MoonLite and LunarEx penetrator missions to the Moon

1. 1 7 2 6 4 3 5 MoonLite and LunarEx penetrator missions to the Moon Alan Smith1, Martin Sweeting2,3, Rob Gowen1, Yang Gao2, Andrew Ball4, Andrew Coates1, Ian Crawford5, Rob Scott6, Phil Church6, Tom Pike7 and Lionel Wilson3

2. What Characterizes Penetrators ? • Low mass instrumented packages (c.f. Lunar A 13.5Kg; DS-2 3.6Kg) • High impact speed ~ 200-300 m.s-1 • Very rugged ~10-50kgee • Few metres surface penetration • Highly autonomous scientific payloads

3. Penetrator Descent Module Design Concept • Payload • DESCENT CAMERA • IMPACT ACCELEROMETER • SEISMOMETERS/TILTMETER • THERMAL SENSING (TEMP, CONDUCTIVITY,HEAT FLOW) • GEOCHEMISTRY(E.G. WATER/VOLATILES DETECTOR) • GROUND CAMERA (MINALOGY/ASTROBIOLOGY) • OTHER (permitivity, magnetometer, radiation monitor) • Platform • S/C SUPPORT • AOCS • STRUCTURE • POWER/THERMAL • COMMS • CONTROL & DATA HANDLING DETACHABLE De-orbit and attitude control STAGE POINT OF SEPARATION • ESTIMATED PENETRATOR SIZE • LENGTH:- 480mm to 600mm (8:1 to 10:1 RATIO) • DIAMETER:- 60mm • ESTIMATED MASS 13kg SINGLE-PIECE PENETRATOR TUNGSTEN TIP ALUMINIUM CASING ALUMINIUM NOSE SECTION

4. PROS • It is difficult to envisage any other method which allows widely spaced surface exploration of airless planetary bodies that is not prohibitively expensive. • Thruster descent technology through an atmospheric body can allow more specific targetting of surface locations for investigation than for parachute or balloon investigations. • Able to target areas which are not accessible to soft landers. • Provide ground truth for interpreting remote sensing data. • CONS • Can achieve key science, but low payload mass and high-gee constraints will limit capability c.f. soft landers. • Limited Communications due to finite battery life. • Surviving for long periods for e.g. seismic network will be a challenge with limited mass. (Insulation and RHU’s with primary batteries) • …good for pre-cursor investigations, seismic networks, and cost effective targetting of specific terrain features. • …good also for a first step to exploration. PROS and CONS ?

5. Planetary Penetrators - History No survivable high velocity impacting probe has been successfully operated on any extraterrestrial body DS2 (Mars) NASA 1999 ? Mars96 (Russia) failed to leave Earth orbit  Japanese Lunar-A cancelled (maybe now to fly on Russian Lunar Glob?)  TRL 5/6 Many paper studies and ground trials 

6. Suitable Bodies for Investigation ? • Moon (MoonLite- UK Intiative/LunarEX – Cosmic Vision)- is closeby – ideal technical demonstrator + excellent science (polar water, core structure, astrobiology…) • Airless -> like Europa, Enceladus - Very cold (polar traps) -> like Europa, Enceladus,Titan • Europa,Titan/Enceladus (Cosmic Vision) • Astrobiology, interior ocean(s). • Europa – very high radiation environment • - Titan has an atmosphere – different approach !!! • NEO/Asteroids- Accelerometer particularly interesting for • investigating internal structure • Etc, etc, (Mars, Venus, Mercury, Pluto, Triton, …)

7. UK Penetrator Consortium - History • Jan 2006 – First meeting of consortium, now expanded to 8 UK institutes and 3 industries • Dec 2006 - UK Research Council commissioned report of low cost lunar missions, MoonLITE (penetrator) and MoonRaker (lander), MoonLITE given top priority. • Apr 2007 – First funding in place for penetrator trials • June 2007 – ESA Cosmic Vision proposals • LunarEx • Jupiter-Europa (penetrator element) • Saturn-Enceladus (penetrator element) • July 2007 – MoonLITE considered as part of a NASA-BNSC bilateral programme

8. MoonLITE 4 penetrators Limited scientific payload 1 year duration Launch ~ 2011 UK mission LunarEx 4+ penetrators More sophisticated scientific payload 1 year duration Launch ~2016 European mission Austria, Germany, France, Italy, Ireland, Poland, Russia,UK MoonLITE and LunarEx

9. Terminology • Descent Module, consisting of: • Penetrator • De-orbit (delta v ~ 1.7 km.s-1) and attitude control system • Descent Camera • The Descent Module is a spacecraft in its own right, albeit rather short lived.

10. Feasibility • Military have been successfully firing instrumented projectiles for many years to at least comparable levels of gee forces expected.Target materials have been mostly concrete and steel but include sand and ice. • 40,000gee qualified electronics exist (re-used !) • When asked to describe the condition of a probe that had impacted 2m of concrete at 300 m.s-1 a UK expert described the device as ‘a bit scratched’!

11. Examples of hi-gee electronic systems Designed and tested : • Communication systems • 36 GHz antenna, receiver and electronic fuze tested to 45 kgee • Dataloggers • 8 channel, 1 MHz sampling rate tested to 60 kgee • MEMS devices (accelerometers, gyros) • Tested to 50 kgee • MMIC devices • Tested to 20 kgee • TRL 6 MMIC chip tested to 20 kgee Communication system and electronic fuze tested to 45 kgee

12. MoonLITE/LunarEX - Mission Description • Delivery and Communications Spacecraft(Orbiter).Deliver penetrators to ejection orbit, providepre-ejection health status, and relay communications. • Orbiter Payload: 4 Descent Probes (each containing ~12 kg penetrator + ~23 kg de-orbit and attitude control). • Landing sites: Globally spaced Far side, Polar region(s), One near an Apollo landing site for calibration. • Duration: >1 year for seismic network. Other science does not require so long (perhaps a few Lunar cycles for heat flow and volatiles much less). • Penetrator Design: Single Body for simplicity and risk avoidance. Battery powered with comprehensive power saving techniques.

13. MoonLITE/LunarEX – Mission Sequence • Launch & cruise phase • Deployment • Deploy descent probes from lunar orbit, using a de-orbit motor to achieve near vertical impact. • Attitude control to achieve orientation of penetrator to be aligned with velocity vector. • Penetration ~3 metres • Camera to be used during descent to characterize landing site • Telemetry transmission during descent for health status • Impact accelerometer (to determine penetration depth & regolith mechanical properties) • Landed Phase • Telemeter final descent images and accelerometer data • Perform and telemeter science for ~1year.

14. MoonLITE – Science The Origin and Evolution of Planetary Bodies Waterand its profound implications for life andexploration NASA Lunar Prospector

15. 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

16. Science - 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

17. 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

18. 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

19. Payload • Core • Seismology • Water and volatile detection • Accelerometer • Desirable • Heat Flow • Geochemistry/XRF • Descent camera • Mineralogy • Radiation Monitor Ion trap spectrometer (200g, 10-100amu) (Open University)

20. LunarEx

21. LunarEx Payload

22. Key Technologies • Payload instruments - ruggedization • Batteries – Availability (Lunar-A) • Communications – A trailing antenna would require development • Structure material (Aluminium, carbon composite under consideration – needed for heatflow where trailing antenna is not available) • Sample acquisition • Thermal control (RHUs probably needed for polar penetrators) • AOCS (attitude control and de-orbit motor) • Spacecraft attachment and ejection mechanism

23. Penetrator Development Programme Phase 1: Modelling (until Jan 2008) • Key trade studies (Power, Descent, Structure material, Data flow, Thermal) • Interface & System definition • Penetrator structure modelling • Procurement strategy Phase 2: Trials (until Jan 2010) • Payload element robustness proofing • Penetrator structure trials (March 2008) • Payload selection and definition • Baseline accommodation Phase 3: EM (until Jan 2012) • Design and Qualification Phase 4: FM (until Jan 2013) • Flight build and non-destructive testing Generic Mission Specific

24. For more information visit: http://www.mssl.ucl.ac.uk/planetary/missions/Micro_Penetrators.phpor http://www.mssl.ucl.ac.uk and follow the links Or contact Alan Smith on: Alan.Smith@mssl.ucl.ac.uk