Evolution of Lunar to Planetary Landing

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Evolution of Lunar to Planetary Landing

• Miguel San Martin
• Mars Science Laboratory GNC Chief Engineer
• Jet Propulsion Laboratory

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Viking
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MPF/MER EDL
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Mars Science Laboratory vs. Earth Rover
2005 MINI Cooper S
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Lunokhod
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MSL Sky Crane
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Background

• For Entry Descent and Landing (EDL), the Mars
  Program has relied heavily on technology
  infrastructure developed by the ICBM, Apollo
  (manned program), and Viking programs of the 60s
  and early seventies
• Aerodynamics
• Thermal Protection Systems (TPS)
• Parachute design and testing
• Testing facilities
• Wind tunnels, Arc Jet Testing, Vacuum Chambers
  (Plum Brook Station 100 x 120ft chamber), etc.
• Touchdown dynamics
• Plume interactions
• GNC Architectures and Algorithms
• As our missions, and corresponding EDL, became
  more challenging, we started to outgrow such
  heritage, and we were forced to
• Develop new architectures
• Sky-Crane Mars Science Laboratory (MSL)
• Use state of the art CFD analysis
• RCS-Aero interactions, Plume Impingement, Chute
  Inflation dynamic, etc.
• Rely heavily on simulations for VV
• We expect/hope that the Constellation program
  will renew and enlarge the technology
  infrastructure, helping the planetary program
  accomplish ever more challenging missions

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GNC Sensors and Technologies

• Need GNC Sensors and Technologies for
• Precision Pin-Point Landing
• Hazard Detection and Avoidance
• Velocimetry/Altimetry
• Ideally, fully integrated and tested
  off-the-shelf sensors
• The costs and schedule of developing flight
  qualified GNC sensors is almost prohibitive for
  the Planetary Program
• MSL Landing Radar Example
• Hazard Detection and Avoidance is traditionally
  the first de-scope in every Mars Landing mission
• A Lunar Program with continued landings has a
  better chance to field off-the-shelf sensors than
  our one-of-a-kind planetary missions
• But they would have to meet planetary spacecraft
  constraints
• Mass, Volume, Power
• Self contained?

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Testing Facilities and Technologies

• Technical difficulty, cost, and schedule have
  resulted in the elimination of full end-to-end
  hot-fire Terminal Descent tests in the Mars
  Program
• Mars vs. Earth gravity
• Mars vs. Earth atmosphere
• Test infrastructure
• Human and Hardware Safety
• Avionics
• Telemetry/Video
• Need Terminal Descent Testing facility
• Gravity off-loading
• Propulsion choices?
• Purpose
• Test landing sensors
• Test GNC Flight Software
• Test touchdown sensors
• Test touchdown dynamics/stability
• Again, the hope is that a Lunar Program can keep
  a facility like this alive and ready

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Physics

• Need new computational-tools/experiments/theory
  that inform the physics of phenomena like
• Thruster plume interaction
• With landing surface
• Trenching
• Dust S/C contamination and damage
• Dust effects on landing sensors
• Self plume impingement
• Touchdown dynamics
• Stability
• Mechanical loads
• Spacecraft mechanical separations
• GNC Sensor modeling
• RF and optical
• Propulsion modeling
• Water hammer!!!
• Pogo?
• Combustion response time

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Avionics FSW Architectures

• Avionics and FSW are a big source of stress in
  the Planetary Program
• Lack of standardization
• Hardware and software
• Centralized control
• CDH and GNC
• Science and Engineering
• Ad-hoc redundancy management and fault-protection
• COTS Operating Systems
• Multi-tasking, priority based
• Lack of predictability
• Complex
• Viking vs. MSL
• Brittle
• The Constellation Program represents a great
  opportunity to help in this area

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Miscellaneous

• Landing Architectures
• Legged lander vs. Sky-Crane vs. Pallet
• Passive legs vs. active legs
• Descent engine placement
• TVC vs. fixed engine ACS
• Power and Pyro Architectures
• Distributed pyro systems?
• Low EMI
• Dead phasing, cable-cutters, etc.
• Reliable and efficient Primary, Secondary,
  Thermal batteries
• Propulsion
• High ISP
• Throttleable