L1 Series MAG SPEC (Draft).pdf

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Space Weather (SW) Next L1 Series, Code 491.0 L1SERIES-MAG-REQ-0022, Revision DRAFT

L1 Series Magnetometer Specification

SWO CMO

November 17, 2023

DRAFT

U.S. Department of Commerce (DOC) National Oceanic and Atmospheric Administration (NOAA) NOAA Satellite and Information Service (NESDIS) National Aeronautics and Space Administration (NASA)

Effective Date:

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L1 Series Magnetometer Specification

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Preface

This document is under SWO Program configuration control. Once this document is approved, SWO approved changes are handled in accordance with Class I and Class II change control requirements as described in the SWO Configuration Management Procedure, and changes to this document shall be made by complete revision.

In this plan, all mandatory actions (i.e., requirements) are denoted by statements containing the term “shall.” The terms “may” or “can” denote discretionary privilege or permission; “should” denotes a good practice and is recommended but not required; “will” denotes expected outcome;

and “are/is” denotes descriptive material.

Any questions should be addressed to:

SWO Configuration Management Office

NASA/GSFC

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Change History Log

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Deviations/Waivers Record

Section # / Rqmt.

Deviation / Waiver #

CCR # Date Approved

Description

None. None. None. None. None.

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Table of TBCs/TBDs/TBRs/TBSs

Item No.

Identifier Section Summary

Applicable Documents

2 Applicable Documents subject to revision

2 N/A 4.3.2.2

The L1 Series spacecraft will monitor up to three (TBR) analog instrument health and safety parameters defined by the Mag contractor and command the Mag into safe mode when any of those key values have been exceeded.

3 N/A 4.3.2.2

The L1 Series spacecraft will monitor up to 12 (TBR) digital telemetry points that are part of the normal instrument generated data stream for instrument health and safety parameters defined by the Mag contractor and command the Mag into safe mode when any of those key values have been exceeded.

4 MAGSPEC1018 4.4

The instrument shall have a 99.9 % (TBR) probability of operating continuously on-orbit during nominal observation mode (which excludes non-Magnetometer related Spacecraft Safe Holds, instrument calibrations and storm conditions).

5 MAGSPEC1022 4.4

The instrument shall provide a 99% (TBR) or greater probability of providing all of the instrument's HAP data during S4 class solar radiation storms or solar flare conditions including class X50, verifying through analysis using the “Worst Week” October 1989 model in CREME96 or equivalent.

6 MAGSPEC259 6.5

The Mag shall be designed to meet its performance requirements after being subjected to the shock environment shown in Table 4 and Figure 7 (TBR), applied at the Magnetometer interface to the L1 Series spacecraft structure. The shock environment will not exceed those shown in Table 4 and Figure 8.

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7 MAGSPEC267 6.6

The Mag shall be designed to withstand, without any damage or degradation of performance, when acoustic testing to the equivalent Protoflight (TBR) levels, which are +3 dB over those shown in Figure 9.

8 MAGSPEC294 6.10

The Mag electronics unit heat transferred to the spacecraft shall be limited to ≤5 Watts. (TBR)

9 MAGSPEC1015 8.6.1

The Mag shall be designed for a 3-year (TBR) ground storage period.

10 MAGSPEC713 10.2.2

The Mag emulator shall communicate with a spacecraft simulator for instrument command and telemetry using a standard interface (TBD) that matches the Mag instrument design.

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Table of Contents

1 INTRODUCTION

1.1 General Information

1.2 Scope

2 APPLICABLE DOCUMENTS

3 CONTRACT DESCRIPTION

3.1 Magnetometer Description

3.2 Ground Support Equipment Description

4 FUNCTIONAL/PERFORMANCE REQUIREMENTS

4.1 Magnetometer Performance Requirements

4.1.1 Operational Measurement Range

4.1.2 Measurement Accuracy

4.1.3 Orientation Accuracy

4.1.4 Ground Test Measurement Range

4.1.5 Refresh Rate and Latency

4.1.6 Noise

4.1.7 Quantization Error

4.2 Resource Allocations

4.2.1 Mass Allocation

4.2.2 Physical Envelope

4.2.3 Operational Power Allocation

4.2.4 Peak Operational Allocation

4.2.5 Survival Heater Power Allocation

4.2.6 Telemetry

4.2.7 Transient Magnetic Field

4.2.8 Static Magnetic Field

4.3 Magnetometer Operating Modes

4.3.1 Deterministic Power-on Configuration

4.3.2 Safe Mode

4.3.2.1 Provision of Safe Mode

4.3.2.2 Entry into Safe Mode

4.3.3 Fail-safe Recovery Mode

4.3.4 Normal Operational Mode

4.3.5 On-Orbit Operations

4.3.6 Station Keeping

4.3.7 Selective Performance/Contingency Operating Mode

4.4 Instrument Data Availability

4.5 Power

4.5.1 Voltage Range

4.5.2 Abnormal Voltages

4.5.3 Power Transients

4.5.4 Sudden Removal of Power

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4.5.5 Over-Current Protection

4.5.6 Primary Power Return Ground

4.5.7 Turn-on Current Transients

4.6 Electrical Grounding

4.6.1 Primary Power DC Isolation

4.6.2 Survival Power Isolation

4.6.3 Internally Generated Secondary to Primary DC Isolation

4.6.4 Internally Generated Secondary Return

4.6.5 Mechanical Contact Resistance

4.6.6 Grounding

4.6.7 Connector DC Resistance

4.7 Signal And Data Interfaces

4.7.1 Passive Analog Telemetry

4.7.2 Data Signal Interface

4.7.2.1 Telemetry Source Packet Format

4.7.2.2 Command Source Packet Format

4.7.3 Clock Signal Interface

4.7.4 Command and Housekeeping telemetry

4.7.5 Commands for Autonomous Functions

4.7.6 Limits and Triggers

4.7.7 On-Board Processor Reset

4.7.8 Micro-switches

4.8 Flight Software

4.8.1 Flight Load Non-volatile Memory

4.8.2 Software Updates

4.8.3 Software Table Updates

4.8.4 Flexibility and Ease of Software Modification

4.8.5 Version Identifiers

4.8.6 Warm Restart

4.8.7 Memory Tests

4.8.8 Memory Dump

4.8.9 Fault Detection and Correction Control

4.8.10 Health and Safety Monitoring

5 PHYSICAL REQUIREMENTS

5.1 Interface and Design Units and Exclusions

5.2 Mass Properties Accuracy

5.2.1 Magnetometer Instrument Mass Accuracy

5.2.2 Center of Mass Location

5.2.3 Center of Mass Accuracy

5.2.4 Determination of Moments and Products of Inertia

5.3 Mounting

5.3.1 Surface Flatness

5.3.2 Method

5.4 Coordinate System and Alignment

6 ENVIRONMENTAL REQUIREMENTS

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6.1 Mechanical Factors of Safety

6.2 Quasi-Static Acceleration

6.3 Frequency Requirement

6.3.1 Fundamental Launch Frequencies

6.4 Vibration

6.4.1 Sinusoidal Vibration

6.4.2 Random Vibration

6.5 Shock

6.6 Acoustics

6.7 Transportation

6.7.1 Transportation Cleanliness

6.8 Pressure

6.8.1 Operating Pressure Range

6.8.2 Maximum Depressurization Rate

6.8.3 Launch Vehicle (LV) Environmental Control System (ECS) Impingement

6.9 On-Orbit Dynamic Environment

6.9.1 Dynamic Linear Acceleration

6.9.2 Dynamic Angular Acceleration

6.10 Thermal Requirements

6.10.1 Flight Interface Design Temperature Limits

6.11 Charged Particle Radiation Requirements

6.11.1 Definitions

6.11.2 Radiation Hardness Assurance

6.11.2.1 Single-Event Effect Rate Calculations

6.11.3 Destructive Events

6.11.4 Charging Environment

6.11.5 Total Ionizing Dose

6.11.6 Displacement Damage Dose Levels

6.11.7 Single Event Effects

6.11.8 Solar Cycle Performance

6.11.9 Solar Particle Event Operations

6.11.10 Solar Flare Survival

7 CONTAMINATION CONTROL

7.1 Magnetometer Surface Cleanliness Requirements

7.2 Contamination Generation

7.2.1 Particulate Generation

7.2.2 Molecular Contamination Generation

7.2.2.1 Molecular Material Restrictions

7.3 Vacuum Bakeouts

7.4 Contamination Analyses

7.5 Venting Requirements

7.6 Cleanability and Protection

7.7 Electrostatic Cleanliness

7.7.1 Conductive Surface Ground Path

7.7.2 Conductive Surface Resistivity

7.7.3 Closeout of Gaps and Apertures

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7.7.4 Exposed Harness Specific Requirements

7.7.5 Thermal Blankets

8 DESIGN AND CONSTRUCTION REQUIREMENTS

8.1 Electrical

8.1.1 Test Sensors

8.1.2 MGSE Grounding

8.1.3 Connector Specifications

8.1.3.1 Contact Derating

8.1.3.2 Redundant Contact Derating

8.1.3.3 Signal Segregation

8.1.3.4 Test and Flight Signal Isolation

8.1.4 Test Interfaces

8.1.4.1 Facility-Induced Noise

8.1.4.2 Facility-Induced ESD GSE Malfunction

8.1.4.3 Facility-Induced GSE Malfunction

8.1.5 Mitigation of Internal Charging

8.1.5.1 Mitigation Strategies for Internal Charging

8.1.5.2 Floating Conductors

8.1.5.3 Dielectric Structures

8.2 Safety

8.3 Electromagnetic Compatibility

8.3.1 Conducted Emissions

8.3.1.1 Applicability of Conducted Emissions

8.3.1.2 CE101 – Differential Mode Conducted Emissions Limits

8.3.1.3 CE03 – Differential Mode Conducted Emissions Limits

8.3.1.4 Common Mode Bulk Conducted Emissions Limits

8.3.1.5 CETDT - Conducted Emissions, Time Domain, Transients Limits

8.3.2 Conducted Susceptibility

8.3.2.1 Applicability of Conducted Susceptibility

8.3.2.2 CS101 – Conducted Susceptibility Limit

8.3.2.3 CS114 – Conducted Susceptibility Differential Mode Limit

8.3.2.4 CS114 – Conducted Susceptibility, Common Mode, Power and Signal Cables 64

8.3.2.5 CS06 - Conducted Susceptibility, Transients Limits

8.3.2.6 CS115 - Conducted Susceptibility, Bulk Cable Injection, Impulse Excitation ... 66

8.3.3 Radiated Emissions

8.3.3.1 RE102 - Electric Field Emissions Limits

8.3.4 Radiated Susceptibility

8.3.4.1 RS103 - Radiated Susceptibility, Electric Field, Launch Limit

8.3.4.2 RS103 - Radiated Susceptibility, Electric Field, In-Flight Limit

8.4 Identification and Marking

8.5 Workmanship

8.5.1 Connectors

8.6 Reliability and Mission Lifetime

8.6.1 Mission Life

8.6.2 Operating Time

8.6.3 Trouble-Free Time

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8.7 Ground Handling

8.7.1 Ground Support Equipment (GSE) Design

8.7.2 Lifting Hardware

8.7.3 Manual Lifting Hardware

8.7.4 GSE Cleanliness

8.7.5 GSE Bakeout

8.7.6 Test Harness

8.8 Interface Documentation

8.8.1 Mechanical Interface

8.8.2 Electrical Interface

8.8.3 Data Interface

9 MECHANICAL DESIGN REQUIREMENTS

9.1 Structural Requirements

9.1.1 Component Fatigue

9.1.2 Fracture Control Requirements

9.2 Fastening Systems

9.2.1 Factors of Safety

9.2.2 Supplemental Factor

9.2.3 Ultimate Design Loads

9.2.4 Yield Design Loads

9.2.5 Design Separation Load

9.2.6 Fastener Locking and Retention

9.2.6.1 Thread Engagement

9.2.6.2 Locking Feature Verification

9.2.6.3 Locking Feature Installation

9.2.6.4 Snap Ring and Cotter Pin Use Limitation

9.2.6.5 Snap Ring and Cotter Pin Use

9.2.6.6 Liquid Locking Compounds

9.2.6.6.1 Verification

9.2.6.7 Locking Features

9.2.6.7.1 Specification

9.2.6.7.2 Validation

9.2.7 Installation Torque Specification and Control

9.2.7.1 Installation Torque Range

9.2.7.2 Running Torque Identification

9.2.8 Fastened Joints Criteria

9.2.8.1 Minimum and Maximum Preload

9.2.8.2 Analysis Addressing Potential Rupture

9.2.8.3 Ultimate Strength Analysis

9.2.8.3.1 Applied Shear Loading

9.2.8.3.2 Shear Loading

9.2.8.4 Simultaneous Applied Tensile and Shear Loads

9.2.8.5 Allowable Yield Tensile Load

9.2.8.6 Separation Analysis

9.2.8.7 Seal Analysis

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10 LOGISTICS

10.1 I&T Deliverables

10.2 Ground Support Equipment

10.2.1 Electrical System Test Equipment

10.2.2 Magnetometer Emulator (MAGE)

10.3 Transportation Equipment

10.3.1 Shipping Container

11 VERIFICATION REQUIREMENTS

11.1 Verification Methods

11.1.1 Inspection

11.1.2 Analysis

11.1.3 Test

11.1.4 Demonstration

11.2 Inspection Requirements

11.2.1 Visual Inspection

11.2.2 Physical Measurement

11.2.3 Documentation Search

11.3 Analysis Requirements

11.4 Test Requirements

11.4.1 Definitions

11.4.2 Test Factors

11.4.3 Test Tolerances

11.4.4 Test Restrictions

11.4.4.1 Failure During Tests

11.4.4.2 Modification of Hardware

11.4.4.3 External Adjustment

11.4.4.4 Re-Test Requirements

11.4.4.5 Configuration

11.5 Required Tests

11.5.1 Performance Tests

11.5.1.1 Comprehensive Performance Test

11.5.1.2 Limited Performance Test

11.5.1.3 Abbreviated Functional Test

11.5.2 Mass Properties Measurement

11.5.3 Static Loads/Strength Test

11.5.3.1 Sine Burst

11.5.3.2 Static Pull

11.5.4 Sine Sweep Survey

11.5.5 Sine Vibration

11.5.6 Random Vibration

11.5.7 Acoustic Test

11.5.8 Shock

11.5.9 Thermal Vacuum Bake-out

11.5.10 Thermal Vacuum Test

11.5.10.1 Thermal Vacuum Test Parameters

11.5.10.2 Thermal Vacuum Test Profile

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11.5.11 Magnetics Test

11.5.12 Harness Tests

11.5.13 EMI/EMC Tests

APPENDIX A ABBREVIATIONS AND ACRONYMS

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List of Figures Figure 1 Telemetry Source Packet Definition Figure 2 Time Code Format Figure 3 Command Source Packet Figure 4 Spacecraft Time Message Packet Figure Figure 5 Spacecraft Reference System Figure 6 Sine Vibration Environment Figure 7 Mag Acceptance Random Vibration Environment Figure 8 Candidate LV Shock Environment Figure 9 L1 Series S/C Acceptance Acoustic Envelope Figure 10 Allowable Analytical, Flight Operation, Flight Acceptance Test, and Qualification

(ProtoFlight or Prototype) Test Temperature Ranges Figure 11 Total Ionizing Dose (TID) Dose – Depth Curve Figure 12 Displacement Damage Dose (DDD) in Silicon vs. Shielding Thickness Dose-Depth

Curve Figure 13 Displacement Damage Dose in Gallium Arsenide Dose-Depth Curve Figure 14 LET Spectrum of GCR Background Figure 15 Solar LET Spectrum Background Figure 16 Solar Proton Background Spectra Figure 17 Peak Solar Particle Event Flux Figure 18 Peak Solar Proton Flux Figure 19 CE101/CE03 Differential Mode Conducted Emissions Limits Figure 20 Common Mode Bulk Conducted Emissions Limit Figure 21 Inrush Current Transient Default Limit Figure 22 Power Lead Conducted Susceptibility (CS101) Voltage Limit Figure 23 Conducted Susceptibility Power Limit (30 Hz to 150 kHz) Figure 24 Conducted Susceptibility, Power Leads, 150 kHz to 50 MHz Limit Figure 25 Common Mode Conducted Susceptibility Calibration Limit Figure 26 Conducted Susceptibility Transient Waveform Figure 27 CS115 Impulse Waveform Figure 28 Unit Level RE102 Radiated Electric Field Emission Limits Figure 29 Thermal Vacuum Profile

List of Tables

Table 1 Applicable Documents (TBR) Table 2 Factors of Safety Table 3 Mag Design Limit Loads Table 4 Candidate LV Shock Environment Table 5 Transportation Loads Table 6 Total Ionizing Dose vs. Shielding Thickness Table 7 Displacement Damage Dose in Silicon vs. Shielding Thickness Table 8 Displacement Damage Dose in Gallium Arsenide vs. Shielding Thickness Table 9 LET Spectrum of GCR Background Table 10 Solar Background LET Spectrum xvi Check https://ipdtdms.gsfc.nasa.gov/frontmenu_dsp.cfm to verify that this is the correct version prior to use.

Table 11 Solar Proton Background Flux Table 12 Peak Solar Particle Event Flux Table 13 Peak Solar Proton Flux Table 14 Magnetometer Lifetime Contamination Requirements Table 15 Thermal Blanket Area vs. Grounding Tabs Table 16 Emission and Susceptibility Requirements Table 17 RS103 Radiated Susceptibility Levels (Launch) Table 18 Test Factors and Durations Table 19 Test Tolerances Table 20 Thermal Vacuum Test Parameters

L1SERIES-MAG-SPEC-0001, Revision DRAFT

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1 INTRODUCTION

1.1 General Information

1.2 Scope

This specification describes the performance and electrical, mechanical, environmental, and verification testing requirements for a space-qualified Magnetometer Instrument for the Space Weather Next Lagrange-1 (L1-Series) Mission.

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2 APPLICABLE DOCUMENTS

The following documents and drawings in effect on the day this specification was signed shall apply to the fabrication and to the electrical, mechanical, and environmental requirements of the Magnetometer to the extent specified herein. In the event of conflict between this specification and any referenced document, this specification will govern, with the exception of the L1 Series Magnetometer Statement of Work (L1SERIES-MAG-SOW-0005), in which case the Statement of Work takes precedence.

The following is a list of the applicable specifications and publications.

Table 1 Applicable Documents (TBR)

Document Number Title

L1SERIES-MAG-SOW-

L1 Series Magnetometer Statement of Work (SOW)

L1SERIES-MAG-REQ-

L1 Series Magnetometer Contract Deliverables Requirements List

(CDRL)

ANSI/TIA/EIA-422-B Electrical Characteristics of Balanced Voltage Digital Interface Circuits

ANSI/TIA/EIA-644-A-

Electrical Characteristics of Low Voltage Differential Signaling (LVDS) Interface Circuits

NFPA 70 National Fire Protection Association National Electric Code NASA-STD-5001B Structural Design and Test Factors Of Safety For Spaceflight

Hardware NASA-STD-8719.24 NASA Expendable Launch Vehicle Payload Safety Requirements NASA-STD-6016 Standard Materials and Processes Requirements for Spacecraft NASA-HDBK-7005 Dynamic Environment Criteria NASA-STD-7001 Payload Vibroacoustic Test Criteria IEST-STD-CC-1246E Product Cleanliness Levels and Contamination Control Program ASTM E-595-07 Standard Test Method for Total Mass Loss and Collected Volatile

Condensable Materials from Outgassing in a Vacuum Environment MIL-DTL-5541 Chemical Conversion Coatings on Aluminum and Aluminum

Alloys MIL-A-8625F Anodic Coatings for Aluminum and Aluminum Alloys EEE-INST-002 Instructions for EEE Parts Selection, Screening, Qualification, and

Derating MIL-STD-461G Military Standard, Electromagnetic Emission and Susceptibility

Requirements for the Control Of Electromagnetic Interference

(EMI)

GSFC-STD-7000B General Environmental Verification Standard (GEVS) NASA-STD-5019A Fracture Control Requirements for Spaceflight Hardware NASA-STD-5020B Requirements for Threaded Fastening Systems in Spaceflight

Hardware NASA-STD-5017B Design and Development Requirements for Mechanisms NASA-HDBK-4002B Mitigating In-Space Charging Effects—A Guideline

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FAA AC 20-71 Federal Aviation Administration Advisory Circular (AC) 20-71, “Dual Locking Devices on Fasteners".

NASM 33540 Safety Wiring, Safety Cabling, Cotter Pinning, General Practices for

SAE AS567 Safety Cable, Safety Wire, Key Washers, and Cotter Pins for Propulsion Systems, General Practices for Use of

MSFC-STD-3029A Guidelines for the Selection of Metallic Materials for Stress Corrosion Cracking Resistance in Sodium Chloride Environments

MIL-STD-462, Notice 2 Electromagnetic Interference Characteristics, Measurement of, 1 May 1970

ISO 14644-1:2015 Part 1: Classification of air cleanliness by particle concentration ISO 14644-3: 2005 Cleanrooms and associated controlled environments -- Part 3: Test methods CCSDS 133.0-B-1 Space Packet Protocol, Blue Book, Issue 1, September 2003 CCSDS 301.0-B-4 Time Code Formats. Blue Book. Issue 3, January 2002

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3 CONTRACT DESCRIPTION

3.1 Magnetometer Description

The Magnetometer instrument (Mag) suite consists of two magnetometer sensor units (each containing a three-axis magnetic field sensor), up to two electronic unit(s) and the associated interconnecting cables. It is expected that the magnetometer sensors will be mounted on a deployable boom provided by the L1 Series spacecraft contractor. The exact location, mounting configuration and distances between the sensors and the electronics will be negotiated between the magnetometer contractor and the spacecraft contractor in order to develop the required interface control documents for the magnetometer.

The term “Magnetometer Instrument” or suite includes the magnetometer sensors, electronics, cabling between sensors and electronics, up to the spacecraft provided interface. The “Magnetometer Electronics” includes the electronic components and may consist of a single box for both sensor units or two separate boxes, one for each sensor unit. Each “Magnetometer Sensor” includes a tri-axial sensor. The “Magnetometer Harness” includes the Magnetometer Instrument supplier provided harness and cabling necessary to connect each electronics/sensor pair.

The Magnetometer contract includes the delivery of two (2) flight magnetometer suites (where a single magnetometer suite is comprised of (2) flight sensors, (1) or (2) flight electronics unit and the flight harness(es) between the instrument boxes), one (1) Engineering Development Unit (EDU) magnetometer suite, and enough spares and built-up sub-assemblies for two additional FM sensors, an electronics unit and harnesses.

3.2 Ground Support Equipment Description

The Mag contract includes the delivery of (2) sets of the Electrical System Test Equipment (ESTE), (4) Magnetometer Emulators (MAGEs), and (1) One Ground Processing Development System (GPDS). Additionally, Mechanical Ground Support Equipment (MGSE) such as lifting fixtures/handles, shipping containers, drill templates, test fixtures, non-flight protective covers, etc. are included in the delivery. Electrical Ground Support Equipment includes, but is not limited to, test cables and break-out boxes.

The Magnetometer suite delivery includes ground support equipment required to power and operate the magnetometers at the vendor’s and spacecraft contractor’s facilities. The delivery also includes a standalone emulator that will interface to a spacecraft simulator for the purposes of interface testing, operations product development, and training.

Ground Support Equipment is necessary to operate the instrument during spacecraft testing.

Supplying this equipment is considered part of the delivery for the instrument. More information is provided in the Contract Deliverables Requirements List (CDRL).

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4 FUNCTIONAL/PERFORMANCE REQUIREMENTS

This section defines the functional and performance requirements for the L1 Series Magnetometer.

The requirements in this Specification pertain to the Magnetometer ‘system’, which may include all instrument hardware, software, and ground processing algorithms. The Magnetometer contractor is not responsible for the operational ground system, but certain specifications may require ground processing after collection but before data product generation and distribution, which the contractor is responsible for defining and developing.

4.1 Magnetometer Performance Requirements

4.1.1 Operational Measurement Range

MAGSPEC23: The magnetometer shall provide in situ heliospheric magnetic field measurements with a range in field magnitude of ±250 nT.

4.1.2 Measurement Accuracy

MAGSPEC25: The Mag shall measure the magnetic field to an accuracy of ≤ ±0.5 nT when measuring a magnetic field with magnitude ≤ 100 nT.

MAGSPEC26: The Mag shall measure the magnitude of magnetic field to an accuracy of ≤ ± 0.5% when measuring a magnetic field with magnitude >100 nT and ≤250nT.

MAGSPEC1010: The heliospheric magnetic field’s direction shall be provided with an accuracy of +/-1.5 degree accuracy over the required measurement range.

This accuracy requirement must be met with all Mag error sources included for the duration of the mission. One calibration maneuver per month (s/c roll about the sun line) can be assumed.

It is expected that a calibration period for the Mag will occur following launch (during the cruise phase) where inflight calibration will be performed.

MAGSPEC962: The Mag shall measure each Cartesian component of the magnitude of magnetic field to an accuracy of ± 1000 nT when measuring a magnetic field with magnitude >250nT.

4.1.3 Orientation Accuracy

MAGSPEC30: The relative orientation of the Mag axes to each other shall be known and stable to better than +/- 0.1 degrees.

MAGSPEC910: The relative orientation of the Mag measurement coordinate system to the instrument coordinate system shall be known to better than +/- 0.1 degrees.

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4.1.4 Ground Test Measurement Range

MAGSPEC32: The Mag shall have for ground based testing an ambient measurement range of at least ±20000 nT in each of the three orthogonal axes.

4.1.5 Refresh Rate and Latency

The L1 Series mission will make Solar Wind data (including data from the Mag) available to SWPC forecasters within 3 minutes of the completion of each data acquisition.

MAGSPEC35: The mag instrument shall sample and send to the spacecraft ten magnetic field vector per second.

MAGSPEC36: The Mag ground processing algorithm (ref Sec 4.0) shall produce (output) an ambient magnetic field vector measurement with a refresh rate of ≤ 6 seconds derived from the 10 Hz magnetic field measurements.

MAGSPEC37: The Mag instrument measurements shall be timed-tagged to an accuracy ≤ 100 msec relative to the 1 PPS spacecraft reference signal.

MAGSPEC38: The processing of a completed on-orbit data collection by the Mag and the transmission to the spacecraft shall contribute ≤ 2 seconds to the overall latency of the solar wind data product.

MAGSPEC39: The Mag ground processing algorithm contribution to data latency of the Mag ground processing algorithm calibrated output shall be ≤ 116 seconds.

4.1.6 Noise

MAGSPEC41: The Mag noise shall be less than 0.137 nT rms when measured as the square root of the integral of the power spectral density between 0.05 and 0.5 Hz when in the operational measurement range.

4.1.7 Quantization Error

MAGSPEC43: The Mag shall have quantization error of ≤0.05 nT while measuring a field in the ±250 nT range.

MAGSPEC44: The Mag shall have quantization error of ≤13 nT while measuring a field in the ±20000 nT range.

4.2 Resource Allocations

4.2.1 Mass Allocation

MAGSPEC47: The Magnetometer Sensor Unit shall have a mass of ≤ 0.5 kg each.

MAGSPEC48: The Magnetometer Electronics Unit(s) shall have a mass of ≤ 2.0 kg.

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MAGSPEC49: The Magnetometer Electronics Unit to Sensor Units Cable shall have a mass of ≤ 2.3 kg.

MAGSPEC1017: The Magnetometer units specified in MAGSPEC47, MAGSPEC48, and MAGSPEC49 shall comply with the mass margins in GSFC-STD-1000H Section 1.06.

4.2.2 Physical Envelope

MAGSPEC59: Each Magnetometer Sensor Units volume (length*width*height), including mounts, thermal blankets and connectors, for both stowed and operational configurations shall have dimensions that do not exceed a total volume of 1000 cm3 each.

MAGSPEC60: The Magnetometer Electronics Unit(s) total volume (length*width*height), including mounts, thermal blankets and connectors, for both stowed and operational configurations shall have dimensions that do not exceed a total volume of 9000 cm3.

4.2.3 Operational Power Allocation

MAGSPEC51: The Mag shall have a nominal (continuous) EOL operational power, including operational heater power, of less than or equal to 5.6 W.

4.2.4 Peak Operational Allocation

MAGSPEC53: The Mag shall have a peak (instantaneous) power consumption of less than or equal to 7 W for a duration of 20msec at 30V.

4.2.5 Survival Heater Power Allocation

MAGSPEC55: The Mag survival heater power shall be less than or equal to 4 W.

4.2.6 Telemetry

MAGSPEC57: The Mag science and engineering data rate, including all overhead associated with Consultative Committee for Space Data Systems (CCSDS) packetization by the instrument at the spacecraft interface, shall not exceed 7.5 kilobits per second (kbps) averaged over 16 seconds when the instrument is operating in its normal science operating mode.

MAGSPEC961: The Mag science and engineering data rate, including all overhead associated with Consultative Committee for Space Data Systems (CCSDS) packetization by the instrument at the spacecraft interface, shall not exceed 7.5 kilobits per second (kbps) averaged over 16 seconds when the instrument is in calibration (and boom deployment) mode.

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4.2.7 Transient Magnetic Field

MAGSPEC62: The Mag Electronics box shall limit varying magnetic field less than 5 Hz to less than 4 nT zero-to-peak in any axis 1 meter from any face of the unit for any operating mode and changing configurations.

Note: It is expected that the two Mag sensors will not interfere with each other.

4.2.8 Static Magnetic Field

MAGSPEC64: The Mag Electronics Unit shall limit the static magnetic field to less than 40 nT in any axis 1 meter from any face of the unit for any operating mode.

4.3 Magnetometer Operating Modes

MAGSPEC66: The Mag shall be able to be commanded to any one of its dynamic ranges, if it has more than one.

MAGSPEC911: If the magnetometer has any diagnostic modes (e.g. a mode to cycle through available dynamic ranges), such a mode shall be both self-terminating and able to be terminated by a ground command.

MAGSPEC67: The Mag shall provide an in-flight calibration mode that detects changes in the scale factor relative to the ground calibration.

MAGSPEC68: The Mag in-flight calibration shall be both self-terminating and able to be terminated by a ground command.

MAGSPEC69: The Mag’s current operating mode shall be identified by a flag in its telemetry stream.

4.3.1 Deterministic Power-on Configuration

MAGSPEC71: The Mag shall initialize upon power-up into a predetermined configuration.

4.3.2 Safe Mode

4.3.2.1 Provision of Safe Mode

MAGSPEC74: The Mag shall provide a Safe Mode. Safe mode is an operating mode of the instrument during which all non-essential subsystems are shut down and only essential functions are active. Safe mode represents a configuration in which the instrument is thermally, mechanically, and optically “safe” without receiving commands from the Spacecraft.

MAGSPEC75: The Mag shall be capable of remaining in a safe configuration for at least 120 hours without ground intervention.

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4.3.2.2 Entry into Safe Mode

MAGSPEC77: The Mag shall enter Safe Mode upon detection of internal faults that are capable of causing damage to the instrument.

The L1 Series spacecraft will monitor up to three (TBR) analog instrument health and safety parameters defined by the Mag contractor and command the Mag into safe mode when any of those key values have been exceeded.

The L1 Series spacecraft will monitor up to 12 (TBR) digital telemetry points that are part of the normal instrument generated data stream for instrument health and safety parameters defined by the Mag contractor and command the Mag into safe mode when any of those key values have been exceeded.

4.3.3 Fail-safe Recovery Mode

MAGSPEC81: The Mag shall provide a failsafe recovery mode dependent on a minimal hardware configuration capable of accepting and processing a minimal command subset sufficient to load and dump memory.

4.3.4 Normal Operational Mode

MAGSPEC83: In normal operational mode, the Mag shall be in a fully functional configuration in which designed measurements are made in accordance with the performance requirements listed in section 4.1 of this document and are available to be sent to the spacecraft for downlink and in which both magnetometer sensors are operating.

4.3.5 On-Orbit Operations

MAGSPEC85: The Mag shall operate normally, within specification, while flying aboard a 3-axis stabilized spacecraft with orbital limit constraints as stated in this specification.

4.3.6 Station Keeping

MAGSPEC87: The Mag shall continuously operate during all spacecraft maneuvers.

4.3.7 Selective Performance/Contingency Operating Mode

MAGSPEC89: The Mag shall have a mode in which either of the 3-axis sensors can be operated independently.

4.4 Instrument Data Availability

MAGSPEC1018: The instrument shall have a 99.9 % (TBR) probability of operating continuously on-orbit during nominal observation mode (which excludes non-Magnetometer related Spacecraft Safe Holds, instrument calibrations and storm conditions).

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MAGSPEC1019: The instrument shall limit on-orbit calibrations to no more than twelve (12) calibrations per year with each calibration lasting no more than 90 minutes.

MAGSPEC1020: The instrument shall be capable of maintaining nominal observation mode without ground interaction for a minimum of 4 days.

MAGSPEC1021: The instrument shall ensure there are no gaps in HAP data due to planned instrument events during NWS-declared Critical Space Weather Days.

Rationale: Once a Critical Space Weather Day is declared by NWS it is expected that any pre-planned instrument activities (e.g., calibration maneuvers) will have the flexibility to be re-scheduled without impacting instrument performance. The expected cadence and duration of NWS-declared Critical Space Weather Days is (TBD).

MAGSPEC1022: The instrument shall provide a 99% (TBR) or greater probability of providing all of the instrument's HAP data during S4 class solar radiation storms or solar flare conditions including class X50, verifying through analysis using the “Worst Week” October 1989 model in CREME96 or equivalent.

Rationale: the CREME96 model includes the October 1989 solar particle event worst week model that conservatively bounds the single event effects environment in S4 and X50 solar events. It is expected that the probability of occurrence of outages as well as Bit Error Rates (BER) due to SEE will be used in the analysis that verifies this probability (CSPEC323 and CSPEC328 have been deleted and are being replaced with this requirement). Further definition of the worst week model can be found here:

https://creme.isde.vanderbilt.edu/CREME-MC/help/solar-energetic-particle-environment.

4.5 Power

The spacecraft will provide a power feed to the Magnetometer Electronics Unit.

The spacecraft will provide a power feed for the Magnetometer survival heater power.

4.5.1 Voltage Range

MAGSPEC93: The Mag shall operate over the operational bus voltage range of +26 to +34 VDC at the primary power inputs for all expected load conditions (except when turned off).

MAGSPEC967: The Mag survival heaters shall operate over the voltage range of +26 to +34 VDC at the power inputs for all expected load conditions.

4.5.2 Abnormal Voltages

MAGSPEC95: The Mag shall survive without performance degradation after indefinite exposure to an anomalous voltage range of 0 to +40 VDC.

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4.5.3 Power Transients

MAGSPEC97: The Mag shall meet its performance requirements in the presence of transients specified in MIL-STD-461F, Figure CS115-1 and Figure CS116-2.

4.5.4 Sudden Removal of Power

MAGSPEC99: The Mag shall meet its performance requirements without degradation after exposure to an abrupt, unannounced removal of power.

4.5.5 Over-Current Protection

MAGSPEC101: The Mag shall not use non-resetting over-current protection (i.e., fuses) internal to the unit.

4.5.6 Primary Power Return Ground

MAGSPEC103: Mag shall provide a dedicated Primary Power return in the same connector as the primary power.

4.5.7 Turn-on Current Transients

MAGSPEC105: The Mag shall meet its performance requirements without degradation after exposure to a turn-on input voltage (0 – 34V) with a rise time of 500us.

MAGSPEC107: The Mag shall limit the instrument operational power turn-on current in-rush transient(s) to 1.0A for a period less than 20 milliseconds.

MAGSPEC108: Following initial in-rush, the Mag shall limit the instrument operational power current transient(s) to 0.2A peak to peak.

Note: The spacecraft bus will not drop below 26V during the Magnetometer instrument turn on.

4.6 Electrical Grounding

4.6.1 Primary Power DC Isolation

MAGSPEC115: The Mag primary power interfaces, primary power and primary power returns, shall be isolated from the unit chassis by a DC resistance of greater than or equal to 10 Megaohms.

4.6.2 Survival Power Isolation

MAGSPEC117: The Mag survival heater power interfaces shall be isolated from the unit chassis by a DC resistance of greater than or equal to 10 Megaohms.

Check https://ipdtdms.gsfc.nasa.gov/frontmenu_dsp.cfm to verify that this is the correct version prior to use.

4.6.3 Internally Generated Secondary to Primary DC Isolation

MAGSPEC119: Secondary power inputs shall be isolated from primary power by a DC resistance of greater than 10 Megaohms.

4.6.4 Internally Generated Secondary Return

MAGSPEC121: The Mag shall reference its secondary returns (power and signal grounds) to the unit chassis ground.

4.6.5 Mechanical Contact Resistance

MAGSPEC123: The DC resistance of the mechanical contact between two conductive mating mechanical surfaces (internal to the unit) shall be less than or equal to 2.5 mΩ DC resistance.

4.6.6 Grounding

MAGSPEC125: The DC resistance between the Mag Electronics Unit chassis and the observatory chassis shall be ≤ 2.5 milliohms.

MAGSPEC126: The Mag shall provide a ground lug for a grounding strap to be attached from the Mag Electronics Unit chassis for connection to the spacecraft conductive structure.

MAGSPEC127: The grounding lug location on the Mag Electronics Unit chassis or the tie points in contact with the ground strap shall be as defined in the Mechanical Interface Control Drawing (MICD). The ground lug contact area must remain free of any material finish that may affect the reliability of the ground connection and will be shown in the MICD.

4.6.7 Connector DC Resistance

MAGSPEC129: Mag connector backshells shall be electrically connected to Electronics Unit chassis with a DC resistance ≤ 2.5 mΩ.

4.7 Signal And Data Interfaces

4.7.1 Passive Analog Telemetry

MAGSPEC132: The Mag shall utilize no more than three analog signals to monitor critical temperature points when the Magnetometer is powered off.

4.7.2 Data Signal Interface

MAGSPEC134: The Mag Instrument data transfer interface to or from the spacecraft shall either use a serial Universal Asynchronous Receiver Transmitter (UART) using ANSI/TIA/EIA- 422-B Electrical Characteristics of Balanced Voltage Differential Interface Circuits, or

Check https://ipdtdms.gsfc.nasa.gov/frontmenu_dsp.cfm to verify that this is the correct version prior to use.

ANSI/TIA/EIA-644-A-2001 Electrical Characteristics of Low Voltage Differential Signaling (LVDS) Interface Circuits.

The spacecraft will provide two data signal interface feeds to the Magnetometer Electronics Unit for command and telemetry. The spacecraft will also provide an interface line for a Pulse Per Second (PPS).

4.7.2.1 Telemetry Source Packet Format

MAGSPEC137: The Mag shall transfer all data to the spacecraft using the CCSDS 133.0-B-1 Section 4.1 Protocol Data Unit definition shown in the Telemetry Source Packet Definition Figure 1.

Figure 1 Telemetry Source Packet Definition

MAGSPEC139: The Mag telemetry Source packets shall be variable length with a maximum data zone of 8192 octets including Secondary Header.

MAGSPEC140: The Mag shall set the telemetry source packet Secondary Header Flag to the value 1.

MAGSPEC141: The Mag shall set the Telemetry Source Packet Sequence Flags to the value of 11.

Note: Segmentation services are not permitted.

MAGSPEC143: The Mag shall set the Telemetry Source Packet Time Code per CCSDS 301.B- 4 Time Code Formats, Day Segmented format in the Time Code Format Figure 2.

Figure 2 Time Code Format

Note: The P-Field is implied and not included in the actual time message.

Check https://ipdtdms.gsfc.nasa.gov/frontmenu_dsp.cfm to verify that this is the correct version prior to use.

The Spacecraft will maintain a continuous time system on-board that can be related to UTC time on the ground.

4.7.2.2 Command Source Packet Format

MAGSPEC148: The Mag shall receive all data from the spacecraft formatted per CCSDS 133.0-B-1 Section 4.1 Protocol Data Unit definition shown in the Command Source Packet Definition Figure 3.

Figure 3 Command Source Packet

MAGSPEC150: The Mag command Source packets shall be variable length with a maximum data zone of 8192 octets.

MAGSPEC151: The Mag shall receive Command Source Packet with Secondary Header Flag set to the value 0.

MAGSPEC152: The Mag shall receive Command Source Packet with the Sequence Flags set to the value of 11.

Note: Segmentation services are not permitted.

4.7.3 Clock Signal Interface

MAGSPEC155: The Mag shall receive a Pulse Per Second (PPS) time pulse from spacecraft clock line by the interface defined in MAGSPEC134.

The Spacecraft will maintain Spacecraft time correlation to within +/- 0.95 sec of UTC and will provide the Mag a 1 PPS with a time code message.

The spacecraft will provide a clock interface feed to the Magnetometer Electronics Unit.

MAGSPEC158: The Mag shall receive from the spacecraft a time code message on the data line as defined in Spacecraft Time Message Packet Figure 4. The time code message is the time applicable to receipt of the 1 PPS.

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Figure 4 Spacecraft Time Message Packet Figure

4.7.4 Command and Housekeeping telemetry

MAGSPEC161: The Mag instrument shall provide command and housekeeping telemetry functions in all powered modes.

4.7.5 Commands for Autonomous Functions

MAGSPEC163: The Mag shall execute commands to individually enable and disable each autonomous function.

4.7.6 Limits and Triggers

MAGSPEC165: The Mag autonomous limits and triggers shall be changeable by command.

4.7.7 On-Board Processor Reset

MAGSPEC167: The Mag On-Board Processor shall be reset by command.

MAGSPEC168: An autonomous power-on reset occurrence shall be unambiguously identifiable via telemetry.

Note: This does not imply real-time telemetry as the reset is occurring.

4.7.8 Micro-switches

MAGSPEC170: Micro-switches shall be used for information only and not use to initiate on-board autonomous activity or as an on-board interlock.

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4.8 Flight Software

4.8.1 Flight Load Non-volatile Memory

MAGSPEC173: The Mag flight software image shall be contained in its entirety in non-volatile memory.

4.8.2 Software Updates

MAGSPEC175: The flight software modules shall be reprogrammable.

4.8.3 Software Table Updates

MAGSPEC178: Instrument configuration data (e.g. Table Loads or Configuration Parameters) shall be reprogrammable during integration and test phases and on-orbit without computer restart.

MAGSPEC179: Modified instrument configuration data (e.g. Table Loads or Configuration Parameters) shall be committed to operational use by ground command.

4.8.4 Flexibility and Ease of Software Modification

MAGSPEC181: The Mag flight software shall be deterministic in terms of scheduling and prioritization of critical processing tasks to ensure their timely completion.

MAGSPEC182: Instrument configuration data (e.g. Table Loads or Configuration Parameters) shall be referenced such that data can be loaded and dumped by the ground without reference to memory address.

MAGSPEC183: The definition of instrument commands within the ground database (excluding memory diagnostic/load commands) shall not be dependent on physical memory addresses within the flight software.

4.8.5 Version Identifiers

MAGSPEC185: The Mag software and firmware versions shall each have an internal identifier (embedded in the executive program) that can be included in the instrument engineering data.

MAGSPEC186: This software identifier shall be configuration management controlled.

4.8.6 Warm Restart

MAGSPEC188: The Mag flight software shall provide a restart by command with preservation of instrument configuration data and memory tables.

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4.8.7 Memory Tests

MAGSPEC190: The Mag flight software shall provide a mechanism to verify the contents of all memory areas.

4.8.8 Memory Dump

MAGSPEC192: The Mag flight software, and associated on-board computer hardware, shall provide the capability to dump any memory location.

MAGSPEC193: The flight software memory dump capability shall not disturb normal operations and instrument data processing.

4.8.9 Fault Detection and Correction Control

MAGSPEC195: If applicable, the Mag shall provide the capability to enable and disable any internal Fault Detection and Correction (FDC) features.

4.8.10 Health and Safety Monitoring

MAGSPEC197: The Mag flight software shall provide health and safety monitoring, including memory checksum and watchdog timer.

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5 PHYSICAL REQUIREMENTS

5.1 Interface and Design Units and Exclusions

MAGSPEC200: The contractor shall use metric units to design the instrument and for developing interfaces with the spacecraft including any drawings, documents, models, except for the following cases:

Heritage Component or unit: Components or units that has been previously qualified, or of similar design heritage, may be specified in English units where use of metric equivalents would lead to additional cost to the program.

Fasteners: Although bolt patterns will be defined using metric dimensioning, use of English fasteners (with hole dimensioning and tolerancing) is permitted.

Angular Measurement: Angular measurement may be expressed in degree of arc or in an appropriate subdivision of degree of arc such as second of arc (arc-sec) when advantageous to application.

5.2 Mass Properties Accuracy

5.2.1 Magnetometer Instrument Mass Accuracy

MAGSPEC206: The mass of the Mag shall be measured to within ±0.1 kg.

5.2.2 Center of Mass Location

MAGSPEC208: The contractor shall define the center of mass in the MICD.

5.2.3 Center of Mass Accuracy

MAGSPEC210: The center of mass of the Mag shall be determined to within ±5 mm relative to a reference that will be defined in the MICD.

5.2.4 Determination of Moments and Products of Inertia

MAGSPEC212: The Contractor shall determine by analysis the launch and on-orbit moments and products of inertia to an accuracy of ±5.0 percent of the maximum principal moment of inertia, referenced to the coordinate axes with an origin at the center of gravity.

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5.3 Mounting

5.3.1 Surface Flatness

MAGSPEC215: Mounting interface flatness, and co-planarity requirements for the Mag side of the interface (including brackets, if any, and shims) shall be as defined in the MICD.

5.3.2 Method

The method by which the Mag is mounted to the spacecraft will be defined in the Spacecraft to Magnetometer Interface Control Document (ICD).

5.4 Coordinate System and Alignment

MAGSPEC1024: The L1 Series spacecraft coordinate system shall use a right-hand orthogonal, body fixed XYZ coordinate system (Spacecraft Reference Frame - SRF) as follows: the positive XSRF-axis points toward the nominal direction of the Sun, the positive YSRF-axis points towards the nominal direction of the north ecliptic pole and the ZSRF axis is obtained from the right-hand rule. The roll, pitch and yaw rotations are defined about the X, Z, and Y axes, respectively. The origin of coordinate systems is located on the SC to LV separation plane at the intersection with the LV longitudinal axis. See Figure 5 Spacecraft Reference System.

Figure 5 Spacecraft Reference System

The Spacecraft will align one axis of the outer magnetometer sensor interface coordinate system to within 2.0 deg parallel of the magnetometer calibration axis of rotation.

MAGSPEC221: The Mag shall have clear fiducial marks to enable alignment during integration with spacecraft.

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The instrument unit mounting frame is an orthogonal reference frame defined by the locations of the spacecraft side of the instrument unit mounting points. A rigorous definition of this frame will be documented in the ICD.

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6 ENVIRONMENTAL REQUIREMENTS

Environmental design requirements for the Mag are specified in this section.

MAGSPEC226: The Mag shall meet its performance requirements in section 4.0 after exposure to the environments specified in this section.

6.1 Mechanical Factors of Safety

MAGSPEC228: The Mag flight hardware shall demonstrate positive Margins of Safety under limit loads for all yield and ultimate failures using the Factors of Safety (FS) defined in Table 2.

Margin of Safety (MS) is defined as follows:

MS = (Allowable Stress (or Load) / (Applied Limit Stress (or Load) x FS)) -1

Table 2 Factors of Safety

Type Static Sine Random/Acoustic 4,5 Metallic Yield 1.253 1.25 1.6 Metallic Ultimate 1.43 1.4 1.8 Stability Ultimate 1.4 1.4 1.8 Beryllium Yield 1.4 1.4 1.8 Beryllium Ultimate 1.6 1.6 2.0 Composite Ultimate 1.5 1.5 1.9 Bonded…