Attachment B LMXPORD 418 XOLMXPORD 0120 Version 1.0.pdf

Effective Date: June 29, 2023 418-XO-LMXPORD-0120 Responsible Organization: GeoXO Flight Project/Code 418 Baseline Version 1.0

To verify the correct version of this document, please contact the GeoXO Series Configuration Management Office.

Geostationary Extended Observations (GeoXO) Lightning Mapper (LMX)

Performance and Operational Requirements Document (PORD) Signature page

Prepared by:

Electronically approved by: 06/26/2023

Ruth W. Cholvibul Date GeoXO Flight Project, Instrument Systems Engineer NASA GSFC, Code 418

Reviewed by:

Electronically approved by: 06/14/2023

Sivakumara K. Tadikonda Date GeoXO Flight Project, Deputy Mission Systems Engineer

Electronically approved by: 06/28/2023

Tina Gentry Date GeoXO Flight Project, Instrument Manager

Approved by:

Electronically approved by: 06/28/2023

Steve Bidwell Date GeoXO Flight Project, Mission Systems Engineer

Effective Date: June 29, 2023 418-XO-LMXPORD-0120 Responsible Organization: GeoXO Flight Project/Code 418 Baseline Version 1.0

To verify the correct version of this document, please contact the GeoXO Series Configuration Management Office.

Approved by:

Electronically approved by: 06/29/2023

Monica Todirita Date GeoXO Flight Project, Deputy Project Manager NOAA GSFC, Code 418

/GeoXO Flight Project LMX Lightning Mapper

LMXPORD

418-XO-LMXPORD-0120, RM Version, Geostationary eXtended Observations (GeoXO) Lightning Mapper (LMX) Performance and Operational Requirements Document (PORD) Phase B

Version: 1.0 Printed by: rkhoover Printed on: Thursday, June 29, 2023

No filter applied.

No sort applied.

Generated from DOORS 9.7.2.4

Contents

1 1Scope

1.1 1Identification

1.2 1Mission Review

1.3 1Document Overview

1.4 1Terminology

1.5 2Definitions

1.6 5Requirements Applicability

2 6Documents

2.1 6Applicable Documents

2.2 6Reference Documents

3 8Sensor Requirements

3.1 8Functional Requirements

3.1.1 8LMX Modes

3.1.1.1 8Safe Mode

3.1.1.2 8Normal Operational Mode

3.1.1.3 8Diagnostic Mode

3.1.1.4 9Survival Mode

3.1.1.5 9Mode Transitions and Commands

3.1.2 10On-Orbit Operations

3.1.2.1 10Operational Zone

3.1.2.1.1 10Zones of Reduced Data Quality (ZRDQ)

3.1.2.2 10Imaging the Sun

3.1.2.3 10Eclipse

3.1.2.4 10Operations After Maneuvers

3.1.2.4.1 10Yaw Flip

3.1.2.4.2 10Station Keeping

3.1.2.4.3 10Post Storage Activation

3.1.2.5 11Outgas Period

3.2 11Performance Requirements

3.2.1 11Coverage

3.2.1.1 11Coverage Rate

3.2.1.2 11Simultaneity

3.2.1.3 11Data Latency

Project: GeoXO Flight Project LMX Lightning Mapper Module: LMXPORD Baseline Version: 1.0

Contents ii

3.2.1.4 11Data Collection Output

3.2.1.5 12Lightning Event Detection

3.2.1.6 13Spectral Response

3.2.1.7 14SNR

3.2.1.8 14Saturation

3.2.1.9 15Ringing from a Sharp Edge

3.2.1.10 15Spatial Resolution

3.2.2 15Event Navigation

3.2.2.1 15Navigation Performance Requirements

3.2.2.2 16Star Sensing

3.2.2.3 16Reserved

3.2.2.4 16Lossless Data Compression

4 17Design Requirements

4.1 17Reliability

4.2 17Redundancy

4.2.1 17Redundant Component Selectabiltiy

4.2.2 17Interchangability of Flight Model Units

4.2.3 17Reserved

4.3 17Mechanical Requirements

4.3.1 17Design Limit Loads

4.3.2 18Yield Strength

4.3.3 19Ultimate Strength

4.3.4 19Unit Stiffness

4.3.5 19Critical Members Design Values

4.3.6 19Redundant Members Design Values

4.3.7 19Selective Design Values

4.3.8 19Fracture Control

4.3.9 20Mechanisms

4.3.10 21Pressurized Units

4.3.11 21Alignment Reference

4.3.12 21Precision Component Assembly

4.4 21Thermal Requirements

4.4.1 21Mission Allowable Temperatures

4.4.2 22Thermal Gradients

4.4.3 22Non-Operational Temperatures

4.4.4 22Thermal Control Hardware

4.4.5 22Detector Cooling Margin

Contents iii

4.4.6 22Radiator

4.4.7 23Heat Pipe (Two-phase Heat Transfer Device)

4.5 23Power Requirements

4.5.1 23Power Regulators and Supplies

4.5.2 24Fuses

4.5.3 24Covers for test Connectors

4.5.4 24Keyed Connectors

4.6 24Onboard Processors Requirements

4.6.1 24Flight Load Non-Volatile Memory

4.6.2 24Commandable Reinitialization

4.6.3 24Deterministic Power-on Configuration

4.6.4 24Fail-safe Recovery Mode

4.7 24Flight Software Requirements

4.7.1 24Language and Methodology

4.7.2 24Flight Software Upload

4.7.3 25Flexibility and Ease of Software Modification

4.7.4 25Version Identifiers

4.7.5 25Flight Processor Resource Sizing

4.7.6 26Software Event Logging

4.7.7 26Warm Restart

4.7.7.1 26Processor Re-Start

4.7.7.2 26Autonomous Re-Start

4.7.8 27Memory Integrity

4.7.8.1 27Memory Verification

4.7.8.2 27Bit Error Detection and Correction

4.7.9 27Memory Dump

4.7.10 27Telemetry Cadence and Dwell Control

4.7.11 27Long-Duration Test

4.7.12 27Unnecessary and Unreachable Software

5 28Ground Support Equipment and Development

5.1 28Electrical System Test Equipment

5.2 28Flight Software Development Environment

5.3 28Ground Processing Demonstration System

5.4 29FM and GSE Shipping Containers

6 30LMX Simulators

6.1 30LMX Instrument Hardware Simulator (LMX-IHS)

6.2 30LMX Instrument Software Simulator (LMX-ISS)

Contents iv

7 32FM Design Verification Requirements

7.1 32Powered-on Operating Time and Trouble-Free Performance Testing

7.2 32Structural and Mechanical Verification Requirements

7.2.1 32Mechanical Test Factors and Duration

7.2.2 35Minimum Workmanship

7.2.3 35Testing in Flight Configuration

7.2.4 35Structural Proof Testing

7.2.5 36Modal Survey Characterization

7.2.6 36Structural Qualification

7.2.7 36Deployment and Articulation Verification

7.2.8 36Life Test

7.2.9 37Mechanical Clearance Verification

7.3 37Electromagnetic Compatibility Verification

7.3.1 37General

7.3.2 37Electrostatic Arc-Discharge Susceptibility

7.3.2.1 37External Surface-to-Surface direct discharge

7.3.2.2 37Deep Dielectric Charging

7.3.2.3 37ESD Characteristics

7.4 38Thermal Test Requirements

7.4.1 38General

7.4.1.1 38Thermal Test Chronology

7.4.1.2 38Pressure

7.4.2 39Thermal Vacuum

7.4.2.1 39Transition Rates

7.4.2.2 39Corona Operation

7.4.2.3 39Hot and Cold Start Demonstrations

7.4.2.4 39Heater Verification

7.4.2.5 40Flight Temperature Sensor Verification

7.4.3 40TV Thermal Cycling

7.4.3.1 40Cumulative Cycles

7.4.3.2 40Ambient Pressure Thermal Cycling Substitution

7.4.3.3 40Qualification, Protoflight and Acceptance Temperatures

7.4.3.4 41Survival Heater Verification

7.4.3.5 41Temperature test tolerances

7.4.3.6 41Plateau Criteria

7.4.4 42Thermal Balance (TB)

7.4.4.1 42Balance Points

7.4.4.2 42Instrument Configuration

Contents v

7.4.4.3 42Accuracy and Knowledge

7.4.4.4 42Steady State Criteria

7.5 43Test Condition Tolerances

8 45Acronyms

Contents vi

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ID

LMXPORD1

LMXPORD2

LMXPORD3

LMXPORD4

LMXPORD5

LMXPORD6

LMXPORD7

LMXPORD8

LMXPORD9

LMXPORD10

LMXPORD11

LMXPORD12

LMXPORD13

LMXPORD14

LMXPORD15

LMXPORD16

Object Number

1.1

1.1.0-1

1.2

1.2.0-1

1.2.0-2

1.2.0-3

1.2.0-4

1.3

1.3.0-1

1.4

1.4.0-1

1.4.0-2

1.4.0-3

1.4.0-4

1.4.0-5

418-XO-LMXPORD-0120, RM Version, Geostationary eXtended Observations (GeoXO) Lightning Mapper (LMX) Performance and

Operational Requirements Document (PORD) Phase B

1 Scope

1.1 Identification

This Performance and Operational Requirements Document (PORD) sets forth the performance requirements for the National Oceanic and Atmospheric Administration (NOAA) GeoXO (Geostationary eXtended Observations) Lightning Mapper (LMX) instrument.

1.2 Mission Review

The LMX is a single spectral channel instrument used to measure the location and intensity of optical transients produced by lightning as part of a 3-axis stabilized, geostationary satellite system. The LMX remotely collects data over the Earth disk visible from geostationary orbit for severe weather forecasting, hazard warning, and public safety alerts.

The LMX objective is to provide NOAA Lightning Mapper operational data that will be used by NOAA and other public and private agencies to produce forecasts of severe weather and to issue warnings for public safety.

The LMX provides data to the Ground System via the spacecraft communication system. The Ground System takes the LMX data, spacecraft telemetry data, orbit determination data and other required information and autonomously generates radiometrically calibrated and navigated data (Level 1b data) for the NOAA users.

The Ground System will be procured by the Government but will implement algorithms developed by the LMX contractor to satisfy performance requirements.

The Ground System will calibrate and then resample the data to generate the fixed grid. Resampling requires that the raw imagery be adequately sampled to maintain radiometric accuracy after resampling.

1.3 Document Overview

This document contains all performance requirements for the LMX instrument and Ground Support Equipment (GSE). This document, the General Interface Requirements Document (GIRD) and the LMX Unique Instrument Interface Document (UIID) define all instrument to spacecraft interfaces for the LMX instrument.

1.4 Terminology

The use of “shall” designates a requirement that must be met.

The use of “should” designates good practice.

The use of “will” designates a statement of fact or intention of the Government.

The use of "may" designates that permission has been granted by the Government.

The term “(TBD)” means “to be determined” and is used when no value is available, and subsequent Contractor study will be needed to obtain it.

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ID

LMXPORD17

LMXPORD18

LMXPORD19

LMXPORD20

LMXPORD21

LMXPORD22

LMXPORD23

LMXPORD24

LMXPORD25

LMXPORD26

LMXPORD1341

LMXPORD27

LMXPORD28

LMXPORD29

LMXPORD30

Object Number

1.4.0-6

1.4.0-7

1.5

1.5.0-1

1.5.0-2

1.5.0-3

1.5.0-4

1.5.0-5

1.5.0-6

1.5.0-7

1.5.0-8

1.5.0-9

1.5.0-10

1.5.0-11

1.5.0-12

418-XO-LMXPORD-0120, RM Version, Geostationary eXtended Observations (GeoXO) Lightning Mapper (LMX) Performance and

Operational Requirements Document (PORD) Phase B

The term "(TBR)" means "to be refined/reviewed" for a value that is subject to review for appropriateness and is subject to revision. The Contractor is liable for compliance with the information marked "TBR" as if the "TBR" notation did not exist.

Reserved

1.5 Definitions

Throughout this document, the following definitions apply:

Accuracy: Refers to the error in a measurement that is the difference between the measurement result and the object to be measured (the measured or true value).

It includes both systematic and random errors. Systematic errors must be estimated from an analysis of the experimental conditions and techniques.

Random errors can be determined, and reduced, through repeated measurements under identical conditions.

Albedo: Refers to the fraction of the solar spectrum taken from the default MODTRAN solar irradiance file, version 4V1R1 (newkur.dat) that is reflected by the Earth at the top of the atmosphere assuming a Lambertian surface.

Background: Best estimate of the current mean radiometric value of a detector sample.

Background Image: A scene composed of the background from all detector elements in the focal plane.

Channel: A measurement that is an aggregate of one or more spectral samples that meets or exceeds LMX requirements.

Collection: The set of all frames from all telescopes for a single integration period.

Credible Failure: A failure condition that has a reasonable likelihood of occurrence over the mission life. With consideration of reliability analysis and engineering experience, the Government technical authority will determine credibility of failure.

For the purposes of this document, failures of structure, pressure vessels, and pressurized lines and fittings are not considered credible failure modes if those elements comply with the applicable requirements of this document.

Detector noise: 1-sigma noise level required to meet the Signal-to-Noise Ratio (SNR) specification.

Detector sample or element: Refers to the output of a physical detector after the Analog-to-Digital Converter (ADC).

Eclipse: Defined as when the solar disk is completely occulted by the Earth or Moon, as viewed from the GeoXO satellite.

Event: The occurrence of a detector sample exceeding the threshold (not to be confused with event logging or event messages) due to a signal transient. Events may include but are not limited to:

a) Optical lightning events

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ID

LMXPORD30

LMXPORD148

LMXPORD31

LMXPORD32

LMXPORD33

LMXPORD35

LMXPORD149

LMXPORD150

LMXPORD36

LMXPORD151

Object Number

1.5.0-12

1.5.0-13

1.5.0-14

1.5.0-15

1.5.0-16

1.5.0-17

1.5.0-18

1.5.0-19

1.5.0-20

1.5.0-21

418-XO-LMXPORD-0120, RM Version, Geostationary eXtended Observations (GeoXO) Lightning Mapper (LMX) Performance and

Operational Requirements Document (PORD) Phase B

b) Radiation-induced events

c) Surface glint-induced events

d) Electronic noise-induced events

e) Jitter-Induced events

f) Crosstalk

Fixed-Grid Angles: Refers to North/South (NS) and East/West (EW) Euler angles defined as follows. Starting with the orbit reference frame (ORF) in GIRD62 at the ideal satellite location, a positive NS angle is a rotation of the ORF about its +x axis, and a positive EW angle is a subsequent rotation of the rotated frame about its +y axis. The +z axis of the final frame is the line of sight (LOS) represented by the EW and NS fixed-grid angles.

Fixed Grid: Refers to a set of points in fixed-grid angle space that are uniformly-spaced in both coordinates and that define locations in a nadir-centered field of view from the perspective of an ideally-located satellite in geosynchronous orbit.

The fixed grid for LMX has the following characteristics:

a) Each point in the fixed grid designates the center of a pixel;

b) The EW and NS angular spacing of the fixed grid is consistent with

LMXPORD134;

c) The ideal sub-satellite point is at the corner of a pixel on the fixed grid.

Fully Functional Configuration: Being able to perform the following functions:

Lightning optical event detection, sensor health and status data acquisition, CCSDS packet generation (science, health and status data) plus command reception and execution.

Frame: The set of all samples from one focal plane array for a single integration period.

Reserved

Level 0 Data: Raw data reconstructed to unprocessed instrument data at full space-time resolution with all available supplemental information to be used in subsequent processing (e.g. ephemeris, health and safety) appended.

Level 1a Data: Unpacked, reformatted and resampled Level 0 data with all supplemental information to be used in subsequent processing appended. Data generally presented as full space/time resolution. A wide variety of sub-level products are possible.

Level 1b Data: Unpacked, reformatted, and resampled Level 0 data with all supplemental information to be used in subsequent processing appended.

Radiometric and geometric correction applied to produce parameters in physical units. Data generally presented as full space/time resolution. For LMX these are optical lightning events that have been time-tagged, calibrated, and navigated (to the fixed grid) with latitude and longitude information appended. Also for LMX, latitude and longitude will be relative to a fixed reference such as the GRS80 geoid or the lightning ellipsoid.

Level 2+ Data: Retrieved environmental variables and higher products. For LMX these are lightning groups and flashes.

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ID

LMXPORD152

LMXPORD153

LMXPORD37

LMXPORD38

LMXPORD154

LMXPORD39

LMXPORD40

LMXPORD41

Object Number

1.5.0-22

1.5.0-23

1.5.0-24

1.5.0-25

1.5.0-26

1.5.0-27

1.5.0-28

1.5.0-29

418-XO-LMXPORD-0120, RM Version, Geostationary eXtended Observations (GeoXO) Lightning Mapper (LMX) Performance and

Operational Requirements Document (PORD) Phase B

Lightning Full Disk (LFD): Defined as coverage area per LMXPORD109

Mission Allowable Temperatures (MAT): Mission Allowable Temperatures are the established range of temperatures that instrument units are permitted to experience while operating in orbit. MAT are established based upon analytical temperature predictions with appropriate margin based on the state of the thermal design. MAT encompasses worst-case operating temperature predictions, uncertainty, and any Contractor desired temperature margin.

Navigation: Refers to the determination of the location of each pixel relative to a fixed reference, such as the GRS80 geoid or lightning ellipsoid for LMX, viewed from the idealized geostationary position

Navigation Error: Refers to the angular error of locations in the resampled fixed-grid frame.

Non-operational Temperatures (NOT): Non-operational Temperatures are the established range of temperatures that instrument units are permitted to experience while not operating and not powered. NOT represent the permissible range while the hardware is powered off. Survival heaters maintain hardware at or above the cold NOT limits and passive design maintains hardware below the upper NOT limits. NOT are also known as non-operating MAT.

Pixel: Refers to detector samples after resampling during the Level 1b ground processing.

Precision: Refers to the standard deviation of a statistically meaningful number of samples of a measurement.

Pulse: An optical signal generated by lightning whose nominal duration is on the order of 1 millisecond. A pulse, as viewed by the LMX, can generate one or more optical events, distributed spatially and or temporally. The average temporal variation of a lightning pulse is shown in the Lightning Pulse Duration Figure. This definition is used for Detection Efficiency reporting.

Lightning Pulse Duration Figure

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LMXPORD49

LMXPORD50

LMXPORD51

Object Number

1.5.0-30

1.5.0-31

1.5.0-32

1.5.0-33

1.5.0-34

1.6

1.6.0-1

1.6.0-2

1.6.0-3

1.6.0-4

418-XO-LMXPORD-0120, RM Version, Geostationary eXtended Observations (GeoXO) Lightning Mapper (LMX) Performance and

Operational Requirements Document (PORD) Phase B

Radiant Energy: The integral of object radiance at the entrance aperture over the instrument integration time. The preferred units are joules (J).

Reserved

SNR: Signal-to-Noise Ratio

Threshold: Minimum amount which a detector sample must exceed the mean value of the background signal for an event to be detected.

Unit: A functional subdivision of a subsystem and generally a self-contained combination of items performing a function necessary for the subsystem's operation. Examples are electronics unit and sensor unit.

1.6 Requirements Applicability

The requirements in this LMX PORD pertain to the LMX ‘system’, which include optics, detectors, electronics, software, and ground processing algorithm.

All requirements apply over the entire life of the instrument.

The initial phase of ground processing (Level 1b) is to discriminate optical transient signals (lightning events) from the totality of events.

Data performance requirements, such as event navigation, decompression, and calibration apply to data after Level 1b ground processing.

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LMXPORD53

LMXPORD54

LMXPORD55

LMXPORD56

Object Number

2.1

2.1.0-1

2.2

2-1

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Operational Requirements Document (PORD) Phase B

2 Documents

2.1 Applicable Documents

The following documents form a part of this specification to the extent specified herein:

1. LMX Unique Instrument Interface Document, NASA-GSFC, 418-XO-

LMXUIID-0067

2. Geostationary eXtended Observations (GeoXO) General Interface Requirements Document (GIRD), 418-XO-GIRD-0041

3. CCSDS Recommended Standard for Lossless Data Compression, CCSDS 121.0-B-3, August 2020

4. CCSDS Recommended Standard for Image Data Compression, CCSDS 122.0-B-2, September 2017

5. Structural Design and Test Factors of Safety for Spaceflight Hardware, NASA, Document Number NASA-STD-5001B

6. General Environmental Verification Specification for GSFC Flight Programs and Projects, GSFC-STD-7000B, April 28, 2021

7. NASA-STD-8719.24, Annex Rev. B w/ Change 1, Annex to NASA Payload Safety Requirements, 2022

8. NASA-STD-8719.24A, NASA Payload Safety Requirements, 2022

2.2 Reference Documents

The following documents provide reference material for part of this document:

1. Moving Mechanical Assemblies for Space and Launch Vehicles, AIAA S-114A-2020

2. Space Mechanisms Handbook, Document Number NASA TP-1999-206988, March 1, 2002

3. CCSDS Recommendation for Space Data System Standards, Low- Complexity Lossless Multispectral and Hyperspectral Image Compression, Document Number CCSDS 120.0-G-4, November 2021

4. Dual Geostationary Lightning Mapper Observations, S.D. Rudlosky, K.S.

Virts, AMS Monthly Weather Review, Volume 149 Issue 4, https://doi.org/10.1175/MWR-D-20-0242.1, pp. 979–998, April 2021

5. Algorithmic Chain for Lightning Detection and False Event Filtering Based on the MTG Lightning Imager”, Pierre Kokou et al., IEEE Transactions on Geoscience and Remote Sensing, vol. 50, no. 9, 5115 – 5124, 2018

6. Optical Observations of Lightning from a High-Altitude Airplane, H.J.

Christian and S.J. Goodman, J. of Atmospheric and Oceanic Technology, vol. 4, December 1987, pp. 701-711

7. The Detection of Lightning From Geostationary Orbit, Hugh J. Christian, Richard J. Blakeslee and Steven J. Goodman, J. of Geophysical Research, vol. 94, no. D11, September 1989, pp. 13329-13337

8. Laboratory Calibration of the Optical Transient Detector and the Lightning Imaging Sensor, William J. Koshak, Mike F. Stewart, Hugh J. Christian, James W. Bergstrom, John M. Hall, and Richard J. Solakiewicz, J. of Atmospheric and Oceanic Technology, vol. 17, July 2000, pp. 905-915

9. Lightning optical pulse statistics from storm overflights during the Altus Cumulus Electrification Study, D.M. Mach, R.J. Blakeslee, J.C. Bailey, W.M.

Farrell, R.A. Goldberg, M.D. Desch, and J.G. Houser, Atmospheric

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LMXPORD56

Object Number

2-1

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Operational Requirements Document (PORD) Phase B

Research 76 (2005), pp. 386-401

10. Airborne radiometric validation of the geostationary lightning mapper using the Fly’s Eye GLM Simulator, Mason G. Quick, Hugh J. Christian, Katrina S.

Virts, and Richard J. Blakeslee, J. Appl. Remote Sens. 14(4), 044518 (2020)

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ID

LMXPORD57

LMXPORD58

LMXPORD59

LMXPORD60

LMXPORD61

LMXPORD62

LMXPORD63

LMXPORD64

LMXPORD65

LMXPORD66

LMXPORD67

LMXPORD68

LMXPORD69

LMXPORD70

LMXPORD71

LMXPORD72

Object Number

3.1

3.1.1

3.1.1.0-1

3.1.1.1

3.1.1.1.0-1

3.1.1.1.0-2

3.1.1.1.0-3

3.1.1.2

3.1.1.2.0-1

3.1.1.2.0-2

3.1.1.3

3.1.1.3.0-1

3.1.1.3.0-2

3.1.1.3.0-3

3.1.1.3.0-4

418-XO-LMXPORD-0120, RM Version, Geostationary eXtended Observations (GeoXO) Lightning Mapper (LMX) Performance and

Operational Requirements Document (PORD) Phase B

3 Sensor Requirements

3.1 Functional Requirements

3.1.1 LMX Modes

The contractor may propose additional modes and add additional capabilities and functions.

3.1.1.1 Safe Mode

The LMX shall implement a Safe Mode which is a thermally, electrically and optically safe configuration that protects the instrument from the spacecraft and the environment.

The LMX shall enter Safe Mode upon receipt of a ground command, receipt of an autonomous safe mode command from the observatory, or detection of internal faults that could cause damage to the instrument.

The LMX shall be maintainable in Safe Mode for an indefinite period of time.

Rationale: The LMX needs a Safe Mode for contingency operations.

3.1.1.2 Normal Operational Mode

The LMX shall be in a fully functional configuration while in Normal Operational Mode.

Rationale: Normal mode is used for observations that require full functionality.

The LMX shall meet all performance requirements while in Normal Operational Mode without receiving commands or data loads for a minimum of 7 days.

Rationale: Autonomy is required for a period of 7 days, without impacting performance.

3.1.1.3 Diagnostic Mode

The LMX shall implement a Diagnostic Mode.

The LMX shall enter Diagnostic Mode only on command.

The LMX shall be in a fully functional configuration while in Diagnostic Mode.

Rationale: Diagnostic mode is needed for diagnosing anomalies.

The LMX shall by command send background images at increased cadence not to exceed the maximum data rate specified in the LMX UIID while in Diagnostic Mode.

Rationale: Diagnostic mode will afford commandable sampling engagement for diagnosing anomalies. Fill data bandwidth with background images, no events. Or downlink specific detector sample from every data frame.

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ID

LMXPORD73

LMXPORD74

LMXPORD75

LMXPORD76

LMXPORD77

LMXPORD78

LMXPORD79

LMXPORD80

LMXPORD81

LMXPORD82

LMXPORD83

LMXPORD84

LMXPORD85

Object Number

3.1.1.3.0-5

3.1.1.3.0-6

3.1.1.4

3.1.1.4.0-1

3.1.1.5

3.1.1.5.0-1

3.1.1.5.0-2

3.1.1.5.0-3

3.1.1.5.0-4

3.1.1.5.0-5

3.1.1.5.0-6

3.1.1.5.0-7

3.1.1.5.0-8

418-XO-LMXPORD-0120, RM Version, Geostationary eXtended Observations (GeoXO) Lightning Mapper (LMX) Performance and

Operational Requirements Document (PORD) Phase B

If the data is compressed, LMX shall by command send the same data both compressed and uncompressed while in Diagnostic Mode.

Rationale: Diagnostic mode will send compressed and uncompressed to help in validation and in assessing anomalies.

The LMX shall by command send dwell data (increased samples per second of a particular telemetry measurand) while in Diagnostic Mode.

Rationale: Diagnostic mode dwell data will help in validation and in assessing anomalies.

3.1.1.4 Survival Mode

The LMX shall implement a Survival Mode in which all power is off (except for spacecraft provided survival heater power) and only passive telemetry is available.

3.1.1.5 Mode Transitions and Commands

The LMX shall transition from any defined mode to any other defined mode upon command.

The LMX shall execute commands to individually enable and disable each autonomous function.

Rationale: Autonomous capability needs to be able to be disengaged as well.

The LMX shall initiate all commanded mode transitions in no more than 20 seconds after receipt of command.

Rationale: Mode transitions should occur rapidly for operators.

The LMX shall make limits and triggers of autonomous functions changeable by command.

Rationale: Autonomous functions should be controlled by operators if there is a special need to do so.

The LMX shall transition from its current mode to any other mode without causing permanent damage to itself.

Rationale: Mode transitions should occur without damage.

The LMX shall indicate the mode of the instrument in housekeeping telemetry.

Rationale: Knowledge of instrument modes is needed for data processing.

The LMX shall provide command and housekeeping telemetry functions in all powered modes.

Rationale: Command and housekeeping telemetry is necessary for monitoring instrument health at all times.

Receipt and processing of commands and data shall not interfere with LMX data collection in any mode.

Page 10 of 45 Printed Thursday, June 29, 2023

ID

LMXPORD86

LMXPORD87

LMXPORD88

LMXPORD89

LMXPORD90

LMXPORD91

LMXPORD92

LMXPORD93

LMXPORD94

LMXPORD95

LMXPORD96

LMXPORD97

LMXPORD98

LMXPORD99

LMXPORD100

LMXPORD101

LMXPORD102

Object Number

3.1.1.5.0-9

3.1.2

3.1.2.1

3.1.2.1.0-1

3.1.2.1.1

3.1.2.1.1.0-

3.1.2.2

3.1.2.2.0-1

3.1.2.3

3.1.2.3.0-1

3.1.2.4

3.1.2.4.1

3.1.2.4.1.0-

3.1.2.4.2

3.1.2.4.2.0-

3.1.2.4.3

3.1.2.4.3.0-

418-XO-LMXPORD-0120, RM Version, Geostationary eXtended Observations (GeoXO) Lightning Mapper (LMX) Performance and

Operational Requirements Document (PORD) Phase B

The LMX shall provide an event detection threshold that is adjustable by command.

3.1.2 On-Orbit Operations

3.1.2.1 Operational Zone

The LMX shall meet all operational and performance requirements over the required field of view defined in LMXPORD109, except for ZRDQ.

3.1.2.1.1 Zones of Reduced Data Quality (ZRDQ)

The LMX shall meet all performance requirements for all samples whose distance from any part of the uneclipsed Sun and any part of the uneclipsed Sun rotated 180° about the instrument boresight is greater than 7°.

3.1.2.2 Imaging the Sun

The LMX shall survive the presence of the sun within the field of regard without sustaining any permanent degradation in performance.

Rationale: The sun must not result in damage to the instrument.

3.1.2.3 Eclipse

The LMX shall operate continuously through eclipse periods.

3.1.2.4 Operations After Maneuvers

3.1.2.4.1 Yaw Flip

The LMX shall meet all performance requirements within 30 minutes after spacecraft interface is within specification following a yaw-flip.

Rationale: If the spacecraft executes a yaw flip, the instrument recovery will occur in this duration after the interface is restored to nominal conditions.

3.1.2.4.2 Station Keeping

The LMX shall meet all performance requirements within 30 minutes after spacecraft interface is within specification following a station-keeping maneuver outage.

Rationale: If the spacecraft executes a station-keeping maneuver, the instrument recovery will occur in this short duration after the interface is restored to nominal conditions.

3.1.2.4.3 Post Storage Activation

The LMX shall meet all requirements within 2 days of LMX turn-on after being in on-orbit storage, except navigation.

Page 11 of 45 Printed Thursday, June 29, 2023

ID

LMXPORD103

LMXPORD104

LMXPORD105

LMXPORD106

LMXPORD107

LMXPORD108

LMXPORD109

LMXPORD110

LMXPORD111

LMXPORD112

LMXPORD113

LMXPORD114

LMXPORD115

LMXPORD116

Object Number

3.1.2.4.3.0-

3.1.2.5

3.1.2.5.0-1

3.1.2.5.0-2

3.2

3.2.1

3.2.1.0-1

3.2.1.1

3.2.1.1.0-1

3.2.1.2

3.2.1.2.0-1

3.2.1.3

3.2.1.3.0-1

3.2.1.4

418-XO-LMXPORD-0120, RM Version, Geostationary eXtended Observations (GeoXO) Lightning Mapper (LMX) Performance and

Operational Requirements Document (PORD) Phase B

The LMX shall meet all navigation requirements within 3 days of turn-on after being in on-orbit storage.

Rationale: After activation, spectral filters require thermal stabilization. Navigation may require coastline identification or landmarking data.

3.1.2.5 Outgas Period

Reserved

The post-launch outgas period shall be no longer than 14 days.

Rationale: The LMX will sublimate and evaporate contaminants from hardware to prevent contamination from jeopardizing performance.

3.2 Performance Requirements

3.2.1 Coverage

LMX shall view 84% of the visible Earth area seen from geostationary orbit (flat 17.4° diameter disk) with no internal gaps in coverage.

3.2.1.1 Coverage Rate

The LMX shall provide continuous optical lightning event detection over the coverage area defined in LMXPORD109 at a minimum cadence of 500 Hz.

Rationale: The LMX revisit of the coverage area occurs continuously with a rapid cadence to the optical lightning events. The average temporal variation of a lightning pulse is shown in the Lightning Pulse Duration Figure LMXPORD41.

3.2.1.2 Simultaneity

The LMX shall time tag each event to an accuracy of 0.5 milliseconds.

Rationale: Precision is needed for lightning event clustering.

3.2.1.3 Data Latency

The LMX shall contribute no more than 10 seconds to the total data latency from event detection through generation of Level 1b products.

Rationale: Data latency is measured from the time the instrument acquires all samples for a scene to the time the events are available for dissemination on the ground. The LMX contribution to data latency includes delay of delivery of data to the spacecraft and delay due to ground algorithm processing.

3.2.1.4 Data Collection Output

Page 12 of 45 Printed Thursday, June 29, 2023

ID

LMXPORD117

LMXPORD118

LMXPORD119

Object Number

3.2.1.4.0-1

3.2.1.5

3.2.1.5.0-1

418-XO-LMXPORD-0120, RM Version, Geostationary eXtended Observations (GeoXO) Lightning Mapper (LMX) Performance and

Operational Requirements Document (PORD) Phase B

The LMX shall collect each pixel from multiple detector frame samples contained within a single collection.

Rationale: Identify same events in overlap region. Need one report per event, even if sample from multiple detectors. A collection is the set of all frames from all telescopes for a single integration period. A frame is the set of all samples from one detector for a single integration period.

3.2.1.5 Lightning Event Detection

The LMX shall provide the radiant energy of each event with associated data needed by ground processing to detect each event.

Rationale: Provide detection threshold, surrounding pixels, background, detector element, false event filter data, etc.

Page 13 of 45 Printed Thursday, June 29, 2023

ID

LMXPORD120

LMXPORD121

LMXPORD122

LMXPORD123

LMXPORD124

Object Number

3.2.1.5.0-2

3.2.1.5.0-3

3.2.1.5.0-4

3.2.1.5.0-5

3.2.1.6

418-XO-LMXPORD-0120, RM Version, Geostationary eXtended Observations (GeoXO) Lightning Mapper (LMX) Performance and

Operational Requirements Document (PORD) Phase B

The lightning event detection probability over the coverage area specified in LMXPORD109 shall be greater than 70% after Level 1b processing after

- using an equivalent integrated area of 0.57 milliseconds using the curve in Lightning Pulse Duration Figure,

- averaging minimum detectable event energy density over 24 hours,

- using the Lightning Distribution Spectrum Table, and

- averaging the percent lightning detected over any contiguous regions of

1120 microradians x 1120 microradians.

Rationale:

1. The Minimum Detectable Event Energy Density is the optical transient energy density for which half of the transients will be detected.

2. Lightning Distribution Spectrum Table shows that the ability to detect fainter lightning events leads to higher levels of lightning detection.

3. Lightning Distribution Spectrum Table values reflect SNR of 4:1 or better.

4. Although the Level 1b will not be averaged over 5x5 224 microradians spatial resolution samples, averaging 5x5 224 microradians spatial resolution samples allows for degraded detection probability for individual pixels.

Lightning Distribution Spectrum Table

Minimum Detectable Event Energy Density

(µJ/m2/sr)

Percent Lightning Detected

3.8 95 4.5 5.1

5.9 6.7

7.6 8.7

9.9 >9.9

The percentage of false events computed over all temporal samples during any contiguous 24-hours shall be less than 5% after Level 1b processing.

Rationale: This includes at least all events defined in LMXPORD30. False event percentage is the ratio of the number of false events to the total number of events at the end of Level 1b processing expressed as a percentage.

The readout of a background image (if applicable) shall not interfere with the detection and reporting of events.

The LMX shall be able to detect events in the same detector element in consecutive frames.

3.2.1.6 Spectral Response

Page 14 of 45 Printed Thursday, June 29, 2023

ID

LMXPORD125

LMXPORD126

LMXPORD127

LMXPORD128

LMXPORD129

Object Number

3.2.1.6.0-1

3.2.1.7

3.2.1.7.0-1

3.2.1.7.0-2

3.2.1.8

418-XO-LMXPORD-0120, RM Version, Geostationary eXtended Observations (GeoXO) Lightning Mapper (LMX) Performance and

Operational Requirements Document (PORD) Phase B

The LMX system spectral response shall have a spectral range sufficient to collect the lightning signal associated with the oxygen triplet centered near 777.4 nm per the Oxygen Emission Line Table. The table defines spectral locations and relative intensities associated with lightning to be detected by the LMX instrument.

Rationale: LMX must discriminate a small lightning signal on top of a large background signal, so the spectral response envelope must be large enough to collect the lightning signal (nominally from the entire triplet in order to maximize signal), and small enough to avoid collecting too much background signal.

Oxygen Emission Line Table

Wavelength (nm, air)

Wavelength (nm, vac)

Normalized Relative

Intensities Oxygen triplet

777.196 777.408 0.358

777.418 777.630 0.333

777.540 777.753 0.309

Mean Wavelength

777.376 777.589

3.2.1.7 SNR

The LMX shall observe daytime lightning events with a minimum SNR of 4 over the contiguous averaging region specified in LMXPORD109 for a dim lightning signal level of 3.44x1013photons/m2/sr with a background of 1.47x1021 photons/s/m2/sr/ µm.

Rationale: The dim photon energy density listed here is equal to 8.8 µJ/m2/sr and the bright photon radiance is equal to a Lambertian reflector with solar illumination at 777.4 nm.

The LMX shall observe nighttime lightning events with a minimum SNR of 4 over the contiguous averaging region specified in LMXPORD109 for a dim lightning signal level of 2.51x1013photons/m2/sr with a background of 0 photons/s/m2/sr/µm.

Rationale:

1) The dim photon energy density listed here is equal to 6.4 µJ/m2/sr.

2) These SNR values are needed to detect radiance associated with lightning under daytime (LMXPORD127) and nighttime (LMXPORD128) conditions. Driver is daytime. Impulse for lightning signal is in LMXPORD120. Lightning line spectra is integrated in the spectral dimension. Background is a continuum.

3.2.1.8 Saturation

Page 15 of 45 Printed Thursday, June 29, 2023

ID

LMXPORD130

LMXPORD131

LMXPORD132

LMXPORD133

LMXPORD134

LMXPORD135

LMXPORD136

LMXPORD137

LMXPORD138

LMXPORD139

LMXPORD140

Object Number

3.2.1.8.0-1

3.2.1.9

3.2.1.9.0-1

3.2.1.10

3.2.1.10.0-1

3.2.2

3.2.2.0-1

3.2.2.0-2

3.2.2.1

3.2.2.1.0-1

3.2.2.1.0-2

418-XO-LMXPORD-0120, RM Version, Geostationary eXtended Observations (GeoXO) Lightning Mapper (LMX) Performance and

Operational Requirements Document (PORD) Phase B

The LMX shall not saturate any detector element for a background radiance (from Reference Document 4) of 1.78x1021 photons/s/m2/sr/µm.

Rationale: This photon radiance is equal to 1.21 times the radiance of a Lambertian reflector, encompassing a background radiance of 1.1 times the radiance of a Lambertian reflector and 90-percentile of all lightning event energy densities. Earth scene signals need to be observed without saturation. Extreme Lightning cases outside of the radiance above is rare and might generate rare saturation events.

3.2.1.9 Ringing from a Sharp Edge

The LMX shall not overshoot the top of an edge or undershoot the bottom of scene edges by more than 5% of the height of the edge where:

a) The height and the overshoot/undershoot are measured in radiance units,

b) The edge delineates a 10% albedo region from a 90% albedo, and

c) The overshoot is averaged over all resampling phases of the detector sample grid to fixed-grid and edge position to detector sample grid.

Rationale: Requirement limits ringing response or overshoot near a sharp edge in scene.

3.2.1.10 Spatial Resolution

The LMX shall have a maximum ground sample resolution equivalent of 224 µrad.

Rationale: 224 µrad is 8 km ground sample distance at nadir.

3.2.2 Event Navigation

All event navigation requirements listed herein apply to optical lightning events and refer to location error of the fixed-grid pixels. The requirements apply to the end-to-end system, taking all instrument, spacecraft, and ground processing effects into account. Unless otherwise specified, all navigation requirements in this document are specified as North/South and East/West angles, in microradians, 3-sigma, and refer to all hours of operation as defined by the operational zones.

In the context of LMX, 3-sigma error is defined to be equal to the 99.73rd percentile of the absolute values of all navigation error observations collected over each 24-hour period from local noon to local noon. When navigation requirements are temporarily suspended, due to Sun/Earth geometry or maneuver outages (including recovery time), the raw errors during the requirements suspension period should be ignored.

3.2.2.1 Navigation Performance Requirements

The LMX shall navigate each optical lightning event.

The LMX navigation error shall not exceed 98 µrad, 3-sigma, per axis, except during eclipse periods.

Page 16 of 45 Printed Thursday, June 29, 2023

ID

LMXPORD141

LMXPORD142

LMXPORD143

LMXPORD144

LMXPORD145

LMXPORD146

LMXPORD147

Object Number

3.2.2.1.0-3

3.2.2.2

3.2.2.2.0-1

3.2.2.3

3.2.2.3.0-1

3.2.2.4

3.2.2.4.0-1

418-XO-LMXPORD-0120, RM Version, Geostationary eXtended Observations (GeoXO) Lightning Mapper (LMX) Performance and

Operational Requirements Document (PORD) Phase B

The LMX navigation error shall not exceed 126 µrad, 3-sigma, per axis, for up to a four-hour period that includes partial and/or total eclipse of the sun during eclipse periods. The phasing of the four-hour relaxation relative to the eclipse may be design-specific.

3.2.2.2 Star Sensing

If the LMX requires star coordinates on-board, the LMX shall include an on-board catalog that is nominally sufficient for the life of the mission but is loadable and modifiable from ground.

3.2.2.3 Reserved

Reserved

3.2.2.4 Lossless Data Compression

If compression is employed, lossless data compression shall be in accordance with Applicable Document 4.

Page 17 of 45 Printed Thursday, June 29, 2023

ID

LMXPORD1000

LMXPORD1001

LMXPORD1002

LMXPORD1003

LMXPORD1004

LMXPORD1005

LMXPORD1006

LMXPORD1007

LMXPORD1008

LMXPORD1009

LMXPORD1010

LMXPORD1011

LMXPORD1012

LMXPORD1013

LMXPORD1015

LMXPORD1016

LMXPORD1017

LMXPORD1018

Object Number

4.1

4.1.0-1

4.1.0-2

4.1.0-3

4.1.0-4

4.1.0-5

4.1.0-6

4.2

4.2.1

4.2.1.0-1

4.2.2

4.2.2.0-1

4.2.3

4.3

4.3.0-1

4.3.0-2

4.3.1

418-XO-LMXPORD-0120, RM Version, Geostationary eXtended Observations (GeoXO) Lightning Mapper (LMX) Performance and

Operational Requirements Document (PORD) Phase B

4 Design Requirements

4.1 Reliability

The LMX shall demonstrate by analysis a Reliability (R) of at least 0.6 after 10 years of on-orbit operations, preceded by ground storage, and up to 5 years of on-orbit storage.

Rationale: The design life of at least 10 years extends from commencement of on-orbit operations until Reliability falls to 0.6.

The LMX shall demonstrate by analysis a Mean Mission Duration (MMD) of at least

8.4 years by integrating under the Reliability curve for 10 years of on-orbit operations, preceded by the storage periods.

No credible single-point failure in LMX flight heater components shall permanently preclude the Instrument from supporting the mission.

No credible single-point failure in LMX flight temperature-sensing components shall permanently preclude the Instrument from supporting the mission.

To satisfy the Reliability and Design Life Requirements, the Instrument may choose selectively redundant approaches beyond those explicitly required in LMXPORD1004 and LMXPORD1005.

The LMX shall withstand without damage the sudden removal of operational power.

4.2 Redundancy

4.2.1 Redundant Component Selectabiltiy

The LMX redundant components shall be selectable by external command only.

4.2.2 Interchangability of Flight Model Units

The LMX units of any Flight Model (FM) shall be interchangeable, without modification, with the equivalent units of any other FM

4.2.3 Reserved

4.3 Mechanical Requirements

Compliance with the requirements in this section ensures that the LMX unit structures possess sufficient strength, rigidity, and other characteristics required to survive the critical loading conditions that are expected during the GeoXO mission.

All threaded fasteners shall employ a locking feature.

4.3.1 Design Limit Loads

Page 18 of 45 Printed Thursday, June 29, 2023

ID

LMXPORD1019

LMXPORD1020

LMXPORD1021

LMXPORD1022

LMXPORD1023

LMXPORD1024

Object Number

4.3.1.0-1

4.3.1.0-2

4.3.1.0-3

4.3.2

4.3.2.0-1

4.3.2.0-2

418-XO-LMXPORD-0120, RM Version, Geostationary eXtended Observations (GeoXO) Lightning Mapper (LMX) Performance and

Operational Requirements Document (PORD) Phase B

Limit loads are defined as all worst-case load conditions enveloping temperature effects from the environments expected during all phases of the structure's service life including manufacturing, ground handling, transportation, environmental testing, integration, pre-launch, launch, on-orbit operations, and storage.

The LMX Instrument units not mounted on the spacecraft nadir deck shall survive a limit static positive and negative acceleration load applied at the spacecraft interface in each axis individually to the values shown in the Mass Acceleration Table and Mass Acceleration Curve in GIRD385, multiplied by the Static load factors from the GeoXO Flight Hardware Design/Analysis Factors of Safety Applied to Limit Loads Table listed in LMXPORD1024.

The LMX Instrument units mounted on the spacecraft nadir deck shall survive a limit static positive and negative acceleration load applied at the spacecraft interface in each axis individually to the values shown in the Table GIRD387 Nadir Deck Mass Acceleration multiplied by the Static load factors from the GeoXO Flight Hardware Design/Analysis Factors of Safety Applied to Limit Loads Table listed in

LMXPORD1024.

4.3.2 Yield Strength

The LMX structures shall support yield loads without detrimental permanent deformation with load factors from the Flight Hardware Design/Analysis Factors of Safety Applied to Limit Loads Table listed in LMXPORD1024.

GeoXO Flight Hardware Design/Analysis Factors of Safety Applied to Limit Loads 1,2

Table

1 – Factors of safety for pressurized systems to be compliant with NASA- STD-8719.24 Annex Rev.B w/ Change 1

2 – Factors of safety for pressurized bonded glass and glass joints specified in

NASA-STD-5001.

3 – If qualified by analysis only, positive margin must be shown for factors of safety of 2.0 on yield and 2.6 on ultimate. Project approval required for analysis only.

4 – Factors shown should be applied to statistically derived peak response based on RMS level.

5 – Factors shown assume that qualification/protoflight testing is performed at acceptance level plus 3dB. If difference between acceptance and qualification levels is less than 3dB, then above factors may be applied to qualification level minus 3dB instead of analyzing to acceptance level.

Page 19 of 45 Printed Thursday, June 29, 2023

ID

LMXPORD1339

LMXPORD1025

LMXPORD1026

LMXPORD1027

LMXPORD1028

LMXPORD1029

LMXPORD1030

LMXPORD1031

LMXPORD1032

LMXPORD1033

LMXPORD1034

LMXPORD1035

LMXPORD1036

LMXPORD1037

LMXPORD1038

Object Number

4.3.2.0-3

4.3.3

4.3.3.0-1

4.3.4

4.3.4.0-1

4.3.4.0-2

4.3.4.0-3

4.3.5

4.3.5.0-1

4.3.6

4.3.6.0-1

4.3.7

4.3.7.0-1

4.3.8

4.3.8.0-1

418-XO-LMXPORD-0120, RM Version, Geostationary eXtended Observations (GeoXO) Lightning Mapper (LMX) Performance and

Operational Requirements Document (PORD) Phase B

As a minimum, the peak response for Random/Acoustic loads listed in LMXPORD1024 shall be calculated as a 3-sigma value.

4.3.3 Ultimate Strength

The LMX structures shall support ultimate loads without collapse or rupture when subjected to loads with the applied ultimate load factors from the GeoXO Flight Hardware Design/Analysis Factors of Safety Applied to Limit Loads Table listed in

LMXPORD1024.

4.3.4 Unit Stiffness

The fundamental resonant frequency of the LMX Sensor Unit shall be 50 Hz or greater when the sensor unit is rigidly constrained at its spacecraft interface and the sensor unit is in its launch configuration. The fundamental resonant frequency is defined as the lowest mode with more than 2% effective modal mass in any direction.

The fundamental resonant frequency of the LMX Electronics Unit(s) shall be 50 Hz or greater when the electronics units are rigidly constrained at their spacecraft interfaces. The fundamental resonant frequency is defined as the lowest mode with more than 2% effective modal mass in any direction.

The LMX units shall survive the Instrument-level random and sine vibration testing with notching of interface forces to design limits only.

4.3.5 Critical Members Design Values

For critical members, design values shall be selected to assure strength with a minimum of 99 percent probability and 95 percent confidence. Structural members are classified as critical when their failure would result in loss of structural integrity of the flight units.

4.3.6 Redundant Members Design Values

For redundant members, design values shall be selected to assure strength with a minimum of 90 percent probability and 95 percent confidence. Structural members are classified as redundant when their failure would result in the redistribution of applied loads to other structural members without loss of structural integrity.

4.3.7 Selective Design Values

As an exception to LMXPORD1032 and LMXPORD1034, greater design values may be used if a representative portion of the material used in the structural member is tested before use to determine that the actual strength properties of that particular structural member will equal or exceed those used in the design.

4.3.8 Fracture Control

The LMX shall comply with the fracture control requirements for the following elements in compliance with NASA-STD-5019A with Change 3:

a) Pressure vessels, dewars, lines, and fittings

b) Castings unless hot isostatically pressed and the flight article is proof tested

Page 20 of 45 Printed Thursday, June 29, 2023

ID

LMXPORD1038

LMXPORD1039

LMXPORD1040

LMXPORD1041

LMXPORD1042

LMXPORD1043

LMXPORD1044

LMXPORD1045

LMXPORD1046

LMXPORD1047

LMXPORD1048

LMXPORD1049

LMXPORD1050

Object Number

4.3.8.0-1

4.3.8.0-2

4.3.9

4.3.9.0-1

4.3.9.0-2

4.3.9.0-3

4.3.9.0-4

4.3.9.0-5

4.3.9.0-6

4.3.9.0-7

4.3.9.0-8

4.3.9.0-9

4.3.9.0-10

418-XO-LMXPORD-0120, RM Version, Geostationary eXtended Observations (GeoXO) Lightning Mapper (LMX) Performance and

Operational Requirements Document (PORD) Phase B to 1.25 times limit load

c) Weldments

d) Parts made of materials not in Table I of MSFC-STD-3029, if under sustained tensile stress

e) Parts made of materials susceptible to cracking during quenching

f) Nonredundant, mission-critical preloaded springs loaded to greater than 25 percent of ultimate strength

Any glass element subject to loads exceeding 10% of its ultimate tensile strength shall satisfy one of the following: "Safe-life" fracture analysis, "Fail-safe" analysis, or proof load testing at 1.0 times the load level.

4.3.9 Mechanisms

Deployment, sensor, pointing, drive, separation mechanisms and other moving mechanical assemblies may be designed using MIL-A-83577B and NASA

TP-1999-206988.

All LMX mechanisms shall have torque ratios greater than 1.2 while operating in an earth gravity environment with any orientation of the gravity vector.

For the on orbit operational conditions, moving mechanical assemblies shall have torque and force ratios per section 2.4.5.3 of GSFC-STD-7000B using the Torque / Force Margin of Safety Table listed in LMXPORD1044.

Torque/Force Margin of Safety Table

Program Phase Known Torque

Factor of Safety (FSk)

Variable Torque Factor of Safety (FSv)

Preliminary Design Review 2 4 Critical Design Review 1.5 3 Acceptance/Qualification Test 1.5 2

For all operating points of the actuators, all rotational actuators shall have available a continuous maximum torque output greater than 7.0 milli-Newton meters.

For all operating points of the actuators, all linear actuators shall have available a continuous maximum force output greater than 0.28 N.

For mechanisms using closed-loop control, gain and phase margins shall be greater than 12 dB, and greater than 40 degrees, respectively…