10 - 1

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

STN 1
SETN
STN 2
STN 3
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
10 - 3

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

SHEN
10 - 4

H
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 epithermal neutrons
CSHEN 2
CSHEN 1
CSHEN 3
10 - 5

water ice
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 epithermal neutrons high energy neutrons
CSHEN 2
CSHEN 1
CSHEN 3
SHEN
10 - 6

Plastic Anti-coincidence for Sensor of HEN
Collimator of neutrons
Larger counters of neutrons
10 - 7

Design Change
10 - 8

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

LRO
Req.
ESMD-
RLEP-0010
RLEP-LRO-
M110
RLEP-LRO-
M070
RLEP-LRO-
M010
Level 1: Requirements
Instrument
LEND
LEND
LEND
LRO Mission
Requirement
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.
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.
The 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
The LRO shall characterize the deep space radiation environment in lunar orbit, including neutron albedo.
Required Data Products (LEND Level 3 and 4)
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)
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.
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
10 - 10
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

Level 1 Req.
M 110-LEND
M 070-LEND
M 10-LEND
Instrument Level 2 Requirements
(LEND IRD 01)
Concept/Realizability
/Comment
Requirement no.
LEND IMR 1
LEND IMR 2
LEND IMR 3
LEND Instrument Measurement Requirement
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)
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)
Measure 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.
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
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 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
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
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
10 - 11

Level 2
Req.
LEND
IMR 1
LEND
IMR 2
LEND
IMR 3
Instrument Level 2a Requirements
(LEND IRD 01)
Requirement no.
LEND FR 1
LEND Instrument Functional
Requirement
Measure 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
LEND FR 2
LEND FR 2
LEND FR 3
LEND FR 4
LEND FR 5
Concept/Realizability/Comment
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
Measure high energy neutrons by narrow field sensor at 16 energy channels from 300 keV to >
15 MeV
See above
Measure thermal neutrons by two Doppler-filter sensors
Measure thermal neutrons by open-field sensor
Measure epithermal neutrons by open field sensor
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
See above (*
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
Counter 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
10 - 12

Level 2
Req.
LEND FR
1
LEND FR
3, 4 and 5
LEND FR
1, 3-5
Requirement no.
L3-DR 01
L3-DR 02
L3-DR 03
L3-DR 04
Instrument Level 3 Requirements
(LEND IRD 01)
Concept/Realizability
/Comment
LEND Instrument Design
Requirement
Measure epithermal neutrons with counting rate about 0.3 counts/sec inside FOV of about 5.6
 at each collimated counter CSETN 1-4
Measure thermal and epithermal neutrons in CTN 1-3 and SETN with counting rate about 10 cts/sec
Provide signal processing from counters
CSETN 1-4, STN 1-3 and SETN
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.
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.
Each signal will be digitized in 16 channels of amplitude and loaded into corresponding place of LEND telemetry frame (HEND heritage)
Provide 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)
10 - 13

Instrument Level 3 Requirements
Level 2
Req.
Requirement no. or para.
LEND FR 2 L3-DR 05
(LEND IRD 01)
LEND Instrument Design
Requirement
Provide changeable HV about 2 kV for
PMT of SHEN
L3-DR 06
L3-DR 07
L3-DR 08
L3-DR 09
Concept/Realizability/Comment
HEND heritage
Distinguish SHEN counts from neutrons and counts from gamma-rays
Measure high energy neutrons at the energy range (300 keV, >15 MeV) with counting rate about 0.3 cts/sec
Provide 2 signals (neutrons and gammas) processing in 16 energy channels
Provide anti-coincidence shielding for
SHEN for exclusion detection of external charge particles
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)
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).
Each signal will be digitized in 16 channels of amplitude and loaded into corresponding place of
LEND telemetry frame (HEND heritage)
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)
10 - 14

LEND
Data
LEND Level 0
LEND Level 1
LEND level 2
LEND level 3
LEND level 4
Description Required Input
Unprocessed LEND rough telemetry data with science measurements, instrument housekeeping information. Spacecraft LEND-related data
Spacecraft LEND-related data
LEND sensors counting rate, LEND physical calibration data, spacecraft trajectory and pointing data, LEND sensors counting rate from background, solar activity data
LEND neutron mapping data (flux of neutrons per pixel) and/or time profiles with integration time and pixelization individually selected for each sensor
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
Spacecraft timing, trajectory and pointing data, spacecraft data for fuel consumption, CRaTER level
TBD data, GOES solar data
LOLA level TBD data, Diviner level TBD data
LOLA level TBD data, Diviner level TBD data, LAMP level TBD data
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
10 - 15

RLEP-LRO Requirement
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 measurement requirements LRO requirement driven by
LEND
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
RLEP-LRO-M10: The LRO shall characterize the deep space radiation environment in lunar orbit, including neutron albedo.
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
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)
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)
10 - 16

Title
Stereo
Imaging
Mosaickin g
Data Link
Requirement
Require 15 ° to 20° off-point down-track or cross-track for stereo imaging three times a day.
Off-nadir pointing to get contiguous coverage over wider ground swath three times a day. Offpointing requests would range from 2 ° to 20°.
LROC shall receive all commanding and distribute all telemetry over the SpaceWire high speed bus.
Rationale
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.
Allow acquisition of contiguous NAC swaths to cover entire landing site error ellipses and region of surface operations.
Simplify spacecraft to instrument interface at
GSFC request
Data Rate LROC 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.
Mass
Allocation
16.5
kg with margin
Traceability
Stereogrammetric and photometric stereo data
set generation (RLEP-
LRO-M40)
Landing Site safety
(RLEP-LRO-M80)
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).
Includes 20% contingency over CBE.
Science requirements for high resolution, high temporal resolution, etc. data require high bandwidth download
(RLEP-LRO-M40, M80,
M90, M100)
See Data ICD
(RLEP-LRO-M40, M80,
M90, M100)
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)
10 - 17

LEND
Sensor
SETN
SETN/FRE
Sensor
STN1
HV1
STN1/FRE
Sensor
STN2
HV2
STN2/FRE
Sensor
STN3
HV3
STN3/FRE
Sensor
CSETN1
HV4
CSETN1/FRE
Sensor
CSETN2
HV5
CSETN2/FRE
Sensor
CSETN3
HV6
CSETN3/FRE
Sensor
CSETN4
HV7
CSETN4/FRE
HV8
HV9
SC/N/SA
Sensor
SC/N
Stilbene
Sensor
SC/AC
SC/N/
FRE&S
SC/AC/
FRE
LEND
Instrument
Main
Structure
HV1
HV2
HV3
HV4
HV5
HV6
HV7
HV8
HV9
HV/
STN/
CSETN
4
Actel FPGA (RTAX series)
Neutron
Energy
Code
G/N
N/G ACS
Block
High
Voltages
Values
IC
RAM
LVP
Heaters
Control
IO Drivers Redundant MIL-STD-1553B
ADC
TCS
Clock
Generator
10 - 18

Laboratory tests with neutron sources and numerical simulations
LEND LU
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 EU LEND QU LEND FU01 LEND FU02
LEND units
10 - 19

•
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)
10 - 20

• 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?
10 - 21

2004 2005 2006 Name
LU
EIS
EU
QU
FU01
FU02
Work
Development
Testing&verification
Development
Testing&verification
Delivery
Development
Testing&verification
Delivery
Development
Testing&verification
Calibrations
Development
Testing&verification
Calibrations
Delivery
Development
Testing&verification
Calibrations
Delivery
2007 2008
10 - 22

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?
10 - 23