Attachment_B_-_Specifications_-_Sanitized.pdf

RESTORE-L-SPEC-001394

Revision B

CHECK WITH SSCO NGIN DATABASE AT:

https://sscongin.ndc.nasa.gov/

TO VERIFY THAT THIS IS THE CORRECT VERSION PRIOR TO USE.

CM FOREWORD

This document is a Satellite Servicing Capabilities Office (SSCO) Configuration Management

(CM)-controlled document. Changes to this document require prior approval of the applicable

Configuration Control Board (CCB) Chairperson or designee. Proposed changes shall be submitted to the SSCO Code 408 CM Office (CMO), along with supportive material justifying the proposed change. Changes to this document will be made by complete revision.

Questions or comments concerning this document should be addressed to:

NASA/Goddard Space Flight Center

SSCO, Code 408

Attention: Configuration Management Office

Greenbelt, Maryland 20771

SATELLITE SERVICING CAPABILITIES OFFICE

DOCUMENT CHANGE RECORD

Date: August 5, 2016 Sheet 1 of 1

TITLE: Restore-L Vision Sensor Subsystem Camera Performance Specification

REV

LEVEL

DESCRIPTION OF CHANGE AUTHORIZATION

A

B

Initial Release

Document revision

Document revision

Per Signature Page

SSCO CM RELEASE

ii

TABLE OF CONTENTS

Page

1.0 Introduction .................................................................................................................... 1-1

1.1 Purpose ................................................................................................................. 1-1

1.2 Scope .................................................................................................................... 1-1

1.3 Mission Concept of Operations (CONOPS) ........................................................ 1-1

1.4 Verb Application .................................................................................................. 1-2

1.5 Hardware Description .......................................................................................... 1-2

1.5.1 Flight Model............................................................................................. 1-3

1.5.2 Qualification Model ................................................................................. 1-3

1.5.3 Engineering Development Unit ............................................................... 1-3

1.5.4 Electrical Ground Support Equipment ..................................................... 1-3

1.6 Document Change Procedure .............................................................................. 1-3

2.0 Applicable Documents ................................................................................................... 2-1

3.0 Technical Requirements ................................................................................................ 3-1

3.1 General Requirements .......................................................................................... 3-1

3.1.1 Mission Life ............................................................................................. 3-1

3.1.2 Warm-Up Time ........................................................................................ 3-1

3.1.3 Shelf Life ................................................................................................. 3-1

3.1.4 Dormancy ................................................................................................. 3-1

3.1.5 Demise ..................................................................................................... 3-1

3.2 Optical Requirements........................................................................................... 3-2

3.2.1 GFE Lenses .............................................................................................. 3-2

3.2.2 Ultra-Violet (UV) / Infrared (IR) Blocking Filter.................................... 3-3

3.3 Detector Requirements......................................................................................... 3-1

3.3.1 Focal Plane Array Requirements ............................................................. 3-1

3.3.2 Auto-Exposure ......................................................................................... 3-2

3.3.3 Sun Exposure ........................................................................................... 3-3

3.4 Mechanical Characteristics .................................................................................. 3-4

3.4.1 Mechanical Interface ................................................................................ 3-4

3.4.2 Mechanical CAD Model .......................................................................... 3-4

3.4.3 Mass ......................................................................................................... 3-4

3.4.4 Physical Envelope .................................................................................... 3-5

3.4.5 Mechanical Mounting .............................................................................. 3-5

3.4.6 Mechanical Mounting Notation ............................................................... 3-5

3.4.7 Primary Mounting Interface Flatness....................................................... 3-5

3.4.8 Alignment Features .................................................................................. 3-5

3.4.9 Lens Mount .............................................................................................. 3-5

3.4.10 Focal Plane Array Rotational Alignment ................................................. 3-1

3.4.11 Focal Plane Array Translational Alignment ............................................ 3-1

3.4.12 Electrical Connector Location ................................................................. 3-1

3.4.13 Chassis Grounding ................................................................................... 3-1

3.4.14 Identification and Marking ...................................................................... 3-1 iii

3.5 Interface & Electrical Requirements .................................................................... 3-2

3.5.1 Power Interface ........................................................................................ 3-2

3.5.2 Video Interface......................................................................................... 3-4

3.5.3 Command Interface .................................................................................. 3-6

3.5.4 Telemetry Interface .................................................................................. 3-8

3.5.5 General Electrical Requirements ............................................................. 3-9

3.6 Thermal Requirements ....................................................................................... 3-17

3.6.1 Thermal Model....................................................................................... 3-17

3.6.2 Thermal Model Correlation ................................................................... 3-17

3.6.3 Temperature Sensor ............................................................................... 3-17

3.6.4 Temperature Limits ................................................................................ 3-17

3.7 Environmental Qualification Requirements ...................................................... 3-18

3.7.1 Static Loads ............................................................................................ 3-18

3.7.2 Random Vibration .................................................................................. 3-18

3.7.3 Acoustic Impingement ........................................................................... 3-18

3.7.4 Thermal .................................................................................................. 3-18

3.7.5 Vacuum .................................................................................................. 3-18

3.7.6 EMI / EMC ............................................................................................ 3-19

3.7.7 Radiation ................................................................................................ 3-20

3.7.8 Humidity ................................................................................................ 3-28

3.7.9 Venting ................................................................................................... 3-28

3.7.10 Atomic Oxygen ...................................................................................... 3-28

3.7.11 Micrometeoroids and Orbital Debris (MMOD) ..................................... 3-28

4.0 Verification Requirements ............................................................................................ 4-1

4.1 Verification Rationale .......................................................................................... 4-1

4.2 Inspection ............................................................................................................. 4-1

4.2.1 Final Inspection ........................................................................................ 4-1

4.3 Analysis................................................................................................................ 4-1

4.4 Test ....................................................................................................................... 4-1

4.4.1 Test Failure and Control of Nonconforming Product .............................. 4-1

4.4.2 Failure During Tests ................................................................................ 4-2

4.4.3 Modification of Hardware ........................................................................ 4-2

4.4.4 Re-Test Requirements .............................................................................. 4-2

4.5 Required Verification Tests ................................................................................. 4-3

4.5.1 Mass and Envelope Measurements .......................................................... 4-3

4.5.2 Performance and Functional Tests ........................................................... 4-3

4.5.3 EMI / EMC Test....................................................................................... 4-3

4.5.4 Load Tests ................................................................................................ 4-4

4.5.5 Random Vibration .................................................................................... 4-5

4.5.6 Sine Vibration .......................................................................................... 4-5

4.5.7 Low Level Sine Sweep Vibration ............................................................ 4-5

4.5.8 Thermal Vacuum Test.............................................................................. 4-6

4.5.9 Optical Performance Testing ................................................................... 4-9

5.0 Appendix A: Acronym List ........................................................................................... 5-1 iv

LIST OF FIGURES

Figure Page

Figure 1-1: Restore-L Mission ConOps ....................................................................................... 1-1

Figure 3-1: Maximum Volume Resistivity vs. Coating Thickness ............................................ 3-11

Figure 3-2: Maximum Volume Resistivity vs. Distance to Ground .......................................... 3-11

Figure 3-1: Silicon Dose Depth Kernels for Restore LEO and ARRM Environments ............. 3-21

Figure 3-2: Silicon DDD equivalent fluence for Restore-L and ARRM Environments............ 3-23

Figure 3-3: Worst case integral solar proton fluxes for SEE evaluation ................................... 3-26

Figure 4-1: Thermal Vacuum Profile ........................................................................................... 4-6

LIST OF TABLES

Table Page

Table 2-1: Applicable Documents ............................................................................................... 2-1

Table 3-1: Shelf Life .................................................................................................................... 3-1

Table 3-2: Internal & External Wiring Shield Requirements for Restore-L ............................. 3-14

Table 3-3: Internal & External Wiring Shield Requirements for ARRM .................................. 3-15

Table 3-4: Temperature Limits at Mounting Interface .............................................................. 3-18

Table 3-5: Required EMI/EMC Tests ........................................................................................ 3-19

Table 3-6: Restore-L & ARRM Radiation Environment ........................................................... 3-20

Table 3-7: Dose Depth Kernels for Restore LEO and ARRM Environments ........................... 3-22

Table 3-8: DDD equivalent fluence for Restore-L & ARRM Environments ............................ 3-24

Table 3-9: Worst Case Integral Peak Solar Proton Flux (Solar Maximum) .............................. 3-27

1-1

1.0 INTRODUCTION

1.1 PURPOSE

The purpose of this document is to define the technical specifications for a visible wavelength camera system. This camera system is the primary sensor that will comprise the Vision Sensor

Subsystem (VSS) of NASA Goddard Space Flight Center’s (GSFC) Restore-L satellite servicing mission.

1.2 SCOPE

This specification document describes the optical, electrical, mechanical, operating environment, and verification testing requirements for a space qualified, visible wavelength camera system for the GSFC Restore-L satellite servicing mission. This hardware will be referred to herein as the, “VSS camera.” The commercial vendor selected to manufacture the VSS camera will be referred to herein as the, “Contractor.” NASA GSFC will be referred to herein as the, “Government.”

This document contains the majority of the technical information regarding the VSS camera, while the programmatic aspects of its build are covered in the corresponding Statement of Work

(SOW) document number, RESTORE-L-SOW-001885, Rev A.

1.3 MISSION CONCEPT OF OPERATIONS (CONOPS)

The Restore-L satellite servicing mission aims to autonomously rendezvous with, and robotically service an existing government-owned satellite. A summary of the concept of operations for the mission is shown below. The VSS camera will be utilized during the ‘Servicing’ portion of the mission as shown below.

Figure 1-1: Restore-L Mission ConOps

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1.4 VERB APPLICATION

Statements containing the verb “shall” are binding requirements regardless of location within this specification. The verbs “should” and “may” are used for stating non-mandatory goals or denoting a statement of best practice. The verb “will” is used in a statement of fact, expected occurrence, or declaration of purpose.

1.5 HARDWARE DESCRIPTION

The Government desires to procure a small, yet versatile visible wavelength spaceflight camera.

The Government envisions this camera system to be of the type commonly referred to in industry as a, “camera head” unit. That is, this camera system contains a lens, focal plane array, and supporting electronics that outputs the camera’s imagery. Complicated data manipulation and / or image processing is meant to occur outside of the camera, further downstream inside of the

Restore-L avionics subsystem. The primary use of the VSS camera is to provide ground operators with situational awareness imagery of the Restore-L spacecraft. Additionally, VSS cameras will reside on Restore-L’s robotic arm end effector and will provide views of the servicing worksites.

The Government is still in the process of defining the exact optical lens specifications required for each implementation of the VSS camera on Restore-L. Therefore, the Contractor shall assume that they are only responsible for manufacturing the VSS camera body and that the

Government will provide the final spaceflight-ready optical lenses via Government Furnished

Equipment (GFE) methods. The Government intends to provide ruggedized commercial optics for use on the VSS camera. The Contractor shall be responsible for integrating these lenses onto each VSS camera and taking the entire camera system through environmental testing as described in Section 3.7. The Government also requires that some VSS camera units be delivered with a commercial grade laboratory lens. Those specific details are outlined within this document as well as in the accompanying Statement of Work (SOW) document number, RESTORE-L-SOW-001885, Rev A.

The Government is also considering this camera design for future NASA missions such as the

Asteroid Robotic Redirection Mission (ARRM). As such, some of the environmental requirements contained herein include information for both the Restore-L polar LEO orbit as well as the ARRM interplanetary orbit. The Contractor shall assume that the ARRM requirements are only applicable to the ARRM version of the VSS camera, and are not intended for the Restore-L version. Additional information is provided in the accompanying Statement of

Work (SOW) document number, RESTORE-L-SOW-001885, Rev A.

The following hardware descriptions are provided to delineate between the different types of hardware deliverables requested in the Statement of Work (SOW) document number, RESTORE-L-SOW-001885, Rev A.

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1.5.1 Flight Model

A flight model is the actual end item that is intended for deployment and operations in a space environment. It shall be subjected to formal functional and environmental acceptance testing as defined by GSFC-STD-7000A, “General Environment Verification Standard (GEVS) for GSFC

Flight Programs and Projects.” A flight unit will be subject to all sections and specifications within this document.

1.5.2 Qualification Model

A qualification model is the development end item on which a partial or complete prototype qualification test campaign has been performed per GSFC-STD-7000A. The qualification model is tested to levels that demonstrate desired margins, particularly for exposing fatigue stress. In some cases this may mean testing to failure. The VSS camera qualification unit is not intended for spaceflight.

1.5.3 Engineering Development Unit

An Engineering Development Unit (EDU) fully reflects the intended final design of the flight model. In a traditional definition of an EDU, commercial grade Electrical, Electronic and

Electromechanical (EEE) parts may be used in an effort to reduce overall program costs. In this case, the Government desires that the VSS camera EDUs be a carbon copy of the flight units in terms of form, fit, build and function. The EDU cameras will be used for requirements verification, functional performance testing, verification of Electronic Ground Support

Equipment (EGSE), and may be used for Electromagnetic Compatibility (EMC) testing. The

VSS camera EDUs are not intended for spaceflight.

1.5.4 Electrical Ground Support Equipment

The electrical ground support equipment (EGSE) for the VSS camera shall be capable of interfacing with and operating a single VSS camera as a standalone component. The EGSE shall allow a user to power, command, view and save images/video from the VSS camera units.

Additionally, the EGSE shall display a subset of the real-time telemetry emanating from the camera units. Depending on the architecture of the EGSE, components may include a power supply, breakout box and control computer, and operating software.

1.6 DOCUMENT CHANGE PROCEDURE

The Satellite Servicing Capabilities Office (SSCO, Code 408) maintains configuration control of this document. Once baselined, all changes will require a Configuration Change Request (CCR) to be processed through the SSCO Windchill Configuration Management System.

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3.2 OPTICAL REQUIREMENTS

3.2.1 GFE Lenses

a) For the purposes of the Restore-L mission, the Contractor shall assume that the GFE commercial lenses may have focal lengths of between ~6mm and ~75mm. The

Government will make every attempt to provide a GFE lens whose optical format matches that of the detector proposed by the Contractor. However, the Government may elect to under fill or over fill the detector in terms of the lens’ image circle. Example commercial lenses are as follows for a notional 1” format detector:

a. KOWA LM6HC

b. Schneider Cinegon 1.9/10

c. KOWA LM75HC

b) For the purposes of the ARRM mission, the Contractor shall assume that the GFE lenses may have focal lengths of between ~6mm and ~36mm. The Government will make every attempt to provide a GFE lens whose optical format matches that of the detector proposed by the Contractor. However, the Government may elect to under fill or over fill the detector in terms of the lens’ image circle.

The Contractor shall assume that the Government will provide a non-browning, radiation tolerant lens for use on the ARRM version of the VSS camera. For the purposes of radiation analysis, the Contractor shall assume the following:

a) Outermost lens material: Schott LaK9 G15

b) Outermost lens diameter: 21.5 mm

c) Outermost lens thickness: 1.25 mm

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3.2.2 Ultra-Violet (UV) / Infrared (IR) Blocking Filter

The VSS camera shall contain an internal UV / IR blocking filter to maximize the camera’s ability to generate accurate color images. The properties of this UV / IR blocking filter shall be the following:

a) Short-wavelength transmittance cut-on (FWHM): 400 nm

b) Long-wavelength transmittance cut-off (FWHM): 700 nm

c) Wavelength tolerance: ± 15 nm

d) The slope of the short-wave cut-on and long-wave cut-off shall be greater than 5 [1/nm] as defined by:

𝑆𝑙𝑜𝑝𝑒 = | 𝐴𝑦−𝐵𝑦

𝐴𝑥−𝐵𝑥 |, where:

Ax = Wavelength value where transmittance equals ~10%

Ay = Transmittance value at Ax

Bx = Wavelength value where transmittance equals ~80%

By = Transmittance value at Bx

Note: the 10% and 80% values are reversed for the cut-off slope calculation.

e) In-band (400nm – 700nm) average transmittance: > 90%

f) Average Out-of-band transmittance:

a. From 1% of short wavelength cutoff to 300nm: 0.1%

b. From 1% of long wavelength cutoff to 1000nm: 0.1%

g) Maximum filter thickness: 3 mm

h) Scratch - Dig: 40-20

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3.3 DETECTOR REQUIREMENTS

3.3.1 Focal Plane Array Requirements

3.3.1.1 Image Sensor Type

The VSS camera shall contain a solid state Complementary Metal-Oxide Semiconductor

(CMOS) focal plane array.

3.3.1.2 Operational Wavelength

The VSS camera shall contain a focal plane array whose average monochrome Quantum

Efficiency (QE) is greater than 40% over visible wavelengths (400 to 700 nanometers).

3.3.1.3 Color Imagery

The VSS camera shall contain a focal plane array that provides color imagery via a Bayer pattern

Color Filter Array (CFA).

3.3.1.4 Image Resolution

The VSS camera shall contain a focal plane array that provides high-resolution video and imagery with a minimum 1280 x 1024 pixel resolution.

Note: Native sensor resolution may be higher.

3.3.1.5 Active Pixels

The VSS camera shall contain a focal plane array in which greater than 99% of the imaging pixels are alive and active at beginning of life (BOL) (i.e. no more than 1% dead pixels).

3.3.1.6 Dynamic Range

The VSS camera shall contain a focal plane array with a linear dynamic range of ≥ 60 dB.

3.3.1.7 Noise

a) The VSS camera shall contain a focal plane array whose read noise is no greater than 25 electrons at 1x gain settings at room temperature.

b) The VSS camera shall contain a focal plane array whose dark current shall be no greater than 3000 e/s at the maximum VSS camera operational temperature as defined in Table

3-4.

3.3.1.8 Frame Rate

The VSS camera shall contain a focal plane array that (a) provides high resolution video at a minimum frame rate of eight (8) frames per second (fps) at the resolution stated in requirement

3.3.1.4, and (b) outputs all pixels of the full illuminated frame at a minimum rate of one (1) fps.

3.3.1.9 Optical Format Minimum

The VSS camera shall contain a focal plane array whose diagonal dimension across the active pixel area is greater than or equal to ~11mm (i.e. 2/3” optical format).

Note: Native optical format may be larger

3.3.1.10 Analog-to-Digital Conversion

The VSS camera shall contain a focal plane array with an on-chip Analog-to-Digital converter with a resolution of between 8 (minimum) and 12 (maximum) bits per pixel (bpp).

3.3.1.11 Windowing Capability

The VSS camera shall contain a focal plane array that performs on-chip Region-of-Interest (ROI)

(aka windowing) control.

3.3.1.12 Shutter Mode

The VSS camera shall contain a focal plane array that implements a global (snapshot) shutter mode.

3.3.1.13 Subsampling Mode

For focal plane arrays larger than 2 megapixels, the VSS camera shall have the ability to subsample to reduce the output resolution of the camera imagery without reducing the camera

Field-of-View (FOV).

Note: For color sensors, the read-2-skip-2 (window/column) subsampling scheme is required.

3.3.2 Auto-Exposure

The VSS camera shall employ an Automatic Gain & Exposure Control (AGEC) algorithm running internal to the camera to adjust for dynamic on-orbit lighting conditions.

3.3.2.1 Auto-Exposure Control

The auto-exposure control for the VSS camera shall be turned on and off via manual command.

3.3.3 Sun Exposure

3.3.3.1 Unpowered State

The VSS camera shall not be permanently damaged by sun exposure, within the unit’s field of view, for an indefinite duration when the unit is powered off.

3.3.3.2 Powered State

The VSS camera shall not be permanently damaged by sun exposure, within the unit’s field of view, for up to 15 minutes duration when the unit is powered on. The VSS camera shall meet its performance requirements within five (5) minutes after cessation of sun exposure.

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3.4 MECHANICAL CHARACTERISTICS

3.4.1 Mechanical Interface

The VSS camera mechanical interface shall be defined by the Contractor with a mechanical

Interface Control Document (ICD).

3.4.1.1 Coordinate Systems

The Contractor shall define a right-handed orthogonal coordinate frame, including an origin for the mechanical chassis of the VSS camera. This coordinate frame convention shall be defined in the mechanical ICD and used for all environmental testing (vibe, shock, etc.) and optical alignment activities.

3.4.1.2 Mass Properties

The Contractor shall include the approximate mass to within 10 grams and location of the center of mass of the VSS camera to within 1 cm in the mechanical ICD.

3.4.1.3 Physical Dimensions

The Contractor shall include the overall physical dimensions, locations and sizes of electrical connectors, optical datums, centers of optical surfaces, mounting hole locations, types and sizes of mounting bolts or other fasteners and any other critical mechanical infrastructure of the VSS camera in the mechanical ICD.

3.4.2 Mechanical CAD Model

The Contractor shall provide the Government with a STEP file of the as-designed VSS camera.

The step file shall contain all external interfaces/features representative of the as-built VSS camera.

3.4.3 Mass

a) For the Restore-L mission, the total mass of the VSS camera without lens shall be less than or equal to 400 grams.

b) For the ARRM mission, the total mass of the VSS camera without lens shall be less than

750 grams.

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3.4.4 Physical Envelope

The VSS camera shall have bounding box dimensions of equal to or less than:

a) For the Restore-L mission, 6 cm (width) x 7 cm (length) and 6 cm (height), including any protruding electrical connectors, but excluding the optical lens.

b) For the ARM mission, 7.5 cm (width) x 8.5 cm (length) and 7.5 cm (height), including any protruding electrical connectors, but excluding the optical lens.

Note: The length dimension is parallel to the VSS camera optical boresight and the height and width dimensions span the front face of the camera enclosure.

3.4.5 Mechanical Mounting

The VSS camera shall include a mechanical mounting solution that includes multiple threaded fastener holes on each of the three adjoining orthogonal faces of the camera chassis that are parallel to the optical boresight. Fastener holes shall be blind and not penetrate the interior of the camera housing.

3.4.6 Mechanical Mounting Notation

The Contractor shall define one of the mounting interfaces of the VSS camera as the primary mounting interface and note its location on the mechanical ICD.

3.4.7 Primary Mounting Interface Flatness

The flatness control tolerance of the VSS camera’s primary mounting interface shall be 0.005 inches.

3.4.8 Alignment Features

The VSS camera mounting surfaces shall utilize precision alignment features (such as an alignment pin / hole) to maintain alignment when mounting to its primary mounting interface.

Note: Specific alignment method shall be approved by the Government.

3.4.9 Lens Mount

The VSS camera shall include a C-mount type lens mount that accepts any C-Mount lens with a

17.52mm flange focal distance and an ANSI 1-32 UN 2A thread.

3-1

3.4.10 Focal Plane Array Rotational Alignment

The VSS camera focal plane array shall be aligned to the camera’s primary mounting interface to within ± 10 arcminutes in roll, pitch and yaw.

3.4.11 Focal Plane Array Translational Alignment

The optical axis of the VSS camera as defined by a normal vector emanating from the center pixel of the focal plane array shall be aligned to the center of the camera’s C-Mount interface horizontally and vertically to within ± 15 arcminutes.

3.4.12 Electrical Connector Location

The VSS camera shall have all electrical connectors that implement power, video, command, and telemetry located on the camera face opposite of the face containing the camera lens.

3.4.13 Chassis Grounding

The VSS camera shall provide a dedicated electrical chassis ground point that conforms to

Section 3.5.5.7 for use during ground testing.

Note: Specific grounding method shall be approved by the Government.

3.4.14 Identification and Marking

Each unit shall be permanently marked with the part number and a unique sequential serial number on an area designated by the mechanical Interface Control Drawing (ICD) in a manner that will endure the following without fading or removal:

a) Typical handling in aerospace manufacturing

b) Cleaning with isopropyl alcohol

c) Handling with gloves

d) Mechanical fastening

e) Environments listed in Section 3.7

The format of the unique serial number shall be defined such that flight, qualification, and EDU units of the VSS camera are easily distinguishable from one another. (i.e. F001 for flight, Q001 for qual, E001 for EDU, etc.)

3.5 INTERFACE & ELECTRICAL REQUIREMENTS

3.5.1 Power Interface

3.5.1.1 Operating Voltage Level

The VSS camera shall be designed to operate over the input voltage of 4.25 Vdc to 5.25 Vdc at its input.

3.5.1.2 Maximum Steady State Power

The maximum steady state input power of the VSS camera shall not exceed 2.75 Watts.

3.5.1.3 Maximum Steady State Current

The maximum steady state current draw shall not exceed 0.55 amps at 5.0Vdc.

3.5.1.4 Input Ripple

The VSS camera shall comply with the input voltage ripple and noise specification of ≦ 5% peak to peak (p-p) when measured at 100 MHz bandwidth.

3.5.1.5 Camera Reflected Ripple

The VSS camera shall limit the reflected ripple voltage to within +/- 2% peak to peak (p-p) on its input 5.0 Vdc power line.

3.5.1.6 In-Rush Current

Maximum in-rush current of the VSS camera shall not exceed 0.75 amps peak and limited to below 10 microseconds followed by 0.65 amps peak limited to below 10 millisecond period.

Note: This will include transient current limits, single event turn-on and operational mode changes.

3.5.1.7 Input Voltage Transients

The VSS camera shall sustain single event switching voltage transients of +/-120 % on its 5.0

Vdc power line.

3.5.1.8 Power Interruption

The VSS camera shall survive the sudden removal and subsequent resumption of input power without sustaining any permanent damage and/or performance degradation when in use.

3.5.1.9 Input Under-Voltage

The VSS camera shall survive a sustained under-voltage condition on its input power (0 Vdc to

4.5 Vdc) without sustaining any permanent damage.

3.5.1.10 Input Voltage Rise Time

The VSS Camera shall accept the input voltage rise time within the range of 25 microseconds to

50 milliseconds max.

3.5.1.11 Input Voltage Fall Time

The VSS camera shall accept the input voltage fall time within the range of 25 microseconds to

50 milliseconds max.

3.5.1.12 Internal Protection

The VSS camera power design shall protect itself against the following conditions:

a) Any internal sustained overload [120% to 150% of nominal load] conditions

b) Any internal sustained short circuit conditions

c) Any inrush current conditions observed during the start up or during any other normal/abnormal operational conditions observed. This includes all possible worst-case conditions of input line/output load and temperature conditions standalone or combined

3.5.1.13 Initial State

Upon the application of power, the VSS camera shall power up into a known and repeatable state that shall be defined in the electrical ICD.

Note: The Government expresses the desire to work with the Contractor to define the exact power-up parameters of the camera’s focal plane array (e.g. default integration time, frame rate, frame size, etc.)

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3.5.2 Video Interface

3.5.2.1 Video Physical Layer

The VSS camera shall employ Multipoint Low-Voltage Differential Signaling, M-LVDS

(LVDM / Bus-LVDS), as the physical layer for the video data.

3.5.2.2 Data Protocol

The VSS camera may utilize up to four (4) twisted pairs to enable the video data transmission protocol of the Contractor’s choosing. This total of four (4) twisted pairs can be allocated between data, clock and sync lines as deemed necessary by the Contractor to implement the protocol of their choosing. The Contractor is not required to utilize all four (4) twisted pairs if they are not deemed necessary.

3.5.2.3 Data Bandwidth Limit

The VSS camera video interface shall have a configurable data rate that allows a user to determine the maximum bandwidth emanating from the camera in a given mode. At a minimum, the camera shall include the following two modes:

a) Bandwidth down any given twisted pair shall be 50 Mbps

b) Bandwidth down any given twisted pair shall be 25 Mbps

Note: Including additional operating modes both higher and lower than what is specified above is encouraged, but not required. This feature will allow the Government flexibility when operating this camera over a variety of transmission lines.

3.5.2.4 Data Skew

The VSS camera shall have less than or equal to two (2) nanoseconds of data skew on any given data channel, referenced to its rising or falling clock edge while operating at the camera’s nominal clock frequency.

3.5.2.5 Clock Jitter

The VSS camera shall have (a) less than or equal to one (1) nanosecond peak to peak, cycle to cycle clock jitter and (b) less than or equal to one (1) nanosecond peak to peak of clock jitter between rising and falling edges within the clock cycle, while operating at the camera’s nominal clock frequency.

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3.5.2.6 Video Data Format

The VSS camera shall output the raw Bayer pattern data from the image sensor via the video interface in its default operational mode.

Note: If an internal demosaicing algorithm is utilized internal to the VSS camera, a manual command to disable it shall be included in the camera design.

3.5.2.7 Image Latency

The duration between the end of integration of a single frame and the last bit of that frame leaving the VSS camera shall not exceed 50ms.

3.5.2.8 Image Latency Jitter

The image latency shall not vary by more than 5ms.

3.5.2.9 Demosaicing Algorithm

3.5.2.9.1 Ground Support Equipment Implementation

The demosaicing algorithm that interpolates color imagery from the raw Bayer pattern data shall reside in the VSS camera Ground Support Equipment (GSE).

3.5.2.9.2 Flight Implementation

The demosaicing algorithm that interpolates color imagery from the raw Bayer pattern data shall be made available to the Government in one of the following forms:

a) Scientific Journal Reference: If the Contractor’s demosaicing algorithm is based upon an open source algorithm that is readily available in scientific literature, then the algorithm type and referenced journal article shall be provided.

b) Algorithm Description Document (ADD): If the demosaicing algorithm is a unique creation of the Contractor, then an ADD that details the mathematics and implementation of the demosaicing algorithm is required.

Note: Government access to the demosaicing source code software / firmware is not required, but will be accepted in lieu of the above requirement.

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3.5.3 Command Interface

3.5.3.1 Command Ability

The VSS camera shall accept commands to vary critical internal settings of the camera while the camera is in an active video mode.

3.5.3.2 Command Physical Layer

The VSS camera shall employ Low-Voltage Differential Signaling (LVDS) via a single (1) twisted pair as the physical layer for the command interface.

3.5.3.3 Command Transmission Integrity

The VSS camera shall employ an error-detection code on its command line to detect errors during command transmit and receive.

Note: Common approaches that are acceptable to the Government include Cyclic Redundancy

Checks (CRC), checksum, or parity bits.

3.5.3.4 Reset

The VSS camera shall utilize a reset command that causes the processor to start over at the beginning of the boot sequence as if power had been cycled off and on. All parameters shall be reinitialized to their default values when this command is executed.

3.5.3.5 Test Pattern

The VSS camera shall by command, output a test pattern image to verify the functionality of the data interfaces, integrity of the transmission line medium, and image format interpretation.

3.5.3.5.1 Test Pattern Verification

The contractor shall provide the Government with the expected format and content of the VSS camera test pattern image.

3.5.3.6 Valid Command Protection

No sequence or combination of valid commands shall damage the VSS camera, reduce its life expectancy, or cause any malfunction.

3.5.3.7 Valid Command Counter

(a) The VSS camera shall employ an internal command counter that tracks the number of commands that the camera has received and successfully executed. (b) The command counter shall increment by a value of one (1) for each successful command received / executed.

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3.5.3.8 Invalid Commands

The VSS camera shall trigger an error flag that is reported in the camera telemetry when an invalid command is received by the camera.

3.5.3.9 No Operation Command

The VSS camera shall accept a no-operation (no-op) command, the execution of which results in no change in the camera’s operational status other than the command counter incrementing by a value of one (1).

3.5.3.10 Manual Commanding of Camera Parameters

The VSS camera shall accept and execute manual commands for the following specific camera parameters:

Integration time: discrete pre-determined values

Gain: discrete pre-determined values

Frame Size: row & column size values

Frame Rate: discrete pre-determined values

Region of Interest control: window size and location

Analog-to-Digital Conversion: bits per pixel value (if applicable)

Subsampling Mode: on / off (if applicable)

Bandwidth Limit: discrete pre-determined values

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3.5.4 Telemetry Interface

3.5.4.1 Telemetry Ability

The VSS camera shall output the heath and status of critical camera components, including temperature(s) of the detector, necessary to determine the general overall state and configuration of the system.

Note: The Government will define the specific data to be included in the heath and status telemetry at a later date as they will depend on the capabilities / features of the VSS camera proposed by the Contractor.

3.5.4.2 Telemetry Physical Layer

The VSS camera shall employ Low-Voltage Differential Signaling (LVDS) via a single (1) twisted pair as the physical layer for telemetry interface.

3.5.4.3 Telemetry Update Rate

The VSS camera shall provide telemetry packets either automatically or via command at a rate no slower than 1 Hz.

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3.5.5 General Electrical Requirements

3.5.5.1 Interface Control Document

The Contractor shall provide an electrical Interface Control Document (ICD) that includes at a minimum, the following content:

a) Overall definition of the VSS camera system, it’s modes of operations, and command sequence to achieve an active operational state

b) Definition, part numbers and pin outs of the various electrical connectors

c) Power draw under different operating modes while powered at minimum, maximum and nominal voltages

d) Grounding Scheme

e) The format and structuring of any data / command / telemetry / interfaces

f) Full set of commands, their syntax, their variables, and any applicable calibration coefficients capable of being input to the system

3.5.5.2 Input Safety

The presence or absence of any combination of the input signals applied in any sequence shall not damage the VSS camera, reduce its life expectancy, or cause any malfunction, either when the unit is powered or when it is not.

3.5.5.3 Connector Covers / Connector Savers

The Contractor shall provide flight-approved RF, electrostatic discharge control covers and connector savers for all of the VSS camera connectors.

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3.5.5.4 Isolation Requirements

a) The VSS camera shall provide a minimum of 1 MΩ isolation between two independent power feeds (includes supply and return lines).

b) The VSS camera primary power return shall be isolated from the enclosure and chassis by greater than or equal to 1 MΩ DC.

c) The VSS camera secondary power; if any (i.e. DC-DC converter outputs), generated within a component, shall be referenced to the component chassis using a low resistance connection (≤ 5 mΩ DC).

d) All of the grounding and power returns shall be isolated in the VSS camera design.

e) The returns from different power output circuits shall be isolated from each other.

f) The returns of input (primary) and output (secondary) side shall be isolated from each other.

3.5.5.5 Internal Fusing / Over Current Protection

There shall be no internal fusing in the VSS camera. If required, components may use resettable solid-state switches for over-current protection.

3.5.5.6 Test / Debug Inputs

If required, the VSS camera test and/or debug interfaces shall follow the test signal rules below:

a) VSS camera power shall not be applied or accessed at or through a test connector

b) Test connectors shall meet the same specifications as any flight connectors

c) Circuits wired to the test connectors shall be designed to prevent damage due to an external short, test equipment malfunction or electrostatic discharge (ESD) event.

d) Test / debug interfaces are not considered part of the flight interface. As such, the VSS camera shall be able to perform nominally during spaceflight without access to these interfaces

3.5.5.7 Grounding

All services within the VSS camera shall be referenced to a common ground. Mating surfaces shall be free from nonconductive finishes and shall maximize contact surface area. Connector shells shall be electrically bonded to the chassis through an electrical resistance not exceeding

2.5 mΩ. Unless specifically approved by the Government, the component’s ground connection shall be made through its mounting interface.

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3.5.5.8 External Surface and Differential Charging Mitigation

a) The external conductive surfaces of the VSS camera shall be grounded with less than a

100KΩ resistance to the chassis mount.

b) Partially conductive surfaces/coatings applied over a conductive substrate shall comply with Figure 3-1.

Figure 3-1: Maximum Volume Resistivity vs. Coating Thickness

c) Partially conductive surfaces/coatings applied over a dielectric (and grounded at the edges) material shall comply with the requirements of Figure 3-2.

Figure 3-2: Maximum Volume Resistivity vs. Distance to Ground

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d) Any partially conductive surfaces applied over a non-conductive (dielectric) substrate shall be grounded at the edges and shall have a surface resistivity of less than 10E9 ohms per square.

3.5.5.9 Surface Conductivity and External Discharge Protection

a) The VSS Camera’s external surface resistivity shall be < 10E9 ohm/sq. when measured at vacuum and lowest operating temperatures.

3.5.5.10 Internal Charging

a) Internal charging effects shall be controlled by shielding all electronics elements:

a. For the Restore-L Mission: with greater than or equal to 60 mil aluminum equivalent shield thickness.

b. For the ARRM Mission: with greater than or equal to 110 mil aluminum equivalent shield thickness.

b) Internal dielectric materials of the VSS camera shall have a bulk resistivity less than

10E9 ohms-cm, or a surface resistivity less than 109 ohms per square (when measured at lowest temperature and vacuum conditions).

c) Solid Dielectrics such as: G10 spacers stand offs, and structural components shield shall have (a) a grounded conductive coating or (b) a tightly wrapped grounded conductive material.

d) External floating connector pins shall be grounded or ground referenced through < 1M ohm impedance.

e) For the ARRM Mission: The VSS camera design shall provide a conductive bleed path of less than 1 MΩ for all unused connector pins, test points, unused wiring patterns on printed circuit boards, and floating conductors including but not limited to the following items:

a. Signal and power transformer cores

b. Capacitor cans

c. Metallic IC and hybrid device cases

d. Unused wires in cables, including those isolated by switching

e. Relay cans

f. Conductive coatings

g. Radiation spot shields

h. Crystal cans

i. Conductive tape

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For the Restore-L Mission: Above requirement (e) may be waived based on compliance to requirement (f) below.

f) For both the Restore-L and ARRM Missions: All floating metals and PWB material shall be conformal coated (with surface resistivity on the order of 10 E10 or less ohm-cm), with a continuous layer.

g) The VSS camera connectors shall have their unused contact holes filled with contacts and grounded.

h) All internal and external wiring harness shall provide the mission-specific shielding insulation per the guidelines of Table 3-2 and Table 3-3.

i) Shields shall be continuous to the termination point.

j) Shields shall be terminated 360° around a metal-shielded back shell, which will be in turn terminated to the chassis.

k) Shield ground shall not be terminated using a pin.

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Table 3-2: Internal & External Wiring Shield Requirements for Restore-L

Types of Wiring Shield Requirement Driving or Load

Circuit Protection Additional Protection

(Warm cables protected by

30 mil or more enclosure thickness) (Note 1)

None None None

(Cold cables protected by

100 mil or more enclosure thickness) (Note 1)

None None None

Wires for class 1B or better circuits

Two layers of Kapton XC 275 with 50% overlap and grounded None None

Wires for Class 1A circuits

Two layers of Kapton XC 275 with 50% overlap and grounded

May need Transient protection devices

(Case by case analysis)

None

Wires for Class 0 Circuits Two layers of Kapton XC 275 with 50% overlap and grounded

Transient Protection

Devices

May need Filtering -

Case by case analysis

Wires for Class 0 and

Class 1A circuits that cannot be suppressed or filtered

Two layers of Kapton XC 275 with 50% overlap and grounded over 10 mil lead wrap (warm cables) or 25 mil lead wrap (cold cables)

None None

Power Cabling

Two layers of Kapton XC 275 with 50% overlap and grounded

(in addition to EMI shielding)

None None

Flex Cable (Notes 2 & 3), Coax Cable, Unknown

Cable types

Two layers of Kapton XC 275 with 50% overlap and grounded

Transient Protection

Devices Filtering Required

Note-(1): Warm Cables defined as 0 degre C and up, Cold Cables defined as exposure below -20 deg. C for an extended period based on material properties

Note-(2): Flex cable construction to include grounded copper shield layers on top and bottom side of the flex cable.

Note-(3): In lieu of two layers of Kapton XC275 on flex cable, the outer shield of the flex cable can be made of Kapton XC275 of equi. thickness or other dissipative (with surface resistivity < 10E9 at lowest operational temperature and vacuum conditions) outer shield material.

RESTORE-L Mission: Wiring Shield Requirements

Internal Wiring

External Wiring (Exposed to Space Plasma with wide temperature variations (-150C to +150C)

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Table 3-3: Internal & External Wiring Shield Requirements for ARRM

3.5.5.11 Dielectric Strength

a) The strength of the electrical field in the dielectrics (including circuit board materials) shall be kept less than 10E6 V/m.

b) At a junction point between a conducting surface and dielectric surface, a potential difference shall be limited to below 100 volt.

c) Circuit boards shall be designed so that there will be no open (unused) surface areas (both dielectric and conductive) greater than 0.3 cm^2 (based on 80 mil depth of dielectric to ground trace).

Types of Wiring Shield Requirement Driving or Load

Circuit Protection Additional Protection

(Warm cables protected by

110 mil or more enclosure thickness) (Note 1)

None None None

(Cold cables protected by

110 mil or more enclosure thickness) (Note 1)

None None None

Wires for class 1B or better circuits

Two layers of Kapton XC 275 with 50% overlap and grounded

May need Transient protection devices

May need Filtering -

Case by case analysis

Wires for Class 1A circuits

Two layers of Kapton XC 275 with 50% overlap and grounded

Transient protection devices

Filtering - Case by case analysis

Wires for Class 0 Circuits Two layers of Kapton XC 275 with 50% overlap and grounded

Transient Protection

Devices Filtering

Wires for Class 0 and

Class 1A circuits that cannot be suppressed or filtered

Two layers of Kapton XC 275 with 50% overlap and grounded over 10 mil lead wrap (warm cables) or 25 mil lead wrap (cold cables)

None None

Power Cabling

Two layers of Kapton XC 275 with 50% overlap and grounded

(in addition to EMI shielding)

Transient protection devices None

Flex Cable (Notes 2 & 3), Coax Cable, Unknown

Cable types

Two layers of Kapton XC 275 with 50% overlap and grounded

Transient Protection

Devices Filtering Required

Internal Wiring

External Wiring (Exposed to Space Plasma with wide temperature variations (-150C to +150C)

Note-(1): Warm Cables defined as 0 degre C and up, Cold Cables defined as exposure below -20 deg. C for an extended period based on material properties

Note-(2): Flex cable construction to include grounded copper shield layers on top and bottom side of the flex cable.

Note-(3): In lieu of two layers of Kapton XC275 on flex cable, the outer shield of the flex cable can be made of Kapton XC275 of equi. thickness or other dissipative (with surface resistivity < 10E9 at lowest operational temperature and vacuum conditions) outer shield material.

ARRM Mission: Wiring Shield Requirements

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3.5.