1. 10 - 1 LRO System Requirements Review Lunar Exploration Neutron Detector (LEND) Requirements & Implementation Igor Mitrofanov Principle Investigator Russian Institute for Space Research

2. 10 - 2 Institutions of LEND Instrument Team Computer Science Corporation, USA Catholic University of America, USA University of Arizona, USA NASA/Goddard Space Flight Center, USA University of Maryland, USA Joint Institute of Nuclear Research, Russia Sternberg Institute of Astronomy, Russia Institute for Space Research, Russia

3. 10 - 3 SETN STN 2 STN 3 STN 1 LEND sensors of STN1-3 and SETN detect thermal neutrons and epithermal neutrons to characterize Lunar Radiation Environment. STN1 and STN3 operates as Doppler filter for thermal neutrons from front side and back side of LEND SETN and STN2 have open fields of view LRO velocity vector LEND Science Overview and Theory of Operations

4. 10 - 4 SHEN LEND sensor SHEN detects high energy neutrons at 16 energy channels from 300 keV to >15 MeV to characterize Lunar Radiation Environment SHEN has narrow field of view about 20-30  LEND Science Overview and Theory of Operations

5. 10 - 5 CSHEN 1 LEND collimated sensors CSETN1-4 detect epithermal neutrons with high angular resolution to characterize spatial variations of Lunar Neutron Albedo, which depend on content of hydrogen in 1- 2 m of the regolith CSHEN 2 CSHEN 3 epithermal neutrons LEND Science Overview and Theory of Operations H

6. 10 - 6 CSHEN 1 LEND collimated sensors CSETN1-4 and SHEN detect epithermal neutrons and high energy neutrons with high angular resolution to test water ice deposit on the surface CSHEN 2 CSHEN 3 epithermal neutrons LEND Science Overview and Theory of Operations high energy neutrons SHEN water ice

7. 10 - 7 HEND/Odyssey is LEND prototype with few design changes Plastic Anti-coincidence for Sensor of HEN Collimator of neutrons Larger counters of neutrons LEND Heritage

8. 10 - 8 LEND electronics has only one design change in respect to HEND Design Change LEND Heritage

9. 10 - 9 Project: LRO Program Requirements Document; ESMD-RLEP-0010 LRO Mission Requirements Document; 431-RQMT-00004 LRO Technical Resource Allocations; 431-RQMT-000112 Instrument: Instrument Payload Assurance Implementation PlanLEND PAIP 01 Instrument to Spacecraft Interface Control Documents Mechanical 431-ICD-000088 Thermal 431-ICD-000119 Electrical 431-ICD-000097 Data431-ICD-000107 Instrument Requirements Document LEND IRD 01 Contract documents with Russian Federal Space Agency Draft of LEND Implementation Agreement between NASA and FSA LEND Documentation

10. 10 - 10 LRO Req. Level 1: Requirements ESMD- RLEP-0010 Instrument LRO Mission Requirement Required Data Products (LEND Level 3 and 4) RLEP-LRO- M110 LENDThe LRO shall map hydrogen on the Moon's surface with 5 km spatial resolution at the poles for concentrations equal or greater than 100 ppm with 3-sigma confidence. The LRO shall obtain high spatial resolution hydrogen mapping of the Moon's surface to a 20% accuracy and 5 km resolution at the poles. LEND Surface Composition Data Product (LEND SCDP): LEND SCDP#1: Map of hydrogen composition with pixels of 2 km for northern area >60  N LEND SCDP#2: Map of hydrogen composition with pixels of 2 km for southern area >60  S LEND SCDP#3: Map of hydrogen composition with pixels of 5-10 km for equatorial belt between >60  N and >60  S Determine hydrogen content of subsurface at polar regions with spatial resolution from Half-Width Half-Maximum (HWHM)=5km and with variation sensitivity from 100 parts per million (ppm) RLEP-LRO- M070 LENDThe LRO shall identify putative deposits of appreciable surface or near surface water ice in the Moon’s polar cold traps at km’s 100m scale spatial resolution LEND Surface Composition Data Product (LEND SCDP): LEND SCDP#4: Map of water ice deposits with pixels of 2 km for northern area >60  N LEND SCDP#5: Map of water ice deposits with pixels of 2 km for southern area >60  S Develop maps of water ice column density on polar regions of the Moon with spatial resolution from 5-20km. RLEP-LRO- M010 LENDThe LRO shall characterize the deep space radiation environment in lunar orbit, including neutron albedo. LEND Radiation Data Products (LEND RDP): LEND RDP #1: Maps of thermal neutrons below 0.4 eV, epithermal neutrons at two energy ranges (0.4 eV – 3.0 keV) and (3 – 300 ) keV and maps of high energy neutrons at 16 energy channels from 300 keV up to 15 MeV for 52 time periods of 7 days LEND RDP #2: Time profiles of thermal neutrons below 0.4 eV, epithermal neutrons at two energy ranges (0.4 eV – 3.0 keV) and (3 – 300 ) keV and maps of high energy neutrons at 16 energy channels from 300 keV up to 15 MeV for each detected SPE LEND RDP #3 (optional, provided LEND-LRO R3# accepted): Angular distribution of epithermal and high energy neutron components of lunar space radiation environment from Nadir to Horizon at 15  steps Radiation Data Product for global distribution of neutrons at Moon’s orbit with spatial resolution of 50 km at different energy ranges from thermal energy up to >15 MeV separately for periods of quiet Sun and for periods of Solar Particle Events. LEND Mission Level Requirements

11. 10 - 11 Level 1 Req. Instrument Level 2 Requirements (LEND IRD 01) Concept/Realizability /Comment Requirement no. LEND Instrument Measurement Requirement M 110-LENDLEND IMR 1Measure global distribution of hydrogen in lunar subsurface; at polar regions provide spatial resolution from 5 km (Half-Width Half-Maximum, HWHM) and variation sensitivity with confident detection limit of 100 weight parts per million (ppm) Determine hydrogen content of subsurface at polar regions with spatial resolution from Half-Width Half- Maximum (HWHM)=5km and with variation sensitivity from 100 parts per million (ppm) LEND has imaging capability for lunar flux of epithermal neutrons (collimated sensors CSETN 1-4), which variations are the most pronounced signature of hydrogen content in the subsurface layer of 1-2 meters M 070-LENDLEND IMR 2Measure or estimate upper limit of water ice column density on polar regions of the Moon with spatial resolution of 5-20 km Develop maps of water ice column density on polar regions of the Moon with spatial resolution from 5-20km. LEND has imaging capability for lunar flux of epithermal neutrons (collimated sensors CSETN 1-4) and high energy neutrons (sensor SHEN): relationship of variations of these neutrons provides the signature of water ice deposits on polar regions of Mars M 10-LENDLEND IMR 3Measure global distribution of neutrons at Moon’s orbit with spatial resolution of 50 km at different energy ranges from thermal energy to >15 MeV separately for periods of quiet Sun and for periods of Solar Particle Events Radiation Data Product for global distribution of neutrons at Moon’s orbit with spatial resolution of 50 km at different energy ranges from thermal energy up to >15 MeV separately for periods of quiet Sun and for periods of Solar Particle Events. LEND has the necessary-and-sufficient set of sensors for entire energy range from thermal energy domain to 15 MeV and higher, which allow to build up comprehensive physical model of neutron component of radiation environment both for quiet Sun period and for episodes of SPE LEND Instrument System Level Requirements

12. 10 - 12 Level 2 Req. Instrument Level 2a Requirements (LEND IRD 01)Concept/Realizability/Comment Requirement no. LEND Instrument Functional Requirement LEND IMR 1 LEND FR 1Measure epithermal neutrons by 4 similar collimated sensors with counting rate about 0.3 counts/sec within narrow FOV, which allows to detect polar spot with 100 ppm of hydrogen and radius of 5 km at 3-sigma confidence Narrow FOV of CSETN 1-4 is produced by passive collimator module from 10 BC 4 and polyethylene; realizability to be proved by Monte Carlo numerical modeling and physical tests of laboratory prototype unit LEND IMR 2 LEND FR 2Measure high energy neutrons by narrow field sensor at 16 energy channels from 300 keV to > 15 MeV SHEN has plastic anti-coincidence shield to reject counts from charge particles; narrow field of view is produced by center hole of collimator module for counters CSETN 1-4 (*. Joint analysis of data from CSETN 1-4 (FR 1) and from scintillator SHEN (FR 2) allows to detect layering structure of water ice deposits LEND IMR 3 LEND FR 2See aboveSee above (* LEND FR 3Measure thermal neutrons by two Doppler-filter sensors Signal of Doppler filter, which is subtraction of counts of front side counter STN 1 from counts of back side counter STN 3, exclude local background of spacecraft LEND FR 4Measure thermal neutrons by open-field sensorCounter SETN has Cd enclosure and its counts rate characterizes total flux of epithermal neutrons at the orbit. Difference of counts from STN 2 and SETN characterizes total flux of thermal neutrons at the orbit LEND FR 5Measure epithermal neutrons by open field sensor LEND Instrument System Level Requirements

13. 10 - 13 Level 2 Req. Instrument Level 3 Requirements (LEND IRD 01) Concept/Realizability /Comment Requirement no. LEND Instrument Design Requirement LEND FR 1 L3-DR 01Measure epithermal neutrons with counting rate about 0.3 counts/sec inside FOV of about 5.6  at each collimated counter CSETN 1-4 Monte Carlo simulations show that optimal design of collimator together with appropriate selection of 3 He counter of neutrons allow to obtain necessary counting rate for SETN 1-4 sensors within allocated mass (see backup page TBD). Selected prototype for counters is LND 25311. LEND FR 3, 4 and 5 L3-DR 02Measure thermal and epithermal neutrons in CTN 1-3 and SETN with counting rate about 10 cts/sec Monte Carlo simulation of lunar neutron albedo allows to select necessary type of 3 He counters for STN 1-3 and SETN for getting this counting rate. Selected prototype for counters is LND 25311. LEND FR 1, 3-5 L3-DR 03Provide signal processing from counters CSETN 1-4, STN 1-3 and SETN Each signal will be digitized in 16 channels of amplitude and loaded into corresponding place of LEND telemetry frame (HEND heritage) L3-DR 04Provide changeable HV about 2 kV for counters CSETN 1-4, STN 1-3 and SETN Turn on/off and Levels of HV may be operated individually for each counter (HEND heritage) LEND Instrument System Level Requirements

14. 10 - 14 Level 2 Req. Instrument Level 3 Requirements (LEND IRD 01)Concept/Realizability/Comment Requirement no. or para. LEND Instrument Design Requirement LEND FR 2L3-DR 05Provide changeable HV about 2 kV for PMT of SHEN HEND heritage L3-DR 06Distinguish SHEN counts from neutrons and counts from gamma-rays Pulse-shape analyzer will be used for signal from PMT, which allows to separate counts from proton (detection of neutron) from electron (detection of gamma-ray) with probability of mistake less than 10 -3 (HEND heritage) L3-DR 07Measure high energy neutrons at the energy range (300 keV, >15 MeV) with counting rate about 0.3 cts/sec Monte Carlo simulation of lunar neutron albedo allows to select size of sthylbene scintillation sensor SETN for getting this counting rate within narrow FOV (HEND heritage). L3-DR 08Provide 2 signals (neutrons and gammas) processing in 16 energy channels Each signal will be digitized in 16 channels of amplitude and loaded into corresponding place of LEND telemetry frame (HEND heritage) L3-DR 09Provide anti-coincidence shielding for SHEN for exclusion detection of external charge particles Sthylbene crystal will be surrounded by plastic scintillator with photo-diodes read-out, which generates veto anti-coincidence signal for each crossing charge particle (HEND heritage) LEND Instrument System Level Requirements

15. 10 - 15 LEND Data DescriptionRequired Input LEND Level 0 Unprocessed LEND rough telemetry data with science measurements, instrument housekeeping information. Spacecraft LEND-related data Spacecraft LEND-related data LEND Level 1 LEND sensors counting rate, LEND physical calibration data, spacecraft trajectory and pointing data, LEND sensors counting rate from background, solar activity data Spacecraft timing, trajectory and pointing data, spacecraft data for fuel consumption, CRaTER level TBD data, GOES solar data LEND level 2 LEND neutron mapping data (flux of neutrons per pixel) and/or time profiles with integration time and pixelization individually selected for each sensor LOLA level TBD data, Diviner level TBD data LEND level 3 LEND Surface Composition Data Product (LEND SCDP): LEND SCDP#1: Map of hydrogen composition with pixels of 2 km for northern area >60  N LEND SCDP#2: Map of hydrogen composition with pixels of 2 km for southern area >60  S LEND SCDP#3: Map of hydrogen composition with pixels of 5-10 km for equatorial belt between 60  N and 60  S LEND SCDP #4: Map of water ice deposits with pixels of 2 km at northern area > 80  N LEND SCDP #5: Map of water ice deposits with pixels of 2 km at southern area > 80  S LOLA level TBD data, Diviner level TBD data, LAMP level TBD data LEND level 4 LEND Radiation Data Products (LEND RDP): LEND RDP #1: Maps of thermal neutrons below 0.4 eV, epithermal neutrons at two energy ranges (0.4 eV – 3.0 keV) and (3 – 300 ) keV and maps of high energy neutrons at 16 energy channels from 300 keV up to 15 MeV for 52 time periods of 7 days LEND RDP #2: Time profiles of thermal neutrons below 0.4 eV, epithermal neutrons at two energy ranges (0.4 eV – 3.0 keV) and (3 – 300 ) keV and maps of high energy neutrons at 16 energy channels from 300 keV up to 15 MeV for each detected SPE CRaTER level TBD data LEND Data Product Traceability

16. 10 - 16 RLEP-LRO RequirementLEND measurement requirementsLRO requirement driven by LEND RLEP-LRO-M110: The LRO shall map hydrogen on the Moon's surface with 5 km spatial resolution at the poles for concentrations equal or greater than 100 ppm with 3-sigma confidence. LEND IMR 1: Measure global distribution of hydrogen in lunar subsurface; at polar regions provide spatial resolution from 5 km (Half-Width Half-Maximum, HWHM) and variation sensitivity with confident detection limit of 100 weight parts per million (ppm) LEND-LRO R#1: For neutron mapping measurements provide continuously pointing of LEND collimated detectors into nadir direction RLEP-LRO-M70: The LRO shall identify putative deposits of appreciable surface or near surface water ice in the Moon’s polar cold traps at km’s scale spatial resolution LEND IMR 2: Measure or estimate upper limit of water ice column density on polar regions of the Moon with spatial resolution of 5-20 km The same LEND-LRO R#1 (see above) RLEP-LRO-M10: The LRO shall characterize the deep space radiation environment in lunar orbit, including neutron albedo. LEND IMR 2: Measure global distribution of neutrons at Moon’s orbit with spatial resolution of 50 km at different energy ranges from thermal energy to >15 MeV separately for periods of quiet Sun and for periods of Solar Particle Events The same LEND-LRO R#1 (see above) LEND-LRO R#2: Operate LEND constantly from cruise orbit insertion during the entire mission LEND-LRO R#3: Provide opportunity for sessions of special measurements with different angles of collimated detectors from Nadir to Horizon (suggested, as optional. in addition to baseline mission scenario, provides additional LEND Data Product LEND RDP #3) LRO Requirements Driven by LEND

17. 10 - 17 LEND Constraints on LRO TitleRequirementRationaleTraceability Stereo Imaging Require 15° to 20° off-point down-track or cross-track for stereo imaging three times a day. Stereo image of same ground spot under similar lighting conditions. Issue with LOLA’s coverage spec regarding time off-nadir (less than 3% of total time). Working issue. Thermally OK for 20° off-point for 20 minutes total. Stereogrammetric and photometric stereo data set generation (RLEP- LRO-M40) Mosaickin g Off-nadir pointing to get contiguous coverage over wider ground swath three times a day. Off- pointing requests would range from 2° to 20°. Allow acquisition of contiguous NAC swaths to cover entire landing site error ellipses and region of surface operations. Landing Site safety (RLEP-LRO-M80) Data LinkLROC shall receive all commanding and distribute all telemetry over the SpaceWire high speed bus. Simplify spacecraft to instrument interface at GSFC request Science requirements for high resolution, high temporal resolution, etc. data require high bandwidth download (RLEP-LRO-M40, M80, M90, M100) Data RateLROC shall write 8 bit data to the Transmit FIFO at a clock rate for the SpaceWire STROBE signal of 40MHz without invocation of Transmit FIFO flow control. Required to deliver NAC data from SCS to use up downlink allocation, maximize science return, avoid data loss (heritage design does not use flow control). See Data ICD (RLEP-LRO-M40, M80, M90, M100) Mass Allocation 16.5 kg with marginIncludes 20% contingency over CBE.Based on proposal estimates Science FOV NAC: 2.86° per NAC, total 5.7° crosstrack. WAC: 90° crosstrack. Required for swath width(RLEP-LRO-M40, M80, M90, M100)

18. 10 - 18 LEND Block Diagram

19. 10 - 19 LEND units Stages of LEND development Functional Req. Design Req. LRO Env. Req. LRO Integration LEND LULEND QU LEND FU01 LEND FU02 LEND EU Laboratory tests with neutron sources and numerical simulations Laboratory tests with neutron sources, verification tests for LRO environment requirements Qualification tests for LRO environment requirements Acceptance tests for LRO environment requirements Integration tests onboard LRO LEND Development Flow

20. 10 - 20 Reliability Analyses (RA) Failure Modes, Effects and Criticality Analysis (FMECA) Electronic Parts Stress Analysis (PSA) Thermal Stress Analysis Structural Stress Analysis Single Event Effects Analysis (SEE) Screening of all electrical, electronic and electromechanical parts (SEEE) Preparation of Confirmation Lists of Material and Components (CLMC) Environmental Requirements (ER) Radiation durability analysis Random vibration and shock tests Thermal vacuum test Electromagnetic compatibility tests Thermal cycling life test Contamination Control (CC) Preparation of Problem/Failure Anomaly Report (PFAR) Accumulation of Hardware Operating Hours prior delivery (HO) List of Procedures and Verification Tests

21. 10 - 21 Trade studies which have been closed Concept of LEND configuration Electrical interface design Selection of sensors and major electronic components Concept of thermal design Concept of mechanical design Manufacturing documentation for LEND LU Cooperation in Russia for LEND manufacturing Outgoing trade studies Optimization of collimator unit of SETN 1-4 for the best sensitivity for 5 km radius spot at pole with enhancement of H Optimization of narrow field of view for detector of high energy neutrons SHEN Thermal model of instrument Analysis currently being performed Numerical model of Moon neutron albedo at different energy ranges Estimation of instrument fundamental frequency ( > 75 Hz) Software for data processing of LEND LU Hardware currently in development Mechanical elements of LEND LU Collimator units of LEND LU Electronic boards of LEND LU 7. What is the status of the agreements? LEND Current Status

22. 10 - 22 NameWork20042005200620072008 LUDevelopment Testing&verification EISDevelopment Testing&verification Delivery EUDevelopment Testing&verification Delivery QUDevelopment Testing&verification Calibrations FU01Development Testing&verification Calibrations Delivery FU02Development Testing&verification Calibrations Delivery LEND Development Milestones

23. 10 - 23 1.LEND is developing in response to RLEP-LRO M010, M070 and M110: corresponding flows from LRO Mission requirements to LEND Functional Requirements and Design Requirements are well understood 2.Data Products of LEND are defined, which correspond to RLEP-LRO M010, M070 and M110 3.LEND development process ensures that LEND Flight Unit will provide defined Data Products 4.LEND accommodation on LRO ensures that LEND will be able to provide defined Data Products 5.There is only one additional requirement to LRO driven by LEND (measurements at different angles from Nadir to Horizon) which is not presented in the mission baseline. This operation provides additional data products on Lunar Radiation Environment (angular distribution of neutron component) 6. LEND team is ready to move to the preliminary design stage 7. What is the status of the agreements? Summary