Near-Term Mars Colonization

-A DevelopSpace Project-June 28th, 2008

Agenda

• Transportation architecture revisited

• Surface manufacturing strategy

• Surface food production strategy

• Hab update (Arthur)

Transportation Update

• Upper stage diameters:– Falcon 9 heavy: 3.6 m– Delta IV heavy: 5 m

• => Hammerhead required

Trajectory /aerodynamic limit

• Previous transportation strategy was based on use of ~12 mt aeroshells with diameters around 5 m

• This leads to a significantly increased number of aeroshells that need to be built, as well as to reduced maximum volume of items that can be transported to Mars

• Analysis was carried out to determine whether it is possible to use a single ~24 mt aeroshell

Aerodynamic Properties

• Basic shape is blunted cone with 20-degree side-wall angle

• Achieves L/D of 0.3 at 18.5-degree angle of attack

• Drag coefficient of ~1.5 at 18.5-degree angle of attack

• Shape is similar to SpaceX Dragon capsule– May be possible to utilize

aerodynamic database from Dragon– Possibly use Dragon derivative?

SpaceX Dragon

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Aeroshell

Preliminary Transportation Cost Assessment• Falcon 9 Heavy [FY 2008 $]

– $ 94.5 Mn per shot for LEO mission• Lander costs [FY 2004 $]

– Dry mass: 2453 kg– Development: $ 1482 Mn– Production (1st unit): $ 112 Mn

• Aeroshell costs [FY 2004 $]– Dry mass: 8000 kg– Development: $ 2839 Mn– Production (1st unit): $ 245 Mn

• TMI stage [FY 2004 $]– Dry mass: ~5000 kg– Development: $ 560 Mn– Production (1st unit): $ 32 Mn

• Approximate marginal cost for transporting 10 mt to the surface of Mars:

– (3 x 94.5 + 2 x 32 + 112 + 245)*1.2 = 845.4– $ 84540 / kg on the surface of Mars

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Surface Manufacturing Strategy (1)• Major needs during the early toehold stage:

– Manufacturing of spare parts for subsystems– Manufacturing of IVA / EVA tools– Possibly manufacturing of structure for expansion of pressurized

volume and for ISCP

• Materials than can be produced in-situ on Mars:– Polyethylene (PE) and other polymers (from RWGS)– Iron / steel (significant infrastructure required)– Ceramics and bricks (from baking regolith)– Aluminum (significant infrastructure required)– Copper (significant infrastructure required)

• Chapter 7 in Zubrin’s case for Mars provides a good overview• Quantitative assessment of infrastructure required

Surface Manufacturing Strategy (2)

Acquiring water on Mars• 4 possible sources:

– Underground aquifer– Topsoil (1-3% by weight)– Atmosphere– Permafrost

• Extraction from topsoil and atmosphere may be easiest initially (less infrastructure)– Could use tent-like structure,

condenser, and sunlight (concept by Zubrin)

• Water provides breathing oxygen and hydrogen for further ISCP (also PE)

• It has been proposed to synthesize PE based on products from RWGS:– 6H2+2CO2=>2H2O+2CO+4H2– 2CO+4H2=>C2H4+2H2O– n x C2H4 => PE

• We need to carry out a more detailed analysis of these processes

Food Sourcing (1)

• Reminder: food remains one of the largest re-supply items (strong incentive for achieving higher closure)

• Ways to close the food loop (in order of difficulty)– Growing fruits / vegetables with aeroponics / hydroponics– Growing algae, subsequent processing into edible form– Growing edible fungi (for some types no light required)– Traditional soil agriculture using Martian soil / regolith– Breeding animals (chicken, fish; both still quite inefficient)– Chemical regeneration of foods (formose, lipids, starch etc.)

• Analysis required to determine which ways are most effective during different stages of colony

Food Sourcing (2)• Notional roadmap as point of departure:

– Phase 1:• Food mostly imported from Earth in de-hydrated form• Some fruits and vegetables grown hydro- / aeroponically to

supplement de-hydrated food (nutrients brought from Earth)• Possibly use of some fungi / algae as nutrition supplement

– Phase 2:• Food partially imported from Earth, partially generated locally• In-situ nutrient production, use of Martian soil• Possibly use of some fungi / algae as nutrition supplement

– Phase 3:• Food mostly produced on Mars using in-situ nutrients and soil• Algae and fungi as supplement, possibly also some animals• Predominantly vegetarian life-style

Arthur’s Hab Update

• Should be in your inbox at this time…

Backup Slides

Mars Wish List

Transportation• Automated Mars landing and hazard avoidance

navigation systems • Mars in-situ propellant production friendly rocket

combustion / performance characterization (C2H4/LOX; CH4/LOX); more important if people want to come back

• Large-scale (20mt+) Mars aero-entry (and EDL more generally) technology

• Low mass, cost, power and ideally autonomous deep-space (out to at least ~2 AU) navigation systems (software, hardware)

Power

• Automated, large scale (football field+) solar array transport, surface deployment, and maintenance systems

• High energy density electrical power storages systems (aiming in particular towards high energy density relative to Earth imported mass)

• Mars surface internal combustion engines (LOX, plus various fuels, e.g., C2H4, CH4, CO, etc), possibly with water exhaust reclamation.

Life Support, Logistics, ISRU• Mars atmosphere collection systems (at minimum CO2; adding N2 and Ar is useful;

H2O depends on energy/mass intensity relative to other options) • Mars permafrost mining systems (for varying wt% H2O); note, this is much easier

than mining putative lunar ice • Good, high capacity Mars surface cryocoolers (options for just soft/medium

cryogens (e.g., LOX, CH4, C2H4), or also for hard cryogen (LH2)) • Earth-Mars hydrogen transport systems (not necessarily as LH2) • Basic ISRU chemical processing systems (e.g., H2O electrolysis, Sabatier, RWGS,

CO2 electrolysis, ethylene production, etc.) • High closure physical-chemical life support systems (e.g., air revitalization, water

recycling) • "Food system" for food supplied from Earth. Consider being able to survive on

food shipped 5 years ago. • Mars surface food production systems • Simple in-situ manufacturing systems (e.g., for spare parts) • Simple raw materials production (e.g., plastics such polyethylene, epoxies,

ceramics, etc.)

Outpost Ops and Surface Exploration

• Mars surface communication and navigation systems (e.g., for rovers), sans extensive satellite constellation

• Very high data rate Mars-Earth back-haul comm system

• Good Mars surface EVA suits • Data collection, analysis in support of landing site /

outpost location selection • Very long distance surface mobility systems

(including with people) • Solar flare / SPE warning systems