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DRAFT

**Space Segment Requirements Document**

**Landsat Data Continuity Mission**

**June 14, 2006**

**Revision - Draft**

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**CM FOREWORD**

This document is a Landsat Data Continuity Mission (LDCM) Project
Configuration Management (CM)-controlled document. Changes to this
document require prior approval of the applicable Configuration Control
Board (CCB) Chairperson or designee. Proposed changes shall be submitted
to the LDCM 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:

LDCM Configuration Management Office

Mail Stop 427

Goddard Space Flight Center

Greenbelt, Maryland 20771

# Signature Page {#signature-page .Style-Heading-1-+-Left:--0\"-First-line:--0\"}

+---------------------------+------+---------------------------+------+
| Prepared by:              | Date | Prepared by:              | Date |
|                           |      |                           |      |
| Ted Grems                 |      | Jim Nelson                |      |
|                           |      |                           |      |
| LDCM Mission Systems      |      | LDCM Systems Engineer     |      |
| Engineer                  |      |                           |      |
|                           |      | SAIC, contractor to USGS  |      |
| a.i. Solutions / GSFC     |      | EROS                      |      |
| Code 427                  |      |                           |      |
+---------------------------+------+---------------------------+------+
| Reviewed by:              | Date |                           |      |
|                           |      |                           |      |
| Jeanine Morris-Murphy     |      |                           |      |
|                           |      |                           |      |
| LDCM Instrument Manager   |      |                           |      |
|                           |      |                           |      |
| NASA GSFC Code 427        |      |                           |      |
+---------------------------+------+---------------------------+------+
| Reviewed by:              | Date |                           |      |
|                           |      |                           |      |
| LDCM Systems Engineering  |      |                           |      |
| Manager                   |      |                           |      |
|                           |      |                           |      |
| Evan Webb                 |      |                           |      |
|                           |      |                           |      |
| NASA GSFC Code 427        |      |                           |      |
+---------------------------+------+---------------------------+------+
| Reviewed by:              | Date |                           |      |
|                           |      |                           |      |
| LDCM Observatory Manager  |      |                           |      |
|                           |      |                           |      |
| William Anselm            |      |                           |      |
|                           |      |                           |      |
| NASA GSFC Code 427        |      |                           |      |
+---------------------------+------+---------------------------+------+
| Approved by:              | Date | Approved by:              | Date |
|                           |      |                           |      |
| William Ochs              |      | Tom Kalvelage             |      |
|                           |      |                           |      |
| LDCM Project Manager      |      | Acting LDCM Formulation   |      |
|                           |      | Phase Project Manager     |      |
| NASA GSFC Code 427        |      |                           |      |
|                           |      | USGS / EROS               |      |
+---------------------------+------+---------------------------+------+

#  Document Revision History {#document-revision-history .Style-Heading-1-+-Left:--0\"-First-line:--0\"}

This document is controlled by the LDCM Project Management. Changes
require approval of the LDCM Project Manager, LDCM Observatory Manager,
and the LDCM Mission Assurance Manager. Proposed changes shall be
submitted to LDCM Systems Engineering Manager.

  ------------- ---------- ---------- ----------------------------------------
  **RELEASE**   **DATE**   **BY**     **DESCRIPTION**

                                      Initial Version
  ------------- ---------- ---------- ----------------------------------------

# List of TBD's/TBC's/TBR's {#list-of-tbdstbcstbrs .Style-Heading-1-+-Left:--0\"-First-line:--0\"}

This document contains information that is complete as possible. Items
that are not yet defined are annotated with TBD (To Be Determined).
Where final numerical values or data are not available, best estimates
are given and annotated TBC (To Be Confirmed). If there is an
inconsistency between two requirements then the best estimate is given
and annotated with a TBR (To Be Resolved). The following table
summarizes the TBD/TBC/TBR items in the document and supplements the
revision history.

  ---------- --------------- --------------------------------------------------
  **ITEM**   **REFERENCE**   **DESCRIPTION**

                             Data not supplied

                             

                             
  ---------- --------------- --------------------------------------------------

# Table of Contents {#table-of-contents .Style-Heading-1-+-Left:--0\"-First-line:--0\"}

[Signature Page iii](#signature-page)

[Document Revision History iv](#document-revision-history)

[List of TBD's/TBC's/TBR's iv](#list-of-tbdstbcstbrs)

[Table of Contents v](#table-of-contents)

[List of Figures vii](#list-of-figures)

[List of Tables vii](#list-of-tables)

[1 Introduction 8](#introduction)

[1.1 Scope 8](#scope)

[1.2 Document Organization 8](#document-organization)

[1.3 Change Control 8](#change-control)

[1.4 Mission Requirements Flow 9](#mission-requirements-flow)

[2 Applicable Documents 10](#applicable-documents)

[2.1 LDCM Project Level Documents 10](#ldcm-project-level-documents)

[2.2 Government Documents 10](#government-documents)

[2.3 Reference Documentation 11](#reference-documentation)

[3 Definitions 12](#definitions)

[3.1 Observatory Modes 12](#observatory-modes)

[3.2 Mission Phases 12](#mission-phases)

[3.3 Coordinate System 13](#coordinate-system)

[4 Mission 13](#mission)

[4.1 General 13](#general)

[4.2 Mission Lifetime 15](#mission-lifetime)

[4.3 Mission Phases 15](#mission-phases-1)

[4.4 Orbits 17](#orbits)

[4.5 Redundancy Requirements 18](#redundancy-requirements)

[4.6 Autonomy 19](#autonomy)

[4.7 Availability 20](#availability)

[4.8 Ground Support Equipment 21](#ground-support-equipment)

[4.9 Observatory Simulator 21](#observatory-simulator)

[5 Imagery Requirements 23](#imagery-requirements)

[5.1 General 23](#general-2)

[5.2 Ancillary Data 23](#ancillary-data)

[5.3 Data Processing Algorithms 23](#data-processing-algorithms)

[5.4 Spectral Bands 23](#spectral-bands)

[5.5 Spatial Data Sampling Intervals
23](#spatial-data-sampling-intervals)

[5.6 Radiometry 23](#radiometry)

[5.7 LDCM Geometric Precision, Geolocation, and Cartographic
Registration
23](#ldcm-geometric-precision-geolocation-and-cartographic-registration)

[5.8 LDCM Thermal Band Option 23](#ldcm-thermal-band-option)

[5.9 In-Flight Calibration 23](#in-flight-calibration)

[6 Structural and Mechanical Systems
24](#structural-and-mechanical-systems)

[7 Thermal Control 25](#thermal-control)

[8 Electrical System 25](#electrical-system)

[9 Flight Software 27](#flight-software)

[9.1 General 27](#general-3)

[9.2 Event Logging 28](#event-logging)

[9.3 Initialization 28](#initialization)

[9.4 Stored Commands 29](#stored-commands)

[10 Telecommunications 30](#telecommunications)

[10.1 General 30](#general-4)

[10.2 Narrowband 30](#narrowband)

[10.3 Wideband 31](#wideband)

[10.4 Interfaces 32](#interfaces)

[11 Command & Data Handling 32](#command-data-handling)

[11.1 General 32](#general-5)

[11.2 Telemetry 33](#telemetry)

[11.3 Command Capability 34](#command-capability)

[11.4 Mass Storage 35](#mass-storage)

[12 Attitude and Orbit Control 36](#attitude-and-orbit-control)

[12.1 General 36](#general-6)

[12.2 Maneuvers 37](#maneuvers)

[12.3 Ephemeris 37](#ephemeris)

[13 Propulsion System 38](#propulsion-system)

[14 Launch Services 38](#launch-services)

[14.1 Payload Processing Facility Compatibility
38](#payload-processing-facility-compatibility)

[14.2 Launch Site Support 38](#launch-site-support)

[15 SMRD Traceability 38](#smrd-traceability)

[16 SSRD Verification Cross Reference Matrix (VCRM)
38](#ssrd-verification-cross-reference-matrix-vcrm)

# List of Figures {#list-of-figures .Style-Heading-1-+-Left:--0\"-First-line:--0\"}

[Figure 1‑1 LDCM Requirements Flow 9](#__RefHeading___Toc138066723)

# List of Tables {#list-of-tables .Style-Heading-1-+-Left:--0\"-First-line:--0\"}

[Table 2.1‑1 LDCM Project Level Documentation
10](#__RefHeading___Toc138066724)

[Table 2.2‑1 Government Documents 11](#__RefHeading___Toc138066725)

[Table 2.3‑1 Reference Documents and Standards
12](#__RefHeading___Toc138066726)

# Introduction

## Scope 

The Space Segment Requirements Document (SSRD) document establishes the
Level 3procurement requirements for the Landsat Data Continuity Mission
(LDCM). Also include is an allocation matrix of the Space Segment level
requirements to the appropriate subsystems.

## Document Organization 

This document is organized into four general areas. Section 1 provides
scope, general organization of the document and identifies applicable
and reference documents. Section 2 provides a mission definition with an
overview of the LDCM and describes its science objectives and mission
segments. In addition the user community and external interfaces are
identified. Section 3 provides the definitions and terminology that is
used within this document. Sections 4 through 14 provide the level 3
requirements. Section 15 provides for the allocations traceability and
Section 16 provides for the Verification Cross Reference Matrix.

## Change Control 

The approved SSRD will be placed under configuration control. Any
proposed changes to the SSRD will require Configuration Control Board
approval as per the Systems Engineering Management Plan. Requests for
changes to the SSRD will be submitted directly to the LDCM Configuration
Control Manager, who will coordinate the appropriate review process.
Revisions to the SSRD will be made through a formal change process. The
Configuration Control Manager will route change requests to the Mission
Systems Manager, who will obtain the necessary agreements from project
management, scientists, and engineers before release as the official
version. Changes are approved and signed by those on the signature
sheet. NASA Goddard Space Flight Center is responsible for revisions and
will maintain documentation for all change requests.

## Mission Requirements Flow

The general structure of the LDCM Program requirements is shown in
Figure 1-1. The flow down represented in this figure identifies which
organization controls a set of requirements and who has the authority to
change those requirements.

[]{#__RefHeading___Toc138066723 .anchor}Figure 1‑1 LDCM Requirements
Flow

# Applicable Documents

## LDCM Project Level Documents

The SSRD is consistent with, and responsive to, the following documents
of the exact issue and revision shown. Unless otherwise stated in this
document, all inconsistencies in this SSRD will be resolved in the
following order:

1.  LDCM Contract

2.  LDCM SOW

3.  LDCM Mission Assurance Requirements

4.  Space Segment Requirement Document (SSRD, Level 3) and Mission
    Operations Element Requirements Document (MOERD, Level 3)

5.  LDCM Space to Ground Segments Interface Requirements Document (IRD)

  ---------------- ------------- -----------------------------------------
  **GSFC Document  **Revision/   **Document Title**
  Number**         Release       
                   Date**        

  427-xx-xx                      Level 1 Requirements for the LDCM Mission

  427-xx-xx                      Science and Mission Requirements Document

  427-xx-xx                      LDCM Lexicon

  427-xx-xx                      LDCM Operations Concept Document

  427-xx-xx                      Space to Ground Segments IRD

  427-xx-xx                      Statement of Work

  427-xx-xx                      Mission Assurance Requirements

  427-xx-xx        Rev. -, June  Tailored GSFC STD-1000 Rules for the
                   X, 2006       Design, Development, Verification and
                                 Operation of Flight Systems (GOLD Book)

  427-xx-xx        Rev. -, June  LDCM Tailored GSFC GEVS \[TBD\]
                   X, 2006       

  427-xx-xx                      Special Calibration Test Requirements
                                 (SCTR)

  White paper                    LDCM World Reference System-2
  ---------------- ------------- -----------------------------------------

[]{#__RefHeading___Toc138066724 .anchor}Table 2.1‑1 LDCM Project Level
Documentation

## Government Documents

Compliance with the following US Government documents is required:

  -----------------------------------------------------------------------
  **Document      **Revision/     **Document Title**
  Number**        Release Date**  
  --------------- --------------- ---------------------------------------
  NASA STD-5005   Rev. B, Sept.   Ground Support Equipment
                  5, 2003         

  NPD 8710.3      Rev. B, April   NASA Policy for Limiting Orbital Debris
                  28, 2004        Generation

  NSS 1740.14     August 1995     NASA Safety Standard, Guidelines and
                                  Assessment Procedures for Limiting
                                  Orbital Debris

  NPR 2810.1      August 26, 1999 NASA Policy Guideline, Security of
                                  Information Technology

  USAF            July 1, 2004    Air Force Space Command Manual 91-710
                                  Range Safety User Requirements
  -----------------------------------------------------------------------

[]{#__RefHeading___Toc138066725 .anchor}Table 2.2‑2 Government Documents

## Reference Documentation

The SSRD is consistent with the following documents. If the SSRD
conflicts with the any of these listed documents, the SSRD takes
precedence.

+--------------+----------+-------------------------------------------+
| **Document   | **R      | **Document Title**                        |
| Number**     | evision/ |                                           |
|              | Release  |                                           |
|              | Date**   |                                           |
+==============+==========+===========================================+
| CCSDS        |          | Recommendation for Space Data Systems     |
| 122.0--B--1  |          | Standards. Lossless Data Compression.     |
|              |          | CCSDS Recommendation, Blue Book, May      |
|              |          | 1997.                                     |
+--------------+----------+-------------------------------------------+
| CCSDS        | June     | Recommendation for Space Data Systems     |
| 202.0--B--3  | 2001     | Standards. Telecommand, Part 2: Data      |
|              |          | Routing Service. CCSDS Recommendation,    |
|              |          | Blue Book                                 |
+--------------+----------+-------------------------------------------+
| CCSDS        | S        | Recommendation for Space Data Systems     |
| 232.1--B--1  | eptember | Standards. Communications Operations      |
|              |          | Procedure-1. Blue Book. Issue 1.          |
|              | 2003     |                                           |
+--------------+----------+-------------------------------------------+
| CCSDS        |          | Recommendation for Space Data Systems     |
| 701.0--B--3  |          | Standards. Advanced Orbiting Systems,     |
|              |          | Networks, and Data Links: Architectural   |
|              |          | Specification. CCSDS Recommendation, Blue |
|              |          | Book, June 2001.                          |
+--------------+----------+-------------------------------------------+
| 42 U. S. C., | Sept.    | National Environmental Policy Act of 1969 |
| 4321 et seq. | 13, 1982 |                                           |
| NEP          |          |                                           |
+--------------+----------+-------------------------------------------+
| KNPR 8715.3  |          | KSC Safety Requirements                   |
+--------------+----------+-------------------------------------------+
| STDN 101.2   | Rev. 7   | GSFC Space Network (SN) Users' Guide      |
|              | /Nov.    |                                           |
|              | 1995     |                                           |
+--------------+----------+-------------------------------------------+

[]{#__RefHeading___Toc138066726 .anchor}Table 2.3‑3 Reference Documents
and Standards

# Definitions 

## Observatory Modes 

This document uses the following definition of observatory modes. Though
the LDCM contractor is not required to use these same definitions; a
mapping of the contractor's observatory modes to these is required.

**Ground Based Storage Mode**, a non-operational mode, with minimal
support for up to 30 days at a time. This mode may last for as much as
180 days and may be entered into at either the contractor's or
government provided facilities.

**Launch Mode** for integration and testing with the launch vehicle and
for the launch phase through separation. This is a non-nominal
operational mode.

**Survival Mode** provides a maximum power positive attitude and an
observatory configuration that maintains the observatory in a power
safe, thermally safe and optically safe configuration for an indefinite
period of time requiring no ground contact. This is a non-nominal
operational mode.

**Safe Hold Mode** that provides for a coarse nadir earth point attitude
and an observatory configuration that provides maximum ability for
check-out, and diagnostics in a power safe, thermally safe and optically
safe configuration for an indefinite period of time. This is a nominal
operational mode.

**Mission Mode** that provides for a fine earth point achieving mission
attitude requirements which supports continuous operations. This is a
nominal operational mode.

**Calibration Mode** that provides for lunar, celestial and earth's limb
pointing capability. This is a nominal operational mode.

**Propulsion Mode** that provides for orbit and inclination adjustments.
This is a nominal operational mode.

**Off-nadir Point Mode** that provides for the observatory to point one
WRS-2 swath left or right of the current WRS-2 grid. This is a nominal
operational mode.

## Mission Phases 

**Storage Phase** begins after completion of the LDCM Observatory
environmental test campaign and ends with the delivery of the
observatory for final ground processing.

**Pre-Launch Phase** begins after delivery of the LDCM Observatory to
the launch site and ends at liftoff. This phase is divided into two
sub-phases, the Observatory processing at the launch site before
integration to the launch vehicle and the Observatory processing at the
launch pad.

**Launch and Early Orbit Phase** begins at lift-off and ends after the
LDCM Observatory has been commanded into a Safe Hold Mode and normal
operations of the power and attitude control subsystems have been
verified.

**Observatory Commissioning Phase** begins at the completion of the
Launch and Early Orbit Phase and ends with acceptance by the NASA of the
LDCM Observatory for the Operational Phase of the LDCM. During the
Commissioning Phase all on-orbit functional requirements must be
demonstrated.

**Operational Phase** begins at the completion of the Observatory
Commissioning Phase and extends through the life of the LDCM
Observatory. End of mission life for the LDCM Observatory is to be
assessed by a DOI/USGS convened review board which ensures that the
observatory decommission requirements can be meet.

**Decommissioning Phase** is defined as the period of time after the end
of the Operational Phase and extends through the implementation of the
de-orbit maneuvers and de-energize the observatory in compliance with
the NSS 1740.14.

## Coordinate System 

The LDCM Observatory body reference coordinate system is defined as a
right-hand, orthogonal, body fixed, XYZ coordinate system with the +Z
axis aligned with the image sensor field of view. The origin is located
at the observatory to launch vehicle interface plane and in the physical
center of the observatory.

# Mission

## General

The LDCM Observatory shall be capable of acquiring image sensor data at
any point throughout the orbit.

Rationale: Take an image anywhere within the orbit.

The LDCM Observatory shall be capable of acquiring the image sensor data
equivalent to 400 WRS-2 scenes plus the necessary calibration data per
24 hour period.

Rationale: The LDCM Observatory will be capable of acquiring, buffering
and successfully transmitting sensor image data equivalent to 400 WRS-2
scenes per day plus any necessary calibration data. Calibration data may
include lunar, solar, earth limb imaging results.

The LDCM Observatory shall transfer all mission data to the ground
within 12 hours of observation.

The LDCM Observatory shall be capable of acquiring up to 5 priority
scenes per day.

Rationale: For rapidly changing conditions on the earth LDCM will be
able to image either WRS-2 scenes or off-nadir scenes and mark them as
priority

The LDCM Observatory shall transfer priority scenes to the ground within
3 \[TBC\] hours of observation.

The LDCM Observatory shall be capable of acquiring image intervals up to
one WRS-2 path located on either side of the current nadir, WRS-2 path.

Rationale: This acquisition is in lieu of an equivalent amount of nadir
WRS-2 path image acquisition.

The LDCM Observatory shall be capable of acquiring up to 5 off-nadir
image intervals per day.

The LDCM Observatory shall be capable of acquiring up to 38-night
\[TBC\] WRS-2 Scenes during any 24-hour period.

The LDCM Observatory shall be capable of being commanded by the ground
into any operational mode.

The LDCM Observatory shall be designed not to cause orbital debris as
per NPD 8710.3.

Rationale: The NPD provides guidelines for minimizing orbital debris. It
also invokes NASA Safety Standard NSS 1740.14 for assessing debris and
mission survivability.

The LDCM Observatory shall be capable of using the NASA Space Network
Support (TDRSS) for command and telemetry.

The LDCM Observatory shall be capable of using the NASA Ground Network
Support (GN) for command and telemetry.

The LDCM Observatory shall use the LDCM Ground Network for wideband data
reception.

The LDCM Observatory shall use the LDCM Ground Network for command and
telemetry.

The LDCM Observatory shall be capable of transmitting mission data to
International Ground Stations in real time.

Rationale: IC's are provided data directly from the observatory to the
IC's station

The LDCM shall use the Système International (SI) units for defining
interfaces; the usage of any other unit(s) other than the SI shall be
clearly communicated and documented.

## Mission Lifetime

The LDCM Observatory shall be designed for 5 years of mission life
beginning at the NASA Acceptance of the Observatory.

The LDCM Observatory shall be designed for an overall Probability of
Mission Success of 0.80 \[TBC\] or better at the end of design mission
life.

The LDCM Observatory shall have a propellant loading sufficient to
complete orbit raising, 10 years of nominal mission operations and
decommissioning.

## Mission Phases

### Storage Phase

The LDCM Observatory shall be capable of being placed in a low
maintenance state, ground based storage mode for 30 day periods for up
to 180 days.

The LDCM Observatory shall be capable of being placed in physical
storage after assembly, integration and environmental tests in such a
way so as to prevent degradation of its components and to allow for the
rapid transition to the Pre-Launch Phase.

### Pre-Launch Phase

The LDCM Observatory shall be designed for a launch from Vandenberg AFB.

The LDCM Observatory and Ground Support Equipment used at the launch
site shall comply with the US Air Forces Space Command Manual 91-710
Range Safety User Requirements, dated July 1, 2004.

The LDCM Observatory shall make available real-time and stored
housekeeping telemetry while at the launch pad.

The LDCM Observatory shall interface with NASA/KSC provided launch
vehicle as defined in the Delta II \[TBC\] to LDCM Mission Interface
Control Document.

The LDCM Observatory shall be designed to monitor the status of the
propulsion system while the observatory is powered off through the
launch vehicle interface umbilical.

The LDCM Observatory shall be designed to monitor the status of the
electrical storage system while the observatory is powered off through
the launch vehicle interface umbilical.

The LDCM Observatory shall be capable of performing aliveness,
functional and limited performance tests while mated to the launch
vehicle.

### Launch and Early Orbit Phase

The LDCM Observatory shall transmit real-time, narrowband, observatory
housekeeping telemetry during launch ascent starting after launch
vehicle fairing separation.

The LDCM Observatory shall receive real-time, command telemetry during
launch ascent starting after launch vehicle fairing separation.

The LDCM Observatory shall be powered on for launch.

The LDCM Observatory shall transmit real-time observatory housekeeping
telemetry during the launch phase following launch vehicle fairing
separation.

### Observatory Commissioning Phase

Reserved

### Operational Phase

Reserved

### Observatory Decommissioning Phase

The LDCM Observatory shall ensure that onboard energy sources
(mechanical, electrical and chemical) are depleted during this mission
phase.

Rationale: Thus minimizing potential for future orbital debris

The LDCM Observatory shall complete a de-orbit maneuver sufficient to
ensure that the LDCM Observatory enters the Earth's atmosphere in
compliance with NASA Safety Standard (NSS) 1740.14.

## Orbits

### General

The LDCM Observatory shall be capable of performing drag makeup
maneuvers.

The LDCM Observatory shall be capable of performing inclination
maneuvers.

### Injection Orbit

The LDCM Observatory shall achieve the operational orbit after
separation from the launch vehicle at the following injection orbit:

-   Semi-Major Axis: 7063 km \[TBC\]

-   Mean Eccentricity: 0.000 \[TBC\]

-   Mean Inclination: 98.22 deg \[TBC\]

-   Mean Local Time (MLT) of the Descending Node: 1000 \[TBC\]

The LDCM Observatory shall achieve the operational mission orbit when
the following dispersions are applied to the injection orbit:

-   Perigee Altitude error: -25 km, +9.3 km

-   Apogee Altitude error: -9.3 km, +9.3 km

-   Inclination error: +/- 0.05 deg

-   Injection Node MLT error: +/- 2.5 minutes

The LDCM Observatory shall have a daily launch window of 5 minutes
\[TBC\].

The LDCM Observatory shall have a launch readiness capability once every
24 hours.

### Operational Orbit

The LDCM Observatory shall be capable of imaging any area on the earth
surface at least once every 16 days with the exception of 817 km radius
circles centered at the North Pole and South Pole.

The LDCM Observatory shall operate in a sun-synchronous, near circular,
frozen orbit described as follows:

-   Equatorial Altitude: 705 km

-   Semi-Major Axis: \[TBD\]

-   Eccentricity: 0.00125 \[TBC\]

-   Mean Local Time of the Descending Node: 10:00 a.m.

-   Ground Track: WRS-2 Grid

-   Repeat Cycle: 16-days

The LDCM Observatory shall achieve the operational mission orbit when
the following dispersions are applied to the operational orbit:

-   eccentricity: +/- 0.0005

-   Inclination: +/- 0.001 deg

-   MLT of the descending node: +/- 7.5 \[TBC\] minutes

-   Ground Track Error: +/- 5 km cross track at the descending node

The LDCM Observatory shall be capable of maintaining the Operational
Orbit for the life of the mission.

### Disposal Orbit

The LDCM Observatory shall complete a de-orbit maneuver sufficient to
ensure that the LDCM Observatory enters the Earth's atmosphere within 25
years of decommissioning Rationale: See Reference NSS 1740.14).

## Redundancy Requirements

The LDCM Observatory shall be designed such that no single credible
failure permanently precludes the LDCM Observatory from completing the
design mission life.

The LDCM Observatory shall be capable of redefining the prime and backup
unit for redundant systems from the ground.

Rationale: Be able to switch back and forth between prime and backup
units through ground commands

The LDCM Observatory shall provide indication of which unit is operating
in housekeeping data to the ground for redundant systems.

## Autonomy

### Autonomous Features

The LDCM Observatory shall be capable of autonomously transitioning from
the Mission, Calibration, Propulsion and Off-nadir Point Modes into the
Safe Hold Mode.

The LDCM Observatory shall be capable of autonomously transitioning from
the Safe Hold Mode to the Survival Mode.

The LDCM Observatory shall not autonomously transition out of the
Survival Mode.

The LDCM Observatory shall not autonomously transition from the Safe
Hold Mode into the Mission, Calibration, Propulsion or Off-nadir Point
Modes.

The LDCM Observatory shall be capable of operating nominally for 72
\[TBR\] hours autonomously.

The LDCM Observatory shall have the ability to autonomously perform
reconfiguration of redundant components.

The LDCM Observatory shall not autonomously switch control to a failed
redundant component.

The LDCM Observatory shall be capable of programming the downlink
sequence by ground command for the full time span of autonomous
operations.

The LDCM Observatory shall be capable of initiating a stored command in
response to pre-defined conditions.

The LDCM Observatory shall be capable of over-riding autonomous
functions via ground command.

The LDCM Observatory shall report autonomous reconfigurations in normal
telemetry.

The LDCM Observatory shall monitor component, subsystem, and
housekeeping data.

### Failure Detection and Protection

The LDCM Observatory shall automatically detect out of limit conditions
for hardware and software.

The LDCM Observatory shall provide the capability to run on-board
diagnostics and report the results in telemetry.

The LDCM Observatory shall accept ground commands to run on-board
diagnostics and report the results in telemetry.

Rationale: Flexibility is necessary to support debugging conditions that
may not be known until after launch.

The LDCM Observatory shall automatically place itself in a safe
operational mode based on detected out of limit conditions.

The LDCM Observatory shall perform Power On Self Test (POST) diagnostics
at power-on.

The LDCM Observatory shall monitor and report Power On Self Test (POST)
results in the housekeeping telemetry.

The LDCM Observatory shall monitor and reject invalid commands.

The LDCM Observatory shall report false commands in housekeeping
telemetry.

The LDCM Observatory shall attempt a soft recovery of a subsystem
element before power cycling it.

The LDCM Observatory shall safe itself in the event of an anomaly.

The LDCM Observatory shall implement independent time-based monitoring
circuits.

## Availability

The LDCM Observatory shall be available for acquiring image sensor data
at least 93% \[TBC\] of the time during a WRS-2 Observation Period.

## Ground Support Equipment

The LDCM Ground Support Equipment (GSE) shall be in compliance with
NASA-STD-5005 Ground Support Equipment.

The LDCM GSE shall provide necessary stimulus and simulation means to
support the attitude and orbit control system testing.

The LDCM GSE shall provide mission operational simulation of the solar
array power generation capability.

The LDCM GSE shall be capable of battery conditioning, charging, trickle
charge and verification.

The LDCM GSE shall be capable of providing power to the Observatory with
flight batteries installed.

The LDCM GSE shall be capable of providing power to the Observatory
without flight batteries installed.

The LDCM GSE shall provide the necessary RF front ends and check-out
capabilities to verify the Observatory functionality.

The LDCM GSE shall provide means for status verification and leak
detection of the propulsion subsystem.

The LDCM GSE shall provide the capability to monitor the status of the
Service Platform power switches.

## Observatory Simulator 

The LDCM Observatory Simulator shall be capable of operating
independently from the LDCM Flight Operations Segment.

The LDCM Observatory Simulator shall be capable of integration into the
LDCM Flight Operations Segment.

The LDCM Observatory Simulator shall simulate the operations of the
command and data handling system.

The LDCM Observatory Simulator shall simulate the operations of the
attitude and orbital control system.

The LDCM Observatory Simulator shall simulate the operations of the mass
storage system.

The LDCM Observatory Simulator shall simulate the operations of the
power system.

The LDCM Observatory Simulator shall simulate the operations of the
image sensor(s).

The LDCM Observatory Simulator shall simulate the interface between the
Mission Operations Element (MOE) and the observatory telecommunications
system.

Rationale: So that the observatory simulator can talk to the MOE there
needs to be a ground station interface simulator. This requirement
addresses the fact that the ground RF is not present for the simulator.

The LDCM Observatory Simulator shall be capable of simulating all
observatory operational modes and mode transitions.

\*\* The following requirements are to establish a minimum simulation
capability. They may produce unintended results by limiting what the
contractor wants to bring to the table. \*\*

The LDCM Observatory Simulator shall validate commands, table updates
and flight software modifications.

The LDCM Observatory Simulator shall receive commands in any valid
format and data rate.

The LDCM Observatory Simulator shall be capable of receiving, processing
and executing flight software updates.

The LDCM Observatory Simulator shall be capable of generating a
telemetry stream with representative observatory data in all valid
formats and data rates.

The LDCM Observatory Simulator shall simulate the response
characteristics of failed observatory subsystems.

The LDCM Observatory Simulator shall respond to real-time operator
changes in the configuration of the simulated observatory.

The LDCM Observatory Simulator shall accept inputs from the user to set
and change simulation variables.

The LDCM Observatory Simulator shall accept inputs from the user to set
and synchronize simulation time with observatory clock time and ground
system time.

The LDCM Observatory Simulator shall be capable of running a previous
executed simulation.

# Imagery Requirements 

The imaging section of the SSRD was released earlier to industry for
comments. Section 5.0 will be integrated into a final DRAFT release of
this document following integration of comments from industry.

## General

## Ancillary Data

## Data Processing Algorithms

## Spectral Bands

## Spatial Data Sampling Intervals

## Radiometry

## LDCM Geometric Precision, Geolocation, and Cartographic Registration 

## LDCM Thermal Band Option 

## In-Flight Calibration 

The image sensor shall have on-board calibration systems that provide
sufficient data with precision and accuracy to meet the calibration and
stability requirements of the image sensor as described in this
document.

### Reflective Band Calibration Sources 

Sources for the in-flight calibration shall include celestial objects
including both the sun and the moon, and on-board sources such as lamps.

### Reflective Band On-board Calibration Systems 

The calibration systems shall at a minimum include:

> a.) A full aperture full system space-grade Spectralon solar diffuser
> with the capability to assess the diffuser deployment orientation
> stability with time. The solar diffuser shall be designed to operate
> at a solar zenith angle of no greater than 60° and a view zenith angle
> of no greater than 45° (TBR). The in-flight calibration system shall
> maintain absolute radiometric accuracy as stated for the image sensor
> or better.
>
> b.) A lamp calibration source with at least three selectable lamps,
> each of which illuminates all detectors. The lamps shall be operable
> in constant irradiance and constant current modes. This calibration
> source shall have at a minimum an independent total optical power
> output monitor.
>
> c.) A device by which the dark signal of all the detectors can be
> monitored without violation of the image sensor operations
>
> d.) Permanently masked dark detectors on each end of each detector
> array in each band to generate sufficient data to track bias stability
> during daylight acquisitions for each band
>
> e.) A device by which the linearity of the image sensor with respect
> to radiance can be characterized on orbit
>
> f.) A source designed to be stable between prelaunch and on orbit
> environments and throughout launch. This source shall be exercised
> prelaunch and postlaunch to test the transfer to orbit stability of
> the image sensor

### Thermal Calibration Systems

> a\) A full aperture, full system calibration shall be available for
> the thermal band option.

# Structural and Mechanical Systems

The LDCM Observatory structure shall be of sufficient strength and
stiffness to maintain structural integrity and withstand all ground
testing, handling, transportation, launch, and mission orbit
environments.

# Thermal Control

The LDCM Observatory shall be thermally safe for continuous operations
in the Survival, Safe Hold and Mission Modes.

The LDCM Observatory shall maintain all subsystems of the observatory
within their survival temperature range when the Observatory is in
Survival Mode.

The LDCM Observatory shall maintain all subsystems of the Observatory
within their operational temperature range when the Observatory is in
any operational mode.

The LDCM Observatory shall maintain the imaging sensor thermally stable
within its operational temperature range while in the Mission Mode,
Calibration Mode and Off-Nadir Point Mode.

The LDCM Observatory thermal control flight software shall be
reprogrammable on orbit.

# Electrical System

The LDCM Observatory shall provide power generation, power control,
energy storage and distribution for the observatory.

The LDCM Observatory shall provide load shedding control and battery
management for all observatory operational modes.

The LDCM Observatory shall maintain a positive energy balance at the end
of every 1 \[TBC\] orbit.

The LDCM Observatory shall be power positive over each orbit while in
the Survival and Safe Hold modes.

The LDCM Observatory shall provide protection against over voltage,
under voltage and over current for the observatory.

The LDCM Observatory shall be capable of being powered from Observatory
Ground Support Equipment with flight batteries installed.

The LDCM Observatory shall be capable of being powered from Observatory
Ground Support Equipment with flight batteries uninstalled.

The LDCM Observatory shall monitor and report switch positions.

The LDCM Observatory shall monitor and report current.

The LDCM Observatory shall monitor and report voltage.

The LDCM Observatory shall provide electrical energy storage for all
observatory operational modes.

The LDCM Observatory energy storage device state of charge shall remain
above 40% during the design mission life time.

The LDCM Observatory energy storage device state of charge shall remain
above 60% for nominal operational modes.

The LDCM Observatory energy storage device state of charge shall remain
above 40% for the Maneuver and Propulsion Modes.

The LDCM Observatory shall provide power distribution for selecting,
connecting and disconnecting the imaging sensor(s) and selected
observatory equipment to the electrical bus.

The LDCM Observatory shall provide short circuit protection or current
limitation for all power distribution wiring.

The LDCM Observatory shall route redundant power distributions
independently via redundant harness and different connectors.

The LDCM Observatory shall use socket connectors on the power side of an
electrical interface.

The LDCM Observatory shall provide a launch vehicle interface connector
for power to the observatory.

# Flight Software 

## General

The LDCM Observatory flight software shall be reprogrammable on orbit.

The LDCM Observatory shall be capable of accommodating flight software
updates.

The LDCM Observatory shall verify execution of FSW tasks or functions.

The LDCM Observatory flight software shall provide a mechanism to verify
the validity of all memory areas.

The LDCM Observatory flight software shall provide a mechanism to detect
and correct single bit memory errors.

The LDCM Observatory stored commands shall be unaffected by a flight
software upload.

The LDCM Observatory flight software shall be capable of scheduling and
prioritizing tasks.

The LDCM Observatory flight software shall store the version of the
software onboard.

The LDCM Observatory firmware shall store the internal identifier of the
version of the embedded software onboard.

The LDCM Observatory flight software shall maintain a mapping of table
name to memory address location.

The LDCM Observatory flight software shall be capable of updating memory
table locations through ground command table names.

The LDCM Observatory flight software shall provide the capability to
load any location of on-board memory by referencing its physical memory
address.

The LDCM Observatory flight software shall be capable of dumping any
location in program memory.

Rationale: to support debugging efforts and provide additional telemetry
points which may have been unanticipated at development time

The LDCM Observatory flight software memory dump capability shall not
disturb normal operations.

## Event Logging

The LDCM Observatory flight software shall time tag events logged in
telemetry with an accuracy of 125 \[TBC\] milliseconds or better.

Rationale: a reported event would likely contain information on the
source processor, flight software task or function, severity level,
message identifier and informational string that identifies the cause.
The event messages capture anomalous events, redundancy management
switching of components and important system performance events and warm
and cold restarts.

The LDCM Observatory flight software shall be capable of buffering up to
300 \[TBC\] event messages in a telemetry queue.

## Initialization

The LDCM Observatory shall initialize flight software and begin
operations without the need of a ground based command.

The LDCM Observatory flight software shall be capable of a cold restart
of the flight software at the processor level.

The LDCM Observatory flight software shall execute a cold restart
following a hardware reset.

The LDCM Observatory flight software shall default to a known telemetry
configuration following a cold restart.

The LDCM Observatory flight software shall be capable of a warm restart
of the flight software at the processor level.

The LDCM Observatory flight software shall execute a warm restart when
restarting from a flight software-commanded reset.

The LDCM Observatory flight software shall preserve memory contents
following a warm restart.

Rationale: A warm restart preserves command processing statistics,
memory tables and command sequences

The LDCM Observatory flight software shall be capable of executing a
warm restart from a flight software command.

The LDCM Observatory flight software shall execute a cold restart after
a pre-determined number of warm restarts.

## Stored Commands

The LDCM Observatory flight software shall provide stored absolute-time
command sequences and stored relative-time command sequences.

The LDCM Observatory flight software stored command sequences shall be
modifiable by ground command.

The LDCM Observatory flight software command sequences shall be enabled,
disabled, paused, or cancelled by ground command.

The LDCM Observatory flight software shall be capable of dumping stored
commands. Rationale: The stored command buffer needs to be read by the
FOT, stored command sequence table can be dumped to the ground by a
single command.

The LDCM Observatory flight software shall uniquely identify stored
command sequences.

The LDCM Observatory flight software shall use the unique command
sequence identifier to report the status of each actively executing
command sequence in telemetry.

The LDCM Observatory flight software time resolution for stored commands
shall be 0.1 seconds \[TBC\].

The LDCM Observatory flight software shall provide the capability to
execute commands with an accuracy of 0.1 seconds \[TBC\].

The LDCM Observatory flight software shall provide the capability to
store multiple time-tagged command sequences.

The LDCM Observatory flight software shall provide the capability to
execute time-tagged commands at the time identified with each command in
the sequence.

The LDCM Observatory flight software shall have the ability to execute 3
\[TBC\] time-tagged command sequences concurrently.

The LDCM Observatory flight software absolute-time stored command
sequences shall be capable of invoking relative-time stored command
sequences.

# Telecommunications

## General

The LDCM Observatory shall comply with [National Telecommunications and
Information
Administration](http://www.google.com/url?sa=U&start=1&q=http://www.ntia.doc.gov/&e=15235&ei=opiFRP_EJpXCwQKR3OHpCg)
(NTIA) Spectrum Standards.

Rationale: We need a document number to reference.

The LDCM Observatory shall comply with International Telecommunication
Union (ITU) spectrum utilization and sharing requirements.

Rationale: We need a document number to reference.

The LDCM Observatory shall comply with Space Frequency Coordination
Group (SFCG) spectrum masks.

Rationale: We need a document number to reference.

The LDCM shall be capable of transmitting a 10\^23-1 maximal pseudo
noise pattern (TBR) from all transmitters.

Rationale: This is a testability requirement and we do not have a
testability section.

## Narrowband

The LDCM Observatory shall be capable of narrowband reception of ground
commands while in any operational mode.

The LDCM Observatory shall be capable of narrowband reception of ground
commands while in any orientation.

The LDCM Observatory shall be capable of narrowband transmissions in any
observatory operational mode.

Rationale: Real-time HK data is needed to monitor and control the
observatory even if the observatory is tumbling out of control.

The LDCM Observatory shall be capable of narrowband transmissions in any
observatory orientation.

The LDCM Observatory shall be capable of narrowband transmission and
reception concurrently.

The LDCM Observatory shall be capable of a narrowband location beep
transmission in any observatory operational mode.

Rationale: This provides a signal for aiding tracking the observatory

The LDCM Observatory shall be capable of sending and receiving
narrowband transmissions between the observatory and Space Network
S-Band system.

## Wideband

The LDCM Observatory shall be capable of downlinking mission data within
12 hours of an observation.

The LDCM Observatory shall provide a downlink capability of at least 2
\[TBC\] concurrent and distinct downlinks of wideband data.

[]{.mark}

The LDCM Observatory shall be capable of wideband transmission of
real-time mission data when in contact with a ground station.

The LDCM Observatory shall be capable of wideband transmissions with an
attitude of 20 \[TBC\] degrees total angle off the nadir attitude.

The LDCM Observatory shall be capable of continuously and concurrently
transmitting real-time mission data to at least three ground stations.

The LDCM Observatory shall provide isolation between adjacent downlink
channels of 40 dB \[TBC\] or better.

The LDCM Observatory shall provide isolation between simultaneous
downlink channels to separate ground stations of 40 dB \[TBC\] or
better.

### 8 GHz DSN Protection

The LDCM Observatory wideband downlink shall not create RF interference
with NASA Deep Space Network communications.

The LDCM Observatory wideband downlinks out-of-band emissions shall not
exceed -220.9 dBW/Hz.

Rationale: from "DSN 8 GHz RFI Prevention Guideline Draft" protection
criteria applicable to the 8400-8450 MHz SRS (space-to-Earth) deep space
band in accordance with ITU-R SA.1157.

The X-Band power spectral density at 8400 MHz and above shall be -255
dBW/m²/Hz or lower.

Rationale: DSN protection

## Interfaces

The LDCM Observatory shall use socket connectors on the power side of a
communications interface.

The LDCM Observatory shall provide a launch vehicle interface connector
for telecommunications to the observatory.

The LDCM Observatory shall provide an interface to GSE RF test receiver
antennas during ground testing.

Rationale: Observatory testing requires an all cables / connector out
configuration. The RF system should not injure people or other equipment
and should be captured by RF "hats".

# Command & Data Handling

## General

The LDCM Observatory shall be capable of maintaining the health and safe
operations of all elements of the observatory without ground support.

The LDCM Observatory shall continuously monitor the health and safety of
the observatory.

The LDCM Observatory shall report the health and safety of the
observatory.

The LDCM Observatory onboard processors shall be capable of being reset
via hardware commands sent from the ground.

The LDCM Observatory shall be capable of resending stored mission data
multiple times.

Rationale: in the event the data was not received by the ground.

The LDCM Observatory shall produce a complete set of ancillary data at
least once every 4 seconds \[TBC\] during imaging.

The LDCM Observatory shall time-tag image sensor data with an accuracy
of 200 \[TBC\] microseconds.

The LDCM Observatory shall time tag the ancillary data with an accuracy
of 200 \[TBC\] microseconds.

The LDCM Observatory shall time synchronize the ancillary data with the
image sensor data to within 2.4 \[TBC\] seconds.

Rationale: Ancillary data needs to be transmitted 2.4 \[TBC\] seconds
(2.4 = 60% of time to generate or frame rate of the ancillary data) of
the image sensor data so that the IC's will be able to process the image
data upon receipt. If the ancillary data is stale, the ICs can not use
it.

## Telemetry

The LDCM Observatory shall generate Channel Access Data Units (CADU) for
downlink as defined in CCSDS 701.0-B-3.

The LDCM Observatory shall capable of concurrently recording,
downlinking real-time, and downlinking stored telemetry.

Rationale: this capability can be selected in any permutation

The LDCM Observatory shall report commands in housekeeping telemetry
when received.

The LDCM Observatory shall report commands in housekeeping telemetry
when executed.

The LDCM Observatory shall generate and transmit real-time observatory
housekeeping data to the ground.

Rationale: Real-time HK data is needed to monitor and control the
observatory.

The LDCM Observatory shall be capable of playing back stored
housekeeping data while in any operational mode.

The LDCM Observatory shall be capable of processing and storing analog
telemetry from the image sensor.

## Command Capability

The LDCM Observatory shall be capable of decrypting command and data
uploads using civil encryption coding in compliance with NASA NPR
2810.1, Section 4.11.

The LDCM Observatory shall be capable of enabling or disabling
decryption.

The LDCM Observatory shall be capable of source authentication of all
received commands.

The LDCM Observatory shall execute only commands that are source
authenticated.

The LDCM Observatory shall accept and execute discrete commands in real
time only.

The LDCM Observatory shall accept real-time and stored commands.

The LDCM Observatory shall be capable of storing and retrieving commands
for delayed execution.

The LDCM Observatory shall be capable of receiving command loads across
multiple contacts.

The LDCM Observatory shall be capable of receiving flight software loads
across multiple contacts.

The LDCM Observatory shall validate, process, and execute commands and
data loads.

The LDCM Observatory shall be capable of executing absolute time
commands and relative time sequenced commands.

Rationale: Relative time sequenced commands are a sequence of commands
that can be sent from the command storage following a pre-defined
sequence.

The LDCM Observatory shall be capable of updating the stored command
table.

Rationale: This says reloading or editing the command buffer is covered
by one general requirement

The LDCM Observatory shall support Command Operations Procedure-1 as
defined in CCSDS 202.0-B-3 and CCSDS 232.1--B--1.

The LDCM Observatory shall be capable of supporting all nominal
operations with no more than 20 \[TBC\] minutes of command uplink every
24 hours.

The LDCM Observatory shall be capable of executing a command at a
frequency of at least 1 Hz \[TBC\].

## Mass Storage

The LDCM Observatory shall be capable of storing observatory health and
safety data.

The LDCM Observatory shall identify priority scenes in mass storage.

The LDCM Observatory shall downlink priority scenes before downlink
non-priority scenes.

The LDCM Observatory shall overwrite non-priority mission data before
overwriting priority mission data.

The LDCM Observatory shall overwrite mission data starting from oldest
to youngest.

The LDCM Observatory shall be capable of storing 24 \[TBC\] hours of
wideband data onboard.

The LDCM Observatory shall implement error detection and correction
capability to correct single event upsets in mass storage.

The LDCM Observatory shall provide telemetry data to indicate that
stored data has been corrected.

The LDCM Observatory shall provide telemetry data to indicate that
non-correctable data errors have been detected.

The LDCM Observatory shall use a file based data management scheme.

Rationale: This simplifies data handling and prioritization management
in data.

The LDCM Observatory shall have the capability to remove sections of
storage by ground command.

Rationale: Needed when warranted by observed or suspected malfunction.

# Attitude and Orbit Control

## General

The LDCM Observatory shall generate an estimated inertial attitude in
the Mean of J2000 frame.

The LDCM Observatory shall be capable of transforming the estimated
inertial attitude to a geodetic reference frame.

The LDCM Observatory shall time-tag the inertial attitude estimate with
an accuracy of 200 microseconds, 3-sigma.

The LDCM Observatory shall provide inertial attitude knowledge with an
accuracy of 24.3 arcsec, 3-sigma per axis, for each image sensor
line-of-sight during imaging.

The LDCM Observatory shall provide an estimate of the inertial attitude
knowledge at least once per second \[TBC\].

The LDCM Observatory shall provide stable relative inertial attitude
accuracy over a 30 second period of 3.38 arcsec or better, 3-sigma per
axis during imaging.

The LDCM Observatory shall provide stable relative inertial attitude
accuracy over a 2.5 second period of 1.73 arcsec or better, 3-sigma per
axis during imaging.

The LDCM Observatory shall limit the high frequency disturbances applied
to image sensor line of sight to no greater than 0.62 arcsec, 3-sigma
per axis for frequencies greater than 1.0 Hz during imaging.

The LDCM Observatory pointing reference shall be with respect to the
Local Vertical / Local Horizontal reference frame.

The LDCM Observatory shall have a pointing control error less than 108
arcsec, 3-sigma per axis during imaging periods.

The LDCM Observatory shall have a pointing rate error less than 30
arcsec / sec, 3-sigma per axis during imaging periods.

The LDCM Observatory shall be capable of continuous operations in the
normal Earth pointing attitude for a minimum of 16 days.

## Maneuvers

The LDCM Observatory shall be capable of performing drag makeup
maneuvers.

The LDCM Observatory shall be capable of performing inclination change
maneuvers.

The LDCM Observatory shall be capable of performing retrograde
propulsion maneuver during the design life of the observatory and still
be able to meet imaging specifications within 1 \[TBC\] day.

The LDCM Observatory shall be capable of performing calibration
maneuvers to any inertial attitude within 30 minutes \[TBC\].

Rationale: To complete a lunar observation while in total eclipse of the
sun.

The LDCM Observatory shall be nadir-pointing within 180 seconds \[TBC\]
before and 180 seconds \[TBC\] after completing an off-nadir image
interval.

The LDCM Observatory shall achieve attitude stability requirements
within 120 seconds \[TBC\] of completing a maneuver.

## Ephemeris

The LDCM Observatory shall generate on-board ephemeris.

The LDCM Observatory shall use the International Atomic Time (TAI) time
as the observatory time reference.

The LDCM Observatory shall provide the orbital position and velocity in
the WGS84 Earth Centered Earth Fixed coordinate frame.

The LDCM Observatory shall provide an estimate of position and velocity
time-tagged to an accuracy of 200.0 microseconds \[TBC\], 3-sigma or
better.

The LDCM Observatory shall provide orbital position accurate to 30 m
\[TBC\] radial, 30 m \[TBC\] in-track, and 30 m \[TBC\] cross-track --
all values are 3-sigma.

The LDCM Observatory shall provide orbital velocity accurate to 0.06
m/sec \[TBC\] radial, 0.06 m/sec \[TBC\] in-track, and 0.06 m/sec
\[TBC\] cross track -- all values are 3-sigma.

The LDCM Observatory shall provide the orbital position and velocity
once per second \[TBC\].

The LDCM Observatory shall be capable of receiving an ephemeris update
command.

# Propulsion System

The LDCM Observatory propulsion consumables shall provide for 10 years
of operational life time at the operational orbit, assuming a 3 sigma
worst case mission environment (atmospheric density, thruster
misalignment, thruster efficiency, pressurant loading).

The LDCM Observatory propulsion system shall make the fill and drain
valve accessible at all times, even while mated to the Launch Vehicle.

# Launch Services

## Payload Processing Facility Compatibility

## Launch Site Support

# SMRD Traceability

# SSRD Verification Cross Reference Matrix (VCRM)