NOAA GOES Ephemeris SOW.pdf

Ephemeris and Safety of Flight

Services for NOAA Operated Geostationary Satellites

2 September, 2021

Ephemeris and Safety of Flight (SOF) Services for GOES

TABLE OF CONTENTS

1. Introduction

1.1 Purpose of document

1.2 Background

1.3 Scope

2. Services

2.1 High Definition Ephemeris Service

2.2 Safety of Flight Service

2.2.1 Conjunction Screening

2.3 Data Exchange Mechanism

2.3.1 NOAA to Contractor

2.3.2 Contractor to NOAA

3. Assets Requiring Service

4. Security Requirements

1 Introduction

1.1 Purpose of Document

This document describes the NOAA requirement for high definition ephemeris data and safety of flight information that are needed to ensure the protection of the four NOAA owned and operated, on-orbit Geostationary satellites (GOES 14, 15, 16, and 17), and one subsequent follow-on mission (GOES 18) during the period of performance. These services are utilized to provide advanced decision support on objects that pose a close-approach risk to the geostationary satellite operations or impinge upon NOAA’s ability to carry out vital monitoring of the Earth’s environment in near real-time or monitoring solar weather that pose a hazard to power grids, communications and satellites that operate within different orbit regimes.

1.2 Background

The National Oceanic and Atmospheric Administration’s (NOAA) mission is “to understand and predict changes in climate, weather, oceans and coasts; to share that knowledge and information with others;

and, to conserve and manage coastal and marine ecosystems and resources as the Nation’s authoritative environmental intelligence agency.” The National Environmental Satellite, Data, and Information Service (NESDIS) office supports NOAA’s mission by providing timely access to global environmental data from satellite missions and other sources and is the leading, trusted source of environmental data for users around the world. The data and information products and services that NESDIS/OSPO provides are used by the National Weather Service (NWS), the commercial sector, and private citizens for a wide range of applications, including weather forecasting, environmental modeling, and securing life, property, and economic prosperity.

The NESDIS Office of Satellite and Product Operations (OSPO) operates a constellation of Low Earth Orbit (LEO) and Geostationary (GEO) satellites from the NOAA Satellite Operations Facility (NSOF) Satellite Operations Control Center (SOCC), and is also responsible for management of the Environmental Satellite Processing Center (ESPC); moreover, NOAA operates a deep space satellite from Lagrange Point 1.

Protection of these active on-orbit satellite assets are vital to ensure continuity of observations; therefore, services such as object ephemeris used for collision avoidance (CA), or determining proximity of an object that may interfere with effective operations of NOAA’s satellites are necessary.

1.3 Scope

The service scope covers a requirement for high definition ephemeris data and safety of flight information that may impact NOAA’s satellites operating in geostationary orbit or result in impinging upon the effective operations. This scope covers actively managed NOAA geostationary satellites and future geostationary satellites that are scheduled to replace on-orbit assets from the current time to the end of the period of performance.

“Space situational awareness” (SSA) is required to reduce the risk of NOAA assets colliding with other spacecraft or orbital debris. Space situational awareness is accomplished by accurately determining and predicting the locations of all of the NOAA assets in space and working with other institutions and agencies to compare these predictions with the locations of other nearby objects. When a close approach is identified and confirmed, appropriate action must be taken by one of the two objects in conflict in order to avoid a collision and/or satellite or payload failure which could result in profoundly negative impacts on domestic and international commerce, lives and property from gaps in critical meteorological data and products.

As a government agency, OSPO takes advantage of its free use of the services of the Air Force Joint Space Operations Center (JSpOC). The JSpOC service is comprehensive in its inclusion of orbital information of both spacecraft and space debris. However, the JSpOC determination of orbital information through real-time tracking has limitations in terms of its accuracy—it can misidentify satellites—and in providing the future orbit information needed for analysis and planning of spacecraft position maintenance needed for collision avoidance.

In several years of using commercial conjunction services for the geostationary fleet, OSPO has experienced several situations requiring close attention or active intervention that would NOT have been identified by the JSpOC service alone. The Government incurs costs each time the engineering and operations teams need to assemble (day or night) for collision-avoidance maneuvers. Often, last-minute orbit predictions show that a maneuver is not required. Improving collision prediction will save the Government time and cost by avoiding staging for maneuvers needlessly.

2 Services

2.1 High Definition Ephemeris Service

NOAA requires a service which provides the position, velocity and associated uncertainty of a space object (ephemeris) based on tracking data collected by a worldwide network of sensors and active ranging data (if available) collected by the satellite operator for Geostationary asset protection.

Ephemeris shall be delivered in two forms; a state vector representing the position and velocity of the spacecraft or object at an instance in time and an ephemeris file containing not less than two days of definitive ephemeris, and seven days of predicted ephemeris. The ephemeris shall have the position, velocity, and uncertainty of the space object. This future prediction shall include any maneuvers predicted to be performed by the spacecraft for the purposes of safety of flight screenings.

The high definition ephemeris service levels are described in Table 1:

Table 1 - High Definition Ephemeris Service Levels

# Service Description Units % of time goal met

Goal 24/7 Operations

Goal Daily Operations

1 Data Latency Time between observation and delivery of product to customer.

Hours 95% 8 hrs 12 hrs

2 Subscription Service Periodicity

Interval between ephemeris updates.

Hours 80% 8 hrs 24 hrs

3 Orbit re-acquisition

In the event data collection failure (due to power, internet, cloud etc.) upon collection after 24 hours, this is the time to re-compute a new orbit

Hours 90% 12 hrs

4 Measurement Accuracy

RMS distance error against calibration satellites for optical sensor network.

These include GNSS and SBAS satellites. (Optical only, excludes benefit of

RMS

meter s

80% 500 m customer provided tracking data).

5 Covariance The 3-sigma position uncertainty for non-active objects or active objects outside of maneuvers shall be less than:

The 3-sigma position uncertainty for active objects during maneuvers shall be less than:

The 3-sigma position uncertainty for active non-NOAA objects using low thrust (e.g. electric) propulsion during maneuvers shall be less than:

The 3-sigma position uncertainty for objects using canted radial/cross track thrusters shall be less than:

meters 90% 400 meters Radial

2500 meters In-track

2500 meters Cross-track

600 meters Radial

3200 meters In-track

3200 meters Cross-track

1200 meters Radial

5000 meters In-track

9000 meters Cross-track

3000 meters Radial

10000 meters In-track

9000 meters Cross-track

6 Format Standard STK ephemeris file format (.e)

N/A 100

N/A

6 Technical support

Telephone and email support for Contractor subscription services

Time of day

24/7 09:00-17:00 EDT/EST

2.2 Safety of Flight Service

Safety of Flight (SOF) is a service which conducts conjunction screening assessments of hard object proximity to the NOAA satellites, and provides warnings to NOAA according to specified threshold criteria. Table 2 summarizes the high level elements of the SOF service and further detailed descriptions are in the paragraphs below:

Table 2 – Safety of Flight Service Details

Service Detail

1 Regular screening frequency Every 24 hours. Results available within 1 hour of process completion.

2 Gross (coarse) screening threshold 50 km

3 User specified reporting criteria Combinations of absolute or componentized miss distances, maximum probability, or actual probability of collision (Pc) (when able to be computed).

4 Upload frequency of planned maneuvers Daily, with maneuvers first identified at least seven days in advance.

5 Alternate maneuver screening frequency On demand, not more than five per day. Screening results shall be provided within 4 hours of submission.

2.2.1 Conjunction Screening Requirements

2.2.1.1 Regular Screening Requirements

Conjunction Analysis (CA) computation runs shall be conducted regularly as specified in Table 2 for the subscribed-satellites against other satellites over a seven day moving analysis window:

● NOAA will provide and upload planned maneuvers for their satellites to be utilized for computation runs.

● The Contractor shall generate high definition ephemeris that are inclusive of the planned maneuvers for the subscribed satellites.

● The Contractor shall produce a coarse screening threshold that shall be employed as specified in Table 2.

● The Contractor shall generate conjunction reporting based on NOAA-selected conjunction criteria for each satellite, which can be a combination of absolute or by component miss distance at time of closest approach, maximum probability, or actual probability (when possible or available).

● The Contractor shall provide CA run outputs that use the high definition ephemeris for active satellites and debris objects, including inactive satellites.

o In the event that high definition ephemeris is not available, the CA run shall use alternate data available in the form of Joint Space Operations Center (JSpOC) provided Two-Line Element Sets (TLEs).

● The Contractor shall, for each reportable conjunction event, generate a Conjunction Data Message (CDM) that includes:

o Estimated Time of Closest Approach (TCA) o Total and by component (RTN - radial, along track, and cross track) miss distance at TCA o Maximum and actual Probability of Collision (Pc), when permitted or available from that orbit source o Spacecraft size data when available and populated (see “NOAA satellite physical characteristics” in Section 2.3.1.4)

● The Contractor shall deliver results upon completion of the CA screening as specified in Table 2.

2.2.1.2 Alternate Maneuver Screening

NOAA must have the ability to request screening of an alternate maneuver plan that is under consideration for a satellite against all other satellites or objects covering a seven day moving analysis period:

● NOAA shall be able to upload an alternate maneuver plan(s) for the subscribed satellites and initiate an alternate maneuver screening performed by the Contractor.

● The Contractor shall propagate the high definition ephemeris orbit including the alternate maneuver plan(s) for the subscribed satellites.

● The Contractor shall produce a coarse screening threshold that shall be employed as specified in Table 2.

● The Contractor shall generate conjunction reporting based on NOAA-selected conjunction criteria for each satellite, which can be a combination of absolute or by component miss distance at time of closest approach, maximum probability, or actual probability (when possible or available).

● The Contractor shall, in the alternate maneuver screening process, use high definition ephemeris for other active satellites and debris objects, including inactive satellites.

o In the event that high definition ephemeris is not available, the CA run will use alternate data available in the form of Two-Line Element Sets (TLEs) from the 18th Space Control Squadron in Vandenberg AFB, CA .

● The Contractor shall, for each reportable conjunction event, generate a CDM that includes:

o Estimated Time of Closest Approach (TCA) o Total and componentized miss distance at TCA o Maximum and actual probability of collision (when permitted by that orbit source) o Spacecraft size data when available and populated (see “NOAA satellite physical characteristics” Section 2.3.1.4) o Conjunction geometry and relative velocity (if known)

● The Contractor shall provide screening results as specified in Table 2.

2.3 Data Exchanges

2.3.1 NOAA to Contractor

To facilitate the exchange of services, the following data will be made available from NOAA to the awarded Contractor:

● Measurement data o Ground ranging(if available)

▪ Tracking data files

▪ Tracking station locations (latitude, longitude, altitude in WGS84 coordinates)

▪ Transponder bias estimate at the start of service.

▪ Initial estimates of any measurement biases and measurement white noise sigmas at the start of service.

o GNSS data (if available)

▪ GNSS navigation solution data

▪ GNSS pseudorange and phase data

● Planned maneuvers

● Ephemeris , as when requested by the COR

● Satellite physical characteristics

● Operator points of contact information

2.3.1.1 NOAA Sensor Definitions and Measurement Data

In support of initial operations, NOAA will work with the Contractor to provide sensor definitions and support initial calibration of the measurement data, interface definition, data converters, etc. This activity shall occur over a period no longer than three months to commence with initial operations or any time a new measurement sensor is added to the network.

Ground based tracking data provided shall meet the following requirements:

● Latency – The data shall be no more than four hours old in order to be included in timely conjunction screening.

● Periodicity – The data shall be provided daily. The minimum spacing between tracks shall be no less than 1 hour.

● Track Length – The track length shall be no less than 30 minutes and preferably 60 minutes (when controlled by the NOAA).

● Timing – Measurement data shall overlap local daytime hours (relative to the satellite subpoint on the Earth) for no less than 6 hours per day (when controlled by the NOAA).

GNSS tracking data provided shall meet the following requirements.

● Latency – The data shall be no more than 4 hours old.

● Periodicity – The data shall be provided daily.

The format of the measurement data shall be specified. Data shall be delivered via a secure FTP site.

The guidelines above should be considered minimum guidelines for meeting service level requirements.

2.3.1.2 NOAA Planned Maneuvers

NOAA will provide individual spacecraft configuration information. Operationally, NOAA will provide planned maneuver information for ten days into the future, including momentum unload events, in order for the Contractor to maintain the most authoritative and actionable SSA representation for the GOES satellites over the entire conjunction analysis time span.

Expected/Planned/Accomplished Maneuver information shall be provided. Minimally, this information must be comprised of:

● Burn center time

● Duration (or alternatively, burn start and stop time)

● Total delta v (m/s)

● Radial delta v (m/s)

● In-track delta v (m/s)

● Cross-track delta v (m/s)

2.3.1.3 NOAA-provided Ephemeris

When desired, NOAA may share their ephemerides with the Contractor to facilitate ephemeris comparisons.

2.3.1.4 NOAA Satellite Physical Characteristics

In order to permit the Contractor to properly assess performance, NOAA will provide the following physical characteristics for each of their satellites (to the maximum extent possible).

● Satellite size

● Satellite dry mass

● Satellite fuel mass

● Satellite thruster configuration, including pointing/cant angles

2.3.2 Contractor to NOAA

Contractor products shall be posted for NOAA to access, in a manner that is in compliance with current NOAA IT Security protocols, and are to remain readily available for up to 60 days.

2.3.2.1 High Definition Ephemeris Data Product

High definition ephemeris shall be distributed with each orbit update. These updates shall be performed regularly as defined in Table 2. The time period should consist of the orbit fit window not less than 2 days (definitive) and seven days (predicted), as described in Section 2.1. The ephemeris data shall be available for download in the format listed in the service definition. Individual files shall be available online for 60 days. Beyond 60 days, NOAA shall be able to retrieve the definitive ephemeris (as defined in the ICD) for any requested time period going back 12 months.

2.3.2.2 Safety of Flight Data Products

NOAA shall be provided with a set of all identified upcoming conjunctions for the subscribed satellites, that meet NOAA’s reporting criteria as specified in Table 2. A summary email shall be sent to NOAA that contains a table of current reportable conjunctions and includes the primary object name and the Space Surveillance Catalogue (SSC) number, and the secondary object name and the SSC number, as well as the time of closest approach (TCA), the minimum range at TCA and the probability of collision (Pc).

For every reportable conjunction, a Conjunction Data Message (CDM) shall be created. In addition, all CDMs shall be pushed to a secure FTPS site upon completion.

1. 3: Assets Requiring Service

Services will be required for the following Geostationary satellites:

Four NOAA owned and operated on-orbit geostationary satellites-

1) GOES 14

2) GOES 15

3) GOES 16

4) GOES 17

One subsequent follow-on mission (anticipated to launch in FY22)-

5) GOES 18

2. 4: Security Requirements

Products and services for exchange, refurbishing, or recycling of hardware must comply with NOAA IT Security Manual (ITSM) media sanitization requirements (MP-6) and NIST SP 800-88 Revision 1. Pre-configured hardware must comply with FAR 39.101(c) regulations for adherence to the NIST SP 800-70 Rev. 3 common security configuration checklist program (https://nvd.nist.gov/ncp/repository). New hardware must comply with FAR 4.1302 and FIPS PUB 201 [in accordance with Homeland Security Presidential Directive (HSPD-12)]. In addition, new hardware shall be capable of implementing Internet Protocol Version 6 (IPv6) requirements as required by FAR part 11.002 requirements which state that unless the agency Chief Information Officer waives the requirement, when acquiring information technology using Internet Protocol, the requirements documents must include reference to the appropriate technical capabilities defined in the USGv6 Profile (NIST Special Publication (SP) 500-267;

replaced by NIST SP 800-119 in Dec 2010) and the corresponding declarations of conformance defined in the USGv6 Test Program. To meet this requirement, each DOC acquisition of IP protocol technology must express requirements for IPv6 capabilities in terms of the USGv6 Profile (i.e., using the USGV6 Capabilities Checklist) and Contractors must be required to document their product’s support of the https://nvd.nist.gov/ncp/repository https://nvd.nist.gov/ncp/repository requested capabilities through the USGv6 test program (https://www-x.antd.nist.gov/usgv6/) using the USGv6 Suppliers Declaration of Conformity.

1.

https://www-x.antd.nist.gov/usgv6/