Lunar Exploration with Penetrometers
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Transcript Lunar Exploration with Penetrometers
Penetrators for Europa
Rob Gowen
on behalf of UK Penetrator
Consortium
Laplace Meeting - Monrovia, May 30 2008
MSSL/UCL UK
Europa Penetrators
Detachable
Propulsion Stage
– Low mass projectiles
~4Kg+PDS
– High impact speed
~ 200-500 m/s
– Very tough
~10-50kgee
Point of
Separation
Payload
Instruments
– Penetrate surface
~0.5-few metres
– Perform science
from below surface
Laplace Meeting - Monrovia, May 30 2008
Penetrator
PDS
(Penetrator
Delivery System)
MSSL/UCL UK
Penetrator Payload/Science
A nominal 2kg payload …
Seismometers - interior structure (existence/size of
subterrannean ocean) and seismic activity
Chemical sensors – subsurface refactory/volatile
(organic/ astrobiologic (e.g. sulphur mass spec)
material arising from interior
Mineralogy/astrobiology camera – subsurface
mineralogy and possible astrobiological material
Accelerometers – hardness/layering/ composition
of subsurface material. (future landing site assessment)
Thermal sensors - subsurface temperatures
+ other instruments – beeping transmitter, magnetometer,
radiation sensors, etc…
descent camera (surface morphology,
landing site location)
Laplace Meeting - Monrovia, May 30 2008
Micro-seismometer
Imperial College
Ion trap spectrometer
Open University
MSSL/UCL UK
Science/Technology Requirements
Target
– Region of upwelled interior material (e.g. sulphur).
– 2 penetrators would allow improved seismic results and
natural redundancy.
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
Laplace Meeting - Monrovia, May 30 2008
MSSL/UCL UK
Preliminary Estimated Mass
Item
Estimated Mass (kg)
Penetrator (inc. 1.7 kg payload)
~3.7Kg
Delivery system (AOCS)
~8.1Kg
Spacecraft support
~1.5kg
Total mass
Laplace Meeting - Monrovia, May 30 2008
~13Kg/probe
MSSL/UCL UK
Heritage
Lunar-A and DS2 space qualified.
Military have been successfully firing
instrumented projectiles for many
years to comparable levels of gee
forces into concrete and steel.
40,000gee qualified electronics exist
(and re-used).
Currently developing similar
penetrators for MoonLITE.
Payload heritage:
– Accelerometers, thermometers,
sample drill, geophone – fully space
qualified.
– Seismometers (ExoMars) & chemical
sensors (Rosetta) heritage but require
impact ruggedizing.
– Mineralogy camera – new but simple.
Laplace Meeting - Monrovia, May 30 2008
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’!
MSSL/UCL UK
Impact Trial
19-21 May 2008
Full-scale trial
3 Penetrators, ~0.6m long, ~13kg, Aluminum
300m/s impact velocity
Normal Incidence
Dry sand target
0.56m
Laplace Meeting - Monrovia, May 30 2008
MSSL/UCL UK
Impact trial - Contributors
Laplace Meeting - Monrovia, May 30 2008
MSSL/UCL UK
Impact trial – Payload
Radiation sensor
Batteries
Magnetometers
Mass
spectrometer
Acceleromete
Power
Interconnectio
Processing
Micro-seismometers
Accelerometers, Thermometer
Batteries,Data logger
Laplace Meeting - Monrovia, May 30 2008
Drill assembly
MSSL/UCL UK
Impact Trial Objectives
Demonstrate survivability of penetrator shell,
accelerometers and power system.
Determine internal acceleration environment
at different positions within penetrator.
Extend predictive modelling to new impact and penetrator
materials.
Assess impact on penetrator subsystems and instruments.
Assess alternative packing methods.
Assess interconnect philosophy.
Laplace Meeting - Monrovia, May 30 2008
MSSL/UCL UK
Trial Hardware - Status
Inners Stack
Laplace Meeting - Monrovia, May 30 2008
MSSL/UCL UK
Impact Trial - Configuration
Rocket sled
Penetrator
Laplace Meeting - Monrovia, May 30 2008
MSSL/UCL UK
Target
Dry sand
2m x2m x6m
Small front entrance aperture (polythene)
Laplace Meeting - Monrovia, May 30 2008
MSSL/UCL UK
Firing
Laplace Meeting - Monrovia, May 30 2008
MSSL/UCL UK
1’st Firing - Results
Firing parameters:
• Impact velocity: 310 m/s
(c.f. 300m/s nominal)
• Nose-up ~10degs
(c.f. 0 degs nominal)
=> worst case
• Penetrator found in top of target
in one piece ✓
• Glanced off steel girder which
radically changed its orientation
• Much ablation to nose and belly
• Rear flare quite distorted.
• Penetration: ~3.9m
Laplace Meeting - Monrovia, May 30 2008
MSSL/UCL UK
First Firing – Opening up
s
Laplace Meeting - Monrovia, May 30 2008
MSSL/UCL UK
st
1
Firing – internal Results
Micro seismometer bay
Connecting to MSSL accelerometer
and data processing bay
Laplace Meeting - Monrovia, May 30 2008
MSSL/UCL UK
1’srt Firing – QinetiQ
accelerometer data
Initial impact hi-res: Tail slap peak
Overview: 5 kgee smoothed,
~16 kgee peak
high frequency components ~5khz
Laplace Meeting - Monrovia, May 30 2008
MSSL/UCL UK
1’st Firing – MSSL accelerometer data
Firing Along
axis
Vertical Horizo
ntal
1’st
10 kgee
15kgee
4kgee
3’rd
11kgee
17kgee
7kgee
Along axis:
Main: 10kgee
Cutter: 3kgee
Girder: 1kgee
Along axis
Vertical axis
Horizontal axis
Laplace Meeting - Monrovia, May 30 2008
MSSL/UCL UK
Hi-res MSSL accelerometer data
Lots of high frequency structure
Laplace Meeting - Monrovia, May 30 2008
MSSL/UCL UK
2nd & 3rd Firings
All 3 firings remarkably consistent ~308-310m/s velocity, and
~8-10 degs nose up.
2/nd firing penetrator hit steel beam square on.
Penetrators survived all 3 firings. Payload still operational.
Steel nose for 3rd firing
Laplace Meeting - Monrovia, May 30 2008
MSSL/UCL UK
Survival Table
Triple worst case: exceed 300m/s, >8deg attack angle
Item
Firing 1
Firing 2
Firing 3
Penetrator
✓
✓
✓
Q-accel sys
✓
✓
✓
Rad sensor
✓
n/a
n/a
Batteries
✓
n/a
n/a
Drill assembly
✓
n/a
n/a
Magnetometer
Not yet analysed n/a
n/a
Micro
seismometers
n/a
Mass spectrometer n/a
MSSL accel sys
✓
✓ (protected)
✓ (protected)
not yet analysed
(some loose screws)
not yet analysed
✓
✓
No critical failures – currently all minor to unprotected bays or preliminary mountings
Laplace Meeting - Monrovia, May 30 2008
MSSL/UCL UK
Impact Trial Objectives
Demonstrate survivability of penetrator shell,
accelerometers and power system.
Determine internal acceleration environment
at different positions within penetrator.
Extend predictive modelling to new impact and penetrator
materials.
Assess impact on penetrator subsystems and instruments.
Assess alternative packing methods.
Assess interconnect philosophy.
Laplace Meeting - Monrovia, May 30 2008
MSSL/UCL UK
Next Steps…
next trial – aim for Jan’09.
impact into harder material (ice,icy sand,concrete)
full up system (all operating)
transmit from target
imminent funding for analysis and further hardware
development.
Laplace Meeting - Monrovia, May 30 2008
MSSL/UCL UK
Penetrators Conclusions
•
•
•
•
•
Acheived major step in demonstrating confidence in technology
No great history of failure - only 1 planetary delivery to date
Significant TRL with previous space qualified technology
A useful tool in the toolbox of planetary exploration
Capable of addressing fundamental astrobiology signatures and
habitability
• Provide ground truth & new information not possible from orbit
• Provide useful landing information for future missions.
Penetrator website:
http://www.mssl.ucl.ac.uk/planetary/missions/Micro_Penetrators.php
email: [email protected]
Laplace Meeting - Monrovia, May 30 2008
MSSL/UCL UK
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Laplace Meeting - Monrovia, May 30 2008
MSSL/UCL UK