the mid-2020s to support a 2033 launch opportunity.) And these costs should be considered base estimates, not accounting for unexpected problems requiring additional developments.
The NASA budget, of course, is discretionary funding and without some critical rationale based upon national security or prestige will never see this level of funding sustained over that duration. Nor would it be sensible to do so for a program that would provide only very modest scientific and national prestige benefits, with the caveat that it would provide support for high paying technical jobs in STEM fields without contributing materially to military development.
The other issue with a Lunar base is that while it would provide some valuable experience and physiology data operating in fractional gravity, it is unlikely that we could rescue astronauts in time from a critical failure of support, power, or environment systems without adding extraordinary costs, and there are unique challenges of operating on Mars that are not presented by the Lunar environment (dust storms, perchlorate contamination) and vice versa (the Moon’s highly electrostatically charged dust environment), and does not address the largest single known technical challenge of a crewed mission to Mars, which is the entry, descent, and landing environment of a >40T vehicle. And there is relatively little other value on maintaining a Lunar outpost, which would lock us into a single site. While there is still some scientific utility in Lunar missions as the Moon is essentially formed of the same materials as the Earth but without the dynamic volcanism which regularly reshapes the Earth’s surface and hides the deep mantle and core beneath us, there is very little expectation that it would provide much commercially valuable materials that could not be more readily extracted from small Near Earth Objects (NEO).
As for the proposal of the o.p., it is already essentially executed in the ISS, save that the platform receives regular supply and the astronauts serve tours of typically only ~6 months. And what we’ve discovered from ISS missions is that systems which have been tested for high operational reliability on the ground experience unique problems and failures in freefall, and that there are special hazards and challenges to human physiology, not only in adapting to the still-somewhat protected solar radiation by the Earth’s magnetosphere, the deeply penetrating high energy cosmic radiation and the weightless environment, but also by more mundane problems such as hygiene and rest.
And this gets into larger issue of crewed space exploration; that regardless of how much money we spend and how simple or elaborate our plans may be, our current state of technology is not adequate for safely conveying human beings for the required durations to travel to Mars or other planets. The complaint about robotic missions (often termed uncrewed but should really be regarded as “remotely crewed” since each rover is under direction of a large crew of operators and services many science and exploration objectives simultaneously) is that the are so small and travel so slowly; however, this isn’t because they are robotic but because of the limits of the technology propelling them (in particular, the power that is available), and adding the necessary provisions to support and protect crewed operators on the surface would increase the power requirements by orders of magnitude, notwithstanding the costs to return the crew to Earth at end of mission instead of leaving robotic probes and rovers in place and continuing to operate them long pass the mission lifespan. A crewed opposition-class mission to a single site on Mars would cost as much as a hundred Curiosity-type rovers (likely more with economies of scale) or dozens of outer planet exploration missions, which would give us vastly more scientific value and the opportunity to understand more about planetary and interplanetary environments without the consequences of failure of a single multi-hundred billion dollar mission.
This isn’t to say that people don’t have a place in space, but people require enormous resources to protect and sustain them, and at our current state of the art all of those resources have to be shipped up from Earth at tens of thousands of dollars per kilogram. The sine quo non of a sustainable human presence in space is that it be self-supporting using primarily space-based resources (in-situ material utilization, or ISMU), which will require developments in energy, propulsion, and material extraction and processing technology, as well habitat and space physiology to counteract the deleterious effects of the extraplanetary environment. All of this will require remote and automated capabilities to built up and extract these resources in preparation for a human presence. As scr4 notes, whatever funding would be provided for a destination-orieinted crewed Mars mission in the foreseeable timeline would be applied to most rapidly achieving the mission objectives rather than development of a larger infrastructure for regular missions or an indefinite human presence in space.In short, if you want a permanent human presence on the Moon, Mars, or elsewhere off-Earth, you should be in strong support of remote and autonomous missions and efforts to develop ISMU technology.
Stranger
