Lunar University Network for Astrophysics Research Jack Burns, Director A LUNAR LASER RANGING RETRO-REFLECTOR ARRAY for the 21 st CENTURY Professor Douglas Currie University of Maryland, College Park, MD, USA NASA Lunar Science Institute, Moffett Field, CA INFN – LNF, Laboratori Nazionali di Frascati, Italy & The LLRRA-21 Teams with the 1

OUTLINE Outline of Talk Brief History of Lunar Laser Ranging –Original Science Objectives of Our LLR Project –Concept > Apollo 11, 14, 15 –Improvement Kilometers -> 30 cm Not one by Time Series of Measurements –Limiting Accuracy –Continuing Science Due to 40 year Baseline Lunar Physics from Apollo Arrays –Lunar Core Discovery Size and Shape Confirmed –Other Relativity Physics from Apollo Arrays –Inertial Properties of Gravitational Energy –Temporal Change of G –Spatial Change of G –General Review Apollo Array Problem Due to Librations –Ground Station Improvement Factor of 100 –Illustration Decadal Remarks w.r.t. Lunar Laser Ranging –Planetary - Astronomy Panel Discovery Mission –Astronomical - LLRRA-21 Proposal –New Interest in the Moon –LLRRA-21 Concept –Why is a Single CCR a Solution –Design of LLRRA-21 –Challenges –Signal Performance –Emplacement Issues –Advantages Higher Accuracy More Stations Accuracies for Various Deployment Methods –Lander –Surface –Anchored Expected Science Results –Lunar Physics –Relativity Science Possible Flight Opportunities –Google Lunar X Prize –Lunette ILN –LGN – Lunar Geophysical Network Discovery Mission Thank You & Acknowledgements –NASA LSSO Lunar Science Institute > LUNAR Team at UC –INFN-LNF 2

To be done Simulation Results More pictures Find Charts of Accuracy –Lunar with periods –Relativity Statement about Heritage –Science –Technology 3American Geophysical Union 5 December 2011

OUTLINE Brief History of Lunar Laser Ranging Lunar Physics from the Apollo Arrays Relativity Physics from the Apollo Arrays Apollo Array Problem Due to Librations Decadal Remarks w.r.t. Lunar Laser Ranging LLRRA-21 Proposal Accuracies for Various Robotic Deployment Methods Expected Science Results Possible Flight Opportunities Acknowledgements 4American Geophysical Union 5 December 2011

Brief History of Lunar Laser Ranging Operational Procedure –Transmit Narrow Laser Pulse from Earth –Pulse is Reflected from a Fixed Point on the Moon –Measure the Light Travel Time –Analyze Time Series of Measurements for Frequencies Range Improvement due to Apollo LLR –Kilometers (Radar) would go to ~300 mm Continue Measurements for Long Time Series –Originally 3 Measurements per Day 5American Geophysical Union 5 December 2011

Lunar Physics from the Apollo Arrays Discovery of Liquid Core –Ten years Ago –Confirmed This Year by Seismometer Properties of Liquid Core –Size, –Shape –Moment of Inertia 6 American Geophysical Union 5 December 2011

LLR LUNAR SCIENCE OVERVIEW Elastic Tides of the Moon Tidal Dissipation Size and Oblateness of Liquid Core Dissipation at Liquid-Core/Solid-Mantle Interface Lunar Moment of Inertia Fluid Core Moment of Inertia Evolution and Heating Existence of a Smaller Solid Inner Core Selenodetic Site Positions 7 American Geophysical Union 5 December 2011

Relativity Physics from the Apollo Arrays Inertial Properties of Gravitational Energy –Does Gravitational Energy Resist Acceleration –Earth and Moon have Different Gravitational Energy –Do They Fall to the Sun at the Same Rate? Measurement of Temporal Change in G Addresses Alternative MOND Theories of Gravitation Measurement of Spatial Change in G Fundamental Inconsistency of –General Relativity and Quantum Mechanics 8American Geophysical Union 5 December 2011

What have the Apollo Arrays Done Relativity Science The Earth-Moon System Provides an Ideal System –To Evaluate Relativity and Einstein’s Theory Moon is Massive enough to Resist Drag/Pressure Moon is Far Enough to be in a Solar Orbit (Weakly Bound) LLR Currently Provides our Tests of: The Weak Equivalence Principle (WEP)*:  a / a < 1.3  The Strong Equivalence Principle (SEP):  < 4  10  4 Time-Rate-of-Change of G to < 7  10  13 per year Inverse Square Law to 3  10  11 at 10 8 m scales Geodetic Precession to 0.6 % Gravitomagnetism to 0.1 % 9 American Geophysical Union 5 December 2011

Apollo Array Problem Due to Librations Apollo Arrays Consisted of 100 CCR –Arranged in a10 by 10 flat panel Accuracy of Ground Stations –Improved by a Factor of 200 w.r.t Lunar Librations –Rotation of Moon w.r.t. Earth-Moon Axis –+/- 8 degrees in Latitude and Longitude We Cannot Distinguish between Near & Far CCRs A Very Short Laser Pulse is Spread –Return Pulse is ~20 mm Therefore Limiting Accuracy 10American Geophysical Union 5 December 2011

Decadal Remarks w.r.t. Lunar Laser Ranging 2010 Planetary Decadal Survey –Recommended NGL as Discovery Mission –Including Lunar Laser Retroreflectors Astro2010 Gravitational and Astrophysics Panel –Specifically Recommended LLRs –“improvements in Lunar Laser Ranging promise to advance this area” –“G (< /yr) from lunar laser ranging” –“So far, LLR has provided the most accurate tests of the weak equivalence principle, the strong equivalence principle and the constancy in time of Newton’s gravitational constant” –“recommendation below in the context of a recommendation to augment the Explorer program” 11American Geophysical Union 5 December 2011

LLRRA-21 Proposal NASA Revives Interest in Moon – 2006 LSSO Proposal for Improved Lunar Retroreflector –“Lunar Laser Ranging Retroreflector Array for the 21 st Century” –Large Single Solid Cube Corner Reflector –Accuracy to be Improved by Factor of 10 to 100 –Great Reduction in Weight w.r.t. Apollo Arrays –No Power or Communication Required –Very Long Operational Lifetime - Centuries –Great Heritage to Assure Risk Reduction Same Design on the Moon has Provided Excellent Science for 40 years Thousands of Smaller Solid CCRs Operating in Earth Orbit for over 40 years 12American Geophysical Union 5 December 2011

Why Consider a Single CCR No Spreading of Laser Return Pulse –20 mm Uncertainty due to Librations Goes to ~0 Larger Return Signal Level – –Similar to Apollo 15 –Available to More Laser Ranging Ground Stations 13

CHALLENGES for SOLID CCR Fabrication of the CCR to Required Tolerances Sufficient Return for Reasonable Operation –Ideal Case for Link Equation Thermal Distortion of Optical Performance –Absorption of Solar Radiation within the CCR –Mount Conductance - Between Housing and CCR Tab –Pocket Radiation - IR Heat Exchange with Housing –Solar Breakthrough - Due to Failure of TIR Stability of Lunar Surface Emplacement –Problem of Regolith Heating and Expansion –Drilling to Stable Layer for CCR Support –Thermal Blanket to Isolate Support –Housing Design to Minimize Thermal Expansion 14 LUNAR Workshop 6 October 2010

Thermal Simulation Results 154th Allahabad Science Conclave 28 November 2011

164th Allahabad Science Conclave 28 November 2011

ROBOTIC DEPLOYMENT Alterative Deployment Methods –Lander Mounting Few Millimeters Motion Due to Thermal Cycling Thermal Expansion of Lander during Lunation –Surface Deployment Sub-Millimeter Motion Due to Thermal Cycling Regolith Expansion Requires an Arm –Anchored Deployment Tens of Microns 17 American Geophysical Union 5 December 2011

Regolith Drilling in Apollo 18

Kriz Zacny at HoneyBee 19American Geophysical Union 5 December 2011

CURRENT STATUS Preliminary Definition of Overall Package Completed Preliminary Simulations –LSSO – Lunar Science Surface Opportunities –Thermal (CCR, Regolith, Housing), Optical Completed Phase I Thermal Vacuum Tests –Solar Absorption Effects on CCR –CCR Time Constants – IR Camera – Front Face Thermocouples – Volume Preliminary Optical FFDP 20

LLRRA-21 PACKAGE 21American Geophysical Union 5 December 2011

LUNAR Science Fluid Core Moment of Inertia –LLR Detection of Liquid Inner Core has very Recently been Confirmed by Seismometry Whole Moon Moment of Inertia Core Oblateness: –LLR detects fluid-core/solid-mantle boundary (CMB) Inner Core: –A solid inner core apparently exists and can be confirmed by LLRRA-21 Elastic Tides: –Solid-body tidal displacements depend on the Moon’s elastic properties. –Typical monthly variations are ±9 cm. Lunar Tidal Dissipation: –The tidal specific dissipation Q depends on the radial distribution of the material Qs. Core/Mantle Boundary Dissipation: –LLR first demonstrated that the Moon has a fluid core by Free Physical Librations Selenodetic Site Positions: –The Moon-centered locations of four retroreflectors are known with submeter accuracy Tidal Acceleration and Orbit Evolution: –LLR is very sensitive to the tidal acceleration of the lunar orbit. 22

Detailed Lunar Science Results 1 Fluid Core Moment of Inertia: –LLR is sensitive to the fluid core moment of inertia, which depends on core density and radius. This is a new LLR lunar science result for the core. The solution for the ratio of fluid moment to total moment gives Cf/C = (12±4)x10–4, where the subscript f indicates the fluid core (Williams et al., 2009). For a uniform liquid iron core without an inner core this value would correspond to a radius of 390±30 km. Lower fluid densities or presence of A Planetary Science Decadal Survey White Paper: “Lunar Science and Lunar Laser Ranging” Page 2 of 7 Retroreflector arrays on the Moon. –an inner core would give larger outer radii for the fluid. Weakly determined at present, an accurate determination of core moment depends on a long time span of high accuracy range data. There is very little information on the core and it is very important to improve this determination. Whole Moon Moment of Inertia: –The whole Moon moments of inertia A<B<C come from combining LLR results for relative moment differences (C-A)/B and (BA)/C with orbiting spacecraft determined J2 and C22. The most recent published total value (Konopliv et al., 1998) predates the more recent LLR fluid core moment determination, and is limited by the uncertainty of the earlier adopted fluid core moment. As the fluid core momentimproves, so will the whole Moon moment. The lunar moment of inertia constrains model profiles of density vs. radius. 23American Geophysical Union 5 December 2011

Detailed Lunar Science Results 2 Core Oblateness: –LLR detects fluid-core/solid-mantle boundary (CMB) flattening. Currently the product of CMB oblateness and fluid core moment of inertia is determined more strongly than either factor separately. That product is f Cf/C = (Cf–Af)/C =(3±1)x10-7 (Williams et al., 2009). The detection of CMB flattening is one of the demonstrations that there is a fluid core. Inner Core: –A solid inner core might exist inside the fluid core, but it has not yet been detected by any technique. Gravitational interaction between an inner core and the mantle would affect the mantle’s three-axis orientation. A future detection would be possible if the effect on mantle rotation is large enough. A detection of the inner core would reveal the frequency of one or more of the three possible resonances plus associated strength parameters. These quantities depend on multiple unknown parameters that describe the inner core gravity and moment of inertia and its gravitational interaction with the mantle. Elastic Tides: –Solid-body tidal displacements depend on the Moon’s elastic properties. Typical monthly variations are ±9 cm. The solution parameters are the second-degree Love numbers h2 and l2 that scale the global tidal displacements. The existing distribution of LLR sites is weak for determining displacement Love numbers. Future sites with a wider geographic distribution would strongly improve the determination. The physical librations are also sensitive to the Love number k2 that describes the second-degree tidal variations in potential and moments of inertia. LLR is potentially very sensitive to the Love number k2, but k2 correlates with core oblateness, which weakens the determination. 24

Detailed Lunar Science Results 3 Lunar Tidal Dissipation: –The tidal specific dissipation Q depends on the radial distribution of the material Qs. LLR detects tidal dissipation and infers a weak dependence of tidal Q on frequency. The tidal Qs determined from the orientation are surprisingly low, ~30 at a one month period and ~35 at one year. LLR does not distinguish the location of the low-Q material, but at seismic frequencies low-Q material, suspected of being a partial melt, was found for the deep zone above the core. Future LLR sites and very accurate ranges could help increase the frequency span. They could also detect the few mm dissipation effects in the tidal displacements. Core/Mantle Boundary Dissipation: –LLR first demonstrated that the Moon has a fluid core by detecting the energy dissipated by the flow of the fluid along the boundary (Williams et al., A Planetary Science Decadal Survey White Paper: “Lunar Science and Lunar Laser Ranging” Page 3 of ). The CMB dissipation remains strong in LLR solutions (Williams et al., 2009) and is determined in addition to, but correlated with, the tidal dissipation. The CMB dissipation depends on fluid core size, fluid viscosity and CMB roughness. 25American Geophysical Union 5 December 2011

Detailed Lunar Science Results 4 Free Physical Librations: –Normal modes of the rotation may be stimulated by internal or external mechanisms, but they are subject to damping which is short compared to the age of the Moon. Two of the free libration amplitudes are observed by LLR to be large (>10 m) which implies active or geologically recent stimulation (Newhall and Williams, 1997; Chapront et al., 1999; Rambaux and Williams, 2009). The 2.9 yr longitude mode with an 11 m amplitude is stimulated, at least in part, by resonance passage (Eckhardt, 1993). The wobble mode, analogous to the Earth’s Chandler wobble, is a large elliptical (28x69 m) 74.6 yr motion of the pole direction. If wobble is stimulated by eddies at the CMB as suggested by Yoder (1981), then ongoing activity might be revealed by future LLR measurements as irregularities in the path of polar wobble. The third mantle mode, a free precession in space, and the liquid core free core nutations are small (<1 m). The former may be detected, but it appears to be sensitive to the interior model. Site Positions: –The Moon-centered locations of four retroreflectors are known with submeter accuracy (Williams et al., 1996, 2008). Positions for existing and new LLR sites can be used as control points for lunar cartographic networks, as was done by Davies et al. (1987, 1994, 2000). The four site radii are a valuable check on altimetry from orbit (Fok et al., 2009). 26American Geophysical Union 5 December 2011

Detailed Lunar Science Results 5 Tidal Acceleration and Orbit Evolution: –LLR is very sensitive to tidal acceleration of the lunar orbit. Tides on Earth dominate the energy and angular momentum transfer to the orbit and the Moon’s evolution outward. Tidal effects on the Moon are separable from Earth tide effects in the LLR solutions (Chapront et al., 2002; Williams et al., 2009). The total tidal acceleration in orbital mean longitude from Earth and Moon tides is –25.85 arcsec/century2, which corresponds to a 3.81 cm/yr recession of the Moon (Williams et al., 2009). Eccentricity rate is also detected. Evolving the lunar orbit backward in time is an important and surprisingly difficult goal. LLR provides numerical values for two sources of dissipation on Earth and two for the Moon. 27American Geophysical Union 5 December 2011

Projected Relativity Results Science Timescale Current (cm) 1 mm 0.1 mm Weak Equivalence Principle Few years |Δa/a|< 1.3×10 −13 10 ‐ ‐ 15 Strong Equivalence Principle Few years |η| < 4.4×10 −4 3×10 ‐ 5 3×10 ‐ 6 Time variation of G ~10 years yr ‐ 1 9×10 −13 5×10 ‐ 14 5×10 ‐ 15 Inverse Square Law ~10 years |α|< 3×10 ‐ ‐ ‐ 13 PPN β Few years |β−1|< 1.1×10 ‐ 4 10 ‐ 5 10 ‐ 6 28 American Geophysical Union 5 December 2011

MISSION OPPORTUNITES Mission Possibilities for LLRRA-21 –Google Lunar X Prize – Most Exciting Flight in Next Two Years Astrobotics Moon Express Next Giant Leap –Post-Lunette Discovery Program Explicitly Recommended in Planetary 2010 Decadal Report –International Lunar Network Recommend by Planetary 2010 Decadal Report Being Invistigated by NASA for a Launch in 2018 –Italian Space Agency & INFN-LNF MAGIA – ASI & INFN –Proposed ASI Lunar Orbiter to Carry a 100 mm Solid CCR Italian Investigation of the LLRA-21 Retroreflector Instrument –MoonLIGHT-ILN INFN Experiment 29 American Geophysical Union 5 December 2011

Thank You! any Questions? or Comments?. with Special Acknowledgements to NASA Lunar Science Sorties Opportunities NASA Lunar Science Institute Italian Space Agency LUNAR Team INFN-LNF, Frascati. 30 American Geophysical Union 5 December 2011

Backup Viewgraphs 31American Geophysical Union 5 December 2011

LLRRA-21 Teams LSSO Team – NASA Douglas Currie Principal Investigator – University of Maryland, College Park, College Park m MD, USA –NLSI, Moffett Field, CA, USA & –INFN-LNF Frascati, Italy Bradford Behr –University of Maryland, College Park, MD, USA Tom Murphy –University of California at San Diego, San Diego, CA, USA Simone Dell’Agnello –INFN/LNF Frascati, Italy Giovanni Delle Monache –INFN/LNF Frascati, Italy W. David Carrier –Lunar Geotechnical Institute, Lakeland, FL, USA Roberto Vittori –Italian Air Force, ESA Astronaut Corps Ken Nordtveldt –Northwest Analysis, Bozeman, MT, USA Gia Dvali –New York University, New York, NY and CERN, Geneva, CH David Rubincam –GSFC/NASA, Greenbelt, MD, USA Arsen Hajian –University of Waterloo, ON, Canada INFN-LNF Frascati Team Simone Dell’Agnello PI INFN-LNF, Frascati, Italy Giovanni Delle Monache INFN-LNF, Frascati, Italy Douglas Currie U. of Maryland, College Park, MD, USA NLSI, Moffett Field, CA, USA & INFN-LNF, Frascati, Italy Roberto Vittori Italian Air Force & ESA Astronaut Corps Claudio Cantone INFN-LNF, Frascati, Italy Marco Garattini INFN-LNF, Frascati, Italy Alessandro Boni INFN-LNF, Frascati, Italy Manuele Martini INFN-LNF, Frascati, Italy Nicola Intaglietta INFN-LNF, Frascati, Italy Caterina Lops INFN-LNF, Frascati, Italy Riccardo March CNR-IAC & INFN-LNF, Rome, Italy Roberto Tauraso U. of Rome Tor Vergata & INFN-LNF Giovanni Bellettini U. of Rome Tor Vergata & INFN-LNF Mauro Maiello INFN-LNF, Frascati, Italy Simone Berardi INFN-LNF, Frascati, Italy Luca Porcelli INFN-LNF, Frascati, Italy Giuseppe Bianco ASI Centro di Geodesia Spaziale “G. Colombo”, Matera, 32 American Geophysical Union 5 December 2011

ASTRO2010 DECADAL SURVEY Gravitational and Particle Physics Panel Much is unknown about fundamental theory: Modifications of general relativity on accessible scales are not ruled out by today’s fundamental theories and observations. It makes sense to look for them by testing general relativity as accurately as possible. Cost- effective experiments that increase the precision of measurement of PPN parameters, and test the strong and weak equivalence principles, should be carried out. For example, improvements in Lunar Laser Ranging promise to advance this area. 33American Geophysical Union 5 December 2011

ASTRO2010 DECADAL SURVEY Gravitational and Particle Physics Panel The direct detection of gravitomagnetic effects (the Lense-Thirring precession) from Lageos/Grace, Gravity Probe B, and lunar laser ranging. The lunar laser ranging verification of the strong equivalence principle to 10- 4, meaning that the triple graviton vertex is now known to a better accuracy than the triple gluon vertex. Limits on the fractional rate of change of the gravitational constant G (< 10-12) Limits on the fractional rate of change of the gravitational constant G (< 10-12/yr) from lunar laser ranging. Atomic experiments limiting time variation of the fine structure constant to 10-16/yr over periods of several years. Experiments that are in progress include the Microscope equivalence principle experiment, the APOLLO lunar laser ranging observations, and tests of general relativity using torsion balances and atom interferometry. Improved strong and weak equivalence principle limits. Better determination of PPN parameters and and Ġ/G from next generation Lunar laser ranging 34American Geophysical Union 5 December 2011

ASTRO2010 DECADAL SURVEY Gravitational and Particle Physics Panel A new Lunar Laser Ranging (LLR) program, if conducted as a low cost robotic mission or an add-on to a manned mission to the Moon, offers a promising and cost- effective way to test general relativity and other theories of gravity (Figure 8.12). So far, LLR has provided the most accurate tests of the weak equivalence principle, the strong equivalence principle and the constancy in time of Newton’s gravitational constant. These are tests of the core foundational principles of general relativity. Any detected violation would require a major revision of current theoretical understanding. As of yet, there are no reliable predictions of violations. However, because of their importance, the panel favors pushing the limits on these principles when it can be done at a reasonable cost. The installation of new LLR retroreflectors to replace the 40 year old ones might provide such an opportunity. The panel emphasizes again that its opinion that experiments improving the measurements of basic parameters of gravitation theory are justified only if they are of moderate cost. Therefore, it recommends that NASA’s existing program of small- and medium-scale astrophysics missions address this science area by considering, through peer review, experiments to test general relativity and other theories of gravity. The panel notes that a robotic placement of improved reflectors for LLR is likely to be consistent with the constraints of such a program. It returns to this recommendation below in the context of a recommendation to augment the Explorer program. 35American Geophysical Union 5 December 2011

ASTRO2010 DECADAL SURVEY Cosmology and Fundamental Physics Panel These complex spin-induced orbital effects are the consequences of “frame dragging,” a fundamental prediction of Einstein’s theory that has been probed in the Solar System using Gravity Probe B, LAGEOS satellites, and Lunar laser ranging, and has been hinted at in observations of accretion onto neutron stars and black holes. 36American Geophysical Union 5 December 2011

37 APOLLO Data from Tom Murphy

CCR FABRICATION CHALLENGE CCR Fabrication Using SupraSil 1 Completed Specifications / Actual –Clear Aperture Diameter mm / 100 mm –Mechanical Configuration - Expansion of Our APOLLO –Wave Front Error / 0.15 [ /6.7 ] –Offset Angles Specification –0.00”, 0.00”, 0.00” +/-0.20” Fabricated –0.18”, 0.15”, 0.07” Flight Qualified –with Certification 38 American Geophysical Union 5 December 2011

THERMAL ANALYSIS – THEORETICAL Solar Absorption within CCR Solar Heat Deposition in Fused Silica –Solar Spectrum – AMO-2 –Absorption Data for SupraSil 1/311 –Compute Decay Distance for Each Wavelength –Compute Heat Deposition at Each Point Beer’s Law –Thermal Modeling Addresses: Internal Heat Transport and Fluxes Radiation from CCR to Space Radiation Exchange with Internal Pocket Surroundings Mount Conduction into the Support Tabs 39 American Geophysical Union 5 December 2011

MOUNT CONDUCTANCE Challenge: –Heat flow from Housing to CCR at Tabs –Optical Distortion due to Heat Flux Support of CCR with KEL-F “Rings” –Intrinsic Low Conductivity –Use of Wire Inserts - Only Line Contacts Line Contact of Support Reduces Heat Flow –For Support in Launch Environment KEL-F Wire Compresses and Launch Support Comes from Flush on Tab Estimated (to be Validated in SCF) 1 Milli-W/ o K 40 American Geophysical Union 5 December 2011

Challenge: –IR Radiation Between CCR & Housing –SiO 2 Has High IR Absorptivity/Emissivity –Heat Flux Causes Optical Distortion Isolation Between CCR and Housing –Low Emissivity Coatings – 2% Emissivity –Successive Cans or Multiple Layers Simulations Show Isolation is Effective Thermal Vacuum Chamber Validation –In April 2009 at SCF at INFN/LNF at Frascati POCKET RADIATION EXCHANGE 41 American Geophysical Union 5 December 2011

INNER & OUTER THERMAL SHIELDS 42American Geophysical Union 5 December 2011

THERMAL & SUNSHADE Role of Sun Shade –Thermal Control and Sun Blocking –Dust Protection –UltraViolet Light Protection External Surface –Highly Reflective in Visible –High Emissivity in the Infrared Internal Surface –Black in the Visible –Low Emissivity in the Infrared 43American Geophysical Union 5 December 2011

LLRRA-21 PACKAGE 44American Geophysical Union 5 December 2011

ORBITAL THERMAL EVOLUTION Simulation Performed with –Thermal Desktop C&R Technologies –IDL –Code V Initial Analysis –“Steady State” Behavior –Fixed Elevation of Sun But During Lunar Month –Changing Illumination Both Intensity and Angle –For CCR/Housing/Thermal Blanket/Regolith Some Time Constants are Longer than a Month –Analysis of Behavior of Face to Tip Temperature Difference 45 American Geophysical Union 5 December 2011

Simulation Procedure AutoCad Drawing of Total Package –CCR, Housing, Internal and External Support and Regolith 4-D Heat Deposition in CCR – UMd IDL Program –Through a Lunation, 1 Nanometer Wavelength Bands, –Many Thousands of Nodes, Reflection Effects of SunShade Thermal Desktop –Computes Temperature at Each Node PhaseMap – UMd IDL Program –Converts 3D Temperatures to 2D PhaseMap at Each of 400 Sun Angles Code V Optical Analysis Program –Adds Optical Errors (Reflection Phases, Offset Angles to Thermal Errors Analysis Program – UMd IDL Program –Evaluates Laser Return Intensity - Addressing Velocity Aberrations and Station Latitude Polarization Effects 46American Geophysical Union 5 December 2011

FULL Thermal Simulation Anchored Emplacement Regolith from Apollo HFE, Thermal Blanket Current Design Housing Temperature Distribution in CCR and Tip to Face Temperature Difference 47 American Geophysical Union 5 December 2011

SCF Thermal Vacuum Test Infrared Imager Full Dynamic Range Heat Flow Due to Tab Supports American Geophysical Union 5 December

Dust Accelerator University of Colorado Fused Silica Witness Plates American Geophysical Union 5 December

LLRRA-21 SIGNAL STRENGTH 88% of the Current Apollo 15 Signal Level –At End of First Decade still about the same as Apollo 15 and – 2.64 Stronger than Apollo 11 Simulated Pattern with Offset Angles to Correct for Velocity Aberration Relative to Current A11 –On Axis Return is 49% of Apollo 11 –At Velocity Aberrated Latitude, the Return is ~55% of Apollo 11 –But No Dust so Stronger by a Factor of 9.6 –Overall – Stronger Than Apollo 11 by a factor of 2.64 –Overall – 90% of the return of Apollo 15 If Dust on the Apollo Array is due LEM Launch – LLRRA-21 has a Cover for Landing Dust If Dust on the Apollo Arrays is due to Steady Deposit of Dust or High Velocity Impacts –There would be at Least a Decade of Good Returns –But LLRRA-21 Should Expect Better Performance Sun Shade Dust Mitigator APOLLO Station gets Many Thousands of Returns in 5 Minutes on Apollo 15 Almost Every Night –3.6 meter Therefore Smaller Telescopes can Work –At 1,000 Returns on 3.6 Meter, –One Should get 80 Returns on 1 Meter and 25 Returns on 0.6 meter Telescope 50American Geophysical Union 5 December 2011 NLSI Commerce Virtual Lecture 23 February 2011

LUNAR SURFACE EMPLACEMENT CCR Optical Performance at Sub-Micron –Want to Assure as Much of This as Possible We Have Sufficiently Strong Return Emplacement Issues - Diurnal Heating of Regolith –~ 400 Microns of Lunar Day/Night Vertical Motion Solutions – Dual Approach for Risk Reduction –Drill to Stable Layer and Anchor CCR to This Level ~ one meter – Apollo Mission Performed Deeper Drilling ~ 0.03 microns of motion at this depth –Stabilize the Temperature Surrounding the CCR Multi Layer Insulation Thermal Blanket – 4 meters diameter Support Rod Sees a Constant Temperature Environment 51 American Geophysical Union 5 December 2011

SURFACE DEPLOYMENT Issues –CCR Should Point Toward Earth “Center” –Maintain Clocking Angle to Handle Sun Break-through –Handle Longitudinal (toward earth) Tilt of Surface –Handle Azimuthal Tilt of Surface Requirements –Self Orienting Procedure to Keep Clocking Angle –Longitudinal (Elevation) Self Orientation –Azimuth Angle Adjusted by Deployment Arm Calibrated by Goniometer (Sun Dial) 52American Geophysical Union 5 December 2011

ROBOTIC DEPLOYMENT Surface Deployment 53American Geophysical Union 5 December 2011

DEPLOYMENT We have not received any detailed info Therefore have not significantly started If we are selected at a later time –Perhaps the deployment method and procedure –Could be handled by JPL –Who has developed detailed procedures 54American Geophysical Union 5 December 2011

DEPLOYMENT APPROACHS Surface Deployment Candidates –Reference w.r.t. Regolith Surface Uneven Surface a Problem –Reference to Local Gravity Vector Wire Support Clocking and Elevation Self Orienting Azimuth Correction by: –Lander Arm –Dedicated Motor Demonstration Frame Design and Pick-up Procedure –Needs Info on the Capabilities of the Lander Arm 55American Geophysical Union 5 December 2011

ROBOTIC DEPLOYMENT Anchored Deployment Problem with Regolith Expansion –During a Lunation –300K at Surface –~ 400 microns Solution –Anchor CCR below Thermally Active Region –Drill to a Meter or Less –Small Fraction of a Degree Variation –Anchor at Base 56American Geophysical Union 5 December 2011

CRITICAL VENDORS Cube Corner Retroreflectors –ITE, Inc. Laurel, Maryland, USA –Ed Aaron, President –Fabricated CCR #1 of LLRRA-21 Program –Successfully met Specifications –Fabricated Flight CCR Arrays of Apollo Design for: ETS-8, QZSS Japan Naval Research Laboratory NASA U.S. Air Force 57American Geophysical Union 5 December 2011

CRITICAL VENDORS Thermal Shields, Inner & Outer –Epner Technologies, Inc. –David Epner, President –Fabricated Shields for LLRRA-21 SCF Tests –Successful Operation in Thermal Vacuum Test –Epner has Fabricated LaserGold Shields for NOAA – GOES Satellites for 25 years NASA – Hubble WFPC, MOLA Laser Altimiter –Advanced Chemical Experiment 58American Geophysical Union 5 December 2011

CRITICAL VENDORS Housing and Deployment Frame –L-3. SSG, Inc. In –Joseph Robichaud, Chief Technology Officer –Silicon Carbide – Low Thermal Expansion –Fabricated SiC for Space Applications for Jet Propulsion Laboratory NASA Naval Research Laboratory 59American Geophysical Union 5 December 2011