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Shoot for the Moon
Jon Excell, The Engineer
Rob Gowen on behalf of the UK Penetrator
Consortium
MSSL/UCL UK
AMSAT-UK University of Surrey, July 25 2008
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What are kinetic penetrators ?

• Instrumented projectiles
• Survive high impact speed
• Penetrate surface few metres
• An alternative to softlanders
• Low mass/lower costgt multi-site deployment

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Challenges...

• impact survival
• communications
• power/lifetime/cold
• delivery
• radiation
• funding

what the recent trial addressed
Need to counter all elements not just impact
survival
Most difficult
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Impact Velocity ?
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Impact Velocity ?
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Impact Velocity ?
?
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Impact Velocity ?
?
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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
Japanese Lunar-A cancelled (now planned to fly
on Russian Lunar Glob)
?
?
Many paper studies and ground trials
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• Feasibility ?
• Lunar-A and DS2 space qualified.
• Military have been successfully firing
  instrumented projectiles for many years
• Most scientific instruments have space heritage

When asked to describe the condition of a probe
that had impacted 2m of concrete at 300 m/s a UK
expert described the device as a bit scratched!
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MSSL Involvement

• 2002 became interested in micro-probes
• 2004 exploring Aurora route
• 2005 ESA Cosmic Visions (2015-2025)
• Late 2006 PPARC lunar mission studies
• MSSL proposed penetrators
• MoonLITE selected for first mission
• Simultaneous promotion for Cosmic Vision

Inspirational... NASA
Area manager...
Like riding on the back of a tiger...
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Micro-Penetrators
payload instruments
Payload (2kg) Science Capability
Micro seismometers sub-surface ocean, inner body structure (astrobiology, geophysics)
Chemistry package (mass spect.) organics and inorganics (astrobiology)
Soil/environment package (accelerometers, thermometer, dielectric constant, radiation monitor, magnetometer, pH, Redox) soil mechanical properties, thermal electrical properties (astrobiology /geophysics)
Mineralogy/astrobiology camera Soil properties/astrobiology
Descent camera Impact site context PR
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Prime Planetary Targets
EnceladusTitan
Europa
Moon
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Europa

• Subsurface Ocean ?
• Life ?

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Europa
Japanese Lunar-A Continuous launch delays
Several paper studies
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Europa
10Km
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Enceladus

• 500Km dia. (c.f. with UK)
• Fierce south pole plume (ice/dust)
• Hi-albedo covering Saturnian moons ?
• Atmosphere (H2O,N2,CO2,CH4)
• Liquid water under surface (life ?)

(image from Wikipedia)
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Titan
Titan as seen from the CassiniHuygens
spacecraft. Wikipedia
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Titan
Fluvial plain

• heavy atmosphere
• mountains,
• dunes
• lakes
• weather
• winds
• clouds
• precipitation
• seasons
• complex organic chemistry
• very cold
• pre-biotic chemisty ?
• life ?

Dunes
Titan as seen from the CassiniHuygens
spacecraft. Wikipedia
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MoonLITE Science Exploration Objectives
The Origin and Evolution of Planetary Bodies
Water and its profound implications for life
andexploration
Ground truth support for future human lunar
missions
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MoonLITE Mission
Polar comms orbiter
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• Delivery and Comms Spacecraft (Orbiter).
• Payload 4 penetrator descent probes
• Landing sites Globally spaced - far side
  - polar region(s) - one near an Apollo landing
  site for calibration
• Duration gt1 year for seismic network.

Far side
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2
1
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Science ISRU Objectives
3

• Characterize water, volatiles, and
  astrobiologically related material at lunar
  poles. gt Water is key to manned missions
• Constrain origin, differentiation, 3d internal
  structure far side crustal thickness of moon
  via a seismic network.
• Investigate enigmatic strong surface seismic
  signals gt identify potentially dangerous
  sitesfor lunar bases
• Determine thermal compositional differences at
  polar regions and far side.
• Obtain ground truth for remote sensing instruments

4
2
1
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Science Lunar Seismology

• A global network of seismometers will tell us
  
• Size and physical state of the Lunar Core
• Structure of the Lunar Mantle
• Thickness of the far side crust
• The origin of the enigmatic shallow moon-quakes
• The seismic environment at potential manned
  landing sites

Micro-seismometer, IC
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Science Polar Volatiles

• A suite of instruments will detect and
  characterise volatiles (including water) within
  shaded craters at both poles
• Astrobiologically important
• possibly remnant of the original seeding of
  planets by comets
• may provide evidence of important cosmic-ray
  mediated organic synthesis
• Vital to the future manned exploration of
  the Moon

Prototype, ruggedized ion trap mass-spectrometer
Open University
NASA Lunar Prospector
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Science - Geochemistry

• X-ray spectroscopy at multiple, diverse
• sites will address
• Lunar Geophysical diversity
• Ground truth for remote sensing

Leicester University
XRS on Beagle-2
K, Ca, Ti, Fe, Rb, Sr, Zr
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Science Heat Flow

• Heat flow measurements will be made at diverse
  sites, telling us
• Information about thecomposition and thermal
  evolution of planetary interiors
• Whether the Th concentration in the PKT is a
  surface or mantle phenomina

NASA Lunar Prospector
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Development Program

• Studies
• Simulation Modelling
• Impact Trials
• build a real penetrator
• impact it into a sand target at near supersonic
  speed !

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Impact Trial - Objectives

• Demonstrate survivability of penetrator shell,
  accelerometers and power system.
• Assess impact on penetrator subsystems and
  instruments.
• Determine internal acceleration environmentat
  different positions within penetrator.
• Extend predictive modelling to new impact and
  penetrator materials.
• Assess alternative packing methods.
• Assess interconnect philosophy.

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Impact Trial 19-21 May 2008

• Full-scale trial
• 3 Penetrators, Aluminium
• 300m/s impact velocity
• Normal Incidence
• Dry sand target

13 Kg
0.56m
just 9 months from start to end. Starting from
scratch in Sep07
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Impact trial - Contributors
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Impact trial Payload
Mass spectrometer
Radiation sensor
Batteries
Magnetometers
Accelerometers Power Interconnection Processing
Micro-seismometers
Accelerometers, Thermometer Batteries,Data logger
Drill assembly
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Trial Hardware
Inners Stack
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Impact Trial - Configuration

• Rocket sled
• Penetrator

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Target

• Dry sand
• 2m x2m x6m
• Small front entrance aperture (polythene)

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Real-Time Impact Video
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Firing
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1st Firing - Results

• Firing parameters
• Impact velocity 310 m/s
• (c.f. 300m/s nominal)
• Nose-up 8degs (c.f. 0 degs nominal)
• gt worst case

• Penetrator found in top of target
• Glanced off a steel girder which radically
  changed its orientation.
• Penetration 3.9m
• Much ablation to nose and belly
• Rear flare quite distorted.
• Penetrator in one piece ?

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Post Firingbelly up !
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First Firing Opening up

• s

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1st Firing internal Results
Micro seismometer bay
Connecting to MSSL accelerometer and data
processing bay
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1srt Firing QinetiQ accelerometer data
Initial impact hi-res Tail slap peak
Overview 5 kgee smoothed, 16 kgee peak high
frequency components 5khz
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1st Firing MSSL accelerometer data
11 kgee
Peak gee forces in rear of penetrator
Along axis
Firing Along axis Vertical Horizontal
1st 10 kgee 15kgee 4kgee
3rd 11kgee 17kgee 7kgee
Girder
Main impact
cutter
15 kgee
Vertical axis

• Along axis
• Cutter 3kgee
• Main 10kgee
• Girder 1kgee

4 kgee
Horizontal axis
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Hi-res MSSL accelerometer data
Lots of high frequency structure
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2nd Firing
Jaws-3?
..struck steel girder and moved it 6 inches
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Firings Overview

• All 3 firings remarkably consistent 308-310m/s
  velocity, and 8 degs nose up.
• All 3 Penetrators survived Payloads still
  operational.

Steel nose for 3rd firing
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Survival Table
Triple worst case exceed 300m/s, gt8deg attack
angle
Item Firing 1 Firing 2 Firing 3
Penetrator ? ? ?
Q-accel sys ? ? ?
Rad sensor ? not present not present
Batteries ? not present not present
Drill assembly ? not present not present
Magnetometer ? not present not present
Micro seismometers not present ? (protected suspensions ok) ? (protected suspensions ok)
Mass spectrometer other package elements not present ? x pressure sensor x 3u heating element ? x pressure sensor ?6u heating element
MSSL accel sys ? ? ?
No critical failures currently all minor to
unprotected bays or preliminary mountings
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Impact Trial Objectives

• Demonstrate survivability of penetrator body,
  accelerometers and power system.
• Assess impact on penetrator subsystems and
  instruments.
• Determine internal acceleration environmentat
  different positions within penetrator.
• Extend predictive modelling to new penetrator
  materials,and impact materials.
• Assess alternative packing methods.
• Assess interconnect philosophy.

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Next Steps Strategy

• Next trial aiming for Jun09.
• Impact into closer representative lunar regolith
• Design for Moon
• Full-up system (all operating)
• Transmit from target
• Strategy in parallel -
• - MoonLITE Phase-A
• Delta developments for icy planets

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- End -

• Penetrator website
• http//www.mssl.ucl.ac.uk/planetary/missions/Micro
  _Penetrators.php
• email rag_at_mssl.ucl.ac.uk

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Penetrator Payload/Science

• A nominal 2kg payload
• Accelerometers Probe surface/sub-surface
  material (hardness/composition)
• Seismometers - Probe interior structure
  (existence/size of water reservoirs) and seismic
  activity of bodies
• Chemical sensors Probe surface
  refactory/volatile (organic/ astrobiologic)
  chemicals, perhaps arising from interior.
• Thermal sensors - Determine subsurface
  temperatures and possibly probe deep interior
  processes.
• Mineralogy/astrobiology camera Probe surface
  mineralogy and possible astrobiological material.
• other instruments to probe surface magnetic
  field, radiation, beeping transmitter, etc
• descent camera (surface morphology, landing site
  location, etc)

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Enceladus - Science/Technology Requirements

• Target
• E.g. region of upwelled interior material.
• 2 penetrators would allow additional target,
  improved seismic results and natural redundancy
  but require 2xmass.
• Lifetime
• Only minutes/hours required for camera,
  accelerometer, chemistry, thermal
  mineralogy/astrobiologic measurements.
• An orbital period (few days) for seismic
  measurements. (requires RHU)
• Spacecraft support
• 7-9 years cruise phase, health reporting
• Delivery
• Targetting precision.
• Ejection, descent motors orientation,
  pre-impact separation, communications, impact.
• Operation
• Power/thermal (battery/RHU), data handling,
  communications.

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Preliminary Mass Estimates
Item Enceladus Titan Orbit Deployment Titan Balloon Deployment
Penetrator (inc. 2 kg payload) 4.5Kg 4.5Kg 4.5Kg
Delivery system() 32Kg 3.5-23Kg 2.5Kg
Spacecraft support 2.5Kg 1.5-2.5Kg 1.5Kg
Total mass 39Kg 12-30kg 8.5Kg
() heavy penalty for Enceladus delivery
estimate 8x(penetrator mass) with
deployment from Titan with ?V3.7Km/sec