titan saturn system mission workshop - paris, mar 17-19, 2008 mssl/ucl uk penetrators for enceladus...

Titan Saturn System Mission Workshop - Paris, Mar 17-19, 2008 MSSL/UCL UK

Penetrators for EnceladusPenetrators for Enceladus


Dr Rob Gowen on behalf of UK Penetrator Consortium


What are Penetrators ?What are Penetrators ?

– Low mass projectiles Low mass projectiles ~5Kg+PDS for Enceladus~5Kg+PDS for Enceladus

– High impact speed High impact speed ~ 200-500 m/s~ 200-500 m/s

– Very tough Very tough ~10-50kgee~10-50kgee

– Penetrate surface Penetrate surface ~ few metres~ few metres

– Perform science Perform science from below surfacefrom below surface

Penetrator

Point of Separation

Payload Instruments

Detachable Propulsion Stage

PDS (Penetrator

Delivery System)


Penetrator Payload/Science Penetrator Payload/Science A nominal 2kg payload …A nominal 2kg payload …

AccelerometersAccelerometers – Probe surface/sub-surface material – Probe surface/sub-surface material (hardness/composition) (hardness/composition)

SeismometersSeismometers - Probe interior structure (existence/size of water - Probe interior structure (existence/size of water reservoirs) and seismic activity of bodies reservoirs) and seismic activity of bodies

Chemical sensorsChemical sensors – Probe surface refactory/volatile (organic/ – Probe surface refactory/volatile (organic/ astrobiologic) chemicals, perhaps arising from interior.astrobiologic) chemicals, perhaps arising from interior.

Thermal sensorsThermal sensors - Determine subsurface temperatures and possibly - Determine subsurface temperatures and possibly probe deep interior processes.probe deep interior processes.

Mineralogy/astrobiology cameraMineralogy/astrobiology camera – Probe surface mineralogy and – Probe surface mineralogy and possible astrobiological material.possible astrobiological material.

+ other instruments – to probe surface magnetic field, radiation, + other instruments – to probe surface magnetic field, radiation, beeping transmitter, etc…beeping transmitter, etc…

descent cameradescent camera (surface morphology, landing site location, etc) (surface morphology, landing site location, etc)


Science/Technology RequirementsScience/Technology Requirements

TargetTarget– E.g. region of upwelled interior material.E.g. region of upwelled interior material.– 2 penetrators would allow additional target, improved seismic results and 2 penetrators would allow additional target, improved seismic results and

natural redundancy but require 2xmass.natural redundancy but require 2xmass. LifetimeLifetime

– Only minutes/hours required for camera, accelerometer, chemistry, thermal Only minutes/hours required for camera, accelerometer, chemistry, thermal & mineralogy/astrobiologic measurements.& mineralogy/astrobiologic measurements.

– An orbital period (~few days) for seismic measurements. An orbital period (~few days) for seismic measurements. (requires RHU)(requires RHU)

Spacecraft supportSpacecraft support– ~7-9 years cruise phase, health reporting~7-9 years cruise phase, health reporting

DeliveryDelivery– Targetting precision.Targetting precision.– Ejection, descent motors & orientation, pre-impact separation, Ejection, descent motors & orientation, pre-impact separation,

communications, impact.communications, impact. OperationOperation

– Power/thermal (battery/RHU), data handling, communications.Power/thermal (battery/RHU), data handling, communications.


Preliminary Estimated MassPreliminary Estimated Mass

ItemItem Estimated Mass (kg)Estimated Mass (kg)

Penetrator (inc. 2 kg payload)Penetrator (inc. 2 kg payload) ~4.5Kg~4.5Kg

Delivery system(*)Delivery system(*) ~32Kg~32Kg

Spacecraft supportSpacecraft support ~2.5kg~2.5kg

Total massTotal mass ~39Kg~39Kg

(*) heavy penalty for Enceladus delivery: estimate ~8x(penetrator mass) with deployment from Titan with ∆V~3.7Km/sec


HeritageHeritage Lunar-A and DS2 space qualified.Lunar-A and DS2 space qualified. Military have been successfully firing Military have been successfully firing

instrumented projectiles for many instrumented projectiles for many years to comparable levels of gee years to comparable levels of gee forces into concrete and steel.forces into concrete and steel.

40,000gee qualified electronics exist 40,000gee qualified electronics exist (and re-used).(and re-used).

Currently developing similar Currently developing similar penetrators for MoonLITE.penetrators for MoonLITE.

Payload heritage:Payload heritage:– Accelerometers, thermometers, Accelerometers, thermometers,

sample drill – fully space qualified.sample drill – fully space qualified.

– Seismometers (ExoMars) & chemical Seismometers (ExoMars) & chemical sensors (Rosetta) heritage but require sensors (Rosetta) heritage but require impact ruggedizing.impact ruggedizing.

– Mineralogy camera – new but simple.Mineralogy camera – new but simple.

When asked to describe the When asked to describe the condition of a probe that had condition of a probe that had

impacted 2m of concrete at 300 m/s impacted 2m of concrete at 300 m/s a UK expert described the device as a UK expert described the device as

‘a bit scratched’!‘a bit scratched’!


Current Development StatusCurrent Development Status

Full-scale structure impact trial – Scheduled May 19-23 2008


Current Development StatusCurrent Development Status

MoonLITE bids in MoonLITE bids in preparation for :-preparation for :-

a)a) 2 yr development to bring 2 yr development to bring ruggedization of penetrator ruggedization of penetrator subsystems and subsystems and instruments up to TRL 5.instruments up to TRL 5.

b)b) Phase-A study for Phase-A study for MoonLITE mission, MoonLITE mission, currently in discussion with currently in discussion with BNSC and NASA.BNSC and NASA.

Bids prepared for Cosmic Bids prepared for Cosmic Visions mission support.Visions mission support.

a)a) To study deltas to To study deltas to MoonLITE (impact into ice, MoonLITE (impact into ice, reduced mass penetrator, reduced mass penetrator, long descent, long descent, communications)communications)

• 3 penetrator firings• Normal incidence into dry sand at 300m/s

5 inner compartments for full scale penetrator trial


Main Technical ChallengesMain Technical Challenges

Ruggedisation to survive impact into ice Ruggedisation to survive impact into ice (M(M→→C)C) Likely require RHUs for extended lifetime (requires good Likely require RHUs for extended lifetime (requires good

thermal model) thermal model) (M(M→→C)C) Achieve proposed mass savings over MoonLITE Achieve proposed mass savings over MoonLITE

penetrators (reduced lifetime -> power saving, lighter penetrators (reduced lifetime -> power saving, lighter structure, asics) structure, asics) (M(M→→C)C)

Optimise mass estimates of descent system Optimise mass estimates of descent system (M(M→→C)C) Study descent system in detail including target ellipse Study descent system in detail including target ellipse (C)(C) Study descent and landed communications including Study descent and landed communications including

possible trailing aerial. possible trailing aerial. (M(M→→C)C)

(M = MoonLite, C = Cosmic Vision, M→C (M = MoonLite, C = Cosmic Vision, M→C ∆ ∆ development for Cosmic Vision)development for Cosmic Vision)


Penetrators for Titan ?Penetrators for Titan ?

Could be delivered from balloon or orbit.Could be delivered from balloon or orbit. Much smaller mass ~8.5Kg/probeMuch smaller mass ~8.5Kg/probe Delivery from orbit allows :-Delivery from orbit allows :-

(i) deterministic targetting, and (i) deterministic targetting, and (ii) co-temporal placement of multiple penetrators for (ii) co-temporal placement of multiple penetrators for seismic network to allow investigation of subsurface seismic network to allow investigation of subsurface oceans, interior/core, and seismic activity levels.oceans, interior/core, and seismic activity levels.

Multiple penetrators allows examining several different Multiple penetrators allows examining several different terrains (dunes, ice, lake beds)terrains (dunes, ice, lake beds)

Penetrators allow sampling from sub-surface e.g. bottom of Penetrators allow sampling from sub-surface e.g. bottom of lake beds which collect alluvial material deposits and lake beds which collect alluvial material deposits and possible astrobiologic material)possible astrobiologic material)


Further information and contact Further information and contact detailsdetails

email: email: [email protected]

or see penetrator web site ator see penetrator web site at

http://www.mssl.ucl.ac.uk/planetary/missions/Micro_Penetrators.phphttp://www.mssl.ucl.ac.uk/planetary/missions/Micro_Penetrators.php


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titan saturn system mission workshop - paris, mar 17-19, 2008 mssl/ucl uk penetrators for enceladus...

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