Mars for Less

1
Mars for Less

• Human Mars Expeditions with Existing
• Launch Vehicles

Grant Bonin 4Frontiers Corporation gbonin_at_4Frontie
rsCorp.com SpaceVision 2006, Orlando Florida,
November 10-12
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Who is this guy?

Rick Tumlinson
Brian Enke
Bob Richards
SpaceVision 2006, Orlando, Florida,
November 10-12
Joe (my boss)
George Whitesides
me
3
Problem Statement

• 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
• lt insert additional items, probably your work,
  heregt
• A way to get it all off the ground in the first
  place
• This presentation deals with the last two items

SpaceVision 2006, Orlando, Florida,
November 10-12
4
Presentation Outline

• 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

SpaceVision 2006, Orlando, Florida,
November 10-12
5
Getting off this rock
SpaceVision 2006, Orlando, Florida,
November 10-12
Source AIAA-2006-7517
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Background

• 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?

SpaceVision 2006, Orlando, Florida,
November 10-12
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Mars for Less

• 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
• Heres how the mission works

SpaceVision 2006, Orlando, Florida,
November 10-12
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Mars for Less

• 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

SpaceVision 2006, Orlando, Florida,
November 10-12
9
Mars for Less

• Each spacecraft requires 6 launches to deploy

Launch 6 Launch 5 Launch 4
Launch 3 Launch 1 2
SpaceVision 2006, Orlando, Florida,
November 10-12
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Mars for Less

• 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

SpaceVision 2006, Orlando, Florida,
November 10-12
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Mars for Less

• 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

SpaceVision 2006, Orlando, Florida,
November 10-12
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Trajectories and Energy Requirements

• Standard split mission profile
• Forward deployment of cargo (C3 15 km2/s2)
• Fast flight, free return option for crew (C3
  25 km2/s2)
• ?V requirements (incl. 5 gravity losses) 4.1
  km/s 4.5 km/s

SpaceVision 2006, Orlando, Florida,
November 10-12
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Propulsion System Design (I) Design Overview

• 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)

SpaceVision 2006, Orlando, Florida,
November 10-12
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Propulsion System Design (II) Boiloff Sensitivity

• Sensitivity of propulsion system to varying
  boiloff rates assessed

15
Propulsion System Design (III) Conclusions

• 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

SpaceVision 2006, Orlando, Florida,
November 10-12
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Spacecraft Sizing Iterations

• 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

SpaceVision 2006, Orlando, Florida,
November 10-12
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Lunar Mission Implementation

• 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

SpaceVision 2006, Orlando, Florida,
November 10-12
MOON
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Lunar Mission Implementation

• Lunar Surface Vehicle
• Weak stability boundary transfer
• Utilizes ballistic capture
• 25 ?V 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

SpaceVision 2006, Orlando, Florida,
November 10-12
MOON
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The Launch Vehicle Debate

• 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

SpaceVision 2006, Orlando, Florida,
November 10-12
20
Multiple Launches

• Multiple launches frequency cited as great
  weakness
• May be plans 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

SpaceVision 2006, Orlando, Florida,
November 10-12
21
Propulsion System Failure

• Propulsion stage failure less decisive
• Possibility of backup stagedepends on situation
• Single engine reliability 99
• 2 engines per stage
• Probability of stage failure 1/10,000
• Negligible portion of mission risk

SpaceVision 2006, Orlando, Florida,
November 10-12
22
Launch Delays and Loiter Time

• 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)

SpaceVision 2006, Orlando, Florida,
November 10-12
23
Launch Vehicle Economics

• 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?

SpaceVision 2006, Orlando, Florida,
November 10-12
24
Problem Statement

• 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
• lt insert additional items, probably your work,
  heregt
• A way to get it all off the ground in the first
  place
• By circumventing HLLV, we free up for all
  other items

SpaceVision 2006, Orlando, Florida,
November 10-12
25
The Bottom Line

• 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

SpaceVision 2006, Orlando, Florida,
November 10-12
26
Final Remarks

• ... 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

SpaceVision 2006, Orlando, Florida,
November 10-12
27
Final Remarks

• Mars for Less designed to answer question
• Can human Mars missions be accomplished with
  existing launch vehicles?
• The answer is yes.
• Theres more than one way to the red planet
• This generation can reach Mars, with less

SpaceVision 2006, Orlando, Florida,
November 10-12
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Questions?

• 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

SpaceVision 2006, Orlando, Florida,
November 10-12