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Tharsis Bulge
The Tharsis Bulge region of Mars, which includes Olympus Mons (upper left), could be an idea staging location for future human Mars missions. (credit: NASA/JPL/MSSS)

“Moon to Moon to Mons”: Synergies for Moon and Mars development


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A number of authors have proposed Moon and Mars exploration strategies that focus on in-situ resource utilization (ISRU) at stepping-stones from the Earth to the Moon (Spudis, et al. 2011 & Schrunk 2007). This envisioned chain leads from the Earth to low Earth orbit (LEO), with propellant depots refueling reusable in-space cycling vehicles (ferries) from LEO to an Earth-Moon Lagrange gateway (E-M L1 or E-M L2) with cycling vehicles down to and back from the Moon's surface, where a base would be located. While the propellant for LEO depots would be supplied from Earth, propellant for E-M Lagrange fuel depots are hoped to be supplied from volatiles found in polar cold traps in lunar craters (Spudis 2010).

Aside from the well-known “Mars Direct” approach (Zubrin 1996), a parallel strategy for Mars begins at an E-M L2 gateway, reaching Mars orbit with a cycling supply chain connecting to a Mars orbiting infrastructure, then to bases and fuel production on the Martian surface leading to settlement there (Milestones 2014). This creates essentially the same essential strategic architecture for both the Moon and Mars destinations.

Rethinking Mars settlement via two moons and Martian volcanoes

First step: Integrate ISRU into cislunar/lunar-surface system

A new lunar processing technology developed by Peter Schubert, a solar-powered regolith separator he calls a “supersonic dust roaster,” offers another wrinkle on the way to Mars. Schubert’s processing plant would heat lunar regolith into conductive liquid and separate it into oxygen for life support and propellant. His lunar separator would also produce silicon, iron, aluminum, titanium, and slag for construction and additive manufacturing (Schubert et al. 2010). Such ISRU products would greatly increase lunar and cislunar self-sufficiency. Moreover, dealing with the Moon’s sharp-edged and clinging “dust from hell” will give solar system pioneers experience for other dusty-surfaced celestial bodies, such as minor moons and asteroids.

The potential extraction of resources from Deimos regolith makes that moon a particularly tempting target.

At a regional conference presentation in St. Louis on November 8, 2014, Schubert indicated that his proposed dust roaster, delivered on one mission to the lunar surface, could produce sufficient oxygen to combine with hydrogen for refueling its lander four times a year. Because the molecular weight of hydrogen versus oxygen is 1:16, even hydrogen brought from Earth would be feasible. Schubert’s regolith separator would provide pragmatic “lunar ferry” capability based on lunar in-situ production of resources for E-M L1/L2 locations. A number of such production facilities could provide ever more local oxygen production for life support and a higher flight rate.

Second step: Integrating Deimos ISRU

The potential extraction of resources from Deimos regolith makes that moon a particularly tempting target. First, Deimos is easier to get to energetically from LEO than the lunar surface (Logan et al. 2015). The moon is also easier to reach than Phobos by a delta V of 400 meters per second (Hopkins et al. 2011). At around 20,000 kilometers from the Martian surface, telerobotics from Deimos would be nearly real-time. Even better, because Deimos orbits just above Mars synchronous orbit (MSO), from the perspective of Deimos, Mars would appear to slowly rotate eastward at only 2.7 degrees per hour, thus offering a generous line-of-sight telerobotics time that is unavailable from Phobos. In fact, if several Deimos surface assets were placed at regularly spaced longitudes, Deimos-based human teleoperators could circulate westward or rotate control from one to the next and explore 24/7. Over a period of nearly five and a half days, the entire planet could be seen except for its extreme polar regions (Logan et al. 2015 and Hopkins et al. 2011).

Deimos as a resource also goes far beyond being an ideal telerobotics platform. Deimos, measuring 15 x 12.2 x 10.4 kilometers, is much bigger than the near Earth asteroids NASA is considering visiting at considerable expense. Yet escape velocity from Deimos would still only be five meters per second (Logan et al. 2015), making it a fuel-sparing staging platform for solar system transit. In addition, several meters of Deimos regolith between a Deimos-based crew and interplanetary space, would provide shelter from cosmic radiation equivalent to the protection provided by the Earth’s atmosphere at sea level.

Better still, although the origins of both Deimos and Phobos are yet unsettled, both appear to have the characteristics of dark carbonaceous asteroids, with anhydrous silicates, carbon, organic compounds, and ice (Bell et al. 1992). If this bears out, Deimos’ regolith would be able to provide water and other volatiles for life support and propellant. Besides silicates, its regolith will also likely contain metals and other valuable materials for construction and manufacturing (Norton 2002).

Simple heating in an enclosed environment could recover Deimos volatiles (Nichols 1993). For non-volatile material extraction, Schubert has developed an “Isotope Separator” with three patents for various configurations. One of these configurations could be the basis for a device to separate Deimos regolith into components for life support and fabrication (Schubert 2008). Other ideas and devices may also work well. Because the light intensity reaching Mars PhD is only around 44 percent as strong the intensity reaching Earth's Moon, powering a Deimos regolith separator will be harder, but not impossible. Luckily, Deimos does not have a light-scattering atmosphere like Mars. Sufficiently large solar panels could therefore be constructed to power the regolith separator.

Deimos-sourced propellant could power reusable spacecraft (ferries and tankers) going to cislunar space from the Mars-Deimos-Phobos (Mars PhD) system and back; similar reusable spacecraft to Mars and back; and similar spacecraft bound for solar system destinations beyond Mars and back.

To sum up, the resources potentially provided by Deimos includes telerobotics, oxygen and water for life support, vehicle staging and fueling, shelter from cosmic radiation, and construction and manufacturing materials. Deimos would be the best ISRU site for a Mars Orbital Complex (MOC), Mars settlement, and further solar system expansion.

Third step: Basing on the Mars Equatorial Mons Complex

Effective Mars surface exploration will require a phased strategy that will include access to shelter and natural resources for life support and construction, while respecting both forward and back planetary protection. In this regard, the shield volcanos of the Tharsis Montes ridge (Arsia Mons, Pavonis Mons, Ascraeus Mons), as well as Olympus Mons and outlying Elysium Mons, might be excellent sites for initial Mars bases.

Tharsis Bulge
A topographical map of Mars, showing the line of volcanoes that comprise the Tharsis Montes ridge just left of center, and Olympus Mons to the northwest. (credit: NASA)

Olympus Mons and the Tharsis Montes volcanos, in particular, would provide relatively close access to shelter, natural resources, and equatorial sites. These basaltic shield volcanoes are laced with many cubic kilometers of lava tubes likely containing useful frozen volatiles (Wall 2012 & Bleacher 2011). Judging from lava tubes on Earth, the yields for science, life support,and infrastructure development on both the Moon and Mars will be significant. Moreover, our experience exploring the lava tube environments on the Moon (Redd 2014) will likely advance settlement strategies for Mars. The Moon could therefore be a major engineering onramp for the practical experience of exploring and modifying lava tube environments on Mars.

About 600 kilometers wide, the top of Olympus Mons reaches an altitude of 25 kilometers and is very cold. Nevertheless, the north and west sides of this majestic volcano plunge to below Mars zero-elevation or datum, offering relatively warm sites for exploration. Moreover, near-surface ice is likely on the western side. (See map below.)

water map
Dr. William Feldman of Planetary Science Institute in 2012 analyzed data from NASA’s Mars Odyssey Neutron Spectrometer & found evidence of massive amounts of water ice just beneath the surface. (>4.5 % of water equivalent hydrogen in orange & red areas)

The typical atmospheric pressure at the top of Olympus Mons is about 12 percent of the average Martian surface pressure, which in turn is less than 1 percent Earth atmospheric pressure at sea level. Even so, high-altitude orographic clouds frequently drift over the Olympus Mons summit, and airborne Martian dust is still present (Hartmann 2003). Analogous to how our experience with lunar lava tubes will inform us about how to utilize Martian lava tubes, our experience dealing with dust on the Moon should inform us on dealing with dust on Mars.

Occupying the “high ground” on Mars from any of the Mons volcanos would provide a springboard for human expansion into lower altitude sites of interest.

The middle Tharsis volcano, Pavonis Mons, lies smack on the equator. However, because it also lies on the Tharsis bulge, its base remains at a high altitude. Pavonis Mons is the smallest of the Tharsis Montes volcanos. Yet it is still 367 kilometers across and its summit 14 kilometers high (Scott 1998 & Gazetteer). The summit experiences an atmospheric pressure of about 21% of Mars’ mean surface pressure. Data from the Mars Global Surveyor and Mars Odyssey spacecraft suggest that glaciers once existed on Pavonis Mons and significant amounts of near surface, equatorial ice may remain within the deposit today (Shean 2005).

Occupying the “high ground” on Mars from any of the Mons volcanos would provide a springboard for human expansion into lower altitude sites of interest, including the Echus Chasma, Valles Marineris and the lowlands west of Olympus Mons. In sum, Olympus Mons, Pavonis Mons, and the other Mons volcanos are potential base sites with readymade shelter from radiation, materials for fabrication and construction, and volatiles for propellant and life support.

Assuming we are able successfully to establish a permanent base on Earth’s Moon and on Deimos, the conditions (in terms of near vacuum and high radiation) at the summit of the volcanoes should allow for similar infrastructure and life-support technologies that will have previously been demonstrated on the Moon. These technologies should include waste recycling to produce useful products, like fertilizer and fuels (Schubert 2011). In the latter case, for instance, researchers at NASA Ames Research Center has produced a small bioreactor that uses urine as a feedstock to produce, with the help of microbes, electricity, methane, and clean water (Verger 2014). Thermal management in these cold locations will also be critical.

With regard to mission sequencing, the appropriate volatile heater-extractors and element separator systems could begin robotically producing water and oxygen for life support and propellant, as well as metals and other fabrication materials, all before humans arrive. As on Deimos, however, a Schubert-type isotope separator on a Mons volcano will require a great deal of energy from very large solar arrays. Assuming the lack of nuclear power, fabrication of large arrays from silicon and other materials would therefore be a critical first step.

Reaching a volcano from forward orbital base Deimos would give us supporting infrastructure that can back up Martian surface operations. Surface operations can “abort to orbit” if needed, or conversely, a rescue from orbit could also be realized. The ability to provide precursor surface missions with the assistance of real time telepresence from orbit will also be of great advantage in setting up surface accommodations for a sustained presence, whether on a volcano or elsewhere. Robotic and human exploration sorties will be easier and more effective after a Mars ferry system fueled and maintained with Deimos resources is operating.

We do not argue that our proposed architecture will be the fastest way for humans to step on the Martian surface. We argue instead for sustainability and cooperation.

There is still another advantage. Bases on the surface of Mars and in Mars orbit will need resupply of some Earth-sourced materials, especially in the beginning. There will also likely be need to return materials such as soil samples or possibly even astrobiological samples to Earth-Moon Lagrange points, the lunar surface, or terrestrial labs for analysis. However, that will only be the beginning. The movement of people and materials beyond samples is inevitable, and complete protection from forward and back contamination will become impossible. Nevertheless, the planetary protection protocols that should really count to us are those that might present risks to human and other terrestrial life. For this reason, the sequestration of potential lifeform samples arriving from Mars should be restricted to isolation within the life-hostile context of Deimos and the lunar surface. A volcanic summit base might provide an additional way at least to minimize forward and back contamination of life forms.

Lessons learned

To underestimate the challenges of Moon and Mars settlement is to fail in overcoming them. Somehow Antarctica, with a relatively low profile, has for decades successfully drawn the kind of sustained support we need for the settlement of both the Moon and Mars. Apollo, although started with huge national effort, did not create a sustainable political constituency for the settlement of the Moon. Our government sold the Apollo program like a football game between the US and Soviet Union. This time around, space development advocates must sell “season tickets” to a sustainable Moon, Mars PhD, and solar system settlement program.

A long-term commitment to an Antarctic-style research station will not do. Nor is the simple goal of exploration sufficient. For self-sufficiency and sustainability, the selling of goods and services must be an integral part of the settlement mix. Tourism will undoubtedly be one of the first services companies will provide for profit, and the nascent space tourism industry has already taken off. Mining of water and mineral resources will be a close second. Eventually, refined goods and sophisticated services will also evolve. A “Moon to Moon to Mons” strategy could rapidly extend engineering, technological, and commercial advances from cislunar space to the Mars PhD system, greatly facilitating solar system development for the benefit of humankind.

Conclusion

NASA has plans to spend a considerable sum of money on its Asteroid Redirect Mission (ARM). Meanwhile, Deimos is an orbiting “platform” already in place and ready for staging, communications, and telepresence to explore and sustainably settle Mars. In addition, the vast resources on Deimos are likely similar to those found on carbonaceous asteroids, and Phobos is nearby for continued resource utilization. Deimos is relatively accessible compared to most other solar system sites. Methods and technologies for utilizing asteroidal resources could be tested and developed on Deimos, while we otherwise use that moon to enhance lunar and Martian infrastructure. In other words, a “Moon to Moon to Mons” campaign is just the ticket for developing asteroid utilization technologies, and in so doing, vastly accelerate sustainable solar system settlement. It is time to replace the ARM with a Moon to Moon to Mons strategy.

We do not argue that our proposed architecture will be the fastest way for humans to step on the Martian surface. We argue instead for sustainability and cooperation. We urge that various competing camps for destinations such as the Moon, Mars, asteroids, and orbital spaces drop their “us first” postures and see a compelling case unifying their priorities in the context of a Moon to Moon to Mons strategy. We believe that pioneers from Earth can use such a strategy to undertake a rational, cooperative, sustainable campaign for the expansion of human space settlement throughout the solar system.

References

Bleacher, J. E., Richardson, P. W., Garry, W. B., Zimbelman, J. R., Williams, D. A., Orr, T. R. (2011). Identifying Lava Tubes and Their Products on Olympus Mons, Mars, and Implications for Planetary Exploration. 42nd Lunar and Planetary Science Conference 2011.

Gazetteer of Planetary Nomenclature. IAU Working Group for Planetary Nomenclature. Pavonis Mons. U

Hartmann, W. K. (2003). A Travelers Guide to Mars: The Mysterious Landscapes of the Red Planet.

Hopkins, J. B. & Pratt, W. D. (2011). Comparison of Deimos and Phobos as Destinations for Human Exploration and Identification of Preferred Landing Sites. AIAA 2011 Conference and Exposition, September 27–29, 2011.

Logan, J. S. & Adamo, D. R. (2014). Destination Deimos, Part I. The Space Review, November 3, 2014; Destination Deimos, Part II. The Space Review, November 10, 2014.

Milestones to Space Settlement: An NSS Roadmap Milestone 15: Creation of a Logistics System for Transporting Humans and Cargo to the Martian Surface. Ad Astra. Spring 2014, pgs. M17 – M19.

Nichols, C.R. (1993). Volatile Products from Carbonaceous Asteroids. Bose Corporation.

Norton, R. O. (2002). The Cambridge Encyclopedia of Meteorites. Cambridge: Cambridge University Press. p. 139. ISBN 0-521-62143-7

Redd, N.T. (2014). Home, Sweet, Moon Cave: Astronauts Could Live in Lunar Pits. SPACE.com, July 23, 2014.

Scott, D.H., Dohm, J.M., Zimbleman, J.R. (1998) Geologic Maps of Pavonis Mons, Mars. USGS, 1-2561.

Schubert, P. J. (2008). US Patent No.: US 7,462,820 B2. December 9, 2008.

Schubert, P. J., Williams, J., Bundorf, T., Di Sciullo Jones, A. P. (2010). Advances in Extraction of Oxygen and Silicon from Lunar Regolith, AIAA SPACE 2010 Conference and Exposition, August 30 –September 2, 2010, Anaheim, California.

Schubert, P. J. (2011). Dual Use Technologies for Self-Sufficient Settlements: From the Ground Up. International Space Development Conference (ISDC) 2011 in Huntsville, Alabama.

Schrunk, D., Sharpe, B., Cooper, B. L., & Thangavelu, M. (2007). The Moon: Future Resources and Settlement, August 14, 2007.

Shean, D.E., Head, J.W., Marchant, D.R. (2005). Origin and Evolution of Cold-Based Tropical Mountain Glacier on Mars: the Pavonis Mons Fans-Shaped Deposit. Journal of Geophysical Research. Volume 110, Issue E5, May 2005.

Spudis, P. (2010). The Four Flavors of Water. AirSpaceMag.com. May 2, 2010.

Spudis P. D. and Lavoie A.R. (2011). Using the Resources of the Moon to Create a Permanent Cislunar Space Faring System. Space 2011 Conference and Exposition, American Institute of Aeronautics and Astronautics, Long Beach CA, AIAA 2011-7185, 24 pp. See also, Spudis P.D. (2011). The Moon: Port of Entry to Cislunar Space. In Toward a Theory of Space Power: Selected Essays, C.D. Lutes and P.L. Hays, eds., Institute for National Strategic Studies, National Defense University, Washington DC, Chapter 12.

Verger, Rob (2014). Recycling on Mars. Newsweek, May 22, 2014.

Wall, M. (2012). Mars Cave-Exploration Mission Entices Scientists. SPACE.com, November 20, 2012.

Zubrin, Robert, The Case for Mars, 1996.


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