Mars is the Earth’s only nearby early life Analog, but the Moon is on the Path to get there
The passing of John Glenn on December 8, 2016, following that of Neil Armstrong on August 25, 2012, mark milestones in the remarkable history of space exploration in the last half of the 20th Century. Glenn, as the first American to orbit the Earth, and Armstrong, as the first person to step on the Moon, have assured their places in history and in the hearts of their colleagues and countrymen. It was my honor and privilege to have assisted Neil Armstrong in his preparation for landing on and exploring the Moon and to have served with John Glenn in the United States Senate. Both men set the stage for the Apollo missions of exploration that followed and for the remarkable missions back to the Moon and on to Mars that will take place in the 21st Century. The following essay examines how that future may unfold and how the new challenges can be overcome.
Fig. 1. (Left) John Glenn and his Mercury spacecraft, Friendship 7, prior to launch on February 20, 1962. Glenn, the first American to orbit the Earth, successfully completed 3 orbits before splashing down in the Atlantic. (NASA photo). (Right) Only 7 years later Neil Armstrong became the first astronaut to set foot on the Moon. Here, he is seen packing 17 scoops of bulk lunar soil into a rock box just before leaving the lunar surface. This soil was one of the most important of the returned samples because it allowed calibration of the volatile content of the lunar regolith. (NASA photo AS11-40-5886).
Introduction. Mars provides a geological integration of the early solar system impacts recorded by the Moon and the contemporaneous water-rich, pre-biotic period on Earth. Mars exploration has the potential to unravel the origin of life on Earth, as well as being a geopolitical imperative for democratic nations.
Consideration of human missions to Mars logically would include an evaluation of the successful implementation of a comparable space effort, namely Apollo. The keys to the success of the Apollo Program included the existence of:
- A sufficient base of technology,
- A reservoir of young engineers and skilled workers,
- A pervasive environment of national unease,
- The catalytic event of Yuri Gagarin’s orbital flight,
- An articulate, persuasive and patriotic president and congress,
- A commitment of a ~100% management reserve of funding, 
- Tough, competent, disciplined and courageous managers, 
- A goal that could be accomplished in a decade, and
- A working environment of liberty.
Fig. 2. The six landing sites of Apollos 11, 12, 14, 15, 16 and 17. Apollo 17, the last mission, landed on the eastern shore of Mare Serenitatis in the Valley of Taurus-Littrow on Dec. 11, 1972. (Base map, NASA/ASU/GSFC photomosaic from the Lunar Reconnaissance Orbiter Wide Angle Camera).
All these keys to success must accompany a Mars Program with the following additions:
- Improved education in Science, Technology, Engineering, and Math (STEM) skills, and critical thinking,
- Given the advance of technology, a ~30% management reserve through systems’ Critical Design Reviews (CDRs) may be adequate, and
- China’s rapid progress substitutes for the Cold War stimulus,
- A permanent national commitment to deep space exploration,
- Maintenance of an average workforce age of <30 years, and
- Elimination of the political aversion to taking necessary risks.
Major Mars Requirements. The catalysts for initiating a Mars Program include all of the following: geopolitical reality with respect to China and Russia, economic need to stimulate future technologies, and addressing the crisis in engineering and science education facing the United States. Also, deep space operational experience must be regained by continuous generations of young implementers. Finally, there must be a permanent public and political commitment to deep space exploration and development on a par with, and related to a commitment to National Security.
A focused Apollo-style management system will be needed, possibly involving a new national space exploration agency. This system must “stay young-stay lean-stay risk takers.” Once the decision to go to Mars is made, the sole focus should be to do just that. With such a decision, early tradeoff studies will be needed on interplanetary propulsion development, consumables requirements and sources, specialized technology development, and human spaceflight planning and operations. Additionally, first landing mission decisions will drive development and operations, specifically, crew size and capabilities (one or two crews with one or two landers), desired exploration science returns, and space resources delineation and use.
Management Requirements. The success of Apollo depended on the evolution of a management system that, with hindsight, includes many common sense attributes. NASA and its contracting corporation had access to the best engineers and engineering managers available. Because of the short duration of the program, the average age of the workforce remained below 30 years, a characteristic that has been maintained by an equally complex nuclear Navy with similar success. Youth provides the motivation, stamina, patriotism and courage to see projects to successful conclusions, a lesson that has not been lost in the development of China’s Project 921 space program. The bureaucratic newness of NASA meant that management was minimally layered so that decisions could be made quickly and good ideas could move rapidly to implementation (Note: Between November 1968 and November 1969, a Saturn launch and Apollo space mission took place every 2 months). NASA also supported an internal, independent engineering design capability that gave managers alternative viewpoints to those of contractors on major issues. Finally, Administrator James Webb persuaded the White House and Congress to provide a management reserve sufficiently great to maintain schedule in the face of unexpected engineering issues and accidents.
These management lessons and requirements should be embedded in the enabling legislation for a Mars Program, along with providing the Mars implementation agency with the hire, fire and re-assignment personnel authority necessary to maintain the vigor of the program. Such an intense focus on deep space could be accomplished by reassignment of most NASA functions to other agencies and the creation of a new National Space Exploration Agency (NSEA) charged solely with the human exploration of deep space and the re-establishment and maintenance of American dominance as a space-faring nation. This new Agency’s responsibilities should include robotic exploration necessary to support its primary mission. As did the Apollo Program, NSEA should include lunar and planetary science and resource identification as a major component of its human space exploration and development initiatives .
Fig. 3. A possible logo for the proposed new agency responsible for the implementation of human exploration of the Moon and planets (Courtesy of Colin Mackellar).
Moon in the Context of Mars. Consideration of missions to Mars should include the value of returning to the Moon as a means of dealing with many of the challenges such a program presents. The Moon lies only three days away in regard to Mars mission development, simulation and training versus the many months required to reach Mars. Flying to the Moon and working there require similar deep space operational discipline that new generations of space managers, engineers and flight controllers will need to assimilate. Also, many of the same deep space technological capabilities will be needed.
Fig. 4. The author walking past the south side of a large split boulder at Station 6 visited by the Apollo 17 astronauts on Day 2 after the landing, driving there with the Lunar Rover seen at right. The Lunar Module itself is ca. 3.5 km distant in the whitish area just right of the tip of the boulder. (Composite of NASA photos AS17-140-21495, -96 and -97)
The Moon remains geopolitically critical in its own right. The existence of space consumable resources and potential energy sources  of importance to Earth have not been lost on other international players. Accessing these resources presents the possibility of cost reduction through private-government partnerships. Further, evaluation of the effects of 1/6 Earth’s gravity on physiological re-adaptation will answer the question, for better or worse, concerning the consequences of re-adaptation requirements in the 3/8 Earth’s gravity of Mars.
Important new and unique science will come from a return to the Moon. Whereas Mars will give new insights into pre-biotic and, potentially, early biotic history, the Moon provides insights into the extraordinarily violent impact history in which life’s precursors formed. 
Fig. 5. A typical Mars transit trajectory, in this case followed by the Mars Reconnaissance Orbiter spacecraft launched on Aug. 12, 2005 and still operating as of this date. The green line is a minimum energy “Hohmann” transfer orbit between the inner Earth and the outer Mars orbits. Depending on launch times, Hohmann transfers can take 7-8 months one-way. (NASA photo)
Mars Transit Hurdles. Missions to Mars will not be easy for many years to come. Transit alone presents the issues of radiation protection, micro-gravity countermeasures, consumables supplies, spacecraft redundancy and maintenance, crew proficiency for landing and return, crew composition and crew compatibility, and challenging in-flight work. Solutions to some of these issues may relate to solutions to others; however, many potential solutions require consideration of a return to the Moon to stay.
Water, oxygen, nitrogen, hydrogen, methane and other possible consumables provided by lunar resources can significantly reduce the required Earth launch mass of Mars-bound spacecraft. Among those other possible consumables is helium-3, a potential fuel for fusion-powered propulsion that could shorten transit time considerably. Crew suitability and compatibility for long duration missions can be evaluated with an extended stay at the International Space Station (ISS), followed by an exploration mission on the Moon, and then by another extended stay at the ISS.
Fig. 6. A global composite of photos taken by the Mars Global Surveyor orbiting spacecraft. The two stars mark the landing sites of the Spirit and Curiosity Rovers in Gusev Crater (right), southeast of Elysium Planitia; and in Gale Crater (left), due South of Elysium, respectively. The circular white area above the center is probably surface frost on the Elysium volcano as it is early northern Spring, or possibly a summit cloud. (Base photo from NASA/JPL/Malin Space Science Systems photo, PIA08019)
Mars Landing Hurdles . Mars has enough atmosphere (~1/200th of Earth’s) to cause entry, descent and landing (EDL) problems, but not enough to help much in kinetic energy dissipation. It is generally calculated that a Mars Lander will have a mass of at least 40 metric tonnes, so this is not a trivial issue. Further, EDL must be accomplished without real-time assistance from Mission Control. Landing, whether automated or not, likely will utilize a beacon operating from a previously landed, un-crewed habitat-supply precursor necessitating a rover-assisted, surface rendezvous after landing. It also is likely that in situ, return fuel production will need to be demonstrated prior to Earth-launch of the paired crewed mission.
Fig. 7. Gale Crater, the landing site on Aug. 6, 2012 of the Curiosity Rover, marked by the white arrow. The Rover has been exploring to the northeast along the boundary between the bright streak at the base of Mt. Sharp and darker area to the east before crossing to the foothills and beginning its climb to the top. (NASA/JPL photo, PIA14291).
Whatever approaches to EDL ultimately are developed for operational testing, such tests probably will take place at appropriate altitudes in the Earth’s atmosphere. Also, operational technologies and procedures will need to be developed to support consideration of aborts to a landing in contrast to aborts to orbit. Future lunar landings offer the best means of testing abort-to-land concepts along with doing so with simulated Mars communications constraints.
Related to abort-to-land considerations will be evaluation of whether each early Mars mission should consist of two landers and two full crews. The cost, time and risk inherent in Mars missions argue for steps to maximize landing and exploration success. In the likely event that both landers reach the surface successfully, the science return from two separate landing sites will be an added benefit to adopting this approach. (If only one landing is successful, the second prepositioned un-crewed lander will be available for a later mission.) An additional potential benefit of having two crews is that the orbiting crew can provide real-time mission support during landing and ascent and during other nominal or off nominal events. This latter activity compensates, in part, for the absence of real-time Mission Control input.
An additional point relative to landers, as well as Earth-entry modules, is that they should also have the simulation capability for proficiency training during Mars transit.
Major Mars Exploration Hurdles. Exploration of the surface of Mars will have many similarities to future lunar exploration. Lunar preparatory missions provide the means of testing, operating and maintaining Mars-consistent equipment such as mixed-mode rovers, sampling and analytical tools, analytical equipment for return sample selection, bio-containment systems for drills and sample packaging, dust mitigation concepts, food production concepts, and nuclear power systems.
Fig. 8. A recent “selfie” taken by the Curiosity Rover on September 20, 2016 in the Mt. Sharp foothills. Selfies are made by using the Mars Hand Lens Imager located at the end of the robotic arm. It requires many overlapping images that are later seamlessly stitched together on Earth. (NASA/JPL/Malin Space Science Systems photo, PIA20844).
Of particular importance will be the evaluation of Mars extravehicular mobility units (EMU). Whereas, Apollo EMUs were designed for use over a few days, Mars EMUs will need to be designed for long duration use and maintenance. Lunar exploration provides an unique opportunity for testing such systems over extended cycles of use.
Simulation of a variety of operational issues that will arise during Mars exploration can be conducted on the Moon. These include variable communication delays that can be integrated into lunar exploration, providing real-world operational experience with this form of crew-Earth interaction. If assistance from an orbiting crew becomes part of Mars landing and exploration, this concept can be evaluated and refined as well. Also, forward and back contamination protocols can be evaluated for feasibility and efficacy. Further, methods for Mars exploration data synthesis, archiving and near real-time retrieval can be developed and evaluated in the context of actual lunar exploration activities.
Although consumables production (water, oxygen, nitrogen, helium, fuels and food) on the Moon begins with processing regolith rather than the more chemically variable Mars surface materials, the operational experience with such processing, as well as volatiles refining, will provide invaluable experience in the design of consumables production systems for Mars.
Fig. 9. Driving towards Mt. Sharp foothills seen across the dark band of sand dunes in the foreground. The photo was taken on Sept. 9, 2015 and the colors have been “white balanced”, a technique that approximates Earth lighting conditions for geological use in examining rock colors and layering, but renders a false bluish color for the sky. (NASA/JPL/Malin Space Science Systems photo, PIA19912).
Mars Physiological Issues. It is currently unknown if the 3/8 Earth’s gravity of Mars will trigger gravitational re-adaptation in landing crews and, if so, how much time will such re-adaptation require. The integration of a research protocol into future lunar exploration to determine whether 1/6 Earth’s gravity triggers re-adaptation will serve two purposes. If lunar gravity triggers re-adaptation, there will be less complexity in engineering design and operational planning. If this does not happen, then design, planning and development of countermeasures become more complex, but this complexity can be taken into account earlier than otherwise.
Potential Mars Program Milestones: It is estimated that with a sustained annual public funding level of about $15 billion per year, including a 30% management reserve, the following major milestones could be achieved:
- Return to the Moon’s Surface by 2025.
- Lunar Settlement by 2030 (Public / Private Capital Funding).
- Lunar Resource Production by 2035 (Private Capital Funding and Management).
- Mars Landing by 2040.
- Mars settlement by 2045.
An essential ingredient to achieving these milestones is the existence of a space launch system capable of accelerating ~100 metric tonnes to escape velocity. Upgrading and fast-tracking the current Space Launch Systems (SLS) to match these capabilities are essential in this regard.
Conclusion. A return to the Moon appears to be essential to increasing significantly the probability of success of a Mars program and to maximizing the scientific return from such a program. Such a return to deep space exploration, however, requires the unequivocal and sustained commitment of the Nation, even more so than was required for the Apollo Program.
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A more detailed version of this article, entitled The Moon: The Fastest Operational Path to Mars, was presented as the annual von Braun Lecture, U.S. Space and Rocket Center, Huntsville, Alabama, October 27, 2016.
Harrison H. Schmitt is a former United States Senator from New Mexico as well as a geologist and Apollo 17 Astronaut. He is currently an aerospace and private enterprise consultant and a member of the new Committee of Correspondence.