Attachment D - LANDIS LaRD-Rev A.pdf

LaRD LNEXT-LANDIS-REQ-0007 Revision A ii

Landsat Next Instrument Suite (LandIS) Requirements Document (LaRD)

Signature/Approval Page

Prepared by:

Electronic Signature in TDMS Approval Date in TDMS Amy DeLisa Date Landsat Next Payload Systems Engineer Org./Code 426

Approved by:

Electronic Signature in TDMS Approval Date in TDMS Joy Henegar-Leon Date Landsat Next Payload Technical Manager Org./Code 426

Approved by:

Electronic Signature in TDMS Approval Date in TDMS Wen-Ting Hsieh Date Landsat Next Payload Manager Org./Code 426

Approved by:

Electronic Signature in TDMS Approval Date in TDMS James Pontius Date Landsat Next Project Manager Org./Code 426 iii

CM Foreword This document is a Landsat Next Project Configuration Management (CM)-controlled document.

Changes to this document require prior approval of the applicable Configuration Control Board (CCB) Chairperson or designee. Proposed changes shall be submitted to the Landsat Next CM Office (CMO), along with supportive material justifying the proposed change. Changes to this document will be made by complete revision.

Questions or comments concerning this document should be addressed to:

NASA/Goddard Space Flight Center Landsat Next Project Office, Code 426 Attention: Configuration Management Office Greenbelt, Maryland 20771 iv

Change History Log

Revision Effective Date Description of Changes (Reference the CCR/SCoRe Approval Date)

- 12/15/2022 LNEXT-CCR-0035 – Initial Release A 05/05/2023 LNEXT-CCR-0046 – Updates for final LandIS RFP package v

List of TBDs/TBRs Hyperlink to TBx Location Summary Ind.

Name/Org.

Due Date

TBx-1 Section 2.4.3

The Launch Segment will provide the assets and services associated with the Launch Vehicle (LV) and the constellation-to-LV integration. This will include the LV; all Launch Vehicle-Ground Support Equipment (LV-GSE), property, and facilities to integrate the constellation to the LV and verify their integration; and prelaunch testing with ground-based functions. The launch vehicle and launch site are TBD. The three observatories comprising the Landsat Next constellation will be launched together on the same launch vehicle.

Launch Services Segment

(LSS)

MCDR

TBx-2 Section 4.6

LaRD-425 The LandIS shall place itself in a safe configuration within 45 (TBR) seconds upon receipt of a safing command.Rationale: The spacecraft will send a command (likely a discrete pulse command) to inform the instrument of a need to go to its safe mode. Assuming nominal spacecraft attitude rates and a command to safe if the sun were to enter the glint free field of view, then 45 (TBR) seconds is about how long it takes the sun to reach the instrument aperture.

Flight Software IPDR

TBx-3 Section 4.7

LaRD-3273 Over an 18 day cycle, the LandIS shall have no more than 0.05% (TBR) data loss of imaging sensor data and instrument ancillary data collected and transferred to the spacecraft.

Mission Systems Engineer

ISRR

TBx-4 Section 5.2.1

LaRD-384 Upon exiting Survival configuration, the LandIS shall meet performance specifications for all bands within 1 week (TBR).

Instrument Scientist ISRR

TBx-5 Section 5.2.1

LaRD-3313 Upon exiting Survival configuration, the LandIS shall be able to complete a full aliveness checkout within 6 hours (TBR).

Instrument Scientist ISRR

TBx-6 Section 5.6.7.1

LaRD-1013 Less than 0.1% (TBR) of all pixels in a WRS-3 multi-band image shall be inoperable.

Instrument Scientist ISRR

TBx-7 Section 5.6.7.2

LaRD-1016 Less than 0.2% (TBR) of pixels in any spectral band shall be inoperable.

Instrument Scientist ISRR

TBx-8 Section 9.2

LaRD-1620 Upon receipt of a valid cold boot command, LandIS operational flight software shall complete its startup within (TBD) seconds.

Flight Software IPDR vi

TBx-9 Section 9.3

LaRD-1183 The most recent 10 (TBR) minutes of stored event log data shall be preserved following a processor reset/restart.Rationale: To capture the most recent logged events for use in anomaly investigation. In the event of a failure of the flight computer (reboot of a flight computer) at least the most recent 10 (TBR) minutes of event log information is preserved. Capability to preserve more than 10 (TBR) minutes of data is acceptable.

Flight Software ISRR

TBx-10 Section 9.3

LaRD-3429 The most recent 10 (TBR) minutes of housekeeping telemetry data shall be preserved following a processor reset/restart.Rationale: To capture the most recent housekeeping telemetry data for use in anomaly investigation. In the event of a failure of the flight computer (reboot of a flight computer) at least the most recent 10 (TBR) minutes of housekeeping telemetry data is preserved.

Capability to preserve more than 10 (TBR) minutes of housekeeping telemetry data is acceptable.

Flight Software ISRR

TBx-11 Section 10.1

LaRD-3430 The LandIS shall generate an uncompressed imaging sensor data rate less than 1.8 (TBR) Gbps.

Command & Data

Handling

ISRR

TBx-12 Section 10.1

LaRD-3431 The LandIS shall be ready to capture imaging sensor data within 5 (TBR) seconds of receipt of command to capture imaging sensor data.

Command & Data

Handling

ISRR

TBx-13 Section 10.1

LaRD-3432 The instrument ancillary data stored with each instrument data block shall be time-correlated with the full image exposure plus (TBD) margin before and after the image.

Command & Data

Handling

ISRR

TBx-14 Section 10.5

LaRD-1216 The LandIS internal time reference shall be accurate to within 25 (TBR) microseconds or less, 3-sigma, for at least 1 second, with respect to the Spacecraft provided time of day.

Flight Software ISRR

TBx-15 Section 10.5

LaRD-3423 The LandIS shall time tag imaging sensor data, instrument ancillary data, and diagnostic/test pattern data with an accuracy of 25 (TBR) microseconds or less, 3-sigma, of the LandIS internal time reference.Rationale: Maintains image sample timing accuracy of 50 microseconds relative to spacecraft time, 25 (TBR) for internal time reference (LaRD-1216) + 25 (TBR) for time tagging. Enables reconstruction of instrument data, where instrument data means imaging sensor data and instrument ancillary data. Diagnostic/test pattern data will need same timing accuracy in order to troubleshoot any potential timing issues.

Flight Software ISRR

TBx-16 Section 10.5

LaRD-3424 The LandIS shall time tag housekeeping data with an accuracy of (TBD) microseconds or less, 3-sigma, of the LandIS internal time reference.

Flight Software ISRR vii

Table of Contents SIGNATURE/APPROVAL PAGE ................................................................................................ II

CM FOREWORD ..........................................................................................................................III

CHANGE HISTORY LOG .......................................................................................................... IV

LIST OF TBDS/TBRS .................................................................................................................... V

TABLE OF CONTENTS ............................................................................................................. VII

LIST OF FIGURES ........................................................................................................................ X

LIST OF TABLES .......................................................................................................................... X

1.0 INTRODUCTION

1.1 Purpose

1.2 Scope

1.3 Related Documentation

1.3.1 Applicable Documents

1.3.2 Project Applicable Documents

1.3.3 Reference Documents

1.3.4 Project Reference Documents

2.0 MISSION OVERVIEW

2.1 Mission Statement

2.2 Mission Background

2.3 Mission Objectives

2.4 Mission Implementation

2.4.1 Space Segment

2.4.2 Ground Segment

2.4.3 Launch Segment

3.0 FUNCTIONAL OVERVIEW

4.0 LANDIS SYSTEM LEVEL

4.1 General

4.2 LandIS System Lifetime

4.3 Mission Phases

4.3.1 Ground Storage Phase

4.3.2 Pre-Launch Phase

4.3.3 Launch and Early Orbit Phase

4.3.4 Commissioning Phase

4.3.5 Operational Phase

4.3.6 Decommissioning Phase

4.4 Operational Orbit

4.5 Redundancy Requirements

4.6 Autonomy and Safe Configuation

4.7 Availability

4.8 Ground Support Equipment (GSE)

viii

4.8.1 Shipping/ Storage Container(s)

5.0 IMAGERY REQUIREMENTS

5.1 General

5.2 On-Orbit Configurations

5.2.1 Survival Configuration

5.2.2 Power-On Configuration

5.2.3 Mission Configuration

5.2.4 Diagnostic Configuration

5.2.4.1 Focal Plane Diagnostic Sub-Configuration

5.2.4.2 On-Board Source Assembly

5.3 Data Processing Algorithms

5.3.1 Radiometric Correction Algorithms

5.3.1.1 Detector Bias Determination

5.3.1.2 Conversion to Radiance

5.3.1.3 Conversion to Reflectance

5.3.1.4 Inoperable Pixel Replacement

5.3.2 Geometric Correction Algorithms

5.3.2.1 Ancillary Data Preprocessing

5.3.2.2 Line-of-Sight Model Creation

5.3.2.3 LOS Projection

5.3.2.4 LOS Model Correction

5.3.3 Image Resampling

5.3.3.1 Input Image to Resampled Output Image Mapping

5.3.4 Data Processing Algorithm Performance

5.4 Spectral Bands

5.4.1 Spectral Band Passes

5.4.1.1 Spectral Band Edges

5.4.1.2 Center Wavelength

5.4.1.3 TIR Response Uniformity

5.4.2 Spectral Band Shape

5.4.2.1 Spectral Flatness

5.4.2.2 Out of Band Response

5.4.3 Relative Spectral Response Rolloff

5.4.4 Spectral Uniformity

5.4.5 Spectral Stability

5.4.6 Spectral Band Simultaneity

5.5 Spatial Performance

5.5.1 Ground Sample Distance

5.5.1.1 Pixel-to-Pixel Increment

5.5.2 Edge Response

5.5.3 Aliasing

5.5.4 Light Rejection and Internal Scattering

5.5.5 Ghosting

5.6 Radiometry

5.6.1 Absolute Radiometric Uncertainty

5.6.2 Radiometric Signal-to-Noise (SNR) and Uniformity

ix

5.6.2.1 Pixel Signal-to-Noise Ratios

5.6.2.2 Data Quantization

5.6.2.3 Pixel-to-Pixel Uniformity

5.6.2.4 Coherent Noise

5.6.3 Saturation Radiances

5.6.4 Polarization Sensitivity

5.6.5 Relative Radiometric Product Stability

5.6.6 Image Artifacts

5.6.6.1 Bright Target Recovery

5.6.7 Inoperable, and Out-of-Spec Pixels

5.6.7.1 Inoperable Pixels

5.6.7.2 Inoperable Pixels per Band

5.6.7.3 Adjacent Inoperable Pixels

5.6.7.4 Out-of-Spec Pixels

5.7 Geometric Precision, Geolocation, and Cartographic Registration

5.7.1 VSWIR-TIR Band-to-Band Registration Accuracy

5.7.2 Image-to-Image Registration Accuracy

5.7.3 Geodetic Accuracy

5.7.3.1 Absolute Geodetic Accuracy

5.7.3.2 Relative Geodetic Accuracy

5.7.4 Geometric Accuracy

5.8 In-Flight Calibration

5.8.1 Calibration Hardware

5.8.2 Lunar Imaging

6.0 STRUCTURAL AND MECHANICAL SYSTEMS

7.0 THERMAL CONTROL

8.0 ELECTRICAL SYSTEM

8.1 Survival Power

8.2 External Test Interfaces

8.3 Grounding

8.3.1 Secondary Power Return

8.3.2 Class R Grounding

8.3.3 Class S Grounding (Electrostatic)

9.0 FLIGHT SOFTWARE (FSW)

9.1 Startup Read-Only Memory (SUROM)

9.2 Initialization

9.3 Event Logging

9.4 Failure Detection, Protection and Correction

9.5 General Software

9.6 Memory Operations

10.0 COMMAND AND DATA HANDLING

10.1 General

10.2 Preprocessing/Data Reduction and Compression Optimization x

10.2.1 Preprocessing/Data Reduction

10.2.2 Compression Optimization

10.3 Telemetry

10.4 Command Capability

10.5 Timing / Time Tagging Accuracy

APPENDIX A. ABBREVIATIONS AND ACRONYMS

APPENDIX B. DEFINITIONS

List of Figures Figure 2.4-1 Landsat Next Operations Concept (Generated from Landsat Next Common Mission Architecture Diagram LNEXT-SYS-

DESC-0022 Rev -) Figure 5.4.1.1-1 Notional Spectral Band Shape Figure 5.5.2-1 Notional Edge Response Figure 5.6.2.3-1 Top of Atmosphere Spectra for Uniformity Analyses Figure 5.6.2.4-1 Coherent Noise Threshold Curve

List of Tables

Table 4.1-1 Landsat Next Operational Orbit Table 5.4.1.2-1 Spectral Bandpasses Table 5.5.2-1 GSD, Minimum Edge Slope, and Maximum Relative Edge Extent

Specifications Table 5.5.5-1 Ghosting Requirements Table 5.6.1-1 VSWIR Bands Absolute Radiometric Uncertainty Requirements Table 5.6.1-2 TIR Bands Absolute Radiometric Uncertainty Requirements Table 5.6.2.1-1 Reference Radiances, Noise Requirements, and Maximum Expected

Radiance Requirements Table 5.6.5-1 Relative Radiometric Product Stability during Instrument Lifetime Table 5.7-1 Image Requirement to Processing Algorithm Verification Mapping Table 5.7.1-1 Landsat Next Band Co-Registration Performance Requirements

1.0 INTRODUCTION

1.1 PURPOSE

The purpose herein of this document is to impose requirements onto the Landsat Next Instrument Suite (LandIS).

1.2 SCOPE

The Landsat Next Instrument Suite Requirements Document (LaRD) establishes a set of Level 3 requirements for the LandIS imaging sensor(s) for flight in support of the Landsat Next Project.

As a Level 3 document, it contains the functional and performance requirements.

These requirements do not assume the LandIS must be implemented only as a single instrument or telescope and is intended to allow for a wide range of instrument solutions, including scanning methods and disaggregation by spectral regions. However, if multiple imagers are employed, it must be shown how key relative requirements such as Band-to-Band registration and Simultaneity are achieved, as described in the Landsat Next Landsat Instrument Suite (LandIS) Statement of Work (SOW) (LNEXT-LANDIS-SOW-0003).

The following definitions apply to the action verbs used in this requirements document:

• Shall: Directive – Compliance by the Contractor is mandatory. Any deviations from these contractually imposed mandatory requirements require the approval of the contracting officer.

• May: Permissive – Allows an option for compliance at the discretion of the Contractor or Government.

• Will: Informative – Designates the intent of the Government. Unless required by other contract provisions, noncompliance with the will requirements does not require approval of the contracting officer and does not require documented technical substantiation.

• Should: Advisory – Gives guidance to the Contractor for the performance of this contract.

• Must: Advisory – Notifies the Contractor of important relevant conditions that may be outside the context of this contract.

When this document states a requirement for the LandIS to collect scenes, this is to be interpreted to mean that the LandIS instrument will collect imagery intervals sufficient to produce the scenes. The Worldwide Reference System-3 (WRS-3) Scenes are actually generated as part of the Data Processing and Archive Segment (DPAS) after the data has been sent back to the United States Geological Survey (USGS) / Earth Resources Observation and Science (EROS) facility in Sioux Falls, South Dakota. The quality of the mission data (imagery) returned and processed at the EROS facility forms one of the many steps for determining if image data quality requirements have been successfully met. See the Landsat Next Mission Operations Concept Document (LNEXT-SYS-PLAN-0007) for a more complete discussion of the operations.

1.3 RELATED DOCUMENTATION

1.3.1 Applicable Documents

Document Number Title Revision Applicable Section(s) Goddard S-311-P-079 Specification

Procurement Specification for Thermofoil Heater

E All

Goddard S-311-P-18 Specification

Specification for Thermistor, (Thermally Sensitive Resistor), Insulated and Uninsulated, Negative Temperature Coefficient

L All

Goddard S-311-641/02 Specification

Detail Specification for Switch, Thermostatic, Bimetallic, SPST, Narrow Differential, Hermetic

A All

NASA-STD-4003 Electrical Bonding for NASA Launch Vehicles, Spacecraft, Payloads, and Flight Equipment

A w/CHANGE

Section 4.1.4, Appendix B.3.4

NASA-STD-8719.14 Process for Limiting Orbital Debris C All NPR 8715.6 NASA Procedural Requirements for

Limiting Orbital Debris and Evaluating the Meteoroid and Orbital Debris Environments

B All

Wyatt, C.L., Privalsky, V. and Datla, R., 1998.

Recommended practice;

symbols, terms, units and uncertainty analysis for radiometric sensor calibration. National Institute of Standards and Technology

Wyatt, C.L., Privalsky, V. and Datla, R., 1998. Recommended practice;

symbols, terms, units and uncertainty analysis for radiometric sensor calibration. National Institute of Standards and Technology

N/A All

CCSDS 123.0-B-2 Low-Complexity Lossless and Near-lossless Multispectral and Hyperspectral Image Compression

Recommended Standard, Issue 2, Technical corrigendum 3

All

IEST-STD-CC1246 Product Cleanliness Levels and Contamination Control Program

E Annex D

NIMA TR8350.2 Department of Defense World Geodetic System 1984

Third Edition, Amendment 1

All

Digital Elevation Model

(DEM)

Digital Elevation Model (DEM) Collection-2 All

In this document, citations are assumed to be the latest version unless otherwise noted.

This document table was generated from the Landsat Next Common Reference and Applicable Documents List (LNEXT-MGMT-DESC-0008) Rev C.

1.3.2 Project Applicable Documents

Document Number Title Applicable Section(s) LNEXT-SYS-REQ-0005 Landsat Next Environmental Requirements

Document (LNERD) 2.4.5.3

In this document, citations are assumed to be the latest version unless otherwise noted.

This document table was generated from the Landsat Next Common Reference and Applicable Documents List (LNEXT-MGMT-DESC-0008) Rev C.

1.3.3 Reference Documents

Document Number Title Revision GSFC-STD-1000 Rules for the Design, Development, Verification, and Operation of Flight Systems H

GSFC-STD-7000 General Environmental Verification Standard (GEVS) for GSFC Flight Programs and Projects

B

Public Law #105-303 “Commercial Space Act of 1998,” Public Law #105-303, 112 Stat., 2843., H.R. 1702, 105th Congress, Adopted October 28, 1998

N/A

Public Law #102-555 “Land Remote Sensing Policy Act of 1992,” Public Law #102-555, 106 Stat. 4163., H.R.

6133, 102nd Congress, Adopted October 28, N/A

In this document, citations are assumed to be the latest version unless otherwise noted.

This document table was generated from the Landsat Next Common Reference and Applicable Documents List (LNEXT-MGMT-DESC-0008) Rev C.

1.3.4 Project Reference Documents

Document Number Title LNEXT-LANDIS-REQ-0016 Landsat Next Instrument Suite (LandIS) GSFC-STD-1000, Goddard

Open Learning Design (GOLD) Rules, Applicability Matrix LNEXT-LANDIS-SOW-0003 Landsat Next Landsat Instrument Suite (LandIS) Statement of Work

(SOW)

LNEXT-SYS-DESC-0007 Landsat Next Geometric Error Budget (GEB) Support Presentation LNEXT-SYS-DESC-0016 Landsat Next Geometric Error Budget (GEB) LNEXT-SYS-PLAN-0007 Landsat Next Operations Concept (Ops Con) Document LNEXT-SYS-REQ-0009 Landsat Next Space Environments Requirements Document (LSERD) LNEXT-SYS-TN-0001 Systems Technical Memo - Debris Casualty Area (DCA) Suballocation for Landsat Next LSDS-2389 Landsat Next Design Reference Case – 18 Days (DRC-18) Definition In this document, citations are assumed to be the latest version unless otherwise noted.

This document table was generated from the Landsat Next Common Reference and Applicable Documents List (LNEXT-MGMT-DESC-0008) Rev C.

2.0 MISSION OVERVIEW

2.1 MISSION STATEMENT

Landsat Next, consistent with United States (U.S.) law and government policy, will continue the Landsat program's acquisition, archival, and distribution of multi-spectral imagery affording global, synoptic, and repetitive coverage of the Earth's land surfaces at a scale where natural and human-induced changes can be detected, differentiated, characterized, and monitored over time.

2.2 MISSION BACKGROUND

Following the successful launch of Landsat 8 (formally named Landsat Data Continuity Mission, LDCM) in February 2013, and during the development of Landsat 9, the United States Geological Survey (USGS) and National Aeronautics and Space Administration (NASA) recognized the need to assemble a team of experts from within both agencies to evaluate how to inform an acquisition strategy for the Landsat mission to follow Landsat 9. The NASA-USGS Joint Agency Sustainable Land Imaging (SLI) Architecture Study Team (AST) was formed in September 2018 and was tasked with investigating how to best satisfy the diverse set of user needs collected in the USGS “User Needs for the Sustainable Land Imaging Program – Release 2.0.” These investigations resulted in a set of recommendations to the headquarters of both agencies, delivered in December 2019. The highest-recommended “Roadmap 1” architecture described a small constellation of “superspectral” space-based sensors that would substantially improve the spectral, spatial, and temporal capabilities of previous Landsat missions, while continuing to satisfy the primary goal of ensuring a highly calibrated data set that maintains compatibility with the legacy data of the Earth’s land mass held in the National Satellite Land Remote Sensing Data Archive (NSLRSDA) at USGS’s Earth Resources and Observation Science (EROS) Center. In April 2020 NASA/Goddard Space Flight Center (GSFC) received authorization to initiate the Landsat Next project consistent with the AST’s Roadmap 1 recommendation.

The goal of Landsat Next is to continue the acquisition, archival, and distribution of multi-spectral imagery affording global, synoptic, and repetitive coverage of the Earth's land surfaces at a scale where natural and human-induced changes can be detected, differentiated, characterized, and monitored over time. This goal is in keeping with the Landsat programmatic goals stated in both the Commercial Space Act of 1998 (Public Law 105-303) and the Land Remote Sensing Policy Act of 1992 (Public Law 102-555). This policy requires that the Landsat Program provide data into the future that is sufficiently consistent with previous Landsat data to allow the detection and quantitative characterization of changes in or on the land surface of the globe.

Landsat Next continues the long-running partnership of NASA and USGS, with NASA providing the space and launch segments and USGS providing the ground system, providing the longest continuous global record of the Earth’s surface. The Landsat series of satellites have continuously acquired multispectral images of the global land surface since the launch of the Earth Resources Technology Satellite (ERTS, later renamed Landsat 1) in 1972. The Landsat data archive constitutes the longest continuous moderate-resolution record of the global land surface as viewed from space.

2.3 MISSION OBJECTIVES

Landsat Next has these major mission objectives:

• Collect and archive moderate resolution, Visible Through Short Wave Infrared (VSWIR) reflective and Thermal Infrared (TIR) emissive image data affording seasonal coverage of the global landmass for a continuous period of not less than five (5) years.

• Ensure that Landsat Next data are sufficiently consistent with data from the earlier Landsat missions in terms of relative acquisition geometry, calibration, coverage characteristics, spectral characteristics, output product quality, and data availability to permit studies and management of land cover along with land and water resource change over multi-decadal time periods.

• Ensure Landsat Next is responsive to critical emerging user needs and applications as characterized by periodic assessment, currently the User Needs for the Sustainable Land Imaging Program July 2018, Release 2.0, and identified by the operational requirements for collection, processing, archiving, and distribution of land surface data to the United States Government and other users.

• Distribute Landsat Next data products to the public on a nondiscriminatory basis.

2.4 MISSION IMPLEMENTATION

NASA and USGS each have specific responsibilities for Landsat Next and will deliver the major elements to the overall mission. NASA will provide the Space and Launch Segments of Landsat Next, and USGS will provide the Ground System and mission operations. NASA/GSFC will provide overall Landsat Next project management, mission system engineering, and mission assurance during development and will transition the mission to USGS following on-orbit commissioning.

The Landsat Next post-launch nominal mission operations concept is shown graphically in the Figure below.

Figure 2.4-1 Landsat Next Operations Concept

(Generated from Landsat Next Common Mission Architecture Diagram LNEXT-SYS-DESC-0022 Rev -)

2.4.1 Space Segment

NASA/GSFC will provide the Space Segment, which will consist of a constellation of three observatories flying in coordinated sun-synchronous orbits at 653km altitude, each with nominally identical spacecraft and instrument suites. The observatories will be equally spaced in the orbit, providing in aggregate a six-day ground repeat period at the equator.

The instrument suites will each provide 26 spectral bands with a maximum ground sampling distance of 10m-60m dependent on the spectral band, covering a swath on the ground of approximately 164km on a ground track defined by a world-wide reference system known as

WRS-3.

2.4.2 Ground Segment

The Landsat Ground Segment currently supports mission operations for Landsats 8 and 9.

Landsat Next takes advantage of developments on these missions and will upgrade and expand the current systems to accommodate Landsat Next. The Landsat Ground Segment consists of the Ground System (GS) and its external interfaces, including NASA institutional services. The GS includes the Mission Operations Center (MOC), the Ground Network (GN), and the Data Processing and Archive System (DPAS). External interfaces include NASA's Near Space Network (NSN) and Advanced Communications Capabilities for Exploration and Science Systems (ACCESS), GSFC Conjunction Assessment and Risk Analysis (CARA) and its Flight Dynamics Facility, along with other external interfaces.

The MOC provides the primary means to control and monitor the Landsat Next constellation.

The Landsat Next Flight Operations Team (FOT) at the MOC performs mission planning and scheduling, command and control, health and status monitoring, orbit and attitude maintenance, performance analysis, onboard memory management, and flight and ground software maintenance. The FOT utilizes MOC functionality to detect, investigate and resolve spacecraft anomalies and monitor the instrument image collections from the onboard constellation and generate special image collections. The MOC ingests, processes and archives data via the GN.

The GN includes geographically dispersed ground station resources for mission execution and includes both the Landsat Ground Network (LGN) and a wideband data routing capability, which transfers mission data to DPAS across wide area networks. The LGN provides communication capability for each observatory of the constellation for commanding and housekeeping data via the S-Band and will receive mission data from each observatory over a Ka-band downlink.

The DPAS ingests mission data from the GN, processes the mission data to form data products, and archives the data products (Level 0, Level 1R, Level 1Gs, Level 1T). The DPAS also provides a long-term archive capability for raw data and allows the user community to query, download, and directly interact in the cloud with Landsat Next data products, via a public-facing web portal for receiving data products. The DPAS is located at USGS Earth Resources Observation and Science (EROS) near Sioux Falls, South Dakota.

The USGS will lead overall Landsat Next GS development. The USGS will also lead integration of the GS and ensure timely completion of ground readiness testing in preparation for NASA-led mission readiness activities. The MOC will perform planning, scheduling, and observatory operations activities during Landsat Next mission readiness testing.

2.4.3 Launch Segment

The Launch Segment will provide the assets and services associated with the Launch Vehicle (LV) and the constellation-to-LV integration. This will include the LV; all Launch Vehicle- Ground Support Equipment (LV-GSE), property, and facilities to integrate the constellation to the LV and verify their integration; and prelaunch testing with ground-based functions. The launch vehicle and launch site are TBD. The three observatories comprising the Landsat Next constellation will be launched together on the same launch vehicle.

Sections 2.0-2.4.3 were generated using Landsat Next Common Boilerplate (LNEXT-MGMT- DESC-0005) Rev C

3.0 FUNCTIONAL OVERVIEW

The LandIS is a 26 spectral band sensor providing Visible / Near Infrared / Short Wave Infrared / Thermal (Long Wave) Infrared (Thermal IR) (VNIR/SWIR/TIR) imagery consistent with Landsat spectral, spatial, radiometric and geometric qualities as specified in Section 5.0 of this document. The LandIS produces imaging sensor data and instrument ancillary data, both of which are sent to the spacecraft. The spacecraft will combine the imaging sensor data and instrument ancillary data with the spacecraft ancillary data to form mission data. Spacecraft ancillary data includes such items as spacecraft (SC) attitude, navigation, timing data and key telemetry values from SC sensors. The combined observatory (instrument plus spacecraft) ancillary data provides all necessary image reconstruction information for later ground processing.

The LandIS includes but is not limited to the sensor module(s), all associated sensor control electronics and power modules, all required control, signal processing and data formatting, data reduction and data compression electronics, the instrument deck and mounting flexures and all associated hardware (brackets, harnesses, etc.), and all hardware and software required to meet sensor performance requirements, including operational and survival heaters and associated hardware. LandIS receives operational power from the spacecraft, which is used to power components in all on-orbit configurations with the exception of the Survival configuration. In the Survival configuration, operational power is removed and only separate redundant survival power feeds supplied by the spacecraft remain enabled. This survival power will be used to power survival components supplied as part of LandIS.

4.0 LANDIS SYSTEM LEVEL

4.1 GENERAL

LaRD-153 The LandIS shall meet the nadir imaging requirements at all points throughout the operational orbit defined in Table 4.1-1, throughout the year, throughout the mission.

Rationale: Take an image anywhere within the orbit, sunlit or eclipse, and at the full range of altitude variation.

Table 4.1-1 Landsat Next Operational Orbit

Parameter Value Allowable Variation

Equatorial Altitude 653 km

(OO-1-1)

± 1.0 km

(OO-1-2)

Inclination (True – of – Date) 97.9835 °

(OO-2-1)

± 0.1°

(OO-2-2)

Mean Eccentricity (Brouwer-Lyddane) 0.00116

(OO-3-1)

<=0.00125

(OO-3-2)

Across track, ground track error at the descending node

0.0 km

(OO-4-1)

± 5.0 km

(OO-4-2)

Mean Local Time at Descending Node 10:10

(OO-5-1)

± 5 minutes

(OO-5-2)

Ground Track Spacing at Equator 151 km

(OO-6-1)

Mean Semimajor Axis 7026.33 km

(OO-7-1)

± 1.0 km

(OO-7-2)

Mean Argument of Perigee (deg) 90.0°

(OO-8-1)

Altitude Range 651 to 681 km

(OO-9-1)

This table was made from the Landsat Next Common Operational Orbit Tables LNEXT-SYS-DESC-0019 Rev -

LaRD-157 The LandIS shall meet the radiometric performance requirements when the

LandIS Observatory points up to 13.4 degrees, off-nadir, to either side of the current along-track orbit plane.

Rationale: The LandIS half Field of Regard (FOR) is 7.2 degrees, including overlap, supporting a cross-track swath width of 164 km, defined as 151 km + overlap of 5 km on each side + 3 km for ground error margin. Therefore, excluding overlap, off-nadir imaging up to 13.4 degrees either side of the along-track orbit plane allows imaging of an entire adjacent Worldwide Reference System (WRS-3) path on either side at the equator.

LaRD-159 The LandIS shall acquire a maximum of up to 9 minutes of continuous off-nadir imaging within a single orbit period.

Rationale: The LandIS may be needed to image an off-nadir interval encompassing the entire orbital along-track duration over Contiguous United States (CONUS), such as for emergency response. This interval duration is up to 9 minutes. LandIS must be able to maintain thermal stability and be fully functional in off-nadir pointing attitudes for this length of off-nadir imaging sequence.

LaRD-161 The LandIS shall acquire a maximum of up to 36 minutes of continuous daylight imaging within a single orbit period.

Rationale: See the design reference missions in the Landsat Next Mission Operations Concept (LNEXT-SYS-PLAN-0007) and DRC-18 (LSDS-2389) which describes the longest possible daylight contiguous land pass.

LaRD-163 The LandIS shall acquire a maximum of up to 15 minutes of continuous nighttime imaging within a single orbit period.

Rationale: 15 minutes of nighttime imaging on the ascending node is sufficient in support of emergency response, volcano and fire coverage, and urban sprawl assessment.

Note: There will be non-imaging time between daylight and nighttime imaging.

See the design reference missions in the Landsat Next Mission Operations Concept Document (LNEXT-SYS-PLAN-0007), which provides a possible lunar imaging scenario for calibration using the moon.

LaRD-165 The LandIS shall be commandable into any defined operational configuration.

Rationale: So LandIS can be commanded into any valid operational mode.

4.2 LANDIS SYSTEM LIFETIME

LaRD-169 The LandIS instrument shall be designed for a 3-year life after completion of observatory commissioning.

Rationale: Additional selective redundancy for LandIS is specified in LaRD-2716 and further in Section 4.5.

LaRD-2716 The LandIS mechanisms and limited life items shall be designed for a 5-year mission life.

4.3 MISSION PHASES

Reserved

4.3.1 Ground Storage Phase

Reserved

4.3.2 Pre-Launch Phase

LaRD-181 The LandIS shall be able to power-on and operate in an ambient environment to facilitate functional testing.

Rationale: Components are to have the capability to power-on to check aliveness and functionality. Applies to components that cannot meet performance requirements at ambient temperatures such as cryogenic components.

LaRD-189 The LandIS shall perform aliveness tests while mated to the launch vehicle.

Rationale: To ensure the instrument is ready for launch, on pad testing will be performed.

4.3.3 Launch and Early Orbit Phase

LaRD-192 The LandIS shall survive the Launch and Early Orbit mission phase with no operational power applied.

Rationale: LandIS needs to be able to remain in its Survival Configuration indefinitely once the spacecraft enables the survival power for LandIS survival heaters. The spacecraft has the responsibility to enable the survival heater power in a timely manner (i.e., before LandIS temperatures drop below survival temperature limits). Following launch vehicle separation, spacecraft deployment into a power and thermally safe sun pointing attitude, and initial critical spacecraft activation and checkout activities, ground operations will determine when operational power may be safely applied for initiation of instrument activation and checkout.

4.3.4 Commissioning Phase

LaRD-1991 The LandIS shall be ready to support nominal imaging activities 28 days after on-orbit instrument power-on.

Rationale: Provides a reasonable amount of time for activation and bakeout activities. Does not preclude having the LandIS send test pattern data.

4.3.5 Operational Phase

LaRD-202 During the operational phase, the LandIS shall meet the performance requirements within this document.

4.3.6 Decommissioning Phase

LaRD-1992 The LandIS shall result in a debris footprint after re-entry of less than 22 square meters, per NASA Procedural Requirements (NPR) for Limiting Orbital Debris and Evaluating the Meteoroid and Orbital Debris Environments (NPR 8715.6), and Process for Limiting Orbital Debris

(NASA-STD-8719.14).

Rationale: Reference LNEXT-SYS-TN-0001, Systems Technical Memo - Debris Casualty Area (DCA) Suballocation for Landsat Next.

4.4 OPERATIONAL ORBIT

LaRD-207 The LandIS shall meet performance requirements with the operational orbit parameters listed in Table 4.1-1.

Rationale: The WRS-3 orbit will be used by the Landsat Next Observatory. LandIS’s performance may be evaluated at any point in the orbit based on this reference system.

4.5 REDUNDANCY REQUIREMENTS

LaRD-211 The LandIS shall be designed such that no single credible failure in the

Mechanisms, Thermal, and Power Systems permanently precludes the Landsat Next from meeting the mission requirements throughout the design life.

Rationale: Mechanisms, Thermal and Power Subsystems are critical to mission success.

Redundancy in these subsystems ensures higher probability of mission success. Credible failure is defined as Probability of greater than 0.1% in Landsat Next Instrument Mission Assurance Requirements (IMAR), LNEXT-SMA-REQ-0013, Table 4.2-2.

(Ref: LandIS GSFC-STD-1000, Goddard Open Learning Design (GOLD) Rules, Applicability Matrix (LNEXT-LANDIS-REQ-0016), and Rules for the Design, Development, Verification, and Operation of Flight Systems (GSFC-STD-1000), GOLD Rule 1.05)

LaRD-3428 The LandIS shall be designed to preclude the propagation of LandIS component or subsystem failures, to other LandIS components or subsystems, or to the spacecraft.

Rationale: Prevent propagation of failures to SC or other LandIS subsystems.

LaRD-2973 The LandIS shall provide redundant secondary power converters that are cross-strapped to LandIS internal electronics that require regulated voltage.

Rationale: Provides added robustness through LandIS select redundancy.

LaRD-213 When the LandIS is powered, the LandIS shall provide the power status of components.

Rationale: It is important to know the state of all powered components, both primary and redundant.

LaRD-2809 Springs shall be failure tolerant unless spring failure can be shown to be non-credible.

Rationale: Spring redundancy greatly improves mechanism reliability

LaRD-2810 For applications where the motor performance parameters are critical (i.e.

torque margin, mechanism stall, and flea torque) to the mission success, stepper motors shall employ primary and redundant windings that can each independently satisfy all motor performance requirements.

Rationale: Redundant stepper motors used in critical applications such as optical instrument aperture covers and pointing systems typically increase reliability.

LaRD-2829 All LandIS heaters, mechanical thermostats, and thermistors shall conform to their appropriate NASA Goddard S-311 specification for high reliability thermal hardware (S-311-P-079, S-311-641/02, S-311-P-18).

Rationale: High reliability thermal hardware ensures long life for components which could break if temperatures fall outside of temperature limits.

LaRD-2830 All LandIS heaters shall have a primary and redundant circuit.

Rationale: Redundant heater circuits ensure temperatures stay within limits even if there is a hardware failure.

LaRD-2831 All LandIS mechanical thermostats, if used, shall have two thermostats in series for each circuit.

Rationale: Two mechanical thermostats in series prevents a failed-on thermostat overheating the hardware beyond its hot temperature limit.

LaRD-2832 Any LandIS software controlled heaters, if used, shall have a primary and redundant thermistor at each heater location.

Rationale: Primary and redundant thermistors prevent a failed thermistor from erroneously taking the heater circuit outside of the hardware's temperature limits.

LaRD-2974 The survival heaters shall be functionally redundant.

Rationale: Provides added robustness through LandIS select redundancy.

4.6 AUTONOMY AND SAFE CONFIGUATION

LaRD-2773 The LandIS shall survive the sudden unannounced removal of operational power while in any mode.

Rationale: Certain electrical system failure modes may result in unannounced removal of LandIS power from which LandIS must be able to recover. There may be other failure scenarios where power is removed from LandIS, but whenever possible, the spacecraft will allow for a graceful safing and/or power down.

LaRD-228 The LandIS shall override autonomous functions, automatic safing or switchover via command.

Rationale: This permits diagnosis of failures and anomalies within the instrument via command.

LaRD-230 The LandIS shall report autonomous state changes and reconfigurations in housekeeping telemetry.

Rationale: This permits detection of failures and anomalies within the instrument.

LaRD-425 The LandIS shall place itself in a safe configuration within 45 (TBR) seconds upon receipt of a safing command.

Rationale: The spacecraft will send a command (likely a discrete pulse command) to inform the instrument of a need to go to its safe mode. Assuming nominal spacecraft attitude rates and a command to safe if the sun were to enter the glint free field of view, then 45 (TBR) seconds is about how long it takes the sun to reach the instrument aperture.

LaRD-446 LandIS shall survive direct solar illumination on any surface while in safe configuration without damage to any instrument surfaces or components.

Rationale: If necessary, the instrument will need to provide protection against direct solar illumination.

LaRD-1196 The LandIS shall automatically detect and report in housekeeping telemetry hardware and software out-of-limit and fault conditions.

Rationale: Report out-of-limits and fault conditions in housekeeping telemetry for observation by operations and autonomous response by spacecraft, if necessary.

LaRD-1235 The LandIS shall provide housekeeping telemetry to ensure proper control and monitoring of LandIS health and safety.

Rationale: For proper insight into the state of health and ongoing instrument activities, memory dumps, etc. Also allows for spacecraft fault monitoring and response of LandIS telemetry.

LaRD-2769 The LandIS shall remain safe without ground intervention indefinitely, when placed in Safe Configuration.

Rationale: While in steady state Safe Configuration, LandIS will remain indefinitely, until intervention and recovery to normal operation. To bound the timeframe for verification purposes, 28 days may be used to represent that period of steady state condition.

LaRD-2770 The LandIS shall exit Safe Configuration by command.

Rationale: Exiting Safe configuration autonomously, without proper ground evaluation and intervention, could place the LandIS at risk of damage or degradation.

LaRD-2774 The LandIS shall be reconfigurable to a Safe configuration in the event of anomalous conditions.

Rationale: LandIS needs to be able to configure itself to a safe configuration upon detection of anomalous conditions. The fault, fault detection, and initiation of fault response may occur or be initiated by the spacecraft or LandIS.

LaRD-2775 The LandIS shall transition to a safe configuration upon loss of time message/handshake with the spacecraft, with a persistence that is alterable per LaRD-444.

Rationale: Loss of time code messages here is used as an indicator of loss of communications with the spacecraft bus. The instrument needs to be safe in this case without relying on communications with the spacecraft. The term survive is as defined in the Appendix B.

LaRD-444 The LandIS stored number of missed time of day messages which result in safe configuration shall be alterable on-orbit over the range of one (1) up to a maximum of 63 consecutive time of day messages.

Rationale: Allowing the number of consecutive loss of time of day messages here allows for the duration of the communications outage to be varied before the instrument response. Assumes time of day messages are received at 1Hz.

4.7 AVAILABILITY

LaRD-237 The LandIS shall be available to acquire imaging sensor data without interruption during the sunlit imaging sequences that contain a land mass or coastal area.

Rationale: USGS source for defining land masses and coastal areas is the Long Term Acquisition Plan (LTAP).

Availability is based on meeting the radiation environment confidence level defined in the Landsat Next Space Environments Requirements Document (LSERD), LNEXT-SYS-REQ- 0009.

The instrument is considered unavailable (and thus not meeting LaRD-237) for times in which either:

1) the instrument is not meeting performance requirements, or

2) the instrument is performing calibration or maintenance procedures necessary for satisfying performance requirements.

The instrument is considered available for all other times.

LaRD-3307 The LandIS calibration and maintenance activities shall be performed on a non-interference basis with nominal science imaging operations.

Rationale: Ongoing maintenance and calibration should be scheduled or performed without affecting the availability requirement (LaRD-237).

LaRD-3273 Over an 18 day cycle, the LandIS shall have no more than 0.05% (TBR) data loss of imaging sensor data and instrument ancillary data collected and transferred to the spacecraft.

Rationale: This is measured from receipt of the raw detector data to delivery of imaging sensor data and instrument ancillary data to the SC, assuming an 18 day rolling period.

4.8 GROUND SUPPORT EQUIPMENT (GSE)

LaRD-3308 LandIS GSE delivered to the SC vendor and intended for use in a cleanroom shall meet VC-0.5-1000 or better per Product Cleanliness Levels and Contamination Control Program (IEST-STD-CC1246), Annex D, upon cleanroom ingress.

Rationale: Cleanliness of GSE surfaces will help ensure GSE does not contaminate flight hardware surfaces.

LaRD-3309 LandIS GSE delivered to the SC vendor and intended for use in a cleanroom shall be cleanable by using standard cleaning methods, including but not limited to isopropyl alcohol wiping, vacuuming, gaseous blow-off, and/or ultrasonic cleaning.

Rationale: This avoids the need for specialty solvents or equipment when cleaning the GSE.

LaRD-3310 The LandIS GSE to be used in a vacuum shall be compatible with the tested temperature range of the LandIS flight hardware within the chamber.

Rationale: The LandIS GSE will not limit the testing temperature range of the LandIS flight hardware.

4.8.1 Shipping/ Storage Container(s)

LaRD-315 The LandIS Shipping and Storage Container(s) shall be reusable, water-resistant, fire-resistant, and contain a filtered purge capability.

Rationale: These features will ensure the integrity of the shipping and storage environment.

LaRD-317 The LandIS Instrument Shipping and Storage Container(s) shall be instrumented to continuously measure and record shocks, temperature, and humidity within the container.

Rationale: Knowing these environmental parameters is necessary to guarantee that the flight hardware has not been compromised by moisture, temperature, and shock loads.

LaRD-318 The LandIS Instrument Shipping and Storage Container(s) shall have external indicators for temperature, pressure, and humidity monitoring.

Rationale: The internal environment of the container volume needs to be monitored regularly and without opening up the container to do a direct measurement.

LaRD-3402 The LandIS Instrument Shipping and Storage Container(s) shall provide accommodations for contamination monitoring.

Rationale: Contamination monitoring is dependent on the approach for LandIS contamination control while in the container. For example, may use air particle counter for air flow monitoring and/or mount witness mirror for periodic measurements of molecular contamination and particulate fallout, etc.

LaRD-322 The LandIS Instrument Shipping and Storage Container(s) shall be cleanable by using standard cleaning methods, including but not limited to isopropyl alcohol wiping, vacuuming, gaseous blow-off, and/or ultrasonic cleaning.

Rationale: This avoids the need for specialty solvents or equipment when cleaning the LandIS Instrument Shipping and Storage Container(s).

5.0 IMAGERY REQUIREMENTS

5.1 GENERAL

LaRD-366 The LandIS shall have a minimum field of regard (FOR) that provides a continuous 164 km wide cross-track swath width, including overlap, at the equator for the Landsat Next operational orbit.

Rationale: Provides for full coverage at the equator including overlap. The 164 km includes 151 km swath width at equator plus 10 km of overlap plus 3 km for ground track error.

5.2 ON-ORBIT CONFIGURATIONS

5.2.1 Survival Configuration

LaRD-382 The LandIS shall include survival heaters to ensure the instrument stays within the design, survival temperature range.

Rationale: In this configuration, the SC will supply survival heater power but the sizing, and placement of the heaters is the LandIS contractor’s responsibility.

LaRD-384 Upon exiting Survival configuration, the LandIS shall meet performance specifications for all bands within 1 week (TBR).

Rationale: Survive indefinitely for worst case thermal conditions with only Survival Power applied, and with end-of-life optical properties and worst case Solar/IR/Albedo fluxes used in the thermal model. LandIS should be able to acquire image calibration data in normal science mode at stable operational conditions as soon as possible (1 week maximum is based on Landsat 8 (L8) and Landsat 9 (L9) experience) for all bands. These calibration datasets would provide assessment of radiometric and geometric image performance and allow calibration parameter files to be updated to bring final data products back within specs, if necessary. This requirement does not preclude the possibility that some bands may be operational before other bands (e.g.

VNIR bands before TIR bands).

LaRD-3313 Upon exiting Survival configuration, the LandIS shall be able to complete a full aliveness checkout within 6 hours (TBR).

Rationale: An electrical checkout of the full instrument should be performed as soon as possible to ensure there are no damaged components. Telemetry from the aliveness test would aid assessment of possible image calibration updates that may be needed to compensate for any changes due to the survival conditions. Refer to Landsat Next Landsat Instrument Suite (LandIS) Statement of Work (SOW) (LNEXT-LANDIS-SOW-0003) for aliveness test definition.

5.2.2 Power-On Configuration

LaRD-387 The LandIS shall initialize to a known, repeatable configuration upon application of Operational Power.

Rationale: Need a basic engineering state in which to power-on and proceed to configure the instrument into its nominal science configuration.

LaRD-389 The LandIS, once initialized following application of Operational Power, shall remain in current configuration until commanded to a different configuration.

Rationale: It is used for the initial power-on of the instrument electronics and can be performed while the LandIS is at the extremes of the survival temperature range.

LaRD-391 The LandIS shall be able to power-on after exposures to both hot and cold survival (non-operating) temperature conditions.

Rationale: It is possible to power LandIS…