Development of Kinetic Penetrators For Exploration of Airless Solar System Bodies

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Development of Kinetic Penetrators For
Exploration of Airless Solar System Bodies

• A. Smith, R. Gowen, A. Coates, etc MSSL/UCL
• I. Crawford Birkbeck College London
• P. Church, R. Scott - Qinetiq
• A. Ellery, Y. Gao Surrey Space Centre/SSTL
• T. Pike Imperial College
• A. Ball, Open University
• J. Flanagan, Southampton University
• (UK)

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Contents

• Introduction
• Development Program
• Lunar Mission
• Summary

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Mullard Space Science Laboratory
Hinode Launch 22-9-06

• Part of University College London
• 140 Staff
• In-house mechanical and electrical engineering
  design, manufacture and test
• Provided hardware or calibration facilities for
  17 instruments on 12 spacecraft currently
  operating
• Provided stereo cameras for Beagle-2
• Leading PanCam development for EXOMARS

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What are airless kinetic micro-penetrators ?

• Cannot use aero-braking
• High impact speed gt200 m/s
• Very tough gt10,000gee
• Penetrate surface few metres
• Very low mass 2-5Kg (lt12Kg)

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Planetary Penetrators - History
No survivable high velocity impacting probe has
been successfully landed on any extraterrestrial
body
DS2 (Mars) NASA 1999 ?
Mars96 (Russia) failed to leave Earth orbit
?
TRL 6
Japanese Lunar-A much delayed
?
Many paper studies and ground trials
?
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Program Rationale
GOAL To enable key science inexpensively from
vanguard missions to a variety of solar system
bodies.

• Solar system exploration ready for a change of
  focus from orbital to landed missions. Current
  great worldwide interest.
• Micro-penetrators are capable of exploring
  multiple regions of planetary surfaces, including
  areas not suitable for soft landers.
• Micro and other technologies (e.g. mems) rapidly
  advancing, to allow very low mass microprobes
  (few Kg)-gt multiple probes -gthigh redundancy -gt
  low launch cost.
• Potential for innovation.

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Consortium

• MSSL
• Consortium lead, payload technologies, payload
  system design
• Birkbeck College London
• Science
• Imperial College London
• Seismometers
• Open University
• Science and instrumentation
• QinetiQ
• Impact technologies, delivery systems
  technologies
• Southampton University
• Optical Fibres
• Surrey Space Science Centre and SSTL
• Platform technologies, delivery system
  technologies

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Proposed Development Program

• 1. Design generic penetrator system
• - Investment to
• Enable fast response to opportunities (ready
  to respond) Enable cheaper future missions
  (tailoring only)
• 2. Ground-based demonstration
• - To build confidence in the technology
• 3. Lunar mission design
• - Identify strawman accommodation and baseline
  environmental and performance requirements for
  payload elements
• 4. Follow-up mission opportunities
• - Science technology demonstration

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Development Process
Science Requirements
Other Mission Elements
Mission Concept
Define Mission Requirements
Penetrator
Payload elements
Design
Design
Environmental Requirements
Model
Test
Model
Test
Build and Test Penetrator system
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Key Generic Penetrator Design Subsystem
Considerations
1. Spacecraft Support Probe system accommodation Probe system ejection Communications
2. Probe System de-orbiting, attitude control, impact survival, power, communications, data management, payload accommodation, environment (e.g. shock, thermal, electrostatics, radiation)
3. Payload e.g. seismic, thermal, chemistry, radiation, magnetism MEMS-based fibre optics drill camera
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Critical Areas
Item Comments
Funding Without funding cannot develop
Mission Require ESA or bilateral flight opportunity
Cost Need to keep development and flight costs down
Technical Readiness May need probe ready to fly at short notice
Mass Minimise to maximise opportunities (few Kg for total system)
Impact Survival All components, from gt10,000 gee
Impact Test Facility Combined modelling and impact testing
Penetration Correct simulation. Ability to cope with variations. Engineering margin.
Lifetime Power ? 1year seismic network
Communications Effect of overlying material, power
Science Instruments Technical Readiness for new technology instruments
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Lunar Mission Study
In support of a recent MoonLite PPARC UK study
undertaken by SSTL for a Lunar mission
Understanding the Moon is crucial to our understanding of the origin of the Earth-Moon system Moon is Nearby (Provides Ideal science mission/technical demonstration because of short cruise phase c.f. years for most planetary bodies, and regular launch windows) Regolith naturally provides relatively soft impact c.f. ice. Relatively benign environment (sub-regolith limited radiation exposure approximately constant moderate temperature possibility of direct line of sight communications solar power)
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Lunar Penetrator Science

• Lunar Seismology
• Presence and size of lunar core, crustal basal
  fill thickness deep
• structure of lunar mantle Origin location of
  shallow moonquakes.
• (understanding of Moons residual magnetism
  origin of
• Earth-Moon system evolution of planetary
  magnetic fields)
• Lunar Thermal Gradients
• Inhomogeneity of crustal heat producing elements
  (U,K,Th).
• (understanding of Moons early history).
• Lunar Water Sensing
• Presence, extent, concentration and origin of
  water and other volatiles.
• (Lunar evolution, future lunar resource,
  implications to astrobiology)
• Geochemical Analysis
• Provide ground truth for remote sensing XFA and
  multi-spectral
• imaging.
• Far Side
• Differences in regolith, lunar interior
  structure, composition.

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Lunar Mission Definition

• 4 penetrators (13Kg20Kg propulsion each max)
• Science (seismic network, heat-flow, polar
  volatiles, far side landing, camera)
• Surface mission to last ? 1 year (several years
  desirable) for seismic network. Other science do
  not require so long (heat flow perhaps a few
  lunar cycles) and volatiles much less.
• Landing sites to be widely spaced across Lunar
  surface with at least one site on far side, and
  at polar region (probably South Pole Aiken basin)
  for water/volatiles detection.
• Orbiter (provide power, pre-ejection health
  status, and post ejection flight and landed
  communications)
• Technology to be ready for near term launch
• Descent Phase
• Deploy from orbit, using a breaking solid rocket
  motor to kill orbital velocity.(target impact
  velocity 200m/s)
• Attitude control to achieve penetration closely
  perpendicular into Lunar regolith to depth of a
  few metres.
• Camera to be used for descent to characterize
  landing site
• Telemetry to be transmitted continuously during
  descent for health status (technology
  demonstration)
• Impact accelerometer (to determine penetration
  depth)

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Lunar Mission Definition

• Landed Phase
• Single body penetrator (no fore-aft body split)
  for simplicity risk avoidance, to penetrate
  to 1 to few metres into regolith.
• All 4 penetrators same platform, different
  payloads (tbc).
• Powered by batteries (?1 year lifetime) for
  seismic network.
• Receiver not powered continuously to save power,
  possibly by carrier detect and with small
  command capability, or by timer.
• Scientific Instruments
• Micro-seismometer (3-axis)
• Water and Volatiles detector (maybe more than
  one instrument)
• (contenders fibre optics, mems mass
  spectrometer)
• Heat flow detector (not easy)
• Tilt Meter (calibrate seismometer and heat flow
  detector)
• Possible Drill (if within mass budget),
  magnetometer, radiation monitor, microscope?

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Preliminary Penetrator Concept

• POSSIBLE SINGLE-PIECE PENETRATOR
• PRE-IMPACT CAMERA
• IMPACT ACCELEROMETER
• SEISMOMETER
• THERMOMETERS (HEAT FLOW)
• WATER/VOLATILES DETECTOR
• UHF TRANSMITTER AND AERIAL
• BATTERIES
• DC CONVERTERS
• CONTROL DATA HANDLING
• OTHER (micro-drill, magnetometer, rad detector)

DETACHABLE PROPULSION STAGE
POINT OF SEPARATION
6 CALIBRE RADIUS HEAD TO GIVE NOSE FOR MAX.
PENETRATION

• ESTIMATED PENETRATOR SIZE
• LENGTH- 480mm to 600mm (81 to 101 RATIO)
• DIAMETER- 60mm
• ESTIMATED MASS 6-8kg

SINGLE-PIECE PENETRATOR
TUNGSTEN TIP
TITANIUM CASING
TITANIUM NOSE SECTION
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Conclusions

• We have formed a consortium to develop kinetic
• penetrators for airless planetary bodies
  through conceptual
• design -gt ground demonstration -gt technical
  demonstrator
• missions -gt science missions.
• Penetrators are now established as a priority
  for UK
• planetary future directions, and we are
  strongly supporting
• penetrators for a Lunar mission initiative.
• We are happy to gain further partners.
• We are looking for mission opportunities. for
  exciting
• engineering and science.

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