EXHIBIT C-GLIMR ATSRD.pdf

80LARC26R0002

EXHIBIT C

Access to Space Requirements Document

(ATSRD)

For

Geostationary Littoral Imaging and

Monitoring Radiometer (GLIMR) Access to Space (ATS)

Version 1.0

July 1, 2026

Revision: Baseline Document No: EXHIBIT C

Release Date: 07/01/2026 Page 2 of 127

Title: GLIMR Access to Space Requirements Document

REVISION HISTORY PAGE

Revision No. Description Release Date

Preliminary Initial release, for use on GLIMR Mission Access to Space

Industry Concept Study

2/20/2024

Preliminary, V0.1

Removed CUI classification

Added orbit reference frame figure 3-3

Added clarifying notes

Renumbered requirements

Divided SOC responsibilities between GMOC and GSDS;

updated Architecture Figure

Added list of remaining TBD & TBC items

Additional editorial updates

2/28/2026

Preliminary, V0.

Updated additional figures

Incorporated peer review revisions

Updated contamination requirements

Updated environmental limit levels

6/25/2026

Baseline, V1.0 Approved release for request for proposal 7/1/2026

Release Date: 7/1/2026 Page 3 of 127

TBD/TBC Section

TBD 4.11.5 Fault Management / [GLIMR-REQ-134]

TBD 4.11.5 Fault Management / [GLIMR-REQ-135]

TBD 4.11.5 Fault Management / [GLIMR-REQ-136 – GLIMR-REQ-140]

TBC 4.1. General Requirements [GLIMR-REQ-3]

TBC 4.2.2 Clearances / [GLIMR-REQ-12]

TBC 4.2.5 Structural Alignment / [GLIMR-REQ-20]

TBC 4.2.5 Structural Alignment / [GLIMR-REQ-21]

TBC 4.5 EMC/EMI Requirements / [GLIMR-REQ-57]

TBC 4.5 EMC/EMI Requirements / [GLIMR-REQ-58]

TBC 4.5 EMC/EMI Requirements / [GLIMR-REQ-59]

TBC 4.5 EMC/EMI Requirements / [GLIMR-REQ-60]

TBC 4.6 Pointing / [GLIMR-REQ-169, GLIMR-REQ-62, GLIMR-REQ-63]

TBC 4.7 On-Orbit Disturbance Requirements/ [GLIMR-REQ-69 - GLIMR-REQ-71]

TBC 4.8.1 Power / [GLIMR-REQ-181]

TBC 4.8.2 Electrical Interfaces / [GLIMR-REQ-83]

TBC 4.9 Contamination Control / [GLIMR-REQ-97]

TBC 4.11.1 GLIMR Spacecraft Telemetry / [GLIMR-REQ-107, GLIMR-REQ-108]

TBC 4.11.2 Command and Data Handling / [GLIMR-REQ-118]

TBC 4.11.5 Fault Management / [GLIMR-REQ-131]

TBC 4.12.2 Command Uploads / [GLIMR-REQ-147]

TBC 4.12.3 Telemetry Downloads / [GLIMR-REQ-152]

TBC 4.12.3 Telemetry Downloads / [GLIMR-REQ-153]

TBC 4.12.3 Telemetry Downloads / [GLIMR-REQ-190]

TBC 4.12.3 Telemetry Downloads / [GLIMR-REQ-190]

TBC 4.12.4 GLIMR Payload Anomaly Reporting / [GLIMR-REQ-157, GLIMR-

REQ-192, GLIMR-REQ-193]

TBC 4.12.5 GLIMR Spacecraft Communications / [GLIMR-REQ-156]

TBC 4.12.5 GLIMR Spacecraft Communications / [GLIMR-REQ-158]

Release Date: 7/1/2026 Page 4 of 127

Table of Contents

1 INTRODUCTION

1.1 Scope and Purpose

1.2 Document Organization

2 DOCUMENTS

2.1 Applicable Documents

2.2 Reference Documents

2.3 Document Control

3 SYSTEM DESCRIPTION

3.1 Mission Description

3.2 Mission Success Criteria

3.3 System Architecture

3.3.1 GLIMR Data Flow

3.4 GLIMR Payload Description

3.4.1 Sensor Assembly

3.4.2 Payload Control Unit

3.4.3 Digital Encoder Box

3.4.4 Dust Cover

3.5 Coordinate System Definition

3.5.1 Stowed Position

3.5.2 Gimbal Range of Travel

4 REQUIREMENTS

4.1 General Requirements

4.2 Mechanical Requirements

4.2.1 Mechanical Payload Interfaces

4.2.2 Clearances

4.2.3 Payload Volumes

4.2.4 Field of View

4.2.5 Structural Alignment

4.2.6 Mass Properties

4.3 Structural Launch Environment Requirements

4.3.1 Quasi-Static Acceleration Environment

4.3.2 Random Vibration Environment

Release Date: 7/1/2026 Page 5 of 127

4.3.3 Sinusoidal Vibration Environment

4.3.4 Acoustic Environment

4.3.5 Shock

4.3.6 Launch Pressure Profile

4.3.7 Minimum Natural Frequency

4.4 Thermal Requirements

4.4.1 Heat Transfer

4.4.2 Temperature Ranges

4.4.3 Radiator Back Loading

4.5 EMC/EMI Requirements

4.6 Pointing

4.7 On-Orbit Disturbance Requirements

4.8 Electrical

4.8.1 Power

4.8.2 Electrical Interfaces

4.9 Contamination Control

4.10 GLIMR Spacecraft Facility Environments

4.11 GLIMR Spacecraft Operations Requirements

4.11.1 GLIMR Spacecraft Telemetry

4.11.2 Command and Data Handling

4.11.3 Power On Commands

4.11.4 Safing Commands

4.11.5 Fault Management

4.12 GLIMR Spacecraft Mission Operations Center

4.12.1 General Communication

4.12.2 Command Uploads

4.12.3 Telemetry Downloads

4.12.4 GLIMR Payload Anomaly Reporting

4.12.5 GLIMR Spacecraft Communication

5 APPENDICES

5.1 Appendix A: Acronyms

5.2 Appendix B: Glossary

5.3 Appendix C: Requirement Summary Table

Release Date: 7/1/2026 Page 6 of 127

Table of Tables

Table 4-1: Sensor Assembly Stowed Volume (example only - see D4957031-500) Table 4-2: Sensor Assembly Swept Volume (example only - see D4957031-500) Table 4-3: PCU Volume (example only - see D4957031-500) Table 4-4: DEB Volume (example only - see D4957031-500) Table 4-5: Sensor Assembly Maximum Acceleration Limits Table 4-6: PCU Maximum Acceleration Limits Table 4-7: DEB Maximum Acceleration Limits Table 4-8: Sensor Assembly Random Vibration Proto-Flight Limit Levels Table 4-9: Sensor Assembly Random Vibration Proto-Flight Limit Profile Table 4-10: PCU Random Vibration Proto-Flight Limit Levels Table 4-11: PCU Random Vibration Proto-Flight Limit Profile (Q = 25) Table 4-12: DEB Random Vibration Proto-Flight Limit Levels Table 4-13: DEB Random Vibration Proto-Flight Limit Profile (Q = 25) Table 4-14: Payload Sensor Assembly Sinusoidal Test Limit Levels Table 4-15: PCU Sinusoidal Test Limit Levels Table 4-16: DEB Sinusoidal Test Limit Levels Table 4-17: Acoustic Test Limit Levels Table 4-18: Sensor Assembly Shock Limit Levels Table 4-19: PCU Shock Limit Levels Table 4-20: DEB Shock Limit Levels Table 4-21: Dust Cover Limit Levels Table 4-22: Attitude Knowledge Errors Table 4-23: Angular Rate Errors Table 4-24: Low-Frequency Spacecraft-to-Payload Angular Disturbance Environment Table 4-25: High-Frequency Spacecraft-to-Payload Rotational Displacement PSD Specification ... 70 Table 4-26: Spacecraft-to-Payload Rotational Disturbance Allowable Energy Table 4-27: Spacecraft-to-Payload Translational Acceleration PSD Specification Table 4-28: Spacecraft-to-Payload Translational Disturbance Allowable Energy Table 4-29: Uncompensated Torque Values per Axis Table 4-30: Transient Inrush Current Limits Table 4-31: Maximum Steady State Current Table 4-32: GN2 Purge Rates Table 4-33: Prelaunch Environments

Release Date: 7/1/2026 Page 7 of 127

Table of Figures

Figure 3-1: GLIMR Architecture Block Diagram Figure 3-2: GLIMR Data Flow Figure 3-3: Payload Components (harnesses not shown) Figure 3-4: Orbit Reference Frame (ORF) Figure 3-5: GLIMR Stowed Position - +23-deg. Elevation Figure 3-6: GLIMR Stowed Position – +44.8 deg. Azimuth Figure 4-1: Sensor Assembly Mounting Interface (example only – see D4957031-500) Figure 4-2: PCU Mounting Interface (example only – see D4957031-500) Figure 4-3: DEB Mounting Interface (example only – see D4957031-500) Figure 4-4: Dust Cover Relative Position Figure 4-5: Dust Cover Dimensions Figure 4-6: Graphical Representation of Stowed Volume (example only – see D4957031-500) Figure 4-7: Graphical Representation of Swept Volume (example only – see D4957031-500) Figure 4-8: Payload Control Unit Dimensions (example only - see D4957031-500) Figure 4-9: Decoder Electronics Box Dimensions (example only - see D4957031-500) Figure 4-10: Payload Field of View Keep Out Zone Figure 4-11: Radiator Field of View Figure 4-12: GLIMR unit-specific local coordinate systems used for structural analysis Figure 4-13: CE102 Limit (EUT power leads, AC and DC) for all applications (see MIL-STD-461G

Figure CE102-1) Figure 4-14: CS101 voltage limit for all applications (see MIL-STD-461G Figure CS101-1) Figure 4-15: RE102 limit for aircraft and space system applications (see MIL-STD-461G Figure

RE102-3)

Figure 4-16: RS103 Limits Figure 4-17: Rotational Displacement PSD Specification Figure 4-18: Translational Acceleration PSD Specification Figure 4-19: Payload to GLIMR Electronic Interfaces Figure 4-20: Conducted Inrush Current, Primary Power Loads

Release Date: 07/01/2026 Page 8 of 127

1 INTRODUCTION

1.1 Scope and Purpose

This document establishes the Geostationary Littoral Imaging and Monitoring Radiometer

(GLIMR) Access to Space requirements. This document includes both the functional and performance requirements.

1.2 Document Organization

Section 2 lists applicable and reference documents. Section 3 provides an overview of the

GLIMR mission. Section 4 contains the functional and performance requirements. Appendix A provides acronyms, Appendix B provides a Glossary, and Appendix C provides a summary table of requirements.

2 DOCUMENTS

Section 2.1 identifies documents that are applicable to this specification and are referenced within requirement text. The documents’ version at the time of Request for Proposal release is considered applicable unless otherwise noted. Section 2.2 Reference Documents are for information only.

The GLIMR Access to Space Statement of Work (SOW) references this requirements document, and the SOW has precedence in the event of any discrepancies.

2.1 Applicable Documents

Document Number Document Title

ASTM E 595 Standard Test Method for Total Mass Loss and Collected Volatile

Condensable Materials from Outgassing in a Vacuum Environment

D4957031-500 GLIMR Instrument Installation Control Drawing (IICD)

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

MIL-PRF-27401 Performance Specification for Propellant Pressurizing Agent, Nitrogen

MIL-STD-461 Requirements for the Control of Electromagnetic Interference

Characteristics of Subsystems and Equipment

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

NPR 7150.2 NASA Software Engineering Requirements

GLIMR-06-002 GLIMR Payload to GLIMR Spacecraft Interface Definition

Document (IDD)

USNO Circular 179 The IAU Resolutions on Astronomical Reference Systems, Time

Scales, and Earth Rotation Models

Release Date: 7/1/2026 Page 9 of 127

2.2 Reference Documents

Document Number Document Title

UNH-GLIMR-CONOPS-01 GLIMR Concept of Operations Document

UNH-GLIMR-FSUG-01 GLIMR Flight Software User’s Guide

2.3 Document Control

This document is managed by the Earth System Science Pathfinder (ESSP) Program Office.

After initial approval, it will be placed under formal configuration control.

3 SYSTEM DESCRIPTION

This section describes the system architecture for the GLIMR mission and provides context for requirements in Section 4. Refer to the GLIMR Concept of Operations Document (UNH-

GLIMR-CONOPS-01) for a more thorough description of the mission functions and operations.

3.1 Mission Description

GLIMR is a hyperspectral ocean color sensor which targets the Gulf of America and other coastal and ocean waters of North and South America. With its vantage point from geostationary orbit, GLIMR will be the first hyperspectral ocean color sensor in the Western Hemisphere to study ocean processes at the diurnal timescales required to observe the dynamic ecological, biogeochemical, and physical processes typical of coastal and ocean waters. GLIMR is uniquely designed to capture the spatiotemporal evolution of phytoplankton blooms, which grow and dissipate on scales of hours to days, monitor phytoplankton physiology, growth rates and shifts in community composition, resolve coastal features, fronts, eddies, and upwelling features, and monitor biogeochemical fluxes and land-ocean exchanges at sub-diurnal to multi-day scales.

GLIMR will improve quantification of primary productivity, biomass, and carbon fluxes within coastal aquatic ecosystems and across the land-sea interface and contribute observations that will aid development and evaluation of models that project future changes in carbon cycling and marine ecosystems for use in ecological forecasting and as inputs for improved climate change predictions. The two main science goals of GLIMR are (1) to understand the processes contributing to rapid changes in phytoplankton growth rate and community composition, and (2) quantify how high frequency fluxes of sediments, organic matter, and other materials between and within coastal ecosystems regulate the productivity and health of coastal ecosystems. The science application objectives aim to study the formation, magnitude, and trajectories of harmful algal blooms, oil spills, and Sargassum accumulation events.

At the heart of the GLIMR payload is a hyperspectral imaging spectrometer with a spectral range between 340-1040nm, a spectral resolution of about 10 nm, and the capability to scan the Gulf of

America in about 70 minutes. A higher spatial resolution landmark imager co-aligned with the spectrometer enables image navigation and registration of the ocean color pixels collected by the

Release Date: 7/1/2026 Page 10 of 127 spectrometer. A 28 cm diameter telescope provides high throughput and magnification for high signal to noise and spatial resolution.

3.2 Mission Success Criteria

The GLIMR mission will be considered successful if:

a) The mission acquires radiometric observations from geostationary orbit;

b) The mission produces a suite of ocean science products over a diurnal cycle over the northern Gulf of America of sufficient quality to improve scientific knowledge of phytoplankton ecology within and between ocean ecosystems;

c) The mission produces a suite of ocean science products over a diurnal cycle over the northern Gulf of America of sufficient quality to improve scientific knowledge of fluxes of optically active constituents within and between ocean ecosystems; and

d) The mission records, publishes, and delivers for archival science products to an ESD-assigned OB-DAAC for public distribution and use by the scientific and applications communities.

3.3 System Architecture

The GLIMR Architecture is illustrated in Figure 3-1. The GLIMR Mission is decomposed into four segments: the Ground Segment, the Space Segment, the Launch Segment, and the Science

Segment.

Figure 3-1: GLIMR Architecture Block Diagram

Release Date: 7/1/2026 Page 11 of 127

The GLIMR Ground Segment consists of the GLIMR Ground Station and the GLIMR Mission

Operations Center (GMOC), as well as any data teleports, antennas, and terrestrial networks needed to provide communications with the GLIMR Spacecraft and the GLIMR Science Data

System (GSDS). The primary functions of the Ground Segment are to command the GLIMR

Spacecraft and its payload(s), to monitor the GLIMR Spacecraft and its payloads’ health and status telemetry, and to receive data from the payload(s) via the GLIMR Spacecraft to the

GMOC for use by the Science Segment.

The GLIMR Space Segment consists of the GLIMR Spacecraft and the GLIMR Payload. The

GLIMR Spacecraft denotes the space platform proposed by the GLIMR Access to Space

Contractor to host the GLIMR Payload. The GLIMR Spacecraft includes all the on-orbit systems required to host the GLIMR payload in a geostationary orbit and to receive, store, and forward

GLIMR commands to the GLIMR Payload, and transmit health, status, and science data to the

GMOC. The GLIMR Space Segment also includes any required transportation to the launch provider after the initial GLIMR Payload government delivery of the GLIMR Payload to the

GLIMR Spacecraft facilities.

The GLIMR payload is designed to survive specific environmental conditions once integrated with the GLIMR Spacecraft including pre-launch environmental testing, launch, orbit transfer, and on-orbit operations. When the GLIMR payload and the GLIMR Spacecraft are integrated, the term GLIMR Observatory is used.

The Launch Segment denotes the launch vehicle and all services provided by the launch provider to place the GLIMR Spacecraft and payload(s) into the required orbit.

The term GLIMR Host System is used when referencing the GLIMR Access to Space

Contractor-provided combination of the GLIMR Ground Station, GMOC, GLIMR Spacecraft, and the launch vehicle.

The GLIMR Science Segment consists of the GLIMR Science Data System (GSDS) and the

Earth Science Division (ESD)-assigned Ocean Biology Distributed Active Archive Center(s)

(OB-DAAC).

3.3.1 GLIMR Data Flow

Figure 3-2 shows the planned data exchanges for the GLIMR mission during orbit operations.

Telemetry consists of the GLIMR Payload and spacecraft health and status data as well as the science data collected by the GLIMR Payload.

Release Date: 7/1/2026 Page 12 of 127

Figure 3-2: GLIMR Data Flow

3.3.1.1 Power

The GLIMR Spacecraft provides power to itself and the GLIMR Payload.

3.3.1.2 Commands

The GMOC generates commands for the GLIMR Spacecraft and GLIMR Payload to complete science Viewing Requests. The GMOC sends commands to the Ground Station, which forwards them to the GLIMR Spacecraft. The GLIMR Spacecraft and GLIMR Payload receive and execute the commands to gather telemetry for the science products.

3.3.1.3 Telemetry

The GLIMR Payload and GLIMR Spacecraft obtain telemetry and the GLIMR Spacecraft sends it to the Ground Station, which forwards the telemetry to the GMOC. Telemetry consists of

GLIMR Spacecraft health & status, GLIMR Payload health & status, and GLIMR Payload science data. The GMOC uses the telemetry to safely operate the GLIMR Spacecraft and

GLIMR Payload and forwards the telemetry to the GSDS.

3.3.1.4 L0-L3 Products

The GSDS uses the science and telemetry data provided by the GMOC to perform the data processing needed to generate the L0 to L3 levels of science products. The GSDS provides recording, publication, and delivery of science data records and calibrated geophysical data products to the DAAC for data product distribution to the scientific community and data archival.

3.3.1.5 Viewing Requests

The Principal Investigator leads the science community that studies the L0-L3 Products and determines the areas of interest for the GLIMR Payload to scan. These Viewing Requests are sent by the GSDS to the GMOC. Operators at the GMOC receive the Viewing Requests and generate the necessary commands to complete the requests.

Release Date: 7/1/2026 Page 13 of 127

3.4 GLIMR Payload Description

The complete GLIMR payload is made up of four components: the sensor assembly, the Payload

Control Unit (PCU), the Decoder Electronics Box (DEB), and the dust cover, shown in Figure

3-3Error! Reference source not found.. The term “sensor assembly” refers to the collection of all

GLIMR Payload subsystems except for the PCU, DEB, and dust cover.

Payload Components (Not To Scale)

Payload Control Unit

Decoder Electronics Box

Sensor Assembly

Dust Cover

Figure 3-3: Payload Components (harnesses not shown)

3.4.1 Sensor Assembly

The fully integrated sensor assembly consists of the gimbal assembly, the telescope assembly, and portions of the heat exchange subsystem.

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3.4.1.1 Gimbal Assembly Subsystem

The Gimbal Assembly Subsystem is the part of the payload that is commanded in azimuth and elevation across the various scan regions. Each of the two axes contains bearings, a motor, and an optical encoder for position monitoring.

3.4.1.2 Telescope Assembly Subsystem

The Telescope Assembly Subsystem collects the optical signal from the scene and contains a barrel-like sunshade for mitigating stray light onto the detectors. Out of the back of the telescope assembly, the incoming light is directed through the telecentric relay towards the Landmark

Imager (LMI) used for geolocation and the Hyperspectral Imager (HSI) used to collect science data.

3.4.1.3 Heat Exchange Subsystem

The payload Heat Exchange Subsystem contains components both physically on and off the sensor assembly. It manages temperatures for the payload with a combination of heaters, radiators, thermal straps, multilayer insulation and custom thermal isolation components.

Operational heaters maintain operational temperatures of the gimbal assembly, optical assemblies, payload focal plane arrays, and the spectrometer focal plane array. Survival heaters using bang-bang thermostat control are used to maintain temperatures of all sensor assembly components within their survival limits.

3.4.2 Payload Control Unit

The PCU is the main interface electronics box mounted separately from the sensor assembly and controls the gimbal, distributes power, controls the thermal environment, and interfaces to the

GLIMR Spacecraft.

3.4.3 Digital Encoder Box

The DEB contains electronics to integrate sensor assembly encoder read heads and report rotational positions via a serial interface for each axis to the PCU. The DEB is functionally part of the sensor assembly but is mechanically mounted separately from the sensor assembly on the

GLIMR Spacecraft structure.

3.4.4 Dust Cover

The payload dust cover dish is mechanically mounted separate from the sensor assembly in a fixed location on the GLIMR Spacecraft structure. When in the stowed position, the telescope is oriented in a position that aligns the telescope sunshade with the dust cover to provide contamination protection during launch and thermal protection during non-observing periods on-orbit.

Release Date: 7/1/2026 Page 15 of 127

3.5 Coordinate System Definition

GLIMR uses the community standard coordinate system for Geosynchronous Earth Orbit (GEO) orbit reference frame:

• +Z is in the direction of nadir

• +X is in the direction of orbital velocity

• +Y completes the right-handed system

Figure 3-4: Orbit Reference Frame (ORF)

3.5.1 Stowed Position

The gimbal stowed position is Az = 30.8 deg., El = 23 deg.

Nadir is defined as Az = -14 deg., El = 0 deg.

(0 deg. Z_ORF = -14 deg. Az_gimbal)

The following figures show the GLIMR Payload in its stowed position, relative to the orbit reference frame.

Release Date: 7/1/2026 Page 16 of 127

Figure 3-5: GLIMR Stowed Position - +23-deg. Elevation

Figure 3-6: GLIMR Stowed Position – +44.8 deg. Azimuth

3.5.2 Gimbal Range of Travel

The gimbal range of travel is:

• Az: +34.5 deg. to -34.5 deg.

• El: +24.0 deg. to -11.4 deg.

Release Date: 7/1/2026 Page 17 of 127

4 REQUIREMENTS

This section contains requirements for the GLIMR Access to Space.

The convention used in this document, which indicates requirements, goals, and statements of facts, is as follows:

Shall – Used to indicate a binding requirement

Should/May – Used to indicate a desired goal

Every requirement containing a “shall” is binding and will be verified. Goals are non-binding and are included to guide trade studies and will be addressed at design reviews and technical interchange meetings.

Rationale – Used to provide amplifying information to support the requirement.

Verification Method – Used to designate the expected verification methodology for the requirement. Definitions of the verification methods (test, demonstration, analysis, or inspection) can be found in the glossary.

Verification Description – Used to provide amplifying information to support the methodology for the requirement verification.

Success Criteria – Used to designate the expected pass/fail criteria for the requirement verification.

Release Date: 7/1/2026 Page 18 of 127

4.1 General Requirements

[GLIMR-REQ-2] Orbit Insertion

The GLIMR Host System shall insert the GLIMR Payload into a geostationary orbit between 86°

W to 110° W longitude.

Rationale: This geosynchronous orbit location of the GLIMR Spacecraft will allow the

Gulf of America and other scientifically valuable regions to be imaged.

Verification Method: Analysis

Verification Description: Analysis of planned GLIMR Spacecraft orbit insertion.

Success Criteria: Verification will be considered successful if analysis of orbit insertion planning yields the desired geostationary orbit.

[GLIMR-REQ-3] Mission Duration

The GLIMR Spacecraft shall be able to meet all performance requirements for a minimum 90-day GLIMR Payload commissioning period followed by a 1-year GLIMR Payload science collection mission lifetime with a probability of success of 90% [TBC].

Rationale: This period of time will allow the payload to meet its primary science goals.

Note: Any time required by the GLIMR Spacecraft to reach final orbit location and perform spacecraft commissioning activities is in addition to the time needed by the payload.

Verification Method: Analysis

Verification Description: Analysis of anticipated GLIMR Spacecraft orbit lifetime.

Success Criteria: Verification will be considered successful if analysis of orbit lifetime meets or exceeds requirement.

[GLIMR-REQ-4] Launch Duration

The GLIMR Spacecraft shall transfer the GLIMR Payload from the initial launch orbit to the final geosynchronous orbit within six months.

Rationale: Analysis performed by the payload shows it is capable of surviving

Geosynchronous Transfer Orbit conditions for at least six months.

Verification Method: Analysis

Verification Description: Analysis of planned GLIMR Spacecraft orbit insertion.

Success Criteria: Verification will be considered successful if analysis of orbit insertion planning shows that the desired orbit can be achieved within the required timeframe.

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4.2 Mechanical Requirements

4.2.1 Mechanical Payload Interfaces

[GLIMR-REQ-7] Sensor Assembly Mechanical Interface

The GLIMR Spacecraft shall mechanically interface with the sensor assembly in accordance with the GLIMR IICD (D4957031-500) and the GLIMR Payload to GLIMR Spacecraft IDD

(GLIMR-06-002).

Rationale: The GLIMR IICD (D4957031-500), provides the mechanical interface information that the GLIMR Spacecraft will need for accommodation of the payload. An example is shown in Figure 4-1. This mechanical interface will also need to allow the sensor assembly to meet all structural, thermal, and electrical requirements listed below.

Verification Method: Inspection

Verification Description: Inspection of mechanical drawings and post installation measurements.

Success Criteria: Verification will be considered successful if inspection of mechanical drawings and post installation measurements confirms interface is in accordance with the

GLIMR IICD (D4957031-500) and GLIMR Payload to GLIMR Spacecraft IDD

(GLIMR-06-002).

Figure 4-1: Sensor Assembly Mounting Interface (example only – see D4957031-500)

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[GLIMR-REQ-8] PCU Mechanical Interface

The GLIMR Spacecraft shall provide the mechanical interface between the GLIMR Spacecraft and the PCU in accordance with the GLIMR IICD (D4957031-500) and the GLIMR Payload to

GLIMR Spacecraft IDD (GLIMR-06-002).

Rationale: The GLIMR IICD (D4957031-500) provides the mechanical interface information that the GLIMR Spacecraft will need for accommodation of the PCU. An example is shown in Figure 4-2.

Verification Method: Inspection

Verification Description: Inspection of mechanical drawings and post installation measurements.

Success Criteria: Verification will be considered successful if inspection of mechanical drawings and post installation measurements confirms interface is in accordance with the

GLIMR IICD (D4957031-500).

Figure 4-2: PCU Mounting Interface (example only – see D4957031-500)

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[GLIMR-REQ-9] DEB Mechanical Interface

The GLIMR Spacecraft shall provide the mechanical interface between the GLIMR Spacecraft and the DEB in accordance with the GLIMR IICD (D4957031-500) and the GLIMR Payload to

GLIMR Spacecraft IDD (GLIMR-06-002).

Rationale: The GLIMR IICD provides the mechanical interface information that the

GLIMR Spacecraft will need for accommodation of the DEB. An example is shown in

Figure 4-3.

Verification Method: Inspection

Verification Description: Inspection of mechanical drawings and post installation measurements.

Success Criteria: Verification will be considered successful if inspection of mechanical

GLIMR Instrument ICD.

Figure 4-3: DEB Mounting Interface (example only – see D4957031-500)

[GLIMR-REQ-10] Dust Cover Mechanical Interface

The GLIMR Spacecraft shall provide the mechanical interface between the GLIMR Spacecraft and the dust cover which provides the alignment between the fixed dust cover and the telescope sunshade when the GLIMR Payload is in the stowed position, as specified in the GLIMR IICD

(D4957031-500) and the GLIMR Payload to GLIMR Spacecraft IDD (GLIMR-06-002).

Rationale: The GLIMR IICD (D4957031-500) provides the mechanical interface information that the GLIMR Spacecraft will need to interface with the dust cover. This interface will provide a 0.25 ± 0.03 inch gap between the fixed dust cover and the telescope sunshade when the payload is in the stowed position. An example is shown in

Figure 4-4, with the dimensions of the dust cover provided in Figure 4-5. This dust cover

Release Date: 7/1/2026 Page 22 of 127 provides both thermal and contamination avoidance properties for the sensor assembly.

Note that both the outer edge of the sunshade and the surface of the dust cover facing the telescope sunshade have a radius of curvature that prevents interference when the telescope moves through its full range of motion.

Verification Method: Inspection

Verification Description: Inspection of mechanical drawings and post installation measurements.

Success Criteria: Verification will be considered successful if inspection of mechanical

GLIMR IICD (D4957031-500).

Figure 4-4: Dust Cover Relative Position

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Figure 4-5: Dust Cover Dimensions

4.2.2 Clearances

[GLIMR-REQ-11] Clearance

The GLIMR Spacecraft shall accommodate the GLIMR Payload so as to maintain clearance between the payload and surrounding structures, in order to provide access to payload mounting hardware, access to payload connectors, and space for payload interfacing harness service loops.

Rationale: Sufficient clearance around the payload allows for ease of assembly and disassembly. Sufficient clearance around mated connectors allows for ease of assembly and disassembly, allowing for easier troubleshooting if the need arises, reducing any interface and schedule risk. Ensuring sufficient dynamic clearance between the GLIMR

Spacecraft with all payload(s) and the launch vehicle payload fairing is the responsibility of the GLIMR spacecraft provider and the launch vehicle provider.

Verification Method: Inspection

Verification Description: Inspection of installation design.

Success Criteria: Verification will be considered successful if inspection of installation drawings indicates that proper clearance has been maintained and that there is no need for blind mates or the need for removing adjacent components for harness mating/demating.

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[GLIMR-REQ-12] Remove Before Flight

The GLIMR Spacecraft shall accommodate the removal of the following items before flight:

[TBC]

• Coated optical witness samples

• Cleanliness witness samples

• Soft cover over telescope

• Purge lines

Rationale: Remove before flight items must be easily accessible to avoid any potential oversight or difficulty in procedures.

Verification Method: Inspection

Verification Description: Inspection of installation design.

Success Criteria: Verification will be considered successful if access is confirmed by inspection of drawings or models of the surrounding areas.

4.2.3 Payload Volumes

[GLIMR-REQ-13] Sensor Assembly Stowed Volume

The GLIMR Spacecraft shall provide sufficient volume to accommodate the stowed sensor assembly as detailed in the GLIMR IICD (D4957031-500).

Rationale: Volume of payload is based on as built dimensions. An example is shown in

Table 4-1 and Figure 4-6.

Verification Method: Inspection

Verification Description: Inspection of installation design.

Success Criteria: Verification will be considered successful if inspection of installation design confirms volume allocation in accordance with the GLIMR IICD (D4957031-

500).

Table 4-1: Sensor Assembly Stowed Volume (example only - see D4957031-500)

Parameter Maximum Expected Value x-extent (parallel to orbit) 0.94 m y-extent (normal to orbit) 1.55 m z-extent (nadir) 0.95 m

Total Volume 1.4 m3

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Figure 4-6: Graphical Representation of Stowed Volume (example only – see D4957031-

500)

[GLIMR-REQ-14] Sensor Assembly Swept Volume

The GLIMR Spacecraft shall provide sufficient volume on orbit to accommodate the swept sensor assembly volume as detailed in the GLIMR IICD (D4957031-500).

Rationale: Volume of payload is based on as built dimensions. An example is shown in

Table 4-2 and Figure 4-7.

Verification Method: Inspection

Verification Description: Inspection of installation design.

Success Criteria: Verification will be considered successful if inspection of installation design confirms volume allocation in accordance with the GLIMR IICD (D4957031-

500).

Table 4-2: Sensor Assembly Swept Volume (example only - see D4957031-500)

Parameter Maximum Expected Value x-extent (parallel to orbit) 1.13 m y-extent (normal to orbit) 1.26 m z-extent (nadir) 1.13 m

Total Volume 1.60 m3

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Figure 4-7: Graphical Representation of Swept Volume (example only – see D4957031-500)

[GLIMR-REQ-15] PCU Volume

The GLIMR Spacecraft shall provide sufficient volume within a 1.27-meter cable run of the sensor assembly to accommodate the PCU electronics box.

Rationale: Volume of the PCU is based on as-built dimensions. An example is shown in

Table 4-3 and Figure 4-8. The GLIMR Spacecraft shall mount the PCU to accommodate a maximum cable length of 1.27 meters of the W330A cable which carries the SpaceWire and 1PPS signals from the PCU to the Azimuth cable wrap. The clocking of the connectors should also be considered. There are other cables from the PCU to the

Azimuth cable wrap and DEB, however their length is not as critical for achieving functionality. A description of the cables can be found in the GLIMR Payload to GLIMR

Spacecraft IDD (GLIMR-06-002).

(Note: this maximum distance value represents the baseline configuration and potentially can be increased if desired by GLIMR Access to Space Contractor pending a signal integrity analysis.)

Verification Method: Inspection

Verification Description: Inspection of installation design.

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Success Criteria: Verification will be considered successful if inspection of installation design confirms volume allocation.

Table 4-3: PCU Volume (example only - see D4957031-500)

Parameter Maximum Expected Value (MEV)

Volume 0.047 m3 x extent 0.445 m y extent 0.489 m z extent 0.218 m

Figure 4-8: Payload Control Unit Dimensions (example only - see D4957031-500)

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[GLIMR-REQ-16] DEB Volume

The GLIMR Spacecraft shall provide sufficient volume within a 0.6-meter cable run between the

PCU and DEB and within a 1.2-meter cable run between the DEB and the Azimuth Cable Wrap connector on the GLIMR Payload to accommodate the DEB enclosure.

Rationale: Volume of the DEB is based on as built dimensions. An example is shown in

Table 4-4. The primary limitations on the DEB location are the W303A cable between the PCU and DEB (DEB command and data), and the W320A cable which contains the read heads. The distance between W303A P12 (PCU J12) and W303A P1 (DEB J1) is a maximum of 0.6 meters. The distance between W320A P4 and P5 (DEB J4 and J5) and

W320A J29 (Azimuth Cable Wrap, W389 P29) is a maximum of 1.2 meters. The clocking of the connectors should also be considered. A description of the cables can be found in the GLIMR Payload to GLIMR Spacecraft IDD (GLIMR-06-002).

(Note: these maximum distance values represent the baseline configuration and potentially can be increased if desired by GLIMR vendor pending a signal integrity analysis.)

Verification Method: Inspection

Verification Description: Inspection of installation design.

Success Criteria: Verification will be considered successful if inspection of installation design confirms volume allocation.

Table 4-4: DEB Volume (example only - see D4957031-500)

Parameter Maximum Expected Value (MEV)

Volume 0.003 m3 x extent 0.107 m y extent 0.156 m z extent 0.199 m

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Figure 4-9: Decoder Electronics Box Dimensions (example only - see D4957031-500)

4.2.4 Field of View

[GLIMR-REQ-17] Sensor Assembly Field of View

The GLIMR Spacecraft shall provide the telescope with an unobstructed glint-free field of view

(FOV) out to 45° off nadir in every direction.

Rationale: This requirement assures a clear telescope FOV for science data collections.

An example is shown in Figure 4-10. Note that the operational field of regard of the sensor assembly by requirement is a 20.8-degree cone centered on nadir, so if 45 degrees is challenging for a GLIMR implementation there is room for negotiation.

Verification Method: Inspection

Verification Description: Inspection of mechanical drawings.

Success Criteria: Verification will be considered successful if inspection of mechanical drawings and design confirm the unobstructed field of view.

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Figure 4-10: Payload Field of View Keep Out Zone

[GLIMR-REQ-18] Sensor Assembly’s Radiator Field of View

The GLIMR Spacecraft shall provide the north face of the sensor assembly’s radiator with a clear hemispherical Field of View (FOV) over the full anticipated range of motion of -11.4° to

+24° Azimuth.

Rationale: This requirement assures a clear FOV for heat dissipation, as shown in Figure

4-11. If this entire FOV cannot be met, there is room for negotiation as long as the thermal backloading requirement can be met.

Verification Method: Inspection

Verification Description: Inspection of mechanical drawings.

Success Criteria: Verification will be considered successful if inspection of mechanical drawings and design confirm the unobstructed field of view.

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Figure 4-11: Radiator Field of View

4.2.5 Structural Alignment

[GLIMR-REQ-19] Sensor Assembly Alignment

The GLIMR Spacecraft shall align the sensor assembly coordinate reference frame with respect to the GLIMR Spacecraft attitude control system reference frame to within 0.25 degrees (4360 microradians) per axis, post integrated environmental testing.

Rationale: Minimal alignment error is required in order for the sensor assembly range of motion to be able to provide the required field of view.

Note: There are reflectors mounted to the gimbal to assist in this alignment. See Detail G on drawing D4957031-500.

Verification Method: Test

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Verification Description: Test of the alignment of the sensor assembly coordinate reference frame with respect to the GLIMR Spacecraft attitude control system reference frame.

Success Criteria: Verification will be considered successful if the test indicates that the alignment of the sensor assembly coordinate reference frame with respect to the GLIMR

Spacecraft attitude control system reference frame is within the specified tolerance.

[GLIMR-REQ-20] Sensor Assembly Prelaunch Alignment Knowledge

The GLIMR Spacecraft shall provide knowledge of the prelaunch alignment of the sensor assembly alignment reference frame with respect to the GLIMR Spacecraft attitude control system reference frame to better than 300 microradians per axis [TBC], post integrated environmental testing.

Rationale: Supports the image navigation and registration error budget.

Verification Method: Test

Verification Description: Test of the prelaunch alignment of the sensor assembly alignment reference frame with respect to the GLIMR Spacecraft attitude control system reference frame.

Success Criteria: Verification will be considered successful if the test of the prelaunch alignment of the sensor assembly alignment reference frame with respect to the GLIMR

Spacecraft attitude control system reference frame indicates that the alignment will be known within the specified tolerance.

[GLIMR-REQ-21] Sensor Assembly On-orbit Alignment Stability

The GLIMR Spacecraft shall limit the alignment change between the sensor assembly mounting frame and the GLIMR Spacecraft attitude control system reference frame to less than 20 microradians per hour per axis [TBC] during GLIMR Payload imaging operations.

Note: This requirement includes on-orbit environments and GLIMR Spacecraft structural and thermal stability during payload imaging operations.

Rationale: Supports the image navigation and registration error budget. Payload imaging operations can occur any time at which the solar zenith angle within Greater North

America is less than 72 degrees [TBC].

Verification Method: Analysis

Verification Description: Analysis of the deviation from ground alignment compared to while on-orbit (e.g., includes launch, gravity sag, thermal).

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Success Criteria: Verification will be considered successful if the analysis indicates that the alignment change is within the specified tolerance.

4.2.6 Mass Properties

[GLIMR-REQ-22] Sensor Assembly Mass Allocation

The GLIMR Spacecraft shall accommodate a sensor assembly maximum mass allocation of 136 kg NTE (Not to Exceed), exclusive of GLIMR Spacecraft provided interface hardware or cabling.

Rationale: The sensor assembly’s mass allocation includes all hardware listed in the

GLIMR IICD (D4957031-500). It does not include any mass allocation for interface hardware necessary to adapt the sensor assembly to the GLIMR Spacecraft or for the cabling from the GLIMR Spacecraft to the sensor assembly, which are to be provided by the GLIMR Access to Space Contractor. (CBE (Current Best Estimate) = 110 kg)

Verification Method: Analysis

Verification Description: Perform structural analysis of the integrated GLIMR Spacecraft and sensor assembly.

Success Criteria: Verification will be considered successful if analysis shows there are positive margins on the structural analysis.

[GLIMR-REQ-23] PCU Mass Allocation

The GLIMR Spacecraft shall accommodate a PCU maximum mass allocation of 34 kg NTE, exclusive of GLIMR Spacecraft provided interface hardware.

Rationale: The PCU mass allocation includes all hardware listed in the GLIMR IICD

(D4957031-500). It does not include any mass allocation for interface hardware necessary to adapt the PCU to the GLIMR Spacecraft, provisions for thermal control or for the cabling from the GLIMR Spacecraft to the PCU, which are to be provided by the

GLIMR Access to Space Contractor. (CBE = 30 kg)

Verification Method: Analysis

Verification Description: Perform structural analysis of the integrated GLIMR Spacecraft and PCU.

Success Criteria: Verification will be considered successful if analysis shows there are positive margins on the structural analysis.

[GLIMR-REQ-24] DEB Mass Allocation

The GLIMR Spacecraft shall accommodate a DEB maximum mass allocation of 3 kg NTE, exclusive of GLIMR Spacecraft provided interface hardware.

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Rationale: The DEB mass allocation includes all hardware listed in the GLIMR IICD

(D4957031-500). It does not include any mass allocation for interface hardware necessary to adapt the DEB to the GLIMR Spacecraft, provisions for thermal control or for the cabling from the GLIMR Spacecraft to the DEB, which are to be provided by the

GLIMR Access to Space Contractor. (CBE = 1 kg)

Verification Method: Analysis

Verification Description: Perform structural analysis of the integrated GLIMR Spacecraft and DEB.

Success Criteria: Verification will be considered successful if analysis shows there are positive margins on the structural analysis.

[GLIMR-REQ-25] Dust Cover Mass Allocation

The GLIMR Spacecraft shall accommodate a dust cover maximum mass allocation of 2 kg NTE, exclusive of GLIMR Spacecraft provided interface hardware.

Rationale: The dust cover mass allocation includes all hardware listed in the GLIMR

IICD (D4957031-500). It does not include any mass allocation for interface hardware necessary to mount the dust cover to the GLIMR Spacecraft, which is to be provided by the GLIMR Access to Space Contractor. (CBE = 1 kg)

Verification Method: Analysis

Verification Description: Perform structural analysis of the integrated GLIMR Spacecraft and dust cover.

Success Criteria: Verification will be considered successful if analysis shows there are positive margins on the structural analysis.

[GLIMR-REQ-26] Center of Gravity and Moment of Inertia

The GLIMR Spacecraft shall accommodate the sensor assembly center of gravity and moment of inertia values as specified in the GLIMR Payload to GLIMR Spacecraft IDD (GLIMR-06-002).

Rationale: The sensor assembly’s center of gravity and moment of inertia values are specified in the GLIMR Payload to GLIMR Spacecraft IDD (GLIMR-06-002).

Verification Method: Analysis

Verification Description: Perform structural analysis of the integrated GLIMR Spacecraft and payload.

Success Criteria: Verification will be considered successful if analysis shows there are positive margins on the structural analysis.

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4.3 Structural Launch Environment Requirements

The following requirements limit the environmental loads that can be transmitted to the GLIMR

Payload by the launch vehicle, as mounted to the GLIMR Spacecraft. Testing performed by the

GLIMR Spacecraft will verify that the expected launch loads do not cause these limits to be exceeded, but is not required to reach these limits.

Structural analysis was done independently for each element, and each analysis used a different local coordinate system, as described in Figure 4-12.

Figure 4-12: GLIMR unit-specific local coordinate systems used for structural analysis.

Note: For the sensor assembly, the structural environment tables present results in this analysis coordinate system, and transformation based on mounting and launch orientation is necessary to convert to lateral and axial launch loads. The GLIMR Payload can be mounted in any orientation as long as the load limits are met.

4.3.1 Quasi-Static Acceleration Environment

[GLIMR-REQ-27] Sensor Assembly Quasi-Static Acceleration Environment

The GLIMR Spacecraft shall limit the quasi-static acceleration at the sensor assembly interface to a value less than the limit levels specified in Table 4-5.

Rationale: The sensor assembly was design strength qualified to the quasi-static accelerations in the table below. Should these levels be exceeded, there is a risk of structural or functional damage to the sensor assembly.

Verification Method: Analysis

Verification Description: Results from the combination of the coupled loads analysis

(CLA) and the random vibration/vibroacoustic analyses will be used to verify that the quasi-static acceleration specified in each axis will not be exceeded.

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Success Criteria: Verification will be considered successful if the results from the combination of the CLA and random vibration/vibroacoustic analyses indicate that the quasi-static acceleration in each axis will not be exceeded.

Table 4-5: Sensor Assembly Maximum Acceleration Limits

Component Maximum Acceleration (g)

Local x, z Local y

Sensor Assembly 5.4 9

[GLIMR-REQ-28] PCU Quasi-Static Acceleration Environment

The GLIMR Spacecraft shall limit the quasi-static acceleration at the PCU interface to a value less than the limit levels specified in Table 4-6.

Rationale: The PCU was design strength qualified to the quasi-static accelerations in the table below. Should these levels be exceeded, there is a risk of structural or functional damage to the PCU.

Verification Method: Analysis

Verification Description: Results from the combination of the CLA and the random vibration/vibroacoustics analyses will be used to verify that the quasi-static acceleration specified in each axis will not be exceeded.

Success Criteria: Verification will be considered successful if the results from the combination of the CLA and random vibration/vibroacoustics analyses indicate that the quasi-static acceleration in each axis will not be exceeded.

Table 4-6: PCU Maximum Acceleration Limits

Component Maximum Acceleration (g) any axis

PCU 25

[GLIMR-REQ-29] DEB Quasi-Static Acceleration Environment

The GLIMR Spacecraft shall limit the quasi-static acceleration at the DEB interface to a value less than the limit levels specified in Table 4-7.

Rationale: The DEB was design strength qualified to the quasi-static accelerations in the table below. Should these levels be exceeded, there is a risk of structural or functional damage to the DEB.

Verification Method: Analysis

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Verification Description: Results from the combination of the CLA and the random vibration/vibroacoustic analyses will be used to verify that the quasi-static acceleration specified in each axis will not be exceeded.

Success Criteria: Verification will be considered successful if the results from the combination of the CLA and random vibration/vibroacoustic analyses indicate that the quasi-static acceleration in each axis will not be exceeded.

Table 4-7: DEB Maximum Acceleration Limits

Component Maximum Acceleration (g) any axis

DEB 50

[GLIMR-REQ-30] Dust Cover Quasi-Static Acceleration Environment

The GLIMR Spacecraft shall provide an interface to the dust cover which prevents the dust cover from contacting the telescope sunshade during the predicted quasi-static acceleration vibration environments.

Rationale: The dust cover will be mounted to provide a 0.25 ± 0.03 inch gap between the cover and the telescope sunshade while in the stowed position on-orbit, as specified in

GLIMR IICD (D4957031-500). The GLIMR Spacecraft dust cover support structure will provide this gap while being sufficiently robust to the launch quasi-static acceleration environment.

Verification Method: Analysis

Verification Description: Results from the combination of the CLA and the random vibration/vibroacoustic analyses will be used to verify that the quasi-static acceleration specified in each axis will not be exceeded.

Success Criteria: Verification will be considered successful if the results from the combination of the CLA and random vibration/vibroacoustic analyses indicate that the dust cover does not contact the telescope sunshade under expected launch quasi-static acceleration levels.

4.3.2 Random Vibration Environment

[GLIMR-REQ-31] Sensor Assembly Random Vibration Environment

The GLIMR Spacecraft shall limit the random vibration environment at the sensor assembly interface to the random vibration limit levels specified in Table 4-8 and the random vibration limit profile levels specified in Table 4-9.

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Rationale: The sensor assembly was design strength qualified to the random accelerations in the table below. Should these levels be exceeded, there is a risk of structural or functional damage to the payload.

Verification Method: Test

Verification Description: Random Vibration tests.

Success Criteria:…