Lunar Exploration Transportation System (LETS)

1
Lunar Exploration Transportation System (LETS)

• MAE 491 / 492
• 2008 IPT Design Competition
• Instructors Dr. P.J. Benfield and Dr. Matt
  Turner
• Team Frankenstein
• Phase 2 Presentation
• 3/6/08

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Team Disciplines

• The University of Alabama in Huntsville
• Team Leader Matt Isbell
• Structures Matthew Pinkston and Robert Baltz
• Power Tyler Smith
• Systems Engineering Kevin Dean
• GNC Joseph Woodall
• Thermal Thomas Talty
• Payload / Communications Chris Brunton
• Operations Audra Ribordy
• Southern University
• Mobility Chase Nelson and Eddie Miller
• ESTACA
• Sample Return Kim Nguyen and Vincent Tolomio

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Agenda

• Abstract
• Phase 2 Overview
• Design Process Outline
• Concepts
• Subsystems of Concepts

• Selection of Final Concept
• Phase 3 Planning
• Phase 3 Schedule
• Conclusions
• Questions

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Abstract

• Multifaceted and reliable design
• System meets all CDD requirements
• Two concepts developed in Phase 2 using the
  Viking Lander as a baseline
• Each design assessed based on the specifications
  of the CDD
• Both were assessed and ranked
• The best design, Cyclops, was chosen to be
  carried into Phase 3
• Designs ranked by ability to meet scientific
  objectives, weight, ease of design, ability of
  mobility, etc.

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Phase 2 Overview

• Deliverables
• White paper
• Compare baseline, the Viking Lander, with two
  alternative concepts
• Strategy for selecting alternative systems
• Qualitative and quantitative information to
  evaluate each idea
• A logical rationale for selecting one concept
  from among the presented options
• Oral presentation
• Specification Summary
• Lander and rover is required to meet the CDD
  requirements for the mission
• The CDD requirements are the foundation for the
  lander/rover design
• Each subsystem is also directly affected by the
  requirements and lunar environment

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Phase 2 Overview Cont.

• Approach to Phase 2
• Team Structure
• Team Frankenstein is born
• Team split up into separate disciplines
• Concerns
• Harsh lunar environment Electrically charged
  dust, temperature, radiation, micro meteoroids,
  etc.
• 15 Samples in permanent dark Extreme
  temperature of -223 C
• Mobility - non-existent on the baseline lander
  and LETS CDD requires mobility
• Concept Design
• Review baseline lander for detailed information
  about the customers specific requirement
• Investigated possible solutions to meet the given
  CDD requirements
• Each discipline presented design ideas to the
  team
• Team revised these possibilities and created two
  design concepts
• Evaluated the concepts based on the weighted
  values for desired criteria and chose the winning
  concept

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Design Process Outline
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Baseline Concept Viking Lander

• First robotic lander to conduct scientific
  research on another planet
• Total Dry Mass 576 kg
• Science 91kg (16 of DM)
• Dimensions 3 x 2 x 2 m
• Power
• 2 RTG
• 4 NiCd
• Survivability
• -90 days expected
• -V16yrs 3mo
• -V23yrs 7mo

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Alternative 1 Concept Cyclops

• Single rover landing on wheels
• Total Dry Mass 810.5 kg
• Science 320 kg (40 of DM)
• Penetrators
• SRV
• Single site box
• Dimensions 2 x 1.5 x 1 m
• Power
• 8 Lithium Ion Batteries
• 2 Radioisotope
• Thermoelectric Generators (RTG)
• Solar Cells
• Survivability At least 1 yr

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Alternative 2 Concept Medusa

• Stationary lander with rover deployment
• Total Dry Mass 932.8 kg
• Science 195 kg (21 of DM)
• Penetrators
• Dimensions 2 x 1.5 x 1 m
• Rover 1 x 0.5 x 0.5 m
• Power
• 8 Lithium Ion Batteries
• 3 Radioisotope Thermoelectric Generators (RTG)
• Survivability At least 1 yr

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Guidance Navigation

• Viking
• Guidance, Control, and Sequencing Computer
  utilized the flight software to perform guidance,
  steering, and control from separation to landing
• Cyclops
• Decent/Landing
• An altitude control system will be used to
  control, navigate, and stabilize while in descent
• Post Landing
• Operator at mission control navigating rover
• Uses a camera system to obtain terrain features
  of its current environment
• Rover orientation will be accomplished by a
  technique known as Visual Localization
• Uses a camera image to determine its change in
  position in the environment
• Medusa
• Decent/Landing
• An altitude control system will be used to
  control, navigate, and stabilize while in descent
• Post Landing
• Ground command inputs to the rover will be
  provided by onboard planning
• Autonomous Path Planning will be used to navigate
  the rover
• Uses a camera system to obtain terrain features
  of its current environment
• Rover orientation will also be accomplished by
  Visual Localization

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Communications

• A UHF antenna will provide
• surface communications for
• the Lander/Rover
• Communications to mission control
• will be done by medium gain S-Band
• antennas on the lander/rover

13
Structures

• Viking
• Used a silicon paint to protect the surfaces from
  Martian dust
• Structural frame used lightweight aluminum
• Cyclops
• Six wheeled rover
• Structural frame built from Aluminum 6061-T6
• Lightweight properties
• Low cost
• Composites
• Carbon fiber, phenolic, etc.
• Excellent thermal insulation
• Excellent strength to weight ratio
• Lower density
• Medusa
• Four legged lander
• Deployed six wheel rover
• Structural frame built from Aluminum 6061-T6
• Composites

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Power

• Viking
• Bioshield Power Assembly (BPA), Power Control and
  Distribution Assembly (PCDA), Nickel Cadmium
  batteries, RTG, and Load Banks
• Cyclops
• PCDA
• Load Banks
• 8 Lithium Ion Batteries
• Best energy to weight ratio
• Slow loss of charge
• 2 RTG
• Constant power supply
• Thermal output can be utilized for thermal
  systems
• Solar cells for single site box
• Medusa
• PCDA
• Load Banks
• 8 Lithium Ion Batteries
• 3 RTG
• One RTG is needed for Medusas rover

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Thermal

• Viking
• Thermal insulations and coatings, electrical
  heaters, thermal switches, and water cooling
• Cyclops
• 2 RTG
• Each RTG will deliver a maximum
• of 7200 W of heat
• Multi-Layer Insulation
• Lightweight
• Multiple layers of thin sheets can be
• added to reduce radiation
• Marshall Convergent Coating-1 (MCC-1)
• Forms a radiant heat barrier on surfaces that are
  painted
• Medusa
• 3 RTG
• Multi-Layer Insulation
• Marshall Convergent Coating-1 (MCC-1)

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Payload

• Gas Chromatography-Mass Spectrometry
• Multi-spectral Imager
• Miniature Thermal Emission Spectrometer
• Single site box
• Penetrators

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Operations

• Upon reaching the Moon
• Decent
• CONOPS takes over 5km from lunar surface
• Upon decent, shoot 15 penetrators into
  permanently dark regions of the moon
• Dark regions in the Shackleton crater
• Landing
• Drop off sample box for single site goals
• Micrometeorite flux
• Lighting conditions
• Assess electrostatic dust levitation and its
  correlation
• with lighting conditions
• Have 14 days of guaranteed light conditions
• Lunar Surface Mobility
• Have rover move to the rim of the Shackleton
  crater
• Have the penetrators relay the data to the rover
• The rover will send the data to LRO
• Send data from LRO to mission control
• Visit lit regions and collect samples
• Relay data to mission control via LRO

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Selection of Final Concept
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Phase 3 Planning

• Key Issues to Address
• TRL of 9 vs. New Technology
• Penetrators
• Meets all challenges
• Design basis is new
• Expectations
• Provide innovative ideas that meet or exceed the
  base requirements set out by the team
• Partner Tasks
• ESTACA
• Sample Return Vehicle
• Southern University
• Mobility

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Phase 3 Schedule

• Subsystems
• Each subsystem must develop a unique design that
  best fits the requirements for the chosen concept
• Design Critical systems
• Con-ops
• Reliant on subsystems to provide direction for
  daily tasks
• GNC
• Reliant on subsystems to provide basis for
  equipment needed
• System Integration
• Systems will be reviewed for feasibility
• Compromises will be made on each design to create
  the most beneficial product

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Conclusions

• The best design Cyclops
• Theres no place this thing cant go
• Provide superior functionality and reliability
• Develop innovative and cutting edge ideas and
  designs to overcome the objectives
• Concerns of penetrator use and trajectory

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Questions