‘Shoot for the Moon’ Jon Excell, ‘The Engineer’ Rob Gowen on behalf of the UK Penetrator Consortium MSSL/UCL UK AMSAT-UK: University of Surrey, July 25 2008
Detachable Propulsion Stage Point of Separation PayloadInstruments PDS (Penetrator Delivery System) Penetrator What are kinetic penetrators ? • Instrumented projectiles • Survive high impact speed • Penetrate surface ~ few metres • An alternative to softlanders • Low mass/lower cost=> multi-site deployment
Challenges... • impact survival • communications • power/lifetime/cold • delivery • radiation • funding what the recent trial addressed Need to counter all elements not just impact survival Most difficult
History ‘No survivable high velocity impacting probe has been successfully landed on any extraterrestrial body’ DS2 (Mars) NASA 1999 ? Mars96 (Russia) failed to leave Earth orbit Japanese Lunar-A cancelled (now planned to fly on Russian Lunar Glob) Many paper studies and ground trials
Feasibility ? • Lunar-A and DS2 space qualified. • Military have been successfully firing instrumented projectiles for many years • Most scientific instruments have space heritage 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 Involvement • ~2002 – became interested in micro-probes • 2004 – exploring Aurora route • 2005 – ESA Cosmic Visions (2015-2025) • Late 2006 – PPARC lunar mission studies • MSSL proposed penetrators • MoonLITE selected for first mission • Simultaneous promotion for Cosmic Vision ‘Inspirational...’ NASA Area manager... Like riding on the back of a tiger...
Micro-Penetrators payload instruments
Prime Planetary Targets EnceladusTitan Europa Moon
Europa • Subsurface Ocean ? • Life ?
Europa Japanese Lunar-A Continuous launch delays Several paper studies
Enceladus • 500Km dia. (c.f. with UK) • Fierce south pole plume (ice/dust) • Hi-albedo covering Saturnian moons ? • ‘Atmosphere’ (H2O,N2,CO2,CH4) • Liquid water under surface (life ?) (image from Wikipedia)
Titan Titan as seen from the Cassini–Huygens spacecraft. Wikipedia
Fluvial plain Titan • heavy atmosphere • mountains, • dunes • lakes • weather • winds • clouds • precipitation • seasons • complex organic chemistry • very cold • pre-biotic chemisty ? • life ? Dunes Titan as seen from the Cassini–Huygens spacecraft. Wikipedia
MoonLITE Science & Exploration Objectives “The Origin and Evolution of Planetary Bodies” “Waterand its profound implications for life andexploration” “Ground truth & support for future human lunar missions”
Polar comms orbiter MoonLITE Mission 3 • Delivery and Comms Spacecraft(Orbiter). • Payload:4 penetrator descent probes • Landing sites:Globally spaced - far side - polar region(s) - one near an Apollo landing site for calibration • Duration:>1 year for seismic network. Far side 4 2 1
Science & ISRU Objectives lunar base ? Far side 3 • Characterize water, volatiles, and astrobiologically related material at lunar poles. => Water is key to manned missions • Constrain origin, differentiation, 3d internal structure & far side crustal thickness of moon via a seismic network. • Investigate enigmatic strong surface seismic signals => identify potentially dangerous sitesfor lunar bases • Determine thermal & compositional differences at polar regions and far side. • Obtain ground truth for remote sensing instruments 4 2 1
Science – Lunar 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 Micro-seismometer, IC
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
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
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
Development Program • Studies • Simulation & Modelling • Impact Trials • build a real penetrator • impact it into a sand target at near supersonic speed !
Impact Trial - Objectives Demonstrate survivability of penetrator shell, accelerometers and power system. Assess impact on penetrator subsystems and instruments. Determine internal acceleration environmentat different positions within penetrator. Extend predictive modelling to new impact and penetrator materials. Assess alternative packing methods. Assess interconnect philosophy.
Impact Trial: 19-21 May 2008 • Full-scale trial • 3 Penetrators, Aluminium • 300m/s impact velocity • Normal Incidence • Dry sand target 13 Kg 0.56m … just 9 months from start to end. Starting from scratch in Sep’07
Impact trial – Payload Mass spectrometer Radiation sensor Batteries Magnetometers Accelerometers Power Interconnection Processing Micro-seismometers Accelerometers, Thermometer Batteries,Data logger Drill assembly
Trial Hardware Inners Stack
Impact Trial - Configuration • Rocket sled • Penetrator
Target • Dry sand • 2m x2m x6m • Small front entrance aperture (polythene)
1’st Firing - Results • Firing parameters: • Impact velocity: 310 m/s • (c.f. 300m/s nominal) • Nose-up ~8degs (c.f. 0 degs nominal) • => worst case • Penetrator found in top of target • Glanced off a steel girder which radically changed its orientation. • Penetration: ~3.9m • Much ablation to nose and belly • Rear flare quite distorted. • Penetrator in one piece ✓
1st Firing – internal Results Micro seismometer bay Connecting to MSSL accelerometer and data processing bay
1’srt Firing – QinetiQ accelerometer data Initial impact hi-res: Tail slap peak Overview: 5 kgee smoothed, ~16 kgee peak high frequency components ~5khz
1’st Firing – MSSL accelerometer data 11 kgee Peak gee forces in rear of penetrator Along axis: • Cutter: 3kgee • Main: 10kgee • Girder: 1kgee Along axis cutter Main impact Girder 15 kgee Vertical axis 4 kgee Horizontal axis
Hi-res MSSL accelerometer data Lots of high frequency structure
2nd Firing “Jaws-3?” ..struck steel girder and moved it 6 inches
Firings Overview • All 3 firings remarkably consistent ~308-310m/s velocity, and ~8 degs nose up. • All 3 Penetrators survived & Payloads still operational. Steel nose for 3rd firing
Survival Table Triple worst case: exceed 300m/s, >8deg attack angle No critical failures– currently all minor to unprotected bays or preliminary mountings
Impact Trial Objectives Demonstrate survivability of penetrator body, accelerometers and power system. Assess impact on penetrator subsystems and instruments. Determine internal acceleration environmentat different positions within penetrator. Extend predictive modelling to new penetrator materials,and impact materials. Assess alternative packing methods. Assess interconnect philosophy.
Next Steps & Strategy … • Next trial – aiming for Jun’09. • Impact into closer representative lunar regolith • Design for Moon • Full-up system (all operating) • Transmit from target Strategy: in parallel :- - MoonLITE Phase-A • Delta developments for icy planets
- End - Penetrator website: http://www.mssl.ucl.ac.uk/planetary/missions/Micro_Penetrators.php email:email@example.com
Penetrator Payload/Science A nominal 2kg payload … • Accelerometers – Probe surface/sub-surface material (hardness/composition) • Seismometers - Probe interior structure (existence/size of water reservoirs) and seismic activity of bodies • Chemical sensors – Probe surface refactory/volatile (organic/ astrobiologic) chemicals, perhaps arising from interior. • Thermal sensors - Determine subsurface temperatures and possibly probe deep interior processes. • Mineralogy/astrobiology camera – Probe surface mineralogy and possible astrobiological material. • + other instruments – to probe surface magnetic field, radiation, beeping transmitter, etc… • descent camera (surface morphology, landing site location, etc)
Enceladus - Science/Technology Requirements • Target • E.g. region of upwelled interior material. • 2 penetrators would allow additional target, improved seismic results and natural redundancy but require 2xmass. • 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 • Delivery • Targetting precision. • Ejection, descent motors & orientation, pre-impact separation, communications, impact. • Operation • Power/thermal (battery/RHU), data handling, communications.