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Mars for Less

Mars for Less. Grant Bonin 4Frontiers Corporation gbonin@4FrontiersCorp.com SpaceVision 2006, Orlando Florida, November 10-12. Human Mars Expeditions with Existing Launch Vehicles. Rick Tumlinson. Brian Enke. Who is this guy?. Bob Richards.

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Mars for Less

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  1. Mars for Less Grant Bonin 4Frontiers Corporation gbonin@4FrontiersCorp.com SpaceVision 2006, Orlando Florida, November 10-12 Human Mars Expeditions with Existing Launch Vehicles

  2. Rick Tumlinson Brian Enke Who is this guy? Bob Richards SpaceVision 2006, Orlando, Florida, November 10-12 Joe (my boss) George Whitesides me

  3. Problem Statement SpaceVision 2006, Orlando, Florida, November 10-12 How do we get off this rock? More specifically, how do we get off this rock and to other ones? We need: Improved life support technologies Better understanding of spaceflight physiology Space-based nuclear power Better understanding of EDL of massive payloads <… insert additional items, probably your work, here…> A way to get it all off the ground in the first place $$$ This presentation deals with the last two items

  4. Presentation Outline SpaceVision 2006, Orlando, Florida, November 10-12 Background and Motivation Heavy Lift Launch Vehicles (HLLVs) Mars for Less Mission Overview Trajectories and Energy Requirements Propulsion System Design Spacecraft Sizing Lunar Exploration Options The Launch Vehicle Debate The Case for Heavy-Lift The Case for Smaller Launch Vehicles Risks and Arguments The Bottom Line Summary, Conclusions and Questions

  5. Getting off this rock… SpaceVision 2006, Orlando, Florida, November 10-12 [Source: AIAA-2006-7517]

  6. Background SpaceVision 2006, Orlando, Florida, November 10-12 Heavy-Lift Launch Vehicles Existing Plans (Ares V) – at “crux” of NASA ESAS Issues Development Delays Political Uncertainty Role of the Private Sector Does losing heavy-lift mean losing our shot at Mars?

  7. Mars for Less SpaceVision 2006, Orlando, Florida, November 10-12 MFL circumvents heavy-lift vehicles entirely The “heavy-lift alternative” Key design features: Existing or near-term launch vehicles (MLLV class, ~25 MT ETO) Existing or near-term technologies Only orbital assembly: no orbital construction Subset of vehicles can be used for long-duration lunar missions Here’s how the mission works…

  8. Mars for Less SpaceVision 2006, Orlando, Florida, November 10-12 Modular version of Mars Direct Assembled in orbit using existing launch vehicles two spacecraft per complete mission: Earth Return Vehicle (ERV) Launched to Mars unmanned Produces propellant on Mars Mars Transfer and Surface Vehicle (MTSV) Crew transfer to Mars Long-duration surface habitat

  9. Mars for Less Launch 6 Launch 5 Launch 4 Launch 3 Launch 1 & 2 SpaceVision 2006, Orlando, Florida, November 10-12 Each spacecraft requires 6 launches to deploy:

  10. Mars for Less SpaceVision 2006, Orlando, Florida, November 10-12 Propulsion stages used at successive perigees for TMI Earth Return Vehicle: Hohmann transfer to Mars Aerocapture and parachute/powered descent Methane/oxygen production on surface Mars Transfer and Surface Vehicle: Fast conjunction transfer to Mars Aerocapture and parachute/powered descent 500 day surface stay

  11. Mars for Less SpaceVision 2006, Orlando, Florida, November 10-12 Mating propulsion stages = operationally complex However, mission = developmentally simpler No new launch technology Relies only on orbital docking/rendezvous Think “Lego” (non-ISS) Orbital assembly is most time-tested mission req. Spacecraft can be delivered by many boosters: Delta IV Ariane V Falcon 9-S9 Proton Crew Launch Vehicle

  12. Trajectories and Energy Requirements SpaceVision 2006, Orlando, Florida, November 10-12 Standard split mission profile Forward deployment of cargo (C3 = 15 km2/s2) Fast flight, free return option for crew (C3 = 25 km2/s2) ΔV requirements (incl. 5% gravity losses): 4.1 km/s & 4.5 km/s

  13. Propulsion System Design (I): Design Overview SpaceVision 2006, Orlando, Florida, November 10-12 4-stage hydrogen/oxygen propulsion system Stage Characteristics: Dry Mass = 3 tonnes Wet Mass = 25 tonnes 2 Pratt & Whitney RL-10B-2 Engines 220 kN total thrust Vacuum Isp = 465 s 1 kWe autonomous PVA (tentative) Trans-Mars throw (excluding boiloff losses): 55,077 kg (C3 = 15) 47,607 kg (C3 = 25)

  14. Propulsion System Design (II): Boiloff Sensitivity Sensitivity of propulsion system to varying boiloff rates assessed

  15. Propulsion System Design (III): Conclusions SpaceVision 2006, Orlando, Florida, November 10-12 Mass loss rates ≤ 1%/month realistic 4-month critical propulsion assembly time Resulting requirement: 1 launch/month Adjusted TMI throw: 54 tonnes for cargo missions 46 tonnes for crewed missions Conclusion: boiloff is not a showstopper

  16. Spacecraft Sizing Iterations SpaceVision 2006, Orlando, Florida, November 10-12 Sizing assumptions: Lander & integral propulsion Isp = 380s (CH4/LOX) Lander dry mass = 10% of surface payload total Aeroshield mass = 15% of entry mass CH4/LOX stage fractions = 8% Two sizing iterations performed: 1st iteration based on past studies 2nd iteration based on OTS components and statistical data Estimates converged on similar values Most conservative estimates used

  17. Lunar Mission Implementation SpaceVision 2006, Orlando, Florida, November 10-12 Mars for Less vehicles can be used in long-duration lunar missions Concurrently or as precursor 2 vehicles used: Lunar Transfer Vehicle (LTV) Identical to ERV cabin, upper stage, lander 3-day transfer with free-return option Lunar Surface Vehicle (LSV) Forward deployed to lunar surface Utilizes 90-day transfer MOON

  18. Lunar Mission Implementation SpaceVision 2006, Orlando, Florida, November 10-12 Lunar Surface Vehicle Weak stability boundary transfer Utilizes ballistic capture ~25% ΔV reduction Can support three 150-day expeditions Lunar Transfer Vehicle Conventional Transfer Utilizes propulsive capture Ascent to lunar orbit & Earth return capability Each spacecraft requires 4 launches Long-duration exploration Rapid buildup of surface base MOON

  19. The Launch Vehicle Debate SpaceVision 2006, Orlando, Florida, November 10-12 Small vs. Heavy Payload Fraction Reduced Launch Volume Risks and Arguments Multiple Launch and Assembly issues Launch Delays LEO wait time The Bottom Line Launch Vehicle Economics Recommendations

  20. Multiple Launches SpaceVision 2006, Orlando, Florida, November 10-12 Multiple launches frequency cited as great weakness May be plan’s greatest strength HLLV Loss: Loss of crew; Loss of spacecraft; Loss of mission; Delay (possible loss) of program MLLV loss: Component (replaceable if not crewed) Offset by replacing with different booster Launch failure in MFL less likely to be mission or program critical

  21. Propulsion System Failure SpaceVision 2006, Orlando, Florida, November 10-12 Propulsion stage failure less decisive Possibility of backup stage—depends on situation Single engine reliability ~ 99% 2 engines per stage Probability of stage failure ~ 1/10,000 Negligible portion of mission risk

  22. Launch Delays and Loiter Time SpaceVision 2006, Orlando, Florida, November 10-12 Delays and wait time are always an issue Mars for Less = significant margin 4-month propulsion assembly time Indefinite prior spacecraft assembly time (Delays actually increase performance)

  23. Launch Vehicle Economics SpaceVision 2006, Orlando, Florida, November 10-12 HLLV: Large capital investment Poor cost amortization High man-hours per flight No market, less chance of competitor involvement Puts cost of entry for Mars out of reach MLLV: Smaller capital investment (if necessary) Better cost amortization Reduced man-hours per flight Three rules of rocketry: flight rate, flight rate, flight rate! Existing market, high chance of competitor involvement Lowers cost of entry for Mars mission Why continue to under-utilize existing infrastructure?

  24. Problem Statement SpaceVision 2006, Orlando, Florida, November 10-12 How do we get off this rock? We need: Improved life support technologies Better understanding of spaceflight physiology Space-based nuclear power Better understanding of EDL of massive payloads <… insert additional items, probably your work, here…> A way to get it all off the ground in the first place $$$ By circumventing HLLV, we free up $$$ for all other items

  25. The Bottom Line SpaceVision 2006, Orlando, Florida, November 10-12 In summary: Mars for less predicated on MLLVs and orbital assembly No orbital construction, fuel transfer, etc. Without new launcher, only Mars-bound spacecraft need development HLLVs will represent ideal technology when market exists That market must first be created Destination drives transportation The bottom line: Use what we have, and fly sooner

  26. Final Remarks SpaceVision 2006, Orlando, Florida, November 10-12 [...] the issue of whether or not such a heavy-lift vehicle is the correct strategic path remains unresolved. There are valid arguments on both sides, and this is a hotly debated issue. Fundamentally, the correct answer depends on your objective. If your primary goal is to place humans on the Moon or Mars, as soon as possible in the simplest and lowest risk manner, a super-heavy-lift vehicle is arguably the answer. However, if your primary objective is to open up the frontier to large numbers of people, or to produce large reductions in launch costs, or to increase competition and create redundant pathways to space, or to create a breakthrough in space commerce for the benefit of humankind, or to settle this new frontier, then logic and history suggests a different choice. Space Frontier Foundation, July 2006

  27. Mars for Less designed to answer question: • Can human Mars missions be accomplished with existing launch vehicles? • The answer is yes. • There’s more than one way to the red planet • This generation can reach Mars, with less Final Remarks SpaceVision 2006, Orlando, Florida, November 10-12

  28. …Questions? SpaceVision 2006, Orlando, Florida, November 10-12 The author would like to acknowledge the following individuals for their invaluable assistance and contributions: Joe Palaia Brian Enke Frank Crossman Regan Walker Tarik Kaya and the organizers of SpaceVision 2006

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