Generation II Mars Settlement Study Update
January 2007 – Report by Brian Enke, with generous input from “the whole team."
Any way you view it, 2006 was a banner year for Space Settlement. Photographic evidence of liquid water flowing on the surface of Mars… a successful launch of the first private space-habitat prototype… kickoff of the 4Frontiers Gen-II Mars settlement study… favorable press about NASA’s lunar settlement plans... two Mars rovers that just keep on going and going and going…
With all these dazzling accomplishments, 2006 will be a tough act to follow. Yet 2007 holds even more promise for space settlement breakthroughs, fueled by 4Frontiers, SpaceX, Blue Origin, Bigelow Aerospace, Armadillo, Virgin Galactic, SpaceDev, the X-Prize Foundation, other private efforts, and of course, NASA’s Phoenix Mars lander and lunar Constellation project. Space settlement goals will push research into new technologies directly applicable to life on Earth or any other planet, moon, asteroid, or favored 3-D spatial location.
Even here on the comfortable surface of the Earth, where I assume most of you are reading this, we’re all out “in space” already. Space has no hard physical boundaries or limits (except singularities, perhaps)… but it does have a diversity of environments. Some points are harder to reach than others, too, from wherever you happen to be right now. For example, the winter environment and remoteness of Nome, Alaska must be quite a challenge for its inhabitants. Yet people live in Nome year-round, assisted by technologies that provide power, shelter, food, and transportation.
Hmmm… power, shelter, food, and transportation… the same issues that drive most Gen-II Mars settlement discussions! Coincidence?
Power production is one of the greatest challenges for settlement. You can’t have too much power. Yet the real challenge is producing the right kinds of power (electrical, thermal, mechanical) and sending it to the right places. Industry is the primary driver for bulk power generation and distribution, while living systems (people, plants, food) require 100% reliable power sources.
An efficient Mars settlement will convert local resources into refined materials like plastics, glass, brick, and metals. The Gen-II settlement goal is to produce 90% of the settlement mass using in-situ (local) resources. Many useful in-situ processes, such as the Sabatier reaction that creates methane from CO2 and hydrogen, require electricity and heat as inputs.
The current plan for primary power production is nuclear-based (with limited solar power as a back-up). No other power source generates both electricity and thermal energy in large-enough quantities. As the Gen-II teams discuss power needs, the required number of small, automated, next-generation reactors fluctuates but is currently back down to three.
A great deal of discussion has centered on bootstrapping the first nuclear reactor. The envisioned next-generation reactors are not black-boxes… you can’t just land one on Mars, flip a switch to turn it on, and expect it to produce energy (that process only works in science fiction novels). Besides precise transportation and landing requirements, the reactors will require a complex bootstrapping process that depends on local human-effort, robotics, and energy. All must be on-site and in-place before the reactor produces a single watt.
A design improvement by the Gen-II team has eliminated the need for initial power within the reactor system. The boot-strapping power burden has now been placed upon an external gas turbine start-up motor, with a minor amount of electrical input required for control systems. This change simplifies some of the transportation and set-up requirements. Adding additional reactors becomes more efficient as well.
The power production team has identified a need for multiple experienced nuclear engineers on the Mars surface very early in the staging plan prior to starting up the first reactor. The required staffing level is difficult to satisfy within the overall settlement bootstrapping plan, so the team will continue to innovate and compromise in order to meet these crew task man-hour requirements.
According to the study team, the new location “… is situated on the edge of a very old crater rim which has since eroded away. It appears to offer the lowest altitude (of the three finalist locations in the region), easiest access, and a ridge line along/through which our building can take place. It is also located in an area of reasonable hematite, and close to other higher concentrations....”
Proposed location (settlement size exaggerated ~5x).
Moving the settlement was not an easy decision, as Chandor was an attractive site for many physical and psychological reasons… but it was probably the right decision for the project. Due to Opportunity, we know more about the Terra Meridiani region, whereas much of our information about Chandor Chasma is derived from orbiter observations and theories. An agent on the ground is worth a hundred orbiters and a dozen theories.
The equatorial Terra Meridiani region can be accessed from any Mars orbital plane. Wind speeds will be lower than in any of the deep canyons on Mars, and potential landing sites will be closer, flatter, and safer. Atmospheric pressure will also be lower, however, which presents some landing difficulties (less air for aerobraking)… however, the selected location is still 1600 meters below the average Mars altitude.
The mining team led the push to move the settlement, based on their understanding of the resources available and accessibility of those resources. Deposits of hydrates are known to exist in the Terra Meridiani region, as does iron (in hematite nodules) and probably phyllosilicates for clays and cements. These resources would allow creation of a wide range of useful building materials, including steel, alloy steel, aluminum, concrete, mortar, epoxy resins, fiberglass, and polycarbonate. Other construction materials (ceramics, bricks, plexiglass) are feasible if clays and copper are found in greater abundance.
The change in settlement location affects the 4Frontiers fictional short-stories at http://www.crazy4mars.com/stories.html , leading to equally animated discussions amongst our authors and editors. We have decided to keep the settlement location in the fictional stories unchanged, i.e. the fictional settlement will remain in Chandor Chasma. The emotional appeal and visual topography of the Chandor Chasma region were prime considerations, and we can take “literary license” to create nearby mineral deposits that sustain the settlement (these deposits probably do exist anyway). Inconsistencies might confuse some readers, but this confusion can also spur good learning opportunities. After all, the goal of 4Frontiers is to settle ALL of Mars, not just one region. As on Earth, the environment at different Martian locations will vary, creating unique lifestyles and trade advantages.
Other settlement improvements include a firm decision on the atmospheric pressure inside the settlement: 60kPa total pressure, with 18kPa ppO2, 42kPa ppN2, and ~300ppm CO2. The greenhouses will maintain higher CO2 levels. All breathable air will be produced in-situ.
The internal pressure for EVA space suits has been set at 35kpa, which allows for zero pre-breathe time. Space suits are considered an important extension of the settlement environment. Industry, transportation, and exploration require convenient access to the local Martian terrain, but fast, safe EVA capabilities are also crucial for the psychological health of the settlers. For early suit designs, we envision a hybrid between the lunar hard-shell suits being developed at NASA and the newer, lighter, more flexible MCP (Mechanical Counter-Pressure) suits favored by some university research teams.
Finally, Michael Rudis, our Civil, Structural, Architectural Division Leader, has been constructing a settlement “space matrix”. The due date for input from all Gen-II teams was January 15th. The matrix will allow the physical design of the base (layout) to begin. Stay tuned for details in the next Gen-II update!
A diverse settlement food supply requires three primary systems: controlled storage areas, greenhouses for growing plants and animals, and aquaculture centers for producing fish and other marine food sources.
Our aquaculture experts have designed systems that would support 4, 8, or 12 settlers. Redundancy increases overall reliability and scales up the system to any number of settlers. Key local inputs of each aquaculture module are minerals, water, energy, tools, and filtering systems. Initial feedstocks must come from Earth, along with electronics for sensors and automated devices.
Besides food, the aquaculture systems will also produce solid sediments rich in ammonia, other nitrogenated compounds, and semi-digested organic matter. All are useful inputs to agriculture.
Open issues include the size of each aquaculture module – currently on the order of 7 x 42 meters. Smaller is better, but the team is also considering creative options for making better use of the space, like growing plants within the fish tanks (aquaponics)! Specific construction techniques remain to be researched, too.
The current goal of the agriculture team is to complete the Gen-I design up to the 50% level, so other divisions have a better base to work from. Areas of focus are electrical systems, water, mining, HVACs, general material requirements, and space allotments. Greenhouse power requirements remain a key concern, and using LEDs as a light source seems to be an attractive solution that simplifies the greenhouse design (better heat dissipation, simpler wiring/cabling, no ballasts, less power usage, longer life-times…).
The bootstrapping process is another concern, since we can’t have a fully functioning greenhouse within a day of landing on Mars. Bulk foods from Earth must be stored and eaten during the months of transition. Germinating seeds a week before landing on Mars can speed up the first crops. Initially, hydroponics is seen as the best method of crop cultivation. Once sufficient waste-treatment and composting capabilities are established within the settlement, the system will evolve into soil-based crops.
Jane Poynter, a Biosphere-2 researcher and advisor to 4Frontiers, has offered some creative suggestions on alternative meat (protein) sources. Further research and collaboration in this area (and many others) is ongoing.
(provided by Grant Bonin, edited by ble)
The mission planning segment of human Mars settlement was not considered in the initial Gen I study -- rather, it was assumed that a series of successive Heavy Lift Launch Vehicles (HLLVs) would be used to deploy all candidate hardware to the surface of the red planet. However, this assumption implies many challenges, with disparate issues ranging from launch vehicle economics to constraints on payload entry, descent and landing (since the ability to successfully aerobrake and land large payloads remains a significant question mark in Mars exploration). Consequently, it may be disadvantageous for 4Frontiers to predicate their entire plan on a single deployment scheme as described.
The Mission Planning Taskforce was created to address this critical issue. However, rather than advocating any single deployment option, the current work of the mission planning group aims to give 4Frontiers a series of options; that is, under a given set of launch vehicle, spacecraft sizing and EDL assumptions, a deployment scenario will exist for planned 4Frontiers activities at Mars. While our final recommendations will include different solutions optimized for different considerations (i.e. reliability, cost, etc), we wish to remove the 'transportation issue' from the critical path of Mars exploration while developing scenarios that are commensurate with any set of transportation capabilities at the time of program initiation.
Specifically, as of this writing, the launch vehicle trade study (which encompasses all mission segments) is approximately 75% completed, and individuals on the mission planning task force are working to address issues such as entry, descent, and precision landing. As well, work is being done to address issues pertaining to radiation concerns and 'astrosociology', a term and field being pioneered by team member Dr. Jim Pass.
We anticipate completing all major relevant components of our (transportation) work by mid-February.
There have been a few changes to the Gen-II program study team in the past several months. Team members have been added to fill gaps in the initial staffing, while others have stepped back to an advisory role due to other work commitments. An updated organizational chart can be seen below.
(Click for Larger View)
Putting it all together (and into better context)
While preparing a presentation for an upcoming book signing, I decided to organize my talk about the “future history” of Mars into four chronological sections:
1. Exploration (what we know and need to know about Mars)
2. Design (how we build systems that will work on Mars)
3. Construction (building those systems)
4. Settlement (making it happen)
In recent years, NASA and ESA have made great Mars exploration advances. More will follow in 2007 from Phoenix, Mars Odyssey, Mars Reconnaissance Orbiter, Mars Express, and Mars Global Surveyor (if it can be brought back from the brink of limbo). Construction of the next lander, the 2009 Mars Science Laboratory rover, is well under way. Exploration is alive and well at NASA and elsewhere.
The next logical step, systems design, is far less mature. Besides early Constellation project work at NASA aimed at eventual lunar settlement over a decade from now, few organizations are considering the design of extraterrestrial settlement hardware. In this regard, the 4Frontiers Gen-II study is nearly unique.
The road ahead is a long one, and the chasm between steps 2 and 3 (design and construction) will take years to bridge. First steps have already been taken, however, and substantial progress has already been made.
Stay tuned for more Gen-II settlement updates in the coming months!
"With confidence, you can reach truly amazing heights; without confidence, even the simplest accomplishments are beyond your grasp." - Jim Loehr, sports psychologist