Thoughts on Making Space Exploration Pay Highlights of four papers from 2007,2009, 2010, & 2011

1. Thoughts on Making Space Exploration PayHighlights of four papers from 2007,2009, 2010, & 2011 Future In-Space Operations (FISO) Telecon Colloquium March 21, 2012 Gordon Woodcock grw33@comcast.net

2. The Case for Settlement in a Nutshell • Economic benefit only long-range reason to send people into space. • Many products, from natural resources to manufactured items, could be produced in space and delivered to Earth or to space locations with positive economic benefit, if costs are competitive. Also, highly hazardous manufacture and/or testing could be done on the Moon. • Eventually, migration into space for permanent residence is an economic benefit. • Costs must be dramatically reduced from present levels • Costs can come down dramatically: • Space transportation costs; • Cost of human operations; reduced cost of supporting people. • Expensive items are (in order): transporting people; transporting consumables; transporting infrastructure. • Step-by-step process: (1) Reduce transport cost (2) long tours of duty (3) produce consumables including food on site; (4) fabricate infra-structure on site. 90% on-site produced seems a reasonable goal. • When these are achieved, the result is an initial settlement.

3. Content of an Actionable Program • Goal(s) worth striving for. Why should we do this? • A strategy to achieve the goal(s). • Concepts for actions, systems or both that embody the strategy. • An economically and technically feasible plan (roadmap?) that embodies the strategy and the concepts and meets the goals. More than a roadmap. Must include analysis that substantiates feasibility.

4. Futures for Humans in Space: Goals • Expression of national prowess, the goal of Apollo (goal wasn’t to land men on the Moon). Still relevant, but we are doing a poor job. Human space flight technological progress is stagnating. • Stimulation of interest in science and technology. Not evident today. Young people know our present path has no room for them. • Economic benefit to the taxpayers that support it, and to humanity in general. John Marburger, speaking about the Bush VSE: “It’s about bringing the inner solar system into our economic sphere.” • The view from The Economist (2009): “Human space flight is expensive and dangerous, and doesn’t accomplish anything useful. Stop. Robots are better.”(The magazine was reacting to the oft-cited human space flight goal of “science”. “Science” is not included in the goals above. Robots do it at much lower cost.)

5. Historical Perspective • World GDP per capita was almost constant for thousands of years until the industrial revolution began with: • cotton spinning ~ 1770; • The “improved” steam engine, 1775; • “Improved” iron making ~ 1785. • Exploration sponsored by governments has been mainly about territory and wealth … • The Lewis and Clark exploratory expedition 1804 - 1806 • In following years, development accelerated. Enterprising settlers traveled west to explore and homestead. • In the 1830s, politicians encouraged Americans to move to Oregon to discourage settlement by the British. Gold was found at Sutter’s Mill in 1848. The intercontinental telegraph was completed in 1861 and the intercontinental railroad in 1869. The Oklahoma land rush occurred in 1889. • “Modern” humans emerged from Africa roughly 50,000 years ago. Human progress was very slow for 99.6% of that period. It became rapid about 200 years ago and continues to accelerate. How long can our planet support a growing species with rapidly increasing productivity and technology?

6. Stagnation? • 1919/1920: Dr. Robert Goddard, in a landmark paper, speculated a rocket could hit the Moon. 49 years later, Apollo 11 landed. The Saturn V launcher first flew in 1967. The SLS is scheduled for its first flight with the same technology in 2017, 50 years later. • After Apollo, Space Shuttle. While it didn’t achieve goal of low-cost transportation, a great technical achievement. • Very high-performance re-usable cryogenic engine (SSME) • Re-usable heat shield for entry and landing. • Advanced flight controls for entire speed range Mach 0.3 to 25. • Experience with re-usable vehicles, up to 39 flights on Discovery. • After shuttle, the ISS. Its construction, operation and management are major steps forward in sophisticated space systems and operations. • Re-usability and space assembly are missing in current architectures.

7. Affordable Exploration Transportation The path to affordable transportation emulates mountain climbers. Establish camps in key (high-energy) locations, stock with supplies (mainly propellant), fly from camp to camp to destinations and return with small re-usable vehicles, refueling en route. Resource Base: Lunar Surface X Camp 1: L1 The Moon, and later Mars, will become resource bases, greatly improving supply logistics. Resource Base: Mars Surface Base Camp: LEO Camp 2: Elliptic Mars Polar Orbit Electric propulsion freighters become the propellant and cargo carriers of choice in view of their very low propellant consumption.

8. SEP/Depot Mass Benefit Mission Vehicles Tanker SEP Propellant SEP Crew Cab Aerobrake Lunar Transport Stage Refuel #2 at L1 Refuel Lunar Surface Refuel #1 L1 En Route to L1 TLI Propellant Mission Vehicles Propellant Mass, kg TLI Stage TLI Propellant Mass benefit is mainly because the large amount of TLI propellant is replaced by EP with several times the Isp.

9. 2007: Economic Benefits Examples: Four Representative Projects • Approach • Analyze the market for target costs • Formulate promising concepts • Rough analysis of costs vs returns • The Projects: • Lunar propellant for space transportation operations • Reusable human lunar lander • Later, use for Mars missions; not analyzed • Platinum-group metals for return to Earth • Lunar Tourism • Lunar landing and return … surface tourist facilities not included in analysis. • Helium-3 as a fusion fuel • No market until a working fusion reactor is developed, but then potentially very valuable.

10. Lunar Oxygen Re-Do: Lunar Propellant • Since the earlier paper in 2007, less costly lunar mission architectures found & analyzed; also found water on the Moon. Still pay off? Result: Promising; investment return in a few years. • The 2007 architecture: • Basis … SLS/MPCV/Expendable lander (then Ares V/Orion/Altair) • With lunar oxygen, re-usable lander in lunar orbit, gets all its oxygen from lunar production. Lunar missions use EELV-heavy class instead of SLS. Payoff based on reduced launch cost, not elimination of SLS. • Current evolutionary architecture: No heavy lift; 40-t. class. 6 person crew mission, 12 t. cargo mission. 20 t. cargo feasible 1. 300 kWe SEP cargo and propellant to L1*; re-usable crew vehicle (CTV) LEO-L1-LEO with re-usable booster stage; re-usable lander at L1 2. Lunar O2/H2 for lander ascent (pilot plant). Fewer launches and SEP trips 3. Lunar O2/H2 for all lander operations. No SEP except cargo to L1. 4. Re-usable lunar transporter LEO-lunar landing and return; “runway” with maglev decelerator/accelerator**. Aerocapture to LEO refueled in LEO; lunar propellant for course-correction propulsion on return *L2 also usable. **If there are to be lunar settlers, don’t use up the water resource for propulsion.

11. Results *10% annual cost of money

12. Lunar Oxygen Findings • Lunar propellant pays off. • Amortization times are reasonable at 10% cost of money. • Reduces direct cost of a lunar mission by about 2/3, not considering lunar labor costs. • Labor costs are high. Indicates the initial lunar propellant system needs to be set up by a crew of 3 over a few months. The next step, 8 times bigger, needs to be set up by the same number of crew over 1 – 2 years. • Lunar propellant production should be a high-priority investment for lunar operations. Lunar propellant is the least risk and most mature of the concepts discussed. • Crew transportation could eventually drop to a few million a year, enabling growth of a true settlement.

13. Platinum-Group Metals: Findings Return transportation: • Launch cost $1500/kg; platinum market price about $48,000/kg • Reusable lander, goes to Moon no payload except hydrogen for return • Lunar oxygen replenish; return to Earth orbit; aerobrake Transport cost, percent of platinum-group metals value Baseline all-chemical 20% Add SEP for lander delivery to the Moon 16% SEP plus cryo propellant from the Moon for launch to Earth 6% • Cost including financial costs ballpark $400 M/yr; return $350 M • Use of solar concentrators instead of photovoltaics would help on cost. Power is almost all thermal. • Some heat recovery from retorts could be achieved; trade between duty cycle and power need. • Viability depends on useful ores and/or efficient beneficiation. • To realize this resource for the future, it is vital to: • Prospect the Moon for useful ores; • Initiate experiment program for workable methods of PGMs extraction; most can be done on Earth; • (3) Develop space transportation technology evolution that leads to costs a small fraction of the value of these metals.

14. Lunar Tourism: Market • Sending Apollo astronauts to the Moon, in today’s dollars, was ~ half a billion per person. SLS/MCPV will be similar. (Same technology, same result.) We can infer what lunar tourists would pay from what orbital tourists have paid. • Experience is very limited … people who purchased trips to ISS from the Russians 20 - 30 million dollars, and people pre-paying ~$200,000 for a “pop-up” flight to space and back Travel to the Moon is a more dramatic and significant experience than ISS, so some would pay more. • A viable lunar tourist business needs at least dozens per year, so the price target needs to be lower. Reasonable guess: $10 - $20 million would attract dozens of people per year (runway lander projected to beat that and lunar oxygen can with low launch cost). Enough for a tourist business, if transportation development costs not borne by the tourist business. • Did not evaluate lunar surface tourist facilities.

15. Helium-3: Analysis • Mass of equipment is a little less than for the PGMs scenario. Total • regolith handled about the same. Product 165 kg vs 10 t. Cost is a • little more, and is mainly solar array. Power is 30 x more because half • of the regolith is heated. Could use a solar concentrator here. More • massive, but much less cost. • Capital cost too high by about a factor of 2. Solar concentrator would • help. Helium-3 may be more valuable than 1¢/kWh assumed here. • Solar concentrator and 2¢/kWh puts it in potentially feasible range. • Of course, there’s no current market. $1.5 billion 445 t.

16. Estimated Cost Reduction Potential (2009)(for people) 4/0.5/-/0 6/0.5/-/0 Number of people Stay (years) % Food from ISRU % Infrastructure from ISRU 12/1/30/20 12/1/0/0 24/2/30/20 48/4/50/40 300/20/90/80 SLS/MPCV

17. For Today’s Goals Our Program Definition Process is Backward • Apollo used a classic systems engineering process: • A project objective, like a military objective, and a target date, had been specified. • The implementation chosen was probably the only one within technical reach able to attain the objective by the target date. • Cost was whatever it needed to be and was not a major consideration in choosing the implementation. • Today’s goals have overriding economics components. • Net economic benefits require costs less than benefits. • Human enclaves “across the solar system” must be self-supporting; terrestrial economies will not accept a perpetual financial burden of this nature. • Cost parameters are the first specified • Acceptable implementations must fit the cost parameters.

18. Conclusions • Advanced technologies for in-space transportation greatly lower cost of architectures for lunar and Mars transportation • Reduced launch mass • Re-use of in-space propulsion elements. • Not new, but scale-up/improvement of technologies already in use. • Smaller architecture elements and smaller launch systems, partially re-usable, more affordable, and ready to fly earlier. • Together, these avenues could reduce cost of human exploration and space development one to two orders of magnitude. • This, in turn, enables development of technologies for “living off the land” on the Moon and Mars, the requisite for robust, affordable human operations on these worlds and and thus realization of settlement goals. • But wait a minute! Don’t we need heavy lift for Mars? • Answer: NO! See my FISO briefing a few months ago.

19. The Long Term • Once a stable proto-settlement exists on the Moon, people with enough wherewithal can emigrate there at own expense; others may be sponsored. Evolution of settlements with “volunteer” settlers merits more economics analysis. • Cost for transportation to Mars brings Mars within reach of very well-heeled (tens of millions of dollars) settlers. Future technologies, for example, Mars runway lander/ascent operating with a semi-cycler, will further reduce the cost. • The feasible carrying capacity of the Moon and Mars (number of settlers they can support) is much less than Earth. • O’Neill knew this in the 1970s, one motivation for his fabricated space habitats. Resources of the inner SS are enough to support hundreds of times Earth’s population in such solar-powered habitats. • Productive effort: An O’Neill habitat represents ~ a thousand times more manufactured hardware per person than modern industrial societies. (A lunar or Mars settlement at most a few times.) The key is highly automated robotic manufacturing, raw materials to finished product. Lunar/Mars settlements need the same to a lesser degree.

20. Outcome • Space settlement need not be a distant-future pipe dream. Reshaping human exploration programs to produce tangible benefits “for all mankind” offers a sound foundation for human exploration and settlement, and an orderly path to “bringing the inner solar system into our economic sphere”. • This is the reason to continue human space exploration.

21. Backup Slides

22. Crew Costs: Transportation & Resupply *Estimated cost of pilot-scale lunar propellant system hardware and delivery. ** Estimated cost of full-scale lunar propellant system hardware and delivery. No estimate made for actual on-the-Moon labor effort to set up these plants. Cost of a work-year of labor cited to give a sense of proportion

23. Platinum-Group Metals: Market • Current price for bulk platinum about $48,000/kg and trending up. • Current market about 130 t.; about $6 billion. • Most of the market is industrial demand. • Assumed initial production rate 10 t. per year; not realistic to presume complete market capture. • What we would expect to find on the Moon are platinum-group metals (Ru, Rh, Pd, Os, Ir, Pt). These occur at something like 100 ppm in asteroidal nickel-iron; considerable variability in concentration. • Free nickel-iron typically about 1% of regolith. There may be richer ores; we don’t know.

24. Platinum-Group Metals: Concept • This concept depends on useful ores. • Concept assumptions: • (1) We must deal with nickel-iron concentrations in ordinary regolith, about 1%. • (2) Regolith may be beneficiated by magnetic separation to yield feedstock much richer in nickel-iron. Assumed concentration to 50% nickel-iron, which may be optimistic. • (3) PGM concentration in nickel iron about 100 ppm, • (4) Feedstock must be smelted to separate nickel-iron from oxidized minerals. • (5) PGMs separated by a carbonyl process, nickel-iron is converted to a gas, leaving the PGMs behind. • (6) The CO in the carbonyl process is recycled. • (7) Values of the nickel-iron and volatiles byproducts are neglected, although may be considerable, especially for use on the Moon. • (8) Moderate-cost Earth launch transportation is available • (9) Lunar oxygen production is available.

25. Hauler Digger Concept Flow Chart Rubble Lunar Oxygen Production Magnetic Beneficiator Re-entry Body Fab Ore Payload Processing Spaceport Slag Smelter Carbonyl Reducer Carbonyl Spray Reactor PGMs powder Metal Carbonyls Metals Re-entry bodies fabricated from lunar materials; PGMs payload fraction 50%.

26. Analysis $1,130 M + $660 M Transport 9,100 MW 620 t.

27. Lunar Tourism Analysis Above this blue line, SEP does not reduce cost $20 M very reachable $10 M possible Finding: Tourism cost targets appear reachable, even without a “runway” landing/launch system

28. Helium-3: Market • Caveats: • Sustained confined fusion plasma burn has not been demonstrated. • A helium-3-deuterium power reactor will be very different from a tritium-deuterium power reactor. It may be much less costly to build and operate, which is why helium-3 may be valuable. • Helium-3 is very low concentration on the Moon but a lot overall. • For every billion dollars helium-3 can reduce capital cost (e.g. by eliminating the lithium blanket), its value increases about 1¢ per kWh, or $500K per kg. There may also be operating cost savings. The analysis was based on supplying one 1-GWe power plant. This requires about 170 kg/yr. The ultimate market may be 100 times that, but the startup has to be economically feasible.

29. Helium-3: Concept • Heating the regolith • (~700C) to drive off • volatiles requires so • much heat we need a • recuperative heat • exchanger. • Helium-3 is a very • tiny fraction of the • volatiles; need to • concentrate it. • Hydrogen eliminated • by burning to water. • Nitrogen and argon • liquefied out. • He4/He3 ratio about • 4000; gaseous • diffusion to enrich • He3 to ~ 50%. • Ship to Earth as high- • pressure gas.

30. Overall Lunar Industry Conclusions • These projects represent modest to large scale industrial operations on the Moon. The first three appear operable with net economic value using space transportation technologies developable with current knowledge, and lunar surface operations technologies that could be developed in the early years of a lunar outpost. The fourth needs changes in concept, future developments in fusion technology, or changes in energy markets. • More in common than differences. A core set of technologies and systems, with modest variations, suits all options well. • Projects presented in order of technical and financial challenge; tourism may be less challenging than platinum-group metals. • Large uncertainties exist. Experimental programs, some on the Moon, and major technology advancement efforts, are needed to reduce uncertainties to an acceptable risk level. Reasonable investments; a lunar outpost is needed to support lunar experiments. • Aggressive cost reduction required, including compromises between costs for industrial equipment and space systems as well as efficient space transportation architectures. A change in space systems engineering is needed, similar to industrial/commercial projects: Identify a viable market price and find ways to meet or beat it. • Perspective: Lindbergh’s flight in 1927 won the $25,000 Orteig prize. In fifty years, considering inflation, the cost of crossing the Atlantic by air came down a factor of 100.

31. Annual Operating Costs

32. Export Products • Propellants • Spacecraft structures and parts made from glass-glass composites or aluminum* • Platinum-group metals; other strategic metals • Rare Earths • Scientific data • Tourism -------------------- • Helium-3 • Solar Cells • Artworks and handcrafts Mars mission cost is reduced through use of lunar propellants *Recent measurements of volatiles containing carbon (LCROSS) indicate possibility of graphite composites.

33. Settlement-Class In-Space Transportation for Moon and Mars (2010)

35. Designing an Enduring Mars Campaign (2011) Preliminary “Below” use newer fig Propellant Depot Habitat 500 kWe SEP Tug with Tanker Lander Node MOD Solar Array AIAA Space 2011 Gordon Woodcock Huntsville Alabama

36. Where? Mars 48-Hour Orbit, Periapsis at S. Polewith Typical Arrival & Departure Vectors • This sketch is to scale, with Mars’ axis tilted 24.5 degrees. Parking orbit periapsis is at the pole. • With 90 degree inclination there is no nodal regression. Apsidal advance 0.265 deg/day needs to be nulled, requir-ing about 1.25 m/s per day. • The orbit plane needs to be rotated around its major axis to align with arrival and departure vectors, usually near the ecliptic plane. This can be done with electric propulsion at apoapse, where the orbit velocity is about 287 m/s. • These corrections are readily made by electric propulsion.

37. Typical “Standard Orbit” Mars Departure Delta V Loss Analysis This graph is for Mars departure on the 2024 opposition mission with 30-day stay, assuming the orbit shown on the prior slide. Ideal delta V is 3.426 km/s impulsive in-plane p-p transfer. Delta V is relative to this and derived from integrated trajectories with in-plane transfer and apsidal rotation on departure burn. This shows that departing away from periapsis to minimize apsidal rotation is a lot better than departing near periapsis and having to do a lot of apsidal rotation.

38. Mars Surface Cargo General Manifest

39. Mars Lander ConceptRe-usable operations fueled in orbit for landing and on Mars for ascent. LOX-LH2 propulsion modules fore and aft for balance; attitude control by differential throttling. No gimbals. Engines 115 kN (26 klbf) each, throttling range 3:1 to 4:1. Movable aero surfaces for pitch trim during aero descent. Cargo space • Landed cargo can include built-in crew habitat; expendable and re-usable cargo landers • Early crew: expendable crew ascent stage and lander • Later crew: crew module, re-usable crew lander; this version must refuel on Mars due to delta V and need for thermal protection. Mars’ atmosphere is so tenuous that for ascent, the vehicle can simply fly “sideways”; doesn’t need engines in the tail.

40. Lander Model with Movable Tail (MATLAB® Model) Tail 30° Dihedral Tail 30° Dihedral plus 40° Pitch

41. Mars Entry & Landing TrajectoryFrom Elliptic 48-hour Orbit Entry Mass 65 t. Useful Descent Payload 32 t. Estimated Descent & Landing Delta V 1360 m/s

42. Short-Stay Crew Round Trip Mission Diagram This Mission Uses an Expendable Lander with Storable Ascent Stage, Separately Delivered to Mars Orbit Depot (MOD) Mars Surface Event 9 Lander lands on Mars. Ascent stage returns to MOD MOD Prior opportunity: 2 – EP Tugs deliver 2 tankers & TEI stage LEO to MOS. No aerocapture. Tugs return to L1 but too late for DSH & tankers. Crew mission includes DSH, and CTV. DSH & TEI stage to L1 Event 3. CTV to L1 Event 9. Lander delivered to MOD by aerocapture without cryo propellant; refuels w/prop del Event 1. 3 – RUS’s prop recov at L1. Event 5 Event 8 Event 1 + L1 Event 6 Lander loaded 22 t. cryo, boosted by RUS and self-propelled to L1. Arrives empty except storables Event 3 Event 2 LEO Launch Support for Event 1 Lander, propellant, RUS’s equipment to LEO Crew direct launch to L1 in CTV Event 7 Event 4 Event 10 Earth EP Tugs deliver Deep Space Hab and 2 propellant tankers to L1 & return to LEO. 2 self-propelled RUSs to L1 for Event 8. EP Tugs, DSH, 2 tankers launched to LEO

43. Network Diagram for Short-Stay Mission Event 9 Crew Landing and Ascent Event 1 Prior opportunity: 2 – EP Tugs deliver 2 tankers & TEI stage LEO to MOS. No aero-capture. Tugs return to L1. Lander descent propellant Event 8 Crew mission from L1 to MOS & return to L1 TEI stage & TEI propellant Event 2 Launches to support Event 1 Event 10 Crew launch direct to L1 in CTV or CEV Event 3 EP Tugs deliver Deep Space Hab and 2 propellant tankers to L1 & return to LEO Event 7 4 launches to support Event 6 Event 4 Launches to support Event 3 Event 6 Lander deliv-ered LEO-L1 RUS boost & self-propelled Event 5 Lander delivered L1- MOS: RUS + aerocapture

44. Timelines for Outpost Occupancy Earth Years Repeating Opposition Missions Repeating Opposition-Like (Semi-Cycler) Mars Flybys with Crew Dropoff & Pickup (Gaps are shown to designate crew change; actual gaps only a few days) Repeating Conjunction Missions (Dashed lines show stayover option) Repeating “Stretched” Conjunction Missions (Gaps are about 3 months)

45. 2028 EP Semi-Cycler Trajectory(This year chosen because it’s difficult for chemical propulsion) 1500 kWe EP Tug mission, Earth-Moon L1 to Mars encounter, return to L1.

46. Size Comparison Conventional Interplanetary Vehicle 500 kW SEP tug RUS

47. How Big is a 1.5 Megawatt SEP?

48. Cost Analysis Results Development of Heavy Lift Plus In-Space Systems Development of In-Space Systems Procurement of In-Space Systems

49. Conclusion for Mars A network architecture that uses propellant depots at destinations and electric propulsion vehicles (“tugs”) to provision them with propellant, supplies and equipment achieves two major cost savings: • Eliminates need for very large and expensive heavy lift vehicles; • Offers practical re-use of in-space transportation systems, including electric propulsion and habitats, eliminating acquisition cost for replacement hardware. Opens the way for further cost savings, for example, propellants from in-situ production on the Moon and Mars.

50. Evolution Paths Initial Lunar Return Asteroid Capability Permanent Lunar Presence Mars Landing Capability Lunar Proto-Settlement Mars Proto-Settlement Earth SBSP* Partially Reusable Re-usable Orbiter (Med. Lift) Medium Lift Launch Orion-Like Capsule Retired Lunar Lander Re-usable Earth-Moon Transport Lunar “Runway” Lander Prop. Depots at ISS & L1 Space Ops Habitat Surface Ops Suite Lunar Prop. Production Lunar/Mars Food Growth & Infrastructure Production 1 MWe+ SEP Mars Lander/Ascent Re-usable Earth-Mars Transport Mars “Runway” Lander Mars Prop. Production *Space-based solar power “Runway” on Mars “Runway” on the Moon Lunar SBSP* Mars SBSP* With careful architecture design, a modest suite of technologies enables a rich program.