High Speed Penetrator deployable mass spectrometers. Presented by Simon Sheridan The Open University on behalf of the UK Penetrator Consortium

Transcription

1 High Speed Penetrator deployable mass spectrometers Presented by Simon Sheridan The Open University on behalf of the UK Penetrator Consortium 11 th Workshop on Harsh Environment Mass Spectrometry Oxnard, California. Sept

2 In-Situ sample handling The difficulties Complicated mechanisms long handing chains Unknown sample properties Thermal modification of sample Dependant on lander orientation Lander contamination Martian soil Phoenix inlet funnel : NASA Ptolemy / B2 sample carousel B2 Oven Philae (on its side) : ESA

3 What are penetrators Low mass projectiles High impact speed ~ 300 ms -1 Very tough up to g Impact surface Penetrate to several m depth perform science- based measurements Transmit results to orbiter

4 Penetrators a solution? Ability to directly access sub-surface material Payloads: Decent camera Sample camera Impact accelerometer Thermal sensors Mass Spectrometers

5 Pros and Cons of penetrator deployment Pros ground truth for interpreting of remote sensing data Relatively cheap access to surface and sub-surface material on airless bodies. Multiple target sites possible from single orbiter / flyby craft No need for complicated sample drilling and handling chains Better targeting on an atmospheric body ( vectored thruster descent technology through an atmospheric body) than possible with parachute or balloon systems. Able to target areas which are not accessible to soft landers. Cons High-gee constraints will limit possible instruments. Limited mass for instruments Limited Communications due to finite battery life / transmitter coverage. Survivability issue long periods limited due to thermal issues Need for dedicated deployment system on orbiter / flyby craft Need for orbiter as relay back to Earth

6 History of penetrators X Luna-A (Japanese) Jan 2007 cancelled X Deep Space 2 (NASA) Dec 1999 Lost on Mars No successful mission yet but Lunar-A and DS2 are space qualified Military have been successfully firing instrumented projectiles for many years Most candidate scientific instruments have space heritage X Mars96 Russian 1996 Failure of the second fourth-stage

7 Possible penetrator targets

8 Ganymede General Characteristics Icy body surface temp ~70-150K Subsurface ocean Habitable? Thick crust several 100 s km.

9 Europa General Characteristics Icy body surface temp ~120 K Subsurface ocean Habitable? Thick crust several 100 s km with cracks and surface features.

10 Is sub-surface material on or close to the surface? Sub ocean material present? Diagram adapted from K.Hand et. al. Moscow 09, who adapted it from Figueredo et al. 2003

11 Sampling melt water? Penetrator deployed melting probe Passive RHU heater Sublimation / refreezing close off path/tunnel Liquid melt will form in higher pressure volume Sample as with current ocean sampling techniques? Biele et. al. [2002]

12 The Moon General Characteristics PSRs at poles <100 K Water / volatiles present? Ground truth water measurement.

13 Europa Ganymede Moon Recent penetrator opportunities MoonLITE (UK lead mission) X Postponed - lack of UK funding Current ESA interest? Jupiter Ganymede Orbiter (JGO) ESA Insufficient Xmass on JGO for penetrators AKON M5 (ESA) X Not selected by ESA The moon seems the most likely place to test the penetrator concept

14 The Ptolemy flight instrument uses a silicon nanotip fieldeffect electron source, due to power constraints. These electron sources were produced by the CCLRC Rutherford Appleton Laboratory. These nanotips have a short lifetime (~ 10 h continuous use). During early testing many failures. Post Ptolemy CNTs consider the solution The need for low power

15 The Ptolemy Nano tip emitters 40 x 40 array of tips. A large number of damaged Catastrophic failure in last image.

16 Impact testing Can real instruments survive? What we tested: CNT electron source COTS tungsten filament (6 and 12 ) Gas valves COTS MEMS pressure sensor (Siemens KPY range) COTS Electron multipliers (Dt Sjuts KLB-210 range) Ion trap electrode structure Large scale Rocket sled testing: System level Small scale Gas gun tests: Component level

17 Before impact P (mbar) Lens (V) Tubes (V) Grid (V) Delta (V) Small scale impact tests - CNTs Gas gun at Shrivenham UK 295 to 315 ms m deceleration distance ~ 2000 g Some degradation in extraction voltage Before impact After impact AT 01 Vertically mounted #1 9.00E AT 02 Horizontally mounted #1 1.00E AT 03 Vertically mounted #2 7.40E AT 04 Horizontally mounted #2 1.90E AT 05 Control Device Unfired 4.00E AT 02 Horizontally mounted #1 1.00E Performance degraded by 40 V AT 03 Vertically mounted #2 3.40E Performance degraded by 50 V AT 04 Horizontally mounted #2 4.60E Performance degraded by 70 V AT 05 Control Device Unfired 1.20E Same performance After impactat 01 Vertically mounted #1 4.00E Same performance

18 Large scale tests MS and gas system Ptolemy mass spectrometer CAD model Penetrator mass spectrometer Baseline Penetrator mass spectrometer Baseline gas storage system

19 Pendine full scale tests Designed and built 3 full scale penetrators (~0.5m long, ~13kg mass) Aluminium body Segmented aluminium inner compartments Fired into large sand target (~2m*2m*7m) (lunar regolith simulant) One firing per day for 3 days. All at 300m/s

20 Pendine test range Penetrator mounted on a rocket sled ¼ mile run to target Cut away and fly to target

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24 Post impact penetrator

25 At Impacts of 300 ms -1 What have we learnt? Mass spectrometers can be designed to survive high speed penetrator deployment Carbon Nano tube Ion sources survive COTS Electron multipliers are good too Gas control valves survived Pressure sensors Survived if orientated 90 to impact Surprises: COTS 12 tungsten filaments survived all tests COTS 6 tungsten filaments failed The time is right for a penetrator mission!

26 Thank you for your attention Funded by The Science and Technology Facilities Council research grant ST/H003665/1 to develop an impact tolerant mass spectrometer for deployment by high-speed penetrators.

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