Attachment L - L10 Analytical Math Model Definitions (LAMMD) Rev.pdf

Attachment No. L

Landsat 10 Analytical Math Model Definitions (LAMMD)

RFP 80GSFC26R0015

National Aeronautics and Space Administration Goddard Space Flight Center

Landsat 10 LAMMD L10-SYS-DESC-0003 Revision B ii Use or disclosure of data contained on this page is subject to the restriction(s) on the title page of this document.

Landsat 10 Analytical Math Models Definitions Signature/Approval Page

Prepared by:

Electronic Signature in TDMS Approval Date in TDMS Michael Pryzby Date Landsat 10 Space Environments Engineer NASA/GSFC, Code 426

Approved by:

Cagatay Aymergen Date Landsat 10 Deputy Project Manager / Acting Observatory Manager

Charles Clark Date Landsat 10 Instrument Systems Engineer NASA/GSFC, Code 590

Ross Henry Date Landsat 10 Project Manager

Evan Webb Date Landsat 10 Mission System Manager NASA/GSFC, Code 533 iii Use or disclosure of data contained on this page is subject to the restriction(s) on the title page of this document.

CM Foreword This document is a Landsat 10 Project Configuration Management (CM)-controlled document.

Note: Prior to February 2026, the project name was Landsat Next (LNext).

For the purposes of configuration management, the prefixes “LNEXT” and “L10” are completely interchangeable. For example, LNEXT-MGMT-PLAN-0004 is the same as L10-MGMT-PLAN- 0004.

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 10 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 10 Project Office, Code 426 Attention: Configuration Management Office Greenbelt, Maryland 20771 iv Use or disclosure of data contained on this page is subject to the restriction(s) on the title page of this document.

Change History Log v Use or disclosure of data contained on this page is subject to the restriction(s) on the title page of this document.

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

Name/Org.

Due Date

TBx-1 Section 7.3

The Observatory FEM, the origin and location of the ‘reference coordinate system’ for all nodes will be defined in the Landsat Spacecraft and Launch Vehicle Interface Requirements Document (TBD).

LSP L-2Y

vi Use or disclosure of data contained on this page is subject to the restriction(s) on the title page of this document.

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

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

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

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

TABLE OF CONTENTS .............................................................................................................. VI

LIST OF FIGURES .................................................................................................................... VIII

LIST OF TABLES ...................................................................................................................... VIII

1.0 INTRODUCTION

1.1 Landsat 10 Related Documentation

1.1.1 Reference Documents

1.1.2 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 GLOBAL MODELING GUIDELINES

3.1 Model Submittal and Configuration Control

3.2 Model Archival in the Landsat 10 Library

3.2.1 File Management Control

3.2.2 Model Log Entries

3.2.3 Access Control

3.3 Documentation

3.4 Coordinate Systems

3.5 Mass Conventions

3.6 Units

4.0 MODEL MATERIAL PROPERTIES

4.1 Structural Properties

4.2 Thermal Properties

4.3 Thermal Environmental Parameters

5.0 STRUCTURAL SOLID MODELING

5.1 Structural Model Format

5.2 Model Numbering

5.3 Documentation

5.4 Model Checks

vii Use or disclosure of data contained on this page is subject to the restriction(s) on the title page of this document.

6.0 REDUCED CAD MODELING (ENVELOPE)

6.1 Structural Model Format

6.2 Model Numbering

6.3 Documentation

6.4 Model Checks

7.0 STRUCTURAL MODELING (FEM)

7.1 Finite Element Model Format

7.2 Finite Element Model Numbering

7.3 Documentation

7.4 Model Checks

7.5 Analysis Results

8.0 THERMAL MODELING

8.1 Thermal Modal Format

8.2 Thermal Model Numbering Scheme

8.3 Documentation

8.3.1 Outline of Thermal Model Exchange Document

8.4 Model Checks

9.0 REDUCED THERMAL MODELING (INTERGRATED LV ANALYSIS)

9.1 Thermal Model Size

9.2 Geometric Math Model (GMM) Configuration

9.3 Thermal Math Model (TMM) Configuration

9.4 Documentation

9.4.1 Outline of Thermal Model Exchange Document

9.5 Model Checks

10.0 STRUCTURAL/THERMAL/OPTICAL PERFORMANCE POINTING ANALYSIS

10.1 Model Format

10.2 Model Numbering Scheme

10.3 Documentation

10.4 Model Checks

11.0 ATTITUDE CONTROL SYSTEM MODELING

11.1 Scope of Attitude Control System Model

11.2 Model Naming Convention

11.3 Coordinate Systems

11.4 Documentation

11.5 Model Checks

APPENDIX A ABBREVIATIONS AND ACRONYMS

APPENDIX B DEFINITIONS

viii Use or disclosure of data contained on this page is subject to the restriction(s) on the title page of this document.

List of Figures Figure 2.4-1 Landsat 10 Mission Architecture

List of Tables Table 2.4.1-1 Landsat 10 Mission Parameters Table 3.2.1-1 Example of Configuration Log Spreadsheet for Individual Models/Files Table 3.2.1-2 Configuration Log of Integrated Models Identifying Subassembly Files Table 4.3-1 Recommended Thermal Environmental Parameters for Landsat 10

Use or disclosure of data contained on this page is subject to the restriction(s) on the title page of this document.

1.0 INTRODUCTION

This document defines guidelines for the format, content, and documentation that will accompany analytical models over the course of the Landsat 10 (Landsat 10) program. The analytical models are those required for pre-flight performance prediction, design verification, and post-flight assessment. All math models used to satisfy the verification requirements of mission-critical hardware or subsystems are included. Thus, lower-level math models that are delivered and are to be incorporated into the Observatory model must also adhere to these guidelines. The controlled disciplines include:

• 3D Computer Aided Design (CAD) models

• Thermal

• Structural

• Dynamic

• Attitude Control Subsystem (ACS) The integration of discipline analyses is also the subject of this document. Examples are:

• Structural configuration solid models (STEP)

• Structural Finite Element Models (FEM)

• Observatory thermal analysis models

• Combined Structural /Thermal/ Optical models defining pointing performance These guidelines apply to contractually required math models delivered to the Landsat 10 project. Typically, these deliveries occur in support of the following element-level reviews and mission-level analysis:

• Mission Definition Review/ System Requirements Review (SRR)

• Preliminary Design Review (PDR)

• Critical Design Review (CDR)

• Math models delivered in association with interim analysis cycles

• Models updated based upon ground or flight test data The delivery dates for LandIS, Spacecraft (SC), and Observatory (OBS) level models as identified in the appropriate Data Requirements Description (DRDs) will be identified and tracked in the Landsat 10 Giver/Receiver list. This list will also track mutually agreed interim models generated between contractually required model deliveries. Thus, interim models should be available and will follow the guidelines in a manner consistent with contractually required deliveries.

Applicability of these guidelines is specific to the following models in both their flight (stowed and deployed) and ground based test configurations:

• SC and OBS models delivered by the SC supplier to the Landsat 10 Project Office

• LandIS model(s) delivered by Instrument supplier(s) to the Landsat 10 Project Office

Use or disclosure of data contained on this page is subject to the restriction(s) on the title page of this document.

1.1 LANDSAT 10 RELATED DOCUMENTATION

1.1.1 Reference Documents

Document Number Title Revision ELVL-2016-0044292 Thermal Analysis Report, LSP Flight Analysis

Division Thermal Analysis Group Payload ,Thermal Model Submittal Guideline, Rev 2

NASA/TM 2001-211221 Guidelines for the Selection of Near-Earth Thermal Environment Parameters for Spacecraft Design, B.J. Anderson, C.G. Justus and G.W.

Batts

N/A

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

ISO 10303-242 Industrial automation systems and integration - Product data representation and exchange - Part 242: Application protocol: Managed model-based 3D engineering

MMPDS-2024 Metallic Materials Properties Development and Standardization (MMPDS) Handbook, Complete Document (All 9 Chapters)

MMPDS-24

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

This document table was generated from the Landsat 10 Common Reference and Applicable Documents List (L10-MGMT-DESC-0008), DRAFT Rev F.

1.1.2 Project Reference Documents

Document Number Title L10-LANDIS-ICD-0001 Landsat Instrument Suite (LandIS) Interface Requirements

Document (LIRD) L10-LANDIS-PLAN-0052 Landsat Instrument Suite (LandIS) Contract Data

Requirements List (CDRL) and Data Item Descriptions (DID) L10-SC-ICD-0002 Landsat 10 Spacecraft Interface Requirements Document

(SCIRD)

L10-SC-REQ-0029 Landsat 10 Spacecraft Contract Data Requirements List

(CDRL) and Data Item Descriptions (DID) In this document, citations are assumed to be the latest version unless otherwise noted.

This document table was generated from the Landsat 10 Common Reference and Applicable Documents List (L10-MGMT-DESC-0008), DRAFT Rev F.

Use or disclosure of data contained on this page is subject to the restriction(s) on the title page of this document.

2.0 MISSION OVERVIEW

2.1 MISSION STATEMENT

Landsat 10, consistent with United States (U.S.) law and government policy, will continue the Landsat program's acquisition, archival, and distribution of multi-spectral imagery, thereby affording global, synoptic, and repetitive coverage of the Earth's land surfaces and coastal regions 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 the National Aeronautics and Space Administration (NASA) recognized the need to assemble a team of experts from within both agencies to evaluate and 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 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 July 2018, Release

2.0. This investigation 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 surfaces and coastal regions held in the National Satellite Land Remote Sensing Data Archive at the 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. Landsat Next subsequently passed its Mission Concept Review (MCR) and Key Decision Point-A (KDP-A) reviews in 2022. In March 2026, the Landsat Next mission was re-architected and re-designated Landsat 10 as a single observatory mission.

The goal of Landsat 10 is to continue the acquisition, archival, and distribution of multi-spectral imagery, thereby affording global, synoptic, and repetitive coverage of the Earth's land surfaces and coastal regions 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 10 continues the long-running partnership of NASA and the USGS, with NASA providing the space and launch segments and the USGS providing the ground system (GS), providing the longest continuous global record of the Earth’s land surface and coastal regions.

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.

Use or disclosure of data contained on this page is subject to the restriction(s) on the title page of this document.

2.3 MISSION OBJECTIVES

Landsat 10 has these major mission objectives:

· Collect and archive moderate resolution Visible to Shortwave-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 10 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; all of which permit scientific studies, management of land cover and land use change, along with associated inland and coastal water resources, over multi-decadal periods.

· Ensure Landsat 10 is responsive to documented emerging user needs and applications as characterized by periodic assessment, currently the User Needs for the SLI Program July 2018, Release 2.0, and identified by the operational requirements for acquisition, processing, archiving, and distribution of Earth’s image data to the United States Government and other users.

· Distribute Landsat 10 data products to the public freely on a nondiscriminatory basis.

2.4 MISSION IMPLEMENTATION

The Landsat 10 mission includes a single observatory in a 653 km sun-synchronous low-earth orbit (LEO). The observatory includes a single integrated suite of sensors called LandIS (the Landsat Instrument Suite) that images the full swath required to achieve global coverage via a repeating ground track every 18 days.

The LandIS improves all spectral and spatial capabilities by approximately twofold when compared with the Operational Land Imager (OLI) and Thermal InfraRed Sensor (TIRS) instruments flown on Landsats 8 and 9, while maintaining the historical Landsat data continuity and similar temporal coverage.

Each Landsat 10 partner agency has specific responsibilities and will deliver major elements to the overall mission. NASA will provide the Space Segment (SS) and the Launch Services Segment (LSS), and the USGS will provide the Ground System (GS) and Mission Operations.

NASA/Goddard Space Flight Center (GSFC) will provide overall Landsat 10 project management, mission system engineering and mission assurance during development and will transition the mission to USGS for science operations following on-orbit commissioning.

Use or disclosure of data contained on this page is subject to the restriction(s) on the title page of this document.

Figure 2.4-1 Landsat 10 Mission Architecture

(Generated from Landsat 10 Common Mission Architecture Diagram L10-SYS-DESC-0022 Rev B)

2.4.1 Space Segment

NASA/GSFC provides the Space Segment via competitive procurements for the science instrument suite (LandIS) and the spacecraft bus. The Space Segment will consist of a single observatory flying in a sun-synchronous, near-polar orbit at 653 km altitude. The spacecraft, instrument, and overall Landsat 10 mission are specified as risk class C per NPR 8705.4. The overall mission parameters needed to achieve global coverage are shown below in the Mission Parameters Table.

Table 2.4.1-1 Landsat 10 Mission Parameters

LandIS is a whiskbroom scanner which provides 26 spectral bands covering a swath on the ground of approximately 164 km on a fixed ground track defined by a world-wide reference

Use or disclosure of data contained on this page is subject to the restriction(s) on the title page of this document.

system known as WRS-3. LandIS acquires raw detector data for all spectral bands within 15 seconds to minimize band-to-band and georegistration errors, reduce classification change detection errors due to clouds, and provide simultaneous acquisitions for science applications.

LandIS then performs data compression prior to packaging the data for transfer to the spacecraft storage and subsequent downlink. LandIS also provides internal calibration sources such as blackbody, a space port, stim lamps and solar diffuser.

The Space Segment will also provide simulators for mission, ground system and interface testing during the development phase of the mission and in support of long-term maintenance of systems. These simulators will have varying fidelity and capabilities to meet various mission needs.

2.4.2 Ground Segment

The Landsat Ground Segment (GS) consists of the ground system 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), GSFC Conjunction Assessment and Risk Analysis (CARA) and its Flight Dynamics Facility, along with other external interfaces.

The Landsat 10 MOC will be used for command and control, health and status monitoring, orbit and attitude maintenance, performance analysis, onboard memory management, and flight software maintenance. The MOC will support onboard autonomy for mission planning and scheduling. The MOC ingests, processes and archives telemetry data delivered via the GN. The Landsat 10 Flight Operations Team (FOT) located at the MOC performs these functions and is responsible for monitoring the observatory, detecting, investigating and resolving spacecraft anomalies and monitoring the instrument image collections and special image collections.

The GN provides geographically dispersed ground station resources for mission execution; it includes the Landsat Ground Network (LGN) and a wideband data routing capability to the Landsat cloud. The LGN provides communication capability to and from the observatory and MOC for commanding and housekeeping data via the S-band, and will receive science mission data from the observatory over a Ka-band downlink.

The DPAS ingests, processes, and archives science data returned from the observatory via the GN. LandIS data will be processed into data products with a ground sample distance (GSD) ranging from 10m-60m depending on the particular spectral band. 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 10 data products, via a public-facing web portal for receiving data products.

The USGS will lead overall Landsat 10 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 support Landsat 10 mission readiness activities.

2.4.3 Launch Segment

The Launch Segment will provide the assets and services associated with the Launch Vehicle (LV) and the observatory-to-LV integration. The Launch Segment will include the LV; all Launch Vehicle-Ground Support Equipment (LV-GSE), property, and facilities to integrate the observatory to the LV and verify its integration; and perform prelaunch testing with ground-

Use or disclosure of data contained on this page is subject to the restriction(s) on the title page of this document.

based functions. The launch vehicle and launch site will be specified during late Mission Phase B or early Phase C.

Sections 2.0-2.4.3 were generated using Landsat 10 Common Boilerplate (L10-MGMT-DESC- 0005) Rev E

Use or disclosure of data contained on this page is subject to the restriction(s) on the title page of this document.

3.0 GLOBAL MODELING GUIDELINES

If not specifically stated in the discipline sections, the guidelines specified in this chapter apply to all disciplines.

3.1 MODEL SUBMITTAL AND CONFIGURATION CONTROL

All models delivered will be maintained in the Landsat 10 electronic library as described in this section. The Landsat 10 electronic library will be hosted at GSFC on a server that meets current NASA/GSFC information technology standards for controlled access. Access for each of the suppliers will be controlled to protect property rights and enforce export control rules. The models deposited by the suppliers are either required deliveries or agreed-to deliveries in support of the complete mission analysis effort. Constituent models that are exchanged between suppliers and as required under each suppliers’ contract, Statement of Work (SOW), or implementation plans will be tracked in the Landsat 10 Giver/Receiver list.

Landsat 10 requests that constituent models be provided when design or analysis updates have occurred naturally during the program. This allows the program to work from the latest set of models throughout the program, regardless of formal delivery dates. As suppliers internally release or update baselines, those models should also be updated in the repository. Regarding formal deliveries, if a previously supplied model has had no changes due to its maturity or has a lack of design change or validation activity, then a new model need not be posted to the electronic library site. The Landsat 10 Analytical Math Models Definitions (LAMMD) document does not relieve suppliers of their contract, SOW, or implementation plan required deliveries.

The Contract Data Requirements List (CDRL) deliveries for contract purposes are not readily shared between suppliers and typically take a longer period of time to be available for use. It is expected that the Landsat 10 electronic copy will arrive at the repository before the CDRL delivery to the Contracting Officer (CO).

3.2 MODEL ARCHIVAL IN THE LANDSAT 10 LIBRARY

Model delivery needs to maintain an archival structure in the constituent folder of the Integrated Model folder within the Landsat 10 electronic library. GSFC will establish and maintain the file structure within the electronic library, however, proper placement and archival of model files placed within this system is the responsibility of all suppliers. Folders will be established at the top level for the model disciplines discussed herein (structural solid models [CAD], structural FEMs, motion analysis (ADAMS files), thermal math models [TMMs], ACS models).

Upon completion of a given modeling cycle, the Landsat 10 Project Office may choose to freeze the folder to maintain configuration control and prevent erroneous model information from being added later. At this time write access will be removed, but read access will be retained for all suppliers.

3.2.1 File Management Control

File management factors that must be dealt with consist of the following: asynchronous design of the constituent sub-systems, several disciplines spread across numerous organizations, and computing resources that are distributed and dissimilar. To provide configuration control for Landsat 10, file management control will be implemented in addition to the model folder configuration plan defined in Section 3.2.2. In each of the three top-level folders, a spreadsheet exists to document model deliveries and file revisions for that discipline. When models are

Use or disclosure of data contained on this page is subject to the restriction(s) on the title page of this document.

dropped into the Landsat 10 electronic library, the appropriate descriptive information for that drop must be added into the folder’s spreadsheet, as shown in Table 3.2.1-1. All interim files that are revised as described in Section 3.2.2 must also be included in the folder’s spreadsheet ledger along with the reason for the revision and a short description of the changes. This practice provides a running log of all the models used on Landsat 10 throughout the life of the program.

Table 3.2.1-1 Example of Configuration Log Spreadsheet for Individual Models/Files Submitted by Date Model Name Rev. Description Supplier Thermal Engineer xx/xx/xx yymmdd_SC_Thermal_ - PDR/ reduced SC thermal model for the deployed case

A fourth top-level folder labeled “Integrated Model” will reside in the Landsat 10 electronic library, and this folder will be reserved for the location, archival, and configuration control of the Landsat 10 Observatory-level models. Three folders (one for each discipline) will exist under this top-level folder, where the respective Observatory-level solid models, structural models, and thermal models will reside. Separate configuration control spreadsheets will exist for each of the integrated models so that revision tracking at the Observatory level can be maintained. This spreadsheet log will require the same effort to make sure entries are recorded every time a model is added to the Landsat 10 electronic library, however, more information is required. In addition to providing the reason for the model existence or revision, along with a short description of the changes made, it is imperative that this spreadsheet records WHICH version of each of the subelement models were used to assemble the integrated model. This is critical to maintain integrated model configuration tracking. An example using a Thermal delivery of this spreadsheet is shown in Table 3.2.1-2.

Table 3.2.1-2 Configuration Log of Integrated Models Identifying Subassembly Files Landsat 10 Model Log Submitted by Date Model Name Re v.

Descripti on Sub-Model Names

LandIS SC Name/ Organizati on/ Contact Info xx/xx/ xx yymmdd_OBS_Ther mal_

- Support

SC CDR

yymmdd_LandIS_Ther mal_ yymmdd_SC_The rmal

3.2.2 Model Log Entries

Each analytical model resides in a folder that is labeled with a version number for that particular element based on the design state reflected in the model. Other descriptors can be included as desired or appropriate. All input files, sample case output files, and documentation needs to be grouped together in one folder. The folder name for that model will have the following form:

yymmdd_System_Discipline_Suffix Explanations of each part of the folder naming scheme are included below:

yymmdd: The year, month, and day the model was released/configured from the supplier.

Use or disclosure of data contained on this page is subject to the restriction(s) on the title page of this document.

_System: Refers to the portion of the Observatory at a given level of assembly. It could be the whole Observatory (OBS), a Space Flight element (SC or LandIS), or possibly a particular sub-system.

_Discipline: Describes the particular engineering discipline.

_Suffix: Information pertinent to the model for identification purposes, descriptors to note

PDR/CDR/Pre-Environmental Readiness (PER) drops, or modeled subsystem or revision.

Description: Will address state of the design described by the model. An example would be the second model iteration in the Preliminary Design Review (PDR2) analysis cycle.

This column clarifies the state of the model in terms of factors such as: Stowed or Deployed; Fixed or Free; or Structural or Thermal Distortion.

Format: Details the model file format. CREO, STEP, Thermal Desktop, etc.

Folder Name: Details which folder the file is located.

Archived: Y/N. Notes the status of the file. When updates are deposited into the library, older versions can be moved to the Archive Folder and noted is this column.

Submodels: For integrated models, record the version of the subelement models. Ex. LandIS reduced thermal.

3.2.3 Access Control

Read access will generally be available to the government, the SC supplier, and the Instrument teams. Authorization for access to the model folders within the Landsat 10 electronic library is provided by Landsat 10 Mission Systems Engineering. Access to detailed FEM and detailed TMMs will not be made available to the SC and Instrument suppliers. This restriction will be removed if acceptable by the respective supplier. Reduced Instrument and SC models for structures and thermal analysis are available to all the Landsat 10 team members.

3.3 DOCUMENTATION

A textual/ graphical description of each model in an associated document, in either Microsoft (MS) Office Suite, MS Visio or text file, should be provided. For ACSs analysis and disturbance assessment, MathWorks SimuLink models should be provided. This document will reside in the model folder along with the model data files. Design features included or changed since the prior model update should be noted in the documentation-particular description. Model heritage should include descriptions of the parent models, e.g., the optical prescription and the mechanical design, structural, and/or modal models that form the basis for the model. Model configuration, in terms of the component deployment states, need to be included. For thermal analyses, necessary information includes the particular orbits (beta angle, beginning of life [BOL] or end of life [EOL] conditions, and Observatory attitude history) that are established in the model. In addition, software application version number used in the creation of the model and analysis results must be noted.

At delivery events, the documentation must include results for example cases. Input files will be included along with the documentation to allow the results to be regenerated for crosscheck.

Model checks or verification cases are defined for each model under a “Model Checks” section that follows.

Use or disclosure of data contained on this page is subject to the restriction(s) on the title page of this document.

3.4 COORDINATE SYSTEMS

There are multiple coordinate systems described for Landsat 10. The Observatory and Spacecraft reference coordinate systems are defined in the Landsat 10 Spacecraft Interface Requirements Document, L10-SC-ICD-0002. In addition, the LandIS reference coordinate systems are described in the Landsat Instrument Suite (LandIS) Interface Requirements Document (LIRD), L10-LANDIS-ICD-0001.

Model should specify which coordinate system they are referencing in the model. There is mechanical body reference frame / coordinate system used in ground processing / testing. There is a different reference frame / coordinate system for the orbit. The two coordinate systems are being used due to a lesson learned from prior missions that flew their instruments oriented in wake.

It is expected that subsystem and module elements (e.g., Spacecraft, Instrument suite) coordinate systems will be parallel to the Observatory coordinate system, with origin offsets, as required.

Any auxiliary coordinate system will need to be defined in the appropriate interface control documents, as well.

3.5 MASS CONVENTIONS

All analytical models delivered for inclusion in the integrated Observatory model should use the current best predicted mass as defined by the estimated mass + contingency.

3.6 UNITS

All models should use the International System of Units (SI) units (meter, kilogram, Newton) for communicating data to other models and for all inputs and outputs. Angular measures should use radians or microradians as units. Degrees measurements may be provided for human input or output interface convenience. All parameters will have units clearly marked, regardless of the unit set selected. All angles communicated between computational models will be expressed as radians.

Use or disclosure of data contained on this page is subject to the restriction(s) on the title page of this document.

4.0 MODEL MATERIAL PROPERTIES

All Landsat 10 suppliers are expected to use the same material properties database for all structural, dynamic, and thermal analyses. This document defines the preferred set of properties to use. If a different value is used, it must be identified in the model delivery.

4.1 STRUCTURAL PROPERTIES

Material properties used for all structural modeling should be obtained from the Metallic Materials Properties Development and Standardization (MMPDS) Handbook, Complete Document (All 9 Chapters), MMPDS-2024. A-basis values should be used for all metallic components when calculating margins of safety. All material properties used in models should be labeled.

4.2 THERMAL PROPERTIES

Thermal and optical properties for all thermal modeling should be provided to the GSFC Coatings Committee. Vendors should follow their internal processes to control material processes, using this document as a guide.

4.3 THERMAL ENVIRONMENTAL PARAMETERS

Recommended thermal environmental parameters that should be used to provide consistency across model deliveries are identified in Table 4.3-1. Usage of environmental parameter values different than those in Table 4.3-1 should be approved by the project.

Table 4.3-1 Recommended Thermal Environmental Parameters for Landsat 10 Parameter Hot Case Cold Case Solar (Watts/ m^2) 1419 1317 Earth Infrared (IR) (Watts/ m^2) 261 215 Albedo 0.35 0.25 Optical Properties EOL BOL

Use or disclosure of data contained on this page is subject to the restriction(s) on the title page of this document.

5.0 STRUCTURAL SOLID MODELING

Structural modeling is used to define the solid model configuration of the Landsat 10 Instruments, Spacecraft, and Observatory. These models are used to demonstrate Field of View (FOV) compliances, physical interferences, interface location/definitions, thermal FOVs, stay-out zones, volume envelopes, venting ports, and mechanism deployment sweeps. These models are also used in conjunction with the FEMs to generate integrated structural analysis to validate and verify acceptable load conditions during launch and orbit. Sub-models should follow the requirements of the higher assembly model (Spacecraft and Instrument Models should follow the formats below of the Observatory Model.)

5.1 STRUCTURAL MODEL FORMAT

The preferred format for solid model exchanges is Industrial automation systems and integration

- Product data representation and exchange - Part 242: Application protocol: Managed model-based 3D engineering, ISO 10303-242, STEP AP242. Solid model exchanges must adhere to the following guidelines:

• To be consistent with the launch vehicle supplier, the system of units defined in Section 3.6 is used for all solid models.

• The coordinate systems should per their definitions in their respective ICDs.

• The origin of the local coordinate system should be expressed per their definitions in their respective ICDs.

• The files should be zipped when delivered to Landsat 10.

• The model must have solids and not just surfaces.

• Unnecessary elements should be deleted to minimize model size.

• Assembly structure must be preserved and not compressed into a single part without approval from the Landsat 10 Project.

5.2 MODEL NUMBERING

Numbering or identifying elements in the solid model is not critical or required. However, attachment interfaces and locations must clearly be marked and defined so that integrated models can be accurately assembled.

5.3 DOCUMENTATION

Documentation for solid model exchanges must identify critical changes made to the model since the last model submittal. In addition, any changes to volume envelopes, including FOVs or stay-out zones, must be specified.

5.4 MODEL CHECKS

Model checks for solid model exchanges require that all internal warnings be eliminated. In addition, the supplier should verify that there are no surface interferences contained within the transferred ‘.stp’ file.

Use or disclosure of data contained on this page is subject to the restriction(s) on the title page of this document.

6.0 REDUCED CAD MODELING (ENVELOPE)

Reduced modeling is used to define the outer mold lines (OML) of the Landsat 10 Instruments and Spacecraft, . The Observatory Model includes the Spacecraft and Instrument Models. These models are used to demonstrate maximum physical envelopes, remove before flight items, install before flight items, and launch vehicle adapter protuberances. These models are used to verify close approach points to the payload static envelop. The models are also used to determine fairing access points post-encapsulation. The model is solely in the launch or stowed configuration. Sub-models should follow the requirements of the higher assembly model (reduced Spacecraft and reduced Instrument Models should follow the formats below of the Observatory Model OML.)

6.1 STRUCTURAL MODEL FORMAT

The preferred format for solid model exchanges is Industrial automation systems and integration

- Product data representation and exchange - Part 242: Application protocol: Managed model-based 3D engineering, ISO 10303-242, STEP AP242. Solid model exchanges must adhere to the following guidelines:

• To be consistent with the launch vehicle supplier, the system of units defined in Section 3.6 is used for all solid models.

• The coordinate system should be per their definitions in their respective ICDs.

• The origin of the local coordinate system should be per their definitions in their respective ICDs.

• The files should be zipped when delivered to Landsat 10.

• Unnecessary elements (internal items) should be deleted to minimize model size.

• The Observatory Model's OML will be intact/unaltered.

• The Observatory Model OML will include Multi-Layered Insulation (MLI), flight and/or RBF enable plugs, harness service loops, Insulating Tape, and any other items that affects the OML.

• All components internal to the Observatory interface ring will be included.

• The Observatory Model will be in the “Stowed for Launch” configuration.

• If there are “Remove Before Flight” (RBF) items that will stay on the Spacecraft until after Fairing Encapsulation, then those items will be included in the Model.

• Model RBF items should be clearly marked (e.g., Named as such, Red in color, etc.).

• If there are “Install Before Flight” (IBF) items that will be installed on the Observatory before flight, those items will be included in the Model.

• Model IBF items should be clearly marked (e.g., Named as such, Green in color, etc.).

Use or disclosure of data contained on this page is subject to the restriction(s) on the title page of this document.

6.2 MODEL NUMBERING

Numbering or identifying elements in the reduced model is not critical or required except for the RBF and IBF items. See Section 6.1. However, attachment interfaces and locations must clearly be marked and defined so that integrated models can be accurately assembled.

6.3 DOCUMENTATION

Documentation for solid model exchanges must identify critical changes made to the model since the last model submittal. In addition, any changes to volume envelopes, RBF, IBF must be specified. This documentation should include the following:

• A minimum of Eight (8) Verification “Snapshots” images will be provided; one

(1) from each of the following Spacecraft axis views: +X, -X, +Y, -Y, +Z, and –Z, as well as a minimum of two (2) Isometric views showing all six faces of the Spacecraft. With view orientation labels (+X, etc.).

• The Snapshot Images of the Spacecraft should be taken in the model’s native format and NOT of the converted STEP file model.

6.4 MODEL CHECKS

Model checks for solid model exchanges require that all internal warnings have been eliminated.

In addition, the supplier should verify that there are no surface interferences contained within the transferred ‘.stp’ file.

Use or disclosure of data contained on this page is subject to the restriction(s) on the title page of this document.

7.0 STRUCTURAL MODELING (FEM)

Structural modeling of the individual elements of Landsat 10 (Spacecraft and LandIS Instrument(s)), as well as the integrated Observatory will be performed to predict performance against the levied requirements. This section defines the guidelines in order to provide accurate model representation at the Observatory level as well as ensure that the integrated model can be seamlessly assembled with a minimum number of modifications. Structural models are required for both the stowed (pre-launch, launch, and ascent phases) and deployed (all on-orbit phases and modes) configurations. This includes the Instrument model(s) where on-orbit deployments of radiators, Earth and Sun shields, or other one-time events result in a new configuration. Separate models may be necessary for various analyses, such as dynamics, stress, and thermal distortion.

All models will follow the same guidelines.

7.1 FINITE ELEMENT MODEL FORMAT

Each model provided should be a full physical NASA Structural Analysis (NASTRAN) FEM.

There should be no reduction or simplification. If the NASTRAN model does have mass and stiffness matrices representing components, then the Observatory Craig-Bampton model will not include those points, and no Output Transformation Matrix (OTM) data for that portion of the model will be recovered from a Coupled Loads Analysis (CLA). The model coordinate system needs to be parallel to the Spacecraft coordinate system as indicated in Section 3.4 and defined by the Observatory Interface Requirements Documents, Section 3.4.1.2 Reference Frames.

The criteria for a model for CLA analysis are almost the same for all launch vehicles. There might be differences of how many total numbers of rows in the data recovery matrices are acceptable for each launch vehicle contractor, but typically a total number of rows of 3000 is acceptable, however, this number can be higher. The Observatory integrator will derive allocations between the Spacecraft and the Instruments.

The Craig-Bampton model is typically in a NASTRAN OUTPUT4 ASCII format and includes stiffness, mass, and data recovery matrices. OUTPUT4 binary format has also been used previously. Matlab files have been used as well.

7.2 FINITE ELEMENT MODEL NUMBERING

The full physical NASTRAN models delivered for Landsat 10 will use the following element numbering allocations:

Spacecraft: 1 to 1,999,999 LandIS Instrument: 2,000,000 to 2,999,999

Additional elements, as required This numbering scheme applies to the node, elements, materials, and properties assigned in the respective models. Exceptions to this are the FEMS at their interface points. The Spacecraft FEMs must use GRID IDs starting at 101 for the Spacecraft-to-Launch Vehicle interface points.

The LandIS FEM must use GRID identifications (IDs) 301, 302,303, 304, and 305 for the five

(5) interface points.

Use or disclosure of data contained on this page is subject to the restriction(s) on the title page of this document.

7.3 DOCUMENTATION

Each FEM submittal must be accompanied by a report documenting the delivery. As a minimum, this document will include:

1) A picture representation of the model

2) GRID Point Weight Generator results to identify mass, center-of-gravity, and inertia characteristics

3) A modal mass table that identifies significant mode shapes to at least twice the predicted minimum frequency

4) The definition of all interface nodes or elements with respect to a single-reference coordinate system is needed for each delivery

5) Identification of all interface grid points and locations used in the FEM

6) Identification of all output requests for CLA cycles such as elements of interface forces, displacements, accelerations, etc. to be included in the OTM Each Craig Bampton FEM submittal must be accompanied by a report documenting the delivery.

For the model document, it should include the following:

1) Definition of degrees of freedom of stiffness and mass matrices

2) Description of the coordinate system of the model and the location of its origin

3) Coordinates of interface points

4) Clocking of the Observatory relative to Launch Vehicle coordinate system

5) Damping ratios for the fixed-interface modes of the Craig-Bampton model

6) Units used for the model (stiffness and mass) and units associated with the output of the data recovery matrices

7) Description of rows of data recovery matrices (loads, accelerations, displacements …) as well as description of the format of the data recovery matrices (mode displacement versus mode acceleration)

8) Model uncertainty factor to be used in the analysis

9) Listing of model frequencies (of the Craig-Bampton Modes) – for checking purposes

10) Rigid-Body mass properties (masses, inertias, and CG location) – for checking purposes

11) Modal effective weights for the Craig-Bampton modes (preferred for checking purposes)

12) If needed, identification of rows in the displacement recovery matrix to be used in the dynamic loss of clearance (LOC) analysis Note: There may be limits placed on the number of output requests by the Launch Vehicle provider. Should that occur, the government will work with the Spacecraft supplier to allocate the number of output requests to the various systems.

Use or disclosure of data contained on this page is subject to the restriction(s) on the title page of this document.

For LandIS FEM(s), the origin and location of the “reference coordinate system” for all nodes will be defined in the Landsat Instrument Suite (LandIS) Interface Requirements Document

(LIRD), L10-LANDIS-ICD-0001.

For Observatory FEMs, the origin and location of the “reference coordinate system” for all nodes will be defined in the Landsat 10 Spacecraft Interface Requirements Document (SCIRD), L10-

SC-ICD-0002.

The Observatory FEM, the origin and location of the ‘reference coordinate system’ for all nodes will be defined in the Landsat Spacecraft and Launch Vehicle Interface Requirements Document

(TBD).

7.4 MODEL CHECKS

Deliveries of structural models for the Landsat 10 program must include a set of appropriate standard FEM validity checks to show accurate and correct predictive capability. These checks will include, but are not limited to, grounding, free-free modes, 1-g check to sum forces and unit enforced displacement checks. See https://femci.gsfc.nasa.gov/validitychecks/ for descriptions of the specific validity checks.

7.5 ANALYSIS RESULTS

An Excel file with individual sheets for each results matrix must be provided back to the requesting organization. The information on each should include at least the Acceleration Transformation Matrix (ATM), Displacement Transformation Matrix (DTM), and Loads Transformation Matrix (LTM).

The worksheet title should state which matrix is detailed and the total number Degrees of Freedom (DOF) requested.

ATM

Column Titles should be as follows:

Description Node

ID

CID Output Request

Time History

X Y Z RX RY RZ DOF

Where:

Output Request = ‘Acceleration’ Time History: Place an X if a time history is needed X, Y, Z, RX, RY, RZ: Place an X if that DOF is being requested DOF: Enter the total number of DOF requested for each row (most likely 6)

DTM

CID Output Request

Use or disclosure of data contained on this page is subject to the restriction(s) on the title page of this document.

Output Request = ‘Displacement’ X, Y, Z, RX, RY, RZ: Enter an X if that DOF is being requested

LTM

A separate worksheet for each different type of element being requested (CBAR, CELAS, MPC, etc.). The content of the CBAR table is a continuous row for each element requested (The Title row below was separated to fit the page).

CBAR

Description Element ID Type CID Output

BENDING A1 BENDING A2

Description BENDING

B1

BENDING

B2

SHEAR

SHEAR

AXIAL TORQUE DOF

Output Request = ‘Elforce’ Enter an X if any of those DOFs are being requested DOF: Enter the total number of DOF requested for each row (most likely 7 or 1)

CELAS

Description Element

Type CID DIRECTION Output

FORCE DOF

Output Request = ‘Elforce’ Enter an X under force DOF: Going to be 1

MPC

Type CID Output

Output Request = ‘MPCforce’ Enter an X if that DOF is being requested DOF: Enter the total number of DOF requested for each row

Use or disclosure of data contained on this page is subject to the restriction(s) on the title page of this document.

8.0 THERMAL MODELING

Thermal models are used throughout the life of the Landsat 10 program to provide:

• Early predictive thermal control subsystem performance for sizing

• Thermal interface definition and compliance

• Segment and Observatory-level thermal test design and correlation

• On-orbit predictive scenario simulation Thermal models of the Observatory are required for both the stowed configuration (pre-launch, launch, and ascent phases) and the deployed configuration (all on-orbit phases and modes). The required models include the Instrument models where on-orbit deployments of radiators, Earth and Sun shields, or other one-time events result in a new configuration. The pre-launch stowed model should consider convective thermal effects during all Launch Vehicle encapsulated operations through fairing separation.

A stand-alone reduced Observatory thermal model may be required to support Launch Services' integrated thermal analysis of pre-launch and ascent phases.