Enclosure 6 -Government Owned Direct To Earth (G-DTE) Services Users Guide (UG) Baseline.pdf

457-UG-DTES Effective Date: February 5, 2025 Expiration Date: February 5, 2030 i

NSN Government Owned Direct To Earth (G-DTE) Services User’s

Guide (UG) Signature/Approval Page

Approved by:

Goddard Space Flight Center Greenbelt, Maryland 20771 iii

Preface

The Near Earth Network (NEN) services are now referred to as Direct To Earth (DTE) services within the Near Space Network. Control of the former NEN assets has been distributed across the Advanced Communications Capabilities for Exploration and Science Systems (ACCESS) Project and the Near Space Network (NSN) Project. ACCESS was assigned responsibility for all Government Owned, Contractor Operated (GOCO) ground stations referred to as G-DTE throughout this document.

The Near Space Network (NSN) implements a well-established process to capture and assess user requirements and determine how to best support those requirements. The process is collaborative and relies on continuous communication and exchange of information between the customer and NSN throughout all phases of mission development. It is the responsibility of the Code 457 NSN Advanced Planning team together with the NSN/Mission Services Integration (MSI) team to facilitate this process for the NSN (457-GUIDE-0001_DCN001).

As technology pushes the frontiers of science and discovery, the ACCESS Project is developing new capabilities to extend the reach of ground-based antenna systems beyond near earth orbit customers. ACCESS anticipates that future missions will have diversified telemetry, tracking, and commanding requirements, including high data rates utilizing complex waveforms, and ACCESS is developing capabilities to provide long duration contacts for medium earth orbit and earth/sun Lagrange point observatories. While the G-DTE currently supports high-rate S-band missions at Lagrange point 1 (L1), ACCESS is also developing Ka-band and X-band telemetry services for the L1 and Lagrange point 2 (L2) orbit regimes.

In addition to these new capabilities, ACCESS is exploring technologies that will increase the NSN’s services portfolio. These system enhancements could improve signal margins and allow much higher space to ground data transfer rates. To further enable low earth orbiters, ACCESS is exploring the use of variable telemetry rate and energy efficient modulation and coding technology where the spacecraft and ground station synchronously vary the downlink rate to the highest rate that communications conditions permit.

An Antenna System (AS) includes the antennas, radomes, associated S-band, X-band, and Ka-band signal processing electronics, monitor and control components, timing components, and required facilities infrastructure. Historically, AS and ground stations have been used interchangeably, whereas, sometimes a ground station can also mean a group of AS’ on a site. In this document, AS and sites are both referred to as stations.

As space-based earth sensing technology has increased, so has the demand for ground-based antenna services for low earth, polar orbiting missions. ACCESS developed new ground-based antenna systems, in new locations that increased the availability of S- and X-band services and include new Ka-band services, as well. The Ka-band systems support up to 4 Giga symbol per second, dual polarization telemetry services.

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The G-DTE continues to develop new capabilities that will provide cost effective methods for delivery of large volumes of data to satellite operators via the network of NASA and commercial antenna systems located around the world. NSN Management encourages feedback from the science community to ensure that the capabilities of the G-DTE keep pace with the needs of the missions. As the reader reviews this document, please be mindful that G-DTE capabilities can evolve faster than this document can be updated.

Questions or comments regarding current or future capabilities should be directed to the Goddard Space Flight Center, NSN Project, NSN/MSI team.

This Users’ Guide describes the current and near-term capabilities of the ACCESS ground stations and provides sufficient data for projects to begin interfacing with G-DTE assets.

This document is under the configuration control of the NSN Project Configuration Control Board (CCB). Changes to this document will be made by Documentation Change Notice (DCN) or by complete revision. Proposed changes to this document must be submitted along with supportive material justifying the proposed change.

This document may be downloaded from the Exploration and Space Communications (ESC) Projects Division, NSN Project library at https://ipdtdms.gsfc.nasa.gov/. If you do not have direct access to the library, you may obtain the document from the Code 457 Configuration Management Office (CMO).

Questions and proposed changes concerning this document shall be addressed to:

NSN Project Configuration Management Office, Code 457 NSN Mission Systems Engineer Goddard Space Flight Center Greenbelt, Maryland 20771 cc: DTE Wallops Manager David.R.Mccormick@nasa.gov v

Change History Log

Revision Effective Date Description of Changes

Original TBD 457-UG-DTES, ESC-CCR-0680

This document supersedes all previous issues of the Near Earth Network Users’ Guide, 453-NENUG (formerly 453-GNUG). Destroy all previously issued copies.

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Contents

Preface .......................................................................................................................... iii

Section 1. Introduction .............................................................................................. 1-1

Purpose .................................................................................................. 1-1 Scope...................................................................................................... 1-1 Reference Documents ............................................................................ 1-1 Related Internet Web Sites ..................................................................... 1-3

Section 2. DTE Overview ........................................................................................... 2-1

General ................................................................................................... 2-1 DTE Ground Stations Overview .................. Error! Bookmark not defined.

DTE Customer Services Overview ......................................................... 2-7

Obtaining DTE Services ........................................................... 2-7 Network Loading Analysis ........................................................ 2-8 RF Link Margin and Coverage Analysis ................................... 2-8 Compatibility Testing................................................................ 2-8 DTE Interface Testing and Operational Simulations ................ 2-8 Orbit Analysis ........................................................................... 2-8

DTE Outage and Service Loss Notification ............................................. 2-9 Network Advisory Messages .................................................... 2-9 Status Messages ..................................................................... 2-9 Significant Event Reporting ...................................................... 2-9 Comprehensive Discrepancy System .................................... 2-10

Status Server Overview ........................................................................ 2-10 Selection of an Active Track from the Entrance Page ............ 2-13 Selection of a VC Tab ............................................................ 2-14 Selection of the Report Tab ................................................... 2-15

Tracking Data Formats and Reduction Algorithms ............................... 2-16 General .................................................................................. 2-16

4800-Bit Block Encapsulated in IP Packets .......................................... 2-20 Network Header ..................................................................... 2-20 User Header .......................................................................... 2-21 Time ....................................................................................... 2-21 Data Field .............................................................................. 2-21 Block Error Control Field ........................................................ 2-22

Section 3. Wallops Flight Facility Ground Station ................................................... 3-1

General ................................................................................................... 3-1 Wallops WG1, 11.28-m, S- and X-band .................................................. 3-1

S-band Command .................................................................... 3-1 viii

S-band Telemetry .................................................................... 3-1 X-band Telemetry .................................................................... 3-3 Tracking Services .................................................................... 3-3 Baseband Data Interfaces ....................................................... 3-4

Wallops WG2 – 5-m, S-band .................................................................. 3-5 General .................................................................................... 3-5 S-band Command .................................................................... 3-5 S-band Telemetry .................................................................... 3-5 Baseband Data Interfaces ....................................................... 3-7

Wallops WG3/WG4 VHF Antenna Systems ............................................ 3-7 VHF-1 Voice Antenna Systems, WG3 ..................................... 3-8 VHF-2 Voice Antenna Systems, WG4 ..................................... 3-8 Baseband Voice Interfaces ...................................................... 3-9

Wallops WG5, 11.3m, S-, X- and Ka-band ........................................... 3-10 General .................................................................................. 3-10 S-band Command .................................................................. 3-11 S-band Telemetry .................................................................. 3-11 X-band Telemetry .................................................................. 3-12 Ka-band Telemetry ................................................................ 3-13 Tracking Services .................................................................. 3-13 Baseband Data Interfaces ..................................................... 3-14

Section 4. McMurdo Ground Station (10m) .............................................................. 4-1

General ................................................................................................... 4-1 S-band Command ................................................................................... 4-1 S-band Telemetry ................................................................................... 4-2 X-band Telemetry ................................................................................... 4-2 Baseband Data Interfaces ...................................................................... 4-3

Section 5. Alaska Satellite Facility ............................................................................ 5-1

General ................................................................................................... 5-1 ASF AS1, 11.28-meter ............................................................................ 5-1

S-band Command .................................................................... 5-1 S-band Telemetry .................................................................... 5-1 X-band Telemetry .................................................................... 5-1 Tracking Services .................................................................... 5-4 Baseband Data Interfaces ....................................................... 5-4

ASF AS2, 9.1- meter ............................................................................... 5-5 S-band Command .................................................................... 5-5 S-band Telemetry .................................................................... 5-5 X-band Telemetry .................................................................... 5-5 Tracking Services .................................................................... 5-8 Baseband Data Interfaces ....................................................... 5-8

ASF AS3, 11.3-meter .............................................................................. 5-9 ix

S-band Command .................................................................... 5-9 S-band Telemetry .................................................................... 5-9 X-band Telemetry .................................................................... 5-9 Tracking Services .................................................................. 5-12 Baseband Data Interfaces ..................................................... 5-12

ASF AS4, 11.3-meter ............................................................................ 5-13 S-band Command .................................................................. 5-13 S-band Telemetry .................................................................. 5-13 X-band Telemetry .................................................................. 5-13 Ka-band Telemetry ................................................................ 5-13 Tracking Services ........................ Error! Bookmark not defined.

Tracking Services .................................................................. 5-16

Section 6. Launch Communications Segment (LCS) Stations (6.1m) ................... 6-1

General ................................................................................................... 6-1 Kennedy Uplink Station (KUS) ................................................................ 6-1

S-band Command ................................................................... 6-2 S-band Telemetry ................................................................... 6-3 Tracking Services .................................................................... 6-4

Ponce deLeon (PDL) (6.1m) ................................................................... 6-4 S-band Command .................................................................... 6-5 S-band Telemetry .................................................................... 6-6 Tracking Services .................................................................... 6-7

LCS Baseband Data Interfaces .............................................................. 6-7 LCS Best Frame Select Capability .......................................................... 6-8 LCS Station Status ................................................................................. 6-8

Section 7. White Sands Complex Ground Stations ................................................. 7-1

General ................................................................................................... 7-1 WS1 (18.3) .............................................................................................. 7-1

WS1 S-band Command ........................................................... 7-2 WS1 S-band Telemetry ............................................................ 7-2 WS1 Ka-band Telemetry .......................................................... 7-4 WS1 Tracking Services ............................................................ 7-5 WS1 Baseband Data Interfaces ............................................... 7-6

Section 8. Scheduling ................................................................................................ 8-1

Section 9. Baseband Data Interfaces and Storage .................................................. 9-1

Introduction ............................................................................................. 9-1 IONet Network ........................................................................................ 9-1

Open and Closed IONet ........................................................... 9-1 TCP/IP and UDP/IP ................................................................. 9-1 Packets and Layers ................................................................. 9-1 x

UDP ......................................................................................... 9-4 PTP Encapsulation .................................................................. 9-4 Command Data (Real-Time) .................................................... 9-4 S-band Telemetry Data ............................................................ 9-4

Serial Clock and Data ............................................................................. 9-4 Standard Autonomous File Server .......................................................... 9-5

SAFS Architecture and Operation ............................................ 9-5 SAFS Hardware and Software ................................................. 9-6 SAFS Distribution Methods ...................................................... 9-8 SAFS Project Parameters (Current Mission Set) ..................... 9-9 SAFS File Naming Convention ................................................ 9-9 Telemetry Processor to SAFS Interface Requirements ......... 9-10 SAFS Transfer Protocols ....................................................... 9-14 SAFS Data Archive ................................................................ 9-14

DAPHNE+ ( Replaced NEN Gateway) .................................................. 9-14 Introduction ............................................................................ 9-14 Operations Concept ............................................................... 9-14 Cloud Architecture ....................... Error! Bookmark not defined.

Data Flows and Interfaces ..................................................... 9-16 External Interfaces ................................................................. 9-16

Section 10. Frequency Management ........................................................................ 9-1

Introduction ........................................................................................... 10-1 Determining Frequency Spectrum Requirements ................................. 10-1

International Frequency Spectrum Allocations ....................... 10-1 DSN Protection ...................................................................... 10-6 Protection of Terrestrial Operations and Ground Receivers .. 10-8 ITU-R and SFCG Limits on PFD in X-band for EESS Downlinks

............................................................................................... 10-9 Obtaining Frequency Spectrum Authorization ...................................... 10-9

Regulations, Policies, and Instructions .................................. 10-9 GSFC Spectrum Management Office .................................... 10-9 Flight Project Responsibilities .............................................. 10-10

Bandwidth (BW) Requirements ........................................................... 10-10 Bandwidth Requirements in the 2200-2290 MHz Band ....... 10-10 Bandwidth Requirements in the 8450-8500 MHz Band ....... 10-10

Unwanted Emission Masks ................................................................. 10-10 SFCG Emission Mask .......................................................... 10-12

Section 11. Link Budget Parameters ...................................................................... 11-1

General ................................................................................................. 11-1 S-band Atmospheric and Rain Attenuation Constants .......................... 11-1 X-band Atmospheric and Rain Attenuation Constants .......................... 11-1 Ka-band Atmospheric and Rain Attenuation Constants ........................ 11-1 xi

Ground Station Line-Of-Sight Coverage ............................................... 11-2

Appendix A. 8PSK Strategy ...................................................................................... A-1

Appendix B. Downlink OQPSK Configuration Examples ...................................... B-1

Appendix C. Units of Measurement ......................................................................... C-1

Abbreviations and Acronyms

List of Figures

Figure 2-1. DTE Customers, Mission Examples and Bands ........................................ 2-2 Figure 2-2. DTE Locations .......................................................................................... 2-3 Figure 2-3. Example Network Advisory Message ........................................................ 2-9 Figure 2-4. Example GNSTAT Message ..................................................................... 2-9 Figure 2-5. Significant Event Report Message .......................................................... 2-11 Figure 2-6. Example Discrepancy Report .................................................................. 2-12 Figure 2-7. RSS Entrance Screen ............................................................................. 2-13 Figure 2-8. Active Track Details ................................................................................ 2-14 Figure 2-9. Active Track VC Statistics ....................................................................... 2-15 Figure 2-10. Reports Tab for Viewing and Regenerating .......................................... 2-16 Figure 2-11. NASCOM 4800-Bit Block Format .......................................................... 2-21 Figure 3-1. WG1 Antenna ........................................................................................... 3-2 Figure 3-2. WG2 WFF Antenna ................................................................................... 3-6 Figure 3-3. WG3 and WG4 VHF Antennas ............................................................... 3-10 Figure 3-4. WG5 Antenna w/o Radome .................................................................... 3-11 Figure 4-1. McMurdo 10-m, MG1 Antenna .................................................................. 4-1 Figure 5-1. AS1 Antenna ............................................................................................. 5-2 Figure 5-2. AS2 Antenna ............................................................................................. 5-6 Figure 5-3. AS3 Antenna and Foundation (foreground) Existing AS1 (background) . 5-10 Figure 5-4. AS4 Antenna Inside Radome .................................................................. 5-14 Figure 6-1. Kennedy Uplink Station ............................................................................. 6-2 Figure 6-2. PDL Ground Station .................................................................................. 6-5 Figure 7-1. WS1 Antenna ............................................................................................ 7-2 Figure 9-1. NASCOM IP Network Layers .................................................................... 9-3 Figure 9-2. SAFS Architecture .................................................................................... 9-7 Figure 9-3. DAPHNE+ Architecture ............................................................................ 9-15 Figure 10-1. Spectral Output for NASA/GSFC Recommended S-band Filtering

Referenced to the Output of the Power Amplifier .................................... 10-7 Figure 10-2. Example of Unfiltered and Filtered 3 Mcps Code with DSN Protection

Criteria for S-band ................................................................................... 10-8 Figure 10-3. NTIA OOB Emission Mask for Earth and Space Stations ................... 10-11 xii

Figure B-1. Reed-Solomon OQPSK Downlink Configuration ....................................... B-1 Figure B-2. Rate ½ Convolutional OQPSK Downlink Configuration ............................. B-2 Figure B-3. Rate ½ Convolutional and Reed-Solomon OQPSK Downlink Configuration

.................................................................................................................. B-3 Figure B-4. Synchronous Data Frame Rate 7/8 LDPC OQPSK Downlink Configuration

.................................................................................................................. B-4 Figure B-5. Sliced (Asynchronous) Data Frame Rate 7/8 LDPC OQPSK Downlink

Configuration ............................................................................................. B-5

List of Tables

Table 2-1. DTE Overview ............................................................................................ 2-6 Table 2-2. Universal Tracking Data Format ............................................................... 2-17 Table 2-3. Universal Tracking Data Format (continued) ............................................ 2-18 Table 2-4. Universal Tracking Data Format (continued) ............................................ 2-19 Table 3-1. WG1 S-band Command Characteristics .................................................... 3-2 Table 3-2. WG1 S-band Telemetry Characteristics ..................................................... 3-3 Table 3-3. WG1 X-band Telemetry Characteristics ..................................................... 3-4 Table 3-4. WG1 Doppler Tracking Characteristics ...................................................... 3-4 Table 3-5. WG1 Ranging Characteristics .................................................................... 3-5 Table 3-6. WG2 – S-band Command Characteristics ................................................. 3-6 Table 3-7. WG2 – S-band Telemetry Characteristics .................................................. 3-7 Table 3-8. WFF VHF-1 Uplink Characteristics ............................................................ 3-8 Table 3-9. WFF VHF-1 Downlink Characteristics ........................................................ 3-8 Table 3-10. WFF VHF-2 Uplink Characteristics .......................................................... 3-9 Table 3-11. WFF VHF-2 Downlink Characteristics ...................................................... 3-9 Table 3-12. WG5 S-band Command Characteristics ................................................ 3-12 Table 3-13. WG5 S-band Telemetry Characteristics ................................................. 3-12 Table 3-14. WG5 X-band Telemetry Characteristics ................................................. 3-13 Table 3-15. WG5 Ka-band Telemetry Characteristics ................................................ 3-13 Table 3-16. WG5 Doppler Tracking Characteristics .................................................. 3-14 Table 3-17. WG5 Ranging Characteristics ................................................................ 3-14 Table 4-1. MG1 S-band Command Characteristics ..................................................... 4-2 Table 4-2. McMurdo 10-m MG1 S-band Telemetry Characteristics ............................ 4-2 Table 4-3. MG1 X-band Telemetry Characteristics ..................................................... 4-3 Table 5-1. AS1 S-band Command Characteristics ...................................................... 5-3 Table 5-2. AS1 S-band Telemetry Characteristics ...................................................... 5-3 Table 5-3. AS1 X-band Telemetry Characteristics ...................................................... 5-4 Table 5-4. AS1 Doppler Tracking Characteristics ....................................................... 5-5 Table 5-5. AS2 S-band Command Characteristics ...................................................... 5-7 Table 5-6. AS2 S-band Telemetry Characteristics ..................................................... 5-7 xiii

Table 5-7. AS2 X-band Telemetry Characteristics ...................................................... 5-8 Table 7-8. AS2 Doppler Tracking Characteristics ....................................................... 5-8 Table 5-9. AS3 S-band Command Characteristics .................................................... 5-10 Table 5-10. AS3 S-band Telemetry Characteristics .................................................. 5-11 Table 5-11. AS3 X-band Telemetry Characteristics .................................................. 5-12 Table 5-12. AS3 Doppler Tracking Characteristics ................................................... 5-12 Table 5-13. AS4 S-band Command Characteristics .................................................. 5-14 Table 5-14. AS4 S-band Telemetry Characteristics .................................................. 5-15 Table 5-15. AS4 X-band Telemetry Characteristics .................................................. 5-15 Table 5-16. AS4 Ka-band Telemetry Characteristics ................................................ 5-16 Table 5-17. AS4 Doppler Tracking Characteristics ................................................... 5-16 Table 6-1. KUS S-band Command Characteristics ..................................................... 6-2 Table 6-2. KUS S-band Telemetry Characteristics ...................................................... 6-3 Table 6-3. PDL S-band Command Characteristics ..................................................... 6-5 Table 6-4. PDL S-band Telemetry Characteristics ...................................................... 6-6 Table 7-1. WS1 S-band Command Characteristics ..................................................... 7-3 Table 7-2. WS1 S-band Telemetry Characteristics ..................................................... 7-4 Table 7-3. WS1 Ka-band Telemetry Characteristics ................................................... 7-4 Table 7-4. WS1 Doppler Tracking Characteristics ...................................................... 7-5 Table 7-5. WS1 Range Tracking Characteristics ........................................................ 7-6 Table 9-1. Baseband Data Interface Options .............................................................. 9-2 Table 9-2. SAFS Network Distributions using FastCopy, SFTP, SCP ......................... 9-6 Table 10-1. United States and ITU-R Table of Frequency Allocations ...................... 10-2 Table 10-2. DTE Primary Frequency Allocations ...................................................... 10-6 Table 10-3. Interference Protection Criteria for DSN ................................................. 10-6 Table 10-4. PFD Limits Applicable to Typical DTE Bands ......................................... 10-9 Table 11-1. S-band Rain Attenuation Constants (5° Elevation Angle) [2.3 GHz] ...... 11-2 Table 11-2. X-band Rain Attenuation Constants (5° and 10° Elevation Angle) [8.5

GHz] ........................................................................................................ 11-2 Table 11-3. Ka-band Rain Attenuation Constants (5° and 10° Elevation Angle) [27 GHz]

................................................................................................................ 11-2

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Section 1. Introduction

Purpose The purpose of this document is to describe the technical capabilities of the GOCO ground stations that provide mission communications and tracking services as part of the National Aeronautics and Space Administration (NASA) Near Space Network (NSN).

This document provides sufficient information to enable project engineers and support personnel to begin interfacing with the NSN for G-DTE services. It defines G-DTE basic capabilities and identifies those parameters of particular interest to the user. For more detailed information, see the documents cited in Section 1.3.

G-DTE capabilities evolve based on user requirements and budget allocation. New projects can work with the NSN to use the information contained in this document to explore the G-DTE capabilities available, capturing the service performance assessment calculations in a User Mission’s Radio Frequency Interface Control Document (RFICD) or Mission Interface Description Document (MIDD).

Scope For the purpose of this document, the G-DTE consists of the GOCO ground stations located in Alaska, Antarctica, Virginia, New Mexico, and Florida. The G-DTE also includes support from the Near Space Operations Control Center (NSOCC) located at the Goddard Space Flight Center

(GSFC).

Commercial Service Provider assets that provide services to the NSN are not addressed in this document.

For each G-DTE ground station, this document provides the following information:

a. General characteristics, including geographic location, and transmit/receive capabilities.

b. Detailed performance characteristics.

c. User tracking capabilities.

d. Baseband data interfaces.

Reference Documents The following documents are referenced herein and/or provide background information:

a. Consultative Committee for Space Data Systems (CCSDS) 401.0-B-17, Radio Frequency and Modulation Systems, Part 1, Earth Stations, and Spacecraft, Blue Book, Issue 25

b. CCSDS 732.0-B-2 Cor. 1, AOS Space Data Link Protocol, Blue Book, Issue 2.

c. CCSDS 412.0-G-1, Radio Frequency and Modulation Systems-Spacecraft-Earth Station

Compatibility Test Procedures, Green Book, Issue 1. (Historical)

d. CCSDS 413.0-G-2, Bandwidth-Efficient Modulations: Summary of Definition, Implementation, and Performance, Green Book. Issue 2.

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e. CCSDS 131.0-B-5, Synchronization and Channel Coding, Blue Book, Issue 5.

f. NISN 001-001, NISN Services Document (NSD)

g. 540-028, Earth Observing System (EOS) Data and Information System (EOSDIS)

Backbone Network (EBNet) Operations Concept, Revision 1, GSFC.

h. NASA Policy Directive (NPD) 2570.5, NASA Electromagnetic Spectrum Management

Manual

i. NPD 8074.1, Management and Utilization of NASA's Space Communication and

Navigation Infrastructure.

j. 457-PG-8074.0.1, Near Space Network (NSN) Mission Service Integration Process

k. NASA Procedural Requirement (NPR) 2570.1, NASA Radio Frequency (RF) Spectrum

Management Manual.

l. NTIA Manual of Regulations & Procedures for Federal Radio Frequency Management

(Redbook), May 2014 Revision of the May 2013 Edition.

m. L7-ICD-40.1, Interface Control Document between Landsat 7 Mission Operations

Center (MOC) and the Landsat 7 Ground Network (LGN).

n. 5-1R5, Space Frequency Coordination Group (SFCG) Recommendations regarding

Efficient Spectrum Utilization for Space-To-Earth Links including SFCG Recommendations: SFCG 5-1R5, SFCG 14-1R1, SFCG 14-3R9, SFCG 21-2R4, SFCG 21-3R1, and others as applicable.

o. 450-OIP-WSC, White Sands Complex (WSC) Operations Interface Procedures (OIP).

p. CCSDS 912.1-B-3, Space Link Extension – Forward CLTU Service Specification, Blue

Book, Issue 3.

q. CCSDS 131.0-B-2, TM Synchronization and Channel Coding, Blue Book, Issue 2.

r. 453-UG-NEN Scheduling Rev 3, Users’ Guide for Near Earth Network Scheduling.

s. 700-DOC-007, NASA Communications Operations Procedures (NASCOP), Sanitized

Version. (Historical – replaced by NISN-SOP)

t. NISN-SOP-0002, NISN Standard Operating Procedures for Trouble Reporting, Activity

Scheduling, Mission Freeze, and Major Outage Notifications.

u. 450-CMFP-ESC, Configuration Management Freeze Policy for the Integrated Networks and Supporting Elements.

v. 457-TOOL-0008, Customer Questionnaire (new project questionnaire),

w. ITU-R Recommendations SA.1157, SA.1810 and P.618-8, International

Telecommunications Union Radio Regulations.

x. 453-ICD-IRIS/NENG, Near Earth Network (NEN) Interface Control Document (ICD)

Between the NEN Gateway (NENG) and the Interface Region Imaging Spectrograph (IRIS) Mission Operations Center (MOC)

y. NASA Directory of Station Locations, (NDOSL),

z. SCNS-NEN-UG-0005, Standard Autonomous File Server (SAFS) Users Guide

aa. 457-GUIDE-0001 DCN-001, Near Space Network User’s Guide

bb. ESC-DTE-HDBK-0002 (alternate number 459-UG-NEN Scheduling), Users' Guide for

Near Earth Network Scheduling

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Related Internet Web Sites Alaska Satellite Facility https://asf.alaska.edu/ Flight Dynamics Facility (FDF) Home Page https://fdf.gsfc.nasa.gov/

GSFC Home Page https://www.nasa.gov/goddard/ Exploration and Space Communications Project (ESC) Website https://esc.gsfc.nasa.gov/

International Space Station https://www.nasa.gov/international-space-station/ Johnson Space Center https://www.nasa.gov/johnson/ Kennedy Space Center https://www.nasa.gov/kennedy/ MSFC Home Page https://www.nasa.gov/marshall/ MSFC/Communications Service Office (CSO) Home Page https://cso.nasa.gov/

NASA DTE Stations https://www.nasa.gov/near-space-network/ NASA TV Schedule http://www.nasa.gov/multimedia/nasatv

NSN Customer Portal https://gs450portal.gsfc.nasa.gov/resources DTE Services Users’ Guide https://ipdtdms.gsfc.nasa.gov/ Near Space Network (NSN) https://esc.gsfc.nasa.gov/projects/NSN Technical Data Management System

(TDMS)

https://ipdtdms.gsfc.nasa.gov/

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Section 2. G-DTE Overview

General This section provides an overview of the G-DTE ground stations and customer services. The ground station overview provides general characteristics of G-DTE antenna tracking, telemetry, and command functions and capabilities. Further details on G-DTE ground stations are addressed on a station-by-station basis in the following chapters. The customer service overview describes G-DTE services and how to obtain G-DTE services. Further details on services are available from NSN (GSFC Code 457) 457-GUIDE-0001_DCN001 NSN User’s Guide.

To help a flight project quickly examine, evaluate, and compare capabilities of G-DTE ground station antennas, this section contains several tables summarizing antenna capabilities and specifications. Table 2-1 summarizes general antenna specifications. Please contact the Flight Dynamics Operations Director of the FDF to determine tracking certification for specific antennas.

The information in this document describes the typical performance of the ground stations.

Capabilities are often enhanced, and potential users are encouraged to discuss the mission requirements with NSN/MSI to ensure that requirements and capabilities are fully understood.

Antenna gain-to-noise temperature (G/T) in Table 2-1 is an estimate for 5º antenna elevation for S-band and 10º for X-band and Ka-band.

The NSN and ACCESS projects are customer-driven organizations that provide comprehensive communications services to space assets. The G-DTE provides telemetry, commanding, and tracking services for orbital missions and occasionally sub-orbital missions. The G-DTE customers may have Low-Earth Orbits (LEO), Geosynchronous (GEO) orbits, highly elliptical orbits, Lagrange orbits, Lunar orbits, Lunar surface and transfer, sub-orbital and launch trajectories, at multiple frequency bands through all phases of a mission’s lifetime. This diversity of missions is listed in Figure 2-1.

Figure 2-2 shows the locations of the ACCESS project’s G-DTE assets. G-DTE consists of both the Contractor and University Operated ground stations (located in Alaska, Antarctica, Virginia, New Mexico, and Florida). Please contact NSN/MSI for support from commercial stations.

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Figure 2-2. ACCESS G-DTE Assets Locations

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Additional information can be found at the following URL https://esc.gsfc.nasa.gov. The NSN customer portal can be found at https://gs450portal.gsfc.nasa.gov/resources.

All customers planning on conducting defense-oriented activities with the intent of using G-DTE assets at the MGS are responsible to be compliant with the Antarctic Treaty to obtain service from the SCaN and the antenna site.

Network Loading Analysis To ensure that sufficient network resources are available to meet commitments to current and future users, the NSN provides a representative to each customer flight project as early as possible during concept development to assist in the definition of customer flight project needs for NSN services. Typical information needed for analyses includes the projected requirements for the communications timeline, such as, frequency, modulation, coding, data rate, number of data channels, spacecraft (S/C) antenna masking, and contact constraints.

RF Link Margin and Coverage Analysis Information exchange between the customer mission and the NSN for the RF link margin and coverage analysis begins during the initial flight segment mission analysis phase and continues until firm coverage requirements and flight segment designs are finalized in the mission execution phase. RF link analysis is used to help achieve a flight segment telecommunications design which is compatible with the DTE and will achieve the desired level of performance. Design deficiencies and possible trade-offs are defined during these analyses. The results of the RF analysis are used early in the mission analysis phase to aid in the development of the RFICD/MIDD, which is a controlling input to the flight segment telecommunications specifications. It should be noted that the RFICD/MIDD is under NASAs control via the NSNs CCB and is a bi-lateral document signed by NSN, the mission and ACCESS, if DTE services are required.

Compatibility Testing RF compatibility testing is performed after the flight radio is integrated into the spacecraft. Risk mitigation testing on the prototype model may be performed earlier to reduce risk, but final compatibility is performed on the flight model. Compatibility tests are normally rerun following resolution of significant problems encountered during the original test or following post-test flight segment design modification. Results of these tests are formally published in the mission specific Compatibility Test Report. Satisfactory completion of this testing and certification is required to meet the NASA readiness-for-launch criteria.

NSN DTE Interface Testing and Operational Simulations Mutually agreed upon end-to-end tests are conducted to validate all telecommunications system functions, as defined in the applicable Interface Control Documents (ICD) and Customer Integration and Test Plans. In addition, operational exercises (i.e., simulations, data flows) are conducted to ensure that operations will satisfy requirements and timelines.

Orbit Analysis Pre-launch orbital error analyses are performed by either FDF or the mission, depending upon mission requirements, to determine the frequency with which user spacecraft state vectors are needed to achieve the orbital accuracies required by the user flight project.

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DTE Outage and Service Loss Notification

Network Advisory Messages Network Advisory Messages (NAM) are issued as a result of scheduled outage periods that allows the scheduling office and projects to mitigate impacts. The target date for submission is no later than 7 days prior to the event. However, shorter notice emergency notifications are issued as needed. The distribution is controlled via an email “list serv” collective and is controlled by NSN management. See Figure 2-3.

Figure 2-3. Example Network Advisory Message

Status Messages Ground Network Status Messages (GNSTAT) are issued as a result of system or site failures and an e-mail is generated that details the anomaly (see example). The White Sands Operations Supervisor (OS) uses this information to contact management and ensure project personnel are informed of problems. The OS also assures that supports are moved to other sites via the scheduling office whenever possible. The email distribution is controlled by NSN management.

A closure status message is emailed once the issue is resolved. See Figure 2-4.

Figure 2-4. Example GNSTAT Message

Significant Event Reporting The Significant Event Reporting System is used to notify management and network users of site/system failures. An email is generated that details the anomaly, repair efforts, current/future

2-10 impacts, and closure information. The email distribution is controlled by NSN management. A closure message is issued once the anomaly is resolved. See Figure 2-5.

Comprehensive Discrepancy System The Comprehensive Discrepancy System is used for entering and managing operational, test and engineering discrepancies through disposition and resolution. The execution of this database system requires multiple levels and facets of responsibility to be efficient and effective.

Discrepancy reporting and resolution is initiated and resolved at the respective sites. Discrepancy closure however is administered through a focal point of administrative representatives to maintain control and consistency. A closure message is emailed once the issue is resolved. See Figure 2-6.

Root Cause / Corrective Action (RCCA) is performed anytime there is a service loss during launch and early orbit phase of a mission and anytime there is a catastrophic system operational failure with regard to the performance of a DTE Ground Station. RCCA will also be performed when Discrepancy Report review indicates a possible systemic operational issue, or when management deems it appropriate based on level or potential level of impact. Management serves as the ultimate authority in determining whether an RCCA is required.

Scheduling DTE Services The Direct To Earth Scheduling Office (DTESO) is responsible for scheduling of the DTE assets for Customer services.

The DTE scheduling function is performed at DTESO located at White Sands Complex (WSC) in New Mexico and provides 24x7 schedule management for DTE stations.

DTE scheduling supports GOCO and Commercial Service Link Provider (CSLP) missions.

GOCO DTE services are managed by ACCESS and CLP DTE services are managed by the NSN.

The Near Earth Network Scheduling System (NENSS) is also responsible for acceptance of Customer acquisition data from the Customer, FDF or TLE data retrieved from the Space-Track website, and automatically distributes this data to the sites. In some cases, DTESO personnel perform conversion of the data.

The NENSS forwards Customer acquisition data to the sites using the Secure File Transfer Protocol (SFTP).

For more information reference the Near Earth Network Scheduling User Guide, ESC-DTE- HDBK-0002 (alternate number 459-UG-NEN Scheduling).

Status Server Overview The G-DTE Remote Status Server (RSS) exists on the Open Internet Protocol Operational Network (IONet) at WGS. The RSS currently receives status data from McMurdo Ground Station (MG1), White Sands Complex (WS1), Wallops Ground Station (WG1/WG2/WG5), and Alaska Satellite Facility (AS1/AS2/AS3/AS4).

Data comes in from stations in a fixed field status stream via Transmission Control Protocol/Internet Protocol (TCP/IP) to both servers, one serves as the prime for reporting purposes.

Data is placed in a database for feeding a web page interface, custom reports, and a real time TCP/IP stream. Reports may be generated when the station goes from pre-pass into active track, or active track into post-pass. Reports can also be run on a time basis, such as a daily or weekly summary of operations. Reports may be distributed via email or Secure File Transfer Protocol (SFTP) to the customer.

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Customers may request and be granted access to the RSS web pages for real time monitoring of satellite tracks, as well as historical reports. For access to the RSS, contact the NSN Mission Manager (MM). When connecting into Status Server, the user is presented with an entrance page, see Figure 2-7. At any time, the user may return to the entrance page by clicking the NASA logo.

The top list shows all supports that are currently active for each station. If a station does not have an active support, the next support scheduled is displayed. The drop-down filters for spacecraft and station will affect the contents of the lower window. A user has permission to see only spacecraft with which they are involved.

Figure 2-5. Significant Event Report Message

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Figure 2-6. Example Discrepancy Report

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Figure 2-7. RSS Entrance Screen

Selection of an Active Track from the Entrance Page Clicking on one of the entries in the lower entrance screen window moves the user to the data page. See Figure 2-8. If the pass is active, the data will change in near real time. If the pass is in the past, the data presented is the last data set received from the station during the support. The right side of the screen presents Boolean data points. The color and text is configurable according to station and spacecraft.

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Figure 2-8. Active Track Details

Selection of a VC Tab The user may select the Virtual Channel (VC) tabs, one for each band, to view VC and telemetry statistics of the respective links. See Figure 2-9.

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Figure 2-9. Active Track VC Statistics

Selection of the Report Tab Reports are available from the Reports & Functions tab. See Figure 2-10. The reports are configurable by spacecraft and may be automatically generated at several status transition points in the event such as pre-pass to active, or active to post-pass. The reports may be regenerated at any time during the event, or after the event. The user may also regenerate the report from the alternate status server. Both status servers receive the same data, but only one will automatically deliver the report. Regeneration will redeliver the report regardless of the server used.

Delivery of reports is via SFTP, email, or copy and paste from the web server. Delivery of the report may be conditional, as in the case of a failure to meet certain criteria. The examples below of the dump report show a good dump and a bad dump, where the VC count indicates missing frames. The report is created for email distribution when the dump is bad.

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Figure 2-10. Reports Tab for Viewing and Regenerating

Tracking Data Formats and Reduction Algorithms

General This section describes the tracking data formats transmitted by the G-DTE stations. Applicable reduction algorithms are also given.

2.6.1.1 Universal Tracking Data Format (UTDF)

Universal Tracking Data Format (UTDF) data is transmitted post-pass or at a user specified time via SFTP, in files consisting of 75-byte UTDF frames. See Table 2-2 below.

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Table 2-2. Universal Tracking Data Format

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Table 2-3. Universal Tracking Data Format (continued)

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Table 2-4. Universal Tracking Data Format (continued)

2.6.1.2 Data Reduction Algorithms

The following processes are used to convert UTDF to the decimal form of…