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
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Impact Trial - Configuration
 Rocket sled
 Penetrator
Laplace Meeting - Monrovia, May 30 2008
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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
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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