Lunar Ranging Group LUNAR Team Gravitational Physics Lunar

Lunar Ranging Group LUNAR Team Gravitational Physics Lunar Laser Ranging 12 April 2011 Pasadena, California

Overall Schedule • University of Califonia, San Diego – Tom Murphy – Via Telephone • Goddard Space Flight Centrer – Stephen Merkowitz / Alix Preston – Via Telephone • University of Maryland, College Park – Doug Currie

Decadal Survey Submissions • Astronomy and Astro. Physics Decadal Survey – Gravitational and Particle Physics Panel Report – Many Excellent Comments on the Value of LLR • Planetary Sciences Decadal Survey – Lunar Geophysical Network • Recommended for New Frontier Mission • Would Place Four Retroreflectors on the Moon

murphy

gsfc

Topics UMd • • • Talks Decadal Computer Simulations – • • Review Deployment & Roles GLXP – – • Lander Surface Drilling Lifetime – – – • Candidates Functions Deployment – – – • Result Murphy Sun Shade Dust Bombardment Future Talks & Activities – – Dust ILRS • • – – Status and Suggestions Ground Stations Tests at Frascati NLSI • • Talk Demonstration

Conference Proceedings • Currie, D. G. , , the LLRRA-21/LSSO Team & the Moon. LIGHT/INFN-LNF Team 2010, “A Lunar Laser Ranging Retro. Reflector Array for the 21 st Century” 40 th Lunar and Planetary Science Conference, The Woodlands, TX 1 • Currie, D. G. , Zacny, K. , 2010 Regolith Drilling for the Lunar Laser Ranging Retroreflector Array for the 21 st Century, LUNAR Workshop, Cambridge MA • Currie, D. G. , Zacny, K. , the LLRRA-21/LSSO Team & the Moon. LIGHT/INFN-LNF Team 2010 ”A Lunar Laser Ranging Retro. Reflector Array for the 21 st Century” Lunar Exploration Analysis Group Washington DC. • Dell'Agnello, S. , Delle Monache, G. O. , Currie, D. G. , et. All, G. , & Mc. Elfresh D. “The Moon as a test body for General Relativity and new gravitational theories” presented at the conference European Planetary Science Congress 2010 (ESPC 2010) at the Angelicum Centre – Pontifical University of Saint Thomas Aquinas, Rome, Italy. • Dell’Agnello, S. , Currie, D. G. , Delle Monache. G. O. , et al Cantone, C. Garattini, M. Martini, M. Intaglietta, N. Lops C. , March, R , Tauraso, R, Bellettini G. , Maiello, M , Berardi, S. , Porcelli, L. ; "Next Generation Lunar Laser Ranging and its GNSS Applications"; IEEE Aerospace Conference, Big Sky (MT), • Peron, R. ; Bellettini, G. ; Berardi, S. ; Boni, A. ; Cantone, C. ; Coradini, A. ; Currie, D. G. ; Dell'Agnello, S. ; Delle Monache, G. O. ; , et al. “Advanced instrumentation for Solar System gravitational physics” EGU General Assembly 2010, held 2 -7 May, 2010 in Vienna, Austria, • Currie, D. G. , Delle Monache & G. O. Dell’Agnello, S. 2010 “A Lunar Laser Retroreflector for the FOR the 21 ST Century (LLRRA 21): Selenodesy, Science and Status” 2010 American Geophysical Union Fall Meeting San Francisco, CA • Currie, D. G. , Dell’Agnello, S. & Delle Monache, G. O. 2011 “LUNAR LASER RANGING: FLIGHT HARDWARE SIMULATION, TESTING AND STATUS”. Lunar and Planetary Science Conference, The Woodlands, TX ,

Talks, Colloquia and Public Presentations • • • Talks at Scientific Conferences • Currie, D. G. , & The LLRRA-21 Teams 2010 “A LUNAR LASER RANGING RETRO-REFLECTOR ARRAY for the 21 st CENTURY” LUNAR Workshop Boulder CO • Currie, D. G. , Dell’Agnello, S. & Delle Monache, G. O. 2010 A Lunar Laser Ranging Retroreflector Array for the 21 st Century ISOT 2010 International Symposium on Optomechatronic Technologies , Toronto, Canada • Currie, D. G. , & the LLRRA-21 Teams 2011 “A LUNAR LASER RANGING RETRO-REFLECTOR ARRAY for the 21 st CENTURY” 2 nd Lunar Laser Ranging Workshop, International Space Sciences Institute, Bern Switzerland • Dell’Agnello, S. ; Currie, D. G. ; Delle Monache, G. O. ; Lops, C. ; M. Martini 2010 “LLRRA 21/Moon. LIGHT: a 2 nd Generation Lunar Laser Ranging Array for Precision Gravity Tests and Lunar Science Measurements” at the Conference Global Lunar Conference – Beijing, China. Ddd 31 May-3 June 2010 talk • • • Currie, D. G. , & the LLRRA-21 Teams 2011 “A LUNAR LASER RANGING RETRO-REFLECTOR ARRAY for the 21 st CENTURY” 2 nd Lunar Laser Ranging Workshop, International Space Sciences Institute, Bern Switzerland Colloquia and Public Presentations Currie, D. G. 2011 2 nd NLSI Commerce Virtual Lecture A LUNAR LASER RANGING RETROREFLECTOR FOR THE 21 ST CENTURY

Computer Simulations • Problems – Commercial Software Issues – Computer Failures – 300 Million Beer’s Law Calculations for Each • Computer simulation Objectives – End to End Simulation • Technical Objectives – Selection of Thermal Coatings – Effects of Shorter Sun Shade • GLXP Candidates for Size / Angular Tolerances • Eclipse Effects – For LLRRA-21, not Apollo

Computer Simulations 500 Time Steps Over a Lunation • Heat. Load 3 D – IDL – University of Maryland – Evaluates Solar Heat Loads in CCR at ~ a Million Nodes • Thermal Desktop – Commercial - Cullimorgan and Ring Technologies – Combine CCR Heat Loads with Solar Inputs to Temperature at 1733 Nodes • Temp. To. Phase – IDL – University of Maryland – Converts Temperatures from thermal Desktop into Phase Errors • Code V – Commercial – Combines Thermal Phase Errors with TIR Phases and Effect of Offset Angles • Analysis – IDL – University of Maryland – Converts Far Field Diffraction Patterns into Useful Operational Results

Frascati Testing • Thermal Vacuum Tests – Optical Table for Far Field Diffraction Pattern – Infra. Red Camera for Temperature Meaurements – Optical Simulator for “Sun” – Thermal Sensors on CCR • Images of Chamber and CCR Face

Different Deployment Versions Single Shot Range Accuracy • Current Single Shot Accuracy is ~20 mm • If Mounted on Lander – Thermal Expansion of Lander – Heat Flux from Lander – Single Shot Accuracy of 1 -3 millimeters • If a Surface Deployment – Thermal Expansion of Regolith – Heat Flux from Lander – Sub-Millimeter Single Shot Accuracy • If an Anchored Deployment – Anchored at ~1 meter depth – Better than 100 micron Single Shot Accuracy

Google Lunar X Prize • Prize by Google Corporation for 30 M$ – Only Private Money for GLXP Objectives • Can Be Government Money – For Other Objectives – Like LLRRA-21 • Currently Working with: – – – Lunar Express, Astrobotics Moon Express Next. Great. Leap Penn State University FREDNET Hai Li David Gump Bob Richards Michael Joyce Miles Smith Sean Casey • Multiple Missions that May Be Successful – Achieve an Array of Retroreflectors

Deployment Lander

Surface Deployment

Anchored Deployment Astrobotics & Honeybee

Lifetime of LLRRA-21 • Degradation of Laser Returns – Tom Murphy and APOLLO Station – Factor of 9. 6 over 40 years • Amelioration of Problem – Sun Shade • Blocks Dust Deposition • Block Micrometeorite Bombardment • But What is the Real Reason for Degradation? – For Micrometeorite Bombardment – Test at Horanyi’s Dust Accelerator

Signal Level for One LLRRA-21 • Briefly – LLRRA-21 Signal ~ Equal to Apollo 15 Array – Therefore Can Works with Sub-Meter Telescopes • Will Need to Upgrade of Laser, Timing Electronics • Mc. Donald at 0. 67 meter Currently successfully Ranges to A 15 – Long Life - Dust Issues Handled with Sun. Shade • More Precisely – Iso. Thermal – Station – Latitude – 45 – 00 Angle Offsets Yes No LLRRA-21 Signal Return w. r. t. A 15 78% 58% 88% 71%

Future Objectives • Schedule: >> Driven by the Google Lunar X Prize Launch – – April/December 2013 i. e. , Astrobotics Need to Finalize the Design Need to Attain Sufficient TRL to Obtain Funding i. e. , T/V/O Test Need to Fabricate/Test/Integrate Flight Hardware • Simulations to Optimize Thermal Coatings – To Control Thermal Gradients and thus Signal – Optimize within Limits of Pracitical Coatings – Different Choices for Different GLXP Missions • Interactions with GLXP Teams – Each has Different Physical & Organizational Structures – Therefore Each Requires Somewhat Different Thermal Design – Each Requires Different Emplacement Procedures

Future Talks & Activities • Evaluate Dust Bombardment – Mihaly Horanyi – Dust Accelerator - Early May • International Laser Ranging Service Meeting – Late May – Present Status of LLRRA-21 to Actual Ranging Groups – Collect Suggestions from Operators – Present What is Needed for Ground Stations for LLRRA-21 • Thermal/Vacuum/Optical Tests at Frascati – Early June – TRL 6. 5 -> TRL 7. 0 • NASA Lunar Science Institute – Mid July – Talk on LLRRA-21 Hardware and GLXP Mission Status – Report on Honeybee Grant on Pneumatic Drill for LLRRA-21 – Demonstration of Pneumatic Drilling • Probably Mounted on Astrobotic Lander