LNEXT-MGMT-DESC-0028 Landsat Next Mission Synopsis - January 2025 Update 01302025.pdf

Landsat Next Mission Synopsis

Update January 2025

Previous releases: Feb. and July 2023 with MOC RFI, Feb. 2024 with MOC studies

LNEXT-MGMT-DESC-0028, Revision January 2025 Update

Landsat Next, Code 426

LNext Reviewed – Not Subject to Export Control

1/30/2025

LNext Landsat Next

LNEXT-MGMT-DESC-0028, January 2025 Update

Signature/Approval Page

Prepared by:

Electronic Signature in TDMS Approval Date in TDMS Christopher Kilzer Date Landsat Next Systems Engineering NASA/GSFC, Code 599

Approved by:

Electronic Signature in TDMS Approval Date in TDMS Evan Webb Date Landsat Next Systems Manager NASA/GSFC, Code 599

Approved by:

Electronic Signature in TDMS Approval Date in TDMS Cagatay Aymergen Date Acting Landsat Next Project Manager/ Landsat Next Deputy Project Manager/ Acting Landsat Next Observatory Manager NASA/GSFC, Code 426

The information provided in this presentation is preliminary.

CM Foreword

This document is a Landsat Next 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 Landsat Next CM Office (CMO), along with supportive material justifying the proposed change. Changes to this document will be made by complete revision.

Questions or comments concerning this document should be addressed to:

NASA/Goddard Space Flight Center Landsat Next Project Office, Code 426 Attention: Configuration Management Office Greenbelt, Maryland 20771

LNEXT-MGMT-DESC-0028, January 2025 Update The information provided in this presentation is preliminary.

LNEXT-MGMT-DESC-0028, January 2025 Update

Change History

Revision Change Request Number Description of Change Release Date

May 2024 Update LNEXT-SCoRe-0019 Initial Release 05/30/2024

January 2025 Update LNEXT-SCoRe-0076 Update to Boilerplate, LRD, Simulators, LandIS details, and GS details

01/30/2025

The information provided in this presentation is preliminary.

• The LNext mission synopsis is a notional overview of the mission architecture and segment functions intended to provide high-level context for the objectives of the LNext mission.

• There are no requirements contained in this document, and it should be considered as reference material only.

• Information on requirements definition and compliance is provided in the LNext Spacecraft Statement of Work (SOW) and associated requirements documents.

Disclaimer – note to readers

The information provided in this presentation is preliminary. LNEXT-MGMT-DESC-0028, January 2025 Update

• Motivation for Landsat Next

• LNext Mission Background

• Sustainable Land Imaging (SLI) Program

• NASA/USGS Partnership

• Architecture & Mission Summary

• Observatory Functions

• Earth Imaging Collection

• Data Storage & Downlink

• Ground Segment Architecture

- Ground Network (GN)

- Mission Operations Center (MOC)

- Data Processing and Archive System (DPAS)

• Concept of Operations

- 18-day Design Reference Case (DRC-18)

- World Reference System-3 (WRS-3)

- Nominal Operations Scenarios (List Only)

• LNext Science Data Products

Topics

The information provided in this presentation is preliminary. LNEXT-MGMT-DESC-0028, January 2025 Update

• Landsat Next will continue the 50-year Landsat data record

- Landsat is the most widely used land remote sensing data source within Federal civil agencies

- OSTP-led assessment ranked Landsat 2nd highest in societal benefit (GPS was #1)

- Landsat has dominated science literature since inception, despite other open access EO sources such as MODIS

- Commercial data providers need Landsat’s rigorous calibration to build and improve their products

• Provides enhancements and new capabilities for the next generation of Landsat users

- Improved temporal revisit for monitoring dynamic land and water surfaces such as vegetation crop phenology, burn severity, water use and quality, coastal and wetland change, glacier and ice sheet dynamics.

- Improved spatial resolution for agricultural monitoring, ecological monitoring, urban studies, water resources management and other applications.

- Synergy with European Sentinel-2 bands allowing easier merging of information products.

- Improved spectral resolution to support new and evolving applications, including surface water quality, cryospheric science, geology, and agricultural applications including crop management and water consumption.

• Continues substantial economic benefits to the U.S. economy (>$2 billion/year)

- Landsat data are used to understand our dynamic planet and forms the backbone of the US Sustainable Land Imaging (SLI)

Program, returning an estimated $2 billion/year in benefits to users.

- Information from Landsat contributes to day-to-day decisions on land, water, and resource use that protect life and property;

safeguard the environment; advance science, technology and education; support climate resiliency; and grow the U.S.

economy.

Motivation for Landsat Next

The information provided in this presentation is preliminary. LNEXT-MGMT-DESC-0028, January 2025 Update

• The Landsat Next (LNext) mission is a joint mission being formulated, implemented, and operated by the National Aeronautics and Space Administration (NASA) and the Department of Interior (DOI) United States (U.S.) Geological Survey (USGS)

• LNext is a remote sensing satellite mission that will continue to acquire images of the Earth’s land surfaces, thereby continuing uninterrupted data to assist land managers and policy makers make informed decisions about natural resources and the environment

• This mission continues the more than five decades of global data collection and distribution provided by the Landsat series of satellites

• The mission is a component of the Sustainable Land Imaging (SLI) Program conducted jointly by NASA and USGS of the DOI

• Major LNext mission objectives include:

- Collect and archive moderate resolution, Visible to Shortwave Infrared (VSWIR) reflective and Thermal Infrared (TIR) emissive image data affording seasonal coverage of the global landmass for a continuous period of not less than five (5) years.

- Ensure that Landsat Next data are sufficiently consistent with data from the earlier Landsat missions in terms of relative acquisition geometry, calibration, coverage characteristics, spectral characteristics, output product quality, and data availability; all of which permit scientific studies, management of land cover and land use change, along with associated inland and coastal water resources, over multi-decadal periods.

- Ensure Landsat Next is responsive to documented emerging user needs and applications as characterized by periodic assessment, currently the User Needs for the SLI Program July 2018, Release 2.0, and identified by the operational requirements for acquisition, processing, archiving, and distribution of Earth’s image data to the United States Government and other users.

- Distribute Landsat Next data products to the public freely on a nondiscriminatory basis.

LNext Mission Background

The information provided in this presentation is preliminary. LNEXT-MGMT-DESC-0028, January 2025 Update

• NASA and USGS partner to provide independently funded joint-agency partnership

- Handover of mission to USGS for continued operations following completion of on-orbit commissioning

• NASA is responsible for space segment (instrument(s), Spacecraft), launch and on-orbit checkout

- Includes engineering support for mission operation readiness and support for on-orbit anomalies

Landsat Next NASA/USGS Partnership

Same Roles and Responsibilities as Landsat 9

• USGS will build and deliver the ground segment, operate the observatories after commissioning phase and provide data processing and distribution

- Systems engineering support during development

- Mission Operations Center (and backup)

- Ground Network

- Data processing and Archive System (DPAS)

- Provide MOC capabilities

- Provide Flight Operation Team

The information provided in this presentation is preliminary. LNEXT-MGMT-DESC-0028, January 2025 Update

Space SegmentNASA

• LandIS

• Spacecraft Buses

• Technical Authority (TA)

• Mission Protection

Launch Segment

• Launch Vehicle

USGS Ground Segment

• Mission Operations Center

• Ground Network

• Archive

• Science Products

• User Interface

• NASA Support Services

• Technical Authority

• IT Security

Mission Readiness

• GRTs

• MRTs

• Simulations

USGSNASA

• Flight Operations Readiness

• Pre-launch

• Commissioning

• Initial Operating Capability

• Phase E Operations

• Giver/Receiver Mgmt

• Landsat Next Mission is a constellation of three identical “triplets” observatories with equal orbit spacing

- Each observatory images the full swath required to achieve global coverage; three satellites used to improve revisit

• KDP-A Launch Readiness Date Range: Nov. 2030 – Sept. 2031

• The selected mission architecture is endorsed by Landsat user communities, including over a dozen Federal Agency users & Landsat Science Team

- This architecture improves all temporal, spectral, and spatial capabilities by approximately twofold, while maintaining historical Landsat data continuity

- This architecture satisfies emerging Landsat user needs with maximum resiliency

• With all three observatories operating, revisit is expected to be 6 days

• With two of three observatories operating, revisit is expected to be 9 days

Mission Overview

The information provided in this presentation is preliminary.

Parameter Value

Mission Category Category 2, Class B

Mission Life 5-years

Altitude 653 km Sun-synchronous

Inclination ~98 degrees

Orbital Separation 120 degrees

Mean Local Time Descending Node 10:10 AM +/- 5-min

Obs. Repeating Ground Track 18-day

Swath Width 164 km

Half Angle FOV 7.2 degrees

LNEXT-MGMT-DESC-0028, January 2025 Update

Mission Operational Concept Architecture

Diagram from Mission Architecture Rev. A

The information provided in this presentation is preliminary. LNEXT-MGMT-DESC-0028, January 2025 Update

• The Landsat Next Instrument Suite (LandIS), a whisk-broom Earth-imaging scanner with twenty-six spectral bands and onboard calibration sources

• Autonomous imaging based on an on-board land database and on-board ephemeris, including all nominal calibrations to maintain image quality

• Attitude Control System that provides an array of sensors and actuators to provide precise pointing knowledge to ensure image quality and provide necessary Cal/Val special maneuvers (lunar calibrations, off pointing)

• Propulsion system supports orbit-control capabilities including drag makeup, inclination, orbital debris avoidance, and constellation repositioning maneuvers, as well as controlled deorbit

- 10 years (minimum) of fuel

Space Segment - Observatory Highlights

The information provided in this presentation is preliminary.

LandIS

+X (Ram) velocity direction

Instrument Mounted S/C Components

+Z (nadir)

Boresight

Spacecraft Zenith S-

Band

Nadir S-Band

Nadir Ka-Band

Array (-Y)• Instrument will be mounted on anti-Ram

• Ka-Band downlink of mission data (imaging sensor data, along with instrument and spacecraft ancillary data)

• S-Band downlink of housekeeping data (both real-time telemetry and stored State of Health (SOH) concurrently)

• S-Band decryption of uplinked commands

• S-Band communications providing near full spherical omni-directional coverage

• LNext mission will utilize a Long-Term Acquisition Plan (LTAP) Collection Request (LCR) that will be stored on board each observatory of the constellation

- The LCR uses the World Reference System-3 (WRS-3) grid system to identify various types of LNext intervals/scenes such as land, coastal, or open water regions

- The LCR will nominally contain all sunlit land and a select number of nighttime images

• Each observatory will acquire all land scenes as defined in the LCR and all nominal calibrations

- Observatory is responsible for enforcing the solar elevation constraint (>5 degrees) for sunlit scenes

• Other special imaging requests, such as imaging of natural disasters or unique science research campaigns, and calibration collections are coordinated via a Special Collection Request (SCR)

• Each observatory will be able to collect off-nadir image data up to ~13.4 degrees on either side of the satellite ground track, referred to as “one path over” or “off-nadir” imaging

Earth Imaging Collection

Notional Global Refresh Rate for LNext Constellation

• Each Observatory will also be able to perform off-nadir calibrations, which include lunar imaging, solar calibrations, and other instrument or attitude sensor calibrations

• Daily collection rates vary by how much land is overflown– daily average data volume expected do be approx. 15Tb

LNEXT-MGMT-DESC-0028, January 2025 Update The information provided in this presentation is preliminary.

VSWIR

& TIR

Data

VSWIR

& TIR

Data

Mass Storage Device

---Delete order--->

Observatory Data Functional Block Diagrams

Ka-Band Downlink

CDH Subsystem

Ka-Band Output

Spacecraft

Interleave VTOC with

MDF

Read / Write MDF Data on Mass Storage

Device

S-Band Downlink

Ka

HGA

Instrument

HK/SOH

S-Band RF Output Read / Write

HK/SOH to Local Storage

SC HK/SOH

SC Ancillary DIR Data

Instrument Data Block

Observatory

HK/SOH

MDF

VTOC

LandIS

Collect, Buffer, and Compress (By Band/Type) image data, and add instrument ancillary

VSWIR

& TIR

Data

ACS Subsystem

GPSACS SensorsVTOC

ACS Actuators

Time, Pos., Vel, Raw GPS, etc.

Internal Cal.

Source

External Cal.

Source

Instrument Ancillary

8 6 2.5 2 1.5 0.5 4 3.5 3 1 File Age (hr)

Priority

N N N N N N N N N N PB Flag

Playback orderNon-Priority Priority

10 9.5 9 8.5 8 7.5 … 0.5 0 File Age (hr)

Priority

N Y N Y N Y N N N PB Flag

The information provided in this presentation is preliminary. LNEXT-MGMT-DESC-0028, January 2025 Update

Notional Image Data Processing & SC Formatting

The information provided in this presentation is preliminary. LNEXT-MGMT-DESC-0028, January 2025 Update

• Each array element is n pixels as required per band

• Each Pixel is 16 bits

Organize Image Data by Band for optimal compression

Add Metadata & Mission Data Compression Header, CSUM data & End of File Marker to the compressed image data

Collect 5 sec of Image Data (i.e., n Scanlines)

Scanline #1 Scanline #2 Scanline #3 Scanline #4 Scanline #5

Scanline #n-2 Scanline #n-1 Scanline #n

Compress Image Data

Encapsulated Mission Data File

Science data acquisition times of < 5 seconds per file ensures file sizes <4GB and CCSDS encapsulation compatibility

Mission Data File

Encapsulated VTOC via CCSDS 133.1-B3

VTOC

Packet Encapsulation via

CCSDS 133.1-B3

CCSDS AOS Formatting (732.0-B-4)

CCSDS LDPC with SMTF (131.0-B-4) CCSDS Modulation (401.0-B-32)

Science Data (Compressed Imaging Sensor & Ancillary Data) Block Stream

Metadata (Block Header):

Includes Obs ID, size, time of acquisition, etc..

Start of Compressed Data

Block Pattern

End of File Marker

End of Compression File Marker

Instrument Ancillary Data CSUM over the instrument compressed image data

File Header: Includes File ID, time of acquisition, priority designation, Obs Identifier, etc…SC Ancillary

Instrument AncillaryFile Checksum

EOF

Instrument Ancillary Packaged by LandIS

File Checksum Added to Instrument Data Block Stream

(Encapsulated VTOC is sent as a separate file)

Note: 1) N as denoted in the Science Instrument(s) green box above can be chosen to reduce effective Max data rate between blocks to a more manageable data rate

2) Command IF to LandIS, uplink, detailed S-band functions, etc… are not provided in this diagram.

FPA - ROIC

• A mission data file contains an instrument data block and 30 seconds of spacecraft ancillary data, with a maximum size of 3.5GB

• A nominal science instrument data block is one, 7.5 second, scan of compressed LandIS data (compressed by band) and uncompressed instrument ancillary data

- A 7.5 second scan is composed of approx. 5 seconds of Earth imaging and 2.5 seconds of calibration and setup

• For diagnostic purposes, an instrument data block can also consist of diagnostic information and uncompressed data, as requested

• 30s of spacecraft ancillary is at least 12s pre-image and at least 10s post-image

- 8s (minimum) of ancillary is required for science processing and to initiate the position model for an interval

- 30s, with pre- and post- image ancillary, enables the ground system continue processing through a lost file during an interval

• LandIS will utilize the CCSDS 123.0-B-2 compression engine

• Compression is tunable by band and/or data type – each band and each calibration data type can be compressed utilizing different compression parameters

Mission Data File Description

The information provided in this presentation is preliminary. LNEXT-MGMT-DESC-0028, January 2025 Update

• The spacecraft mass storage system will be sized to ensure 8Tb of mission data is available for downlink

- All files, except those marked as “protected”, can be overwritten whether they have been played back or not.

- Overwriting, or deleting in advance of writing, will be done based on time (age of file) and storage need (only overwrite when memory is needed for new data recording), and will not be based on priority or playback status.

- The spacecraft will overwrite oldest data first, to enable the maximum time for downlink and retransmission.

• Ground has ability to mark a file as "protected", which will only be used in contingency scenarios, but will preserve the file from being overwritten. This will only be used for diagnostics or anomaly investigations, and not routinely.

• Mission data on each observatory will be managed by autonomous capabilities of the on-board flight software, as well as directed commands from the Ground as needed to handle non-nominal operational scenarios.

- Mission data files are downlinked by Priority then by Time – priority first, then non-priority, in age order

- Any change in a file status (new file recorded, played back file marked not played back, file played back, etc.)

will trigger a re-order of the downlink order – this ensures Priority files recorded or changed during a contact are downlinked “next”

Mission Data Storage & Downlink

The information provided in this presentation is preliminary. LNEXT-MGMT-DESC-0028, January 2025 Update

• Each downlinked Mission Data file will be interleaved with an updated Volume Table of Contents (VTOC) with flags for Playback Status ("Not Played Back" or "Played Back"), priority, and protection so the Ground System can determine the latest status of every file on the Mass Storage Device (MSD)

- The VTOC is updated whenever a file is created, downlinked, or its state is changed by command

- The Ground can select mission data to be re-downlinked by commanding a change to the “not played back” flag per file

• CCSDS Virtual Channels (VCs) will be used to separate priority and routine (non-priority) mission data files

- VC for priority data provides an approximate analogue to the Landsat 8 and 9 real time downlink capability for selected areas

• However, there is no capability to transmit priority data only

- Allows for simplified identification of priority data on the ground for expedited delivery and processing

• Mission data files transmitted to the ground are unique and will not be re-transmitted unless by ground command

• Ground schedules communications link configurations and contact and downlink start/stop times

Mission Data Storage & Downlink

The information provided in this presentation is preliminary. LNEXT-MGMT-DESC-0028, January 2025 Update

Observatory Communication Approach

Ground System Spacecraft (per observatory)

• Plans and schedules ground resources

• Builds and Loads contact schedules to observatories

• Autonomously manages ground resources

• Receives real-time SOH and stored SOH via S-Band

• Receives Mission Data via Ka-Band and manages retransmit needs

• Sends retransmit commands via S-Band to S/C

• Converts contact schedule to commands

• Manages antenna pointing based on contact schedule and knowledge of Ground Stations

• Executes pre/during/post contact commanding

• Executes ground received commands during S-Band contacts

• S-Band and Ka-Band contacts will be highly automated to support lights out operations

- Contacts can be S-Band only, Ka-Band only, or both

- All contacts are planned and scheduled by the ground, and the confirmed contact schedule is loaded to each observatory on a periodic basis (approx. weekly, TBD)

- The ground can replace the onboard schedule, as well as add or delete individual contacts, as needed

S and Ka-Band

S-Band Only

Ka-Band OnlyContact Flow

The information provided in this presentation is preliminary. LNEXT-MGMT-DESC-0028, January 2025 Update

• Fully autonomous nominal WRS-3 Scene (Path/Row) imaging

- Built from the LCR, which will be updated by the ground infrequently (approx. 1-2 times per year)

- Special collection requests (SCRs) replace the baseline LCR scenes, until removed by the ground

• Includes capability to do one path over (either direction) off-nadir acquisitions

- LCR/SCR based imaging can continue indefinitely, without ground interaction, unless halted or directed to change by the ground or onboard Fault Management

- Autonomous imaging includes all pre and post imaging configuration (TBD based on LandIS), all nominal path/row based calibrations (TBD based on LandIS), and requested night imaging

• Special Command Requests (SpCRs) are ground-directed (not autonomously generated by the Spacecraft), individual time based requests, for special activities outside of nominal scene based imaging

- Includes spacecraft or instrument activities such as propulsive maneuvers, diagnostic activities, or maintenance activities

- Includes infrequent calibration activities such as lunar calibrations or bi-annual collections

- SpCRs can be interrupting or non-interrupting (able to be concurrent with imaging)

• Important Integrated Onboard Timeline (IOT) generation highlights:

- SpCRs take precedence over any SCR or LCR based activity.

- SpCRs are based on time, while SCRs and the LCR are based on Path/Row.

- Interruption logic expands interrupt “cutout” duration as necessary to ensure the safety of the observatory at all times (not leaving instrument or S/C in an unknown or unsafe state), and maximizes imaging whenever possible.

- If an SpCR is removed (ie. a collision avoidance burn is deleted), the LCR/SCR-based imaging fills back in (resumes, repopulates, etc.) as if it was not interrupted.

Observatory Imaging and Activity Automation

The information provided in this presentation is preliminary. LNEXT-MGMT-DESC-0028, January 2025 Update

SC Diag

Observatory Imaging / Special Request Management – in pictures

SCR SCR

Maneuver

LCR

Interrupt Duration

Integrated Onboard Timeline (IOT)

SCR

LCR Imaging Pre/Post image config (TBD)

Nominal Cals

Path/Row Imaging Plan

Lunar SC Diag ManeuverSpCR

Lunar

Interrupting ActivityNon-interrupting / Concurrent Activity

The information provided in this presentation is preliminary. LNEXT-MGMT-DESC-0028, January 2025 Update

Observatory Special Request Management – examples

SCR Off Nadir SCR

LCR

Interrupt Duration

As Executed

SCR

Imaging Pre/Post image config (TBD)

Interrupt logic attempts to maximize LCR imaging, but can’t so extends length of interrupt to end of interval

Interrupt logic attempts to maximize LCR imaging, and is able to restart imaging before interval end so trims the interval

Interrupt logic extends to include slews for Off Nadir pointing, and also trims affected intervals

SCRs and SpCRs take precedence over LCR imaging, “interrupting” the nominal LCR timeline

Slew

SCR SCR

Priority change only for existing imaging, so no pre and post image configuration changes needed

Imaging and Special Request Logic and Deconfliction Examples

The information provided in this presentation is preliminary. LNEXT-MGMT-DESC-0028, January 2025 Update

Observatory Special Command Request Management Example

SCR SCR Maneuver

SCR SCR Maneuver

LCR

Interrupt Duration

Plan

SCR/SpCR

Imaging Pre/Post image config (TBD)

Ground commands deletion of Maneuver SpCR Maneuver

SCR SCRAs Executed

S/C logic attempts to maximize LCR imaging, and fills back in LCR imaging once Maneuver is deleted by ground command

Once SCRs/SpCRs are deleted the spacecraft will revert to LCR imaging

The information provided in this presentation is preliminary. LNEXT-MGMT-DESC-0028, January 2025 Update

Imaging and Special Command Request Logic – SpCR Removal

Duration: 48 (TBR) Hours Content: Complete

Integrated activity sequence and deconfliction report

LNext Onboard Timeline Generation

LCR

(path/row based)

SCR

(path/row based)

SpCR (time based)

Ground Contact Request

(time based)

Ground Directed

Activity Listing

(GDAL)

Communications Activity Schedule

(CAS)

SpacecraftGround Ground

Ground Directed Activity

Schedule Generation

Autonomous Imaging Schedule

Generation

Autonomous Comm Schedule

Generation

Integrated Onboard Timeline

Onboard Activity

Deconfliction

Duration: 7-10 days Content: Comm activity time sequence

Duration: 18 Days Content: Path/Row imaging sequenceUpdate Frequency:

Seasonally

Functions/Processes Products

Routine Cals (TBD)

Pre/During/Post- Pass Activities

Duration: Spans all ground directed activities

Content: Ground requested SpCR time sequence

Imaging Plan

Update Frequency:

As-needed

Update Frequency:

As-needed

Update Frequency:

Weekly

Ground review and/or approval

The information provided in this presentation is preliminary.

Activity Definitions

LNext Command Input Paths (Notional)

RT Commanding

Ground-Provided Absolute

Command Sequence

Integrated Onboard Timeline

SC FM

SpacecraftGround Ground

Command Processing and Execution

Command Echo / As-Executed

LandIS

SC

Systems

N otional Input Precedence

SC FM will always supersede any onboard loads to ensure the safety of the observatory The information provided in this presentation is preliminary. LNEXT-MGMT-DESC-0028, January 2025 Update

LNext Ground System Input to Spacecraft

• The ground provides a limited set of inputs to the spacecraft, from which the spacecraft will generate onboard the integrated timeline to support imaging, special activities, and comm links. These ground provided inputs are the following:

• Communications Schedule*

• Uploaded ~weekly *Process for generation of the onboard communications schedule is separate from the imaging sequence and comm activities may be executed out of a separate onboard load sequence.

• LTAP Collection Request (LCR)

• Listing of all nominal scenes - defined by path/row - to be acquired by the spacecraft, as defined in the LTAP

• Fairly static, expected to be updated infrequently

• Special Collection Request (SCR)

• Individual requests for acquisitions outside of the baseline LCR. Defined by path/row.

• Requested regularly on an as-needed basis

• Special Command Request (SpCR)

• Individual requests for singular operational activities (e.g. maneuvers). Defined by execution time.

• Requested regularly on an as-needed basis

• Key Assumptions

• The ground will provide SCRs that do not conflict with each other

• The spacecraft has responsibility for deconflicting the LCR with SCRs/SpCRs as requested from the ground – the ground does not resolve the SCRs/SpCRs with respect to the LCR prior to upload

• Activity Definitions maintained onboard are used during conversion from activities to commands and deconfliction

• The spacecraft has responsibility for autonomously generating the integrated onboard timeline and associated command sequences which support all the imaging and activity requests provided by the ground via the inputs listed above

• The integrated onboard timeline generated by the spacecraft is provided to the ground for review

• The spacecraft also provides intermediate schedule products to the ground for longer term planning activities

Ground provides a streamlined set of inputs which enable the spacecraft to generate the integrated timeline autonomously onboard

The information provided in this presentation is preliminary. LNEXT-MGMT-DESC-0028, January 2025 Update

LNext Key Spacecraft Output to the Ground

• The Spacecraft provides the following outputs to the ground

• Imaging Plan

• Duration: 18-days (Starting from last generation time)

• Content: Path/row-based summary of all planned activities for full repeat cycle (includes LCR and SCRs)

• Used for coarse long-term planning, and is based on the LCR and SCRs

• Ground Directed Activity List (GDAL)

• Duration: Span all planned SpCR activities

• Content: Time-based plan of all special command request activities currently maintained onboard

• Communications Activity Schedule (CAS)

• Duration: 1 week (TBR)

• Content: Time-based plan for all comm activities currently maintained onboard

• Onboard Integrated Timeline (IOT) and deconfliction report

• Duration: 48 (TBR) hours

• Content: Absolute command sequence the spacecraft is planning to execute on-orbit

• Ground review and/or approval (LEOC)

• Command Echo/As-Executed Timeline

• Spacecraft will provide telemetry regarding the actuals executed on-orbit

Spacecraft provides a set of outputs of varying fidelity to ensure sufficient ground insight into on-orbit activities

The information provided in this presentation is preliminary. LNEXT-MGMT-DESC-0028, January 2025 Update

• Operational IOT autonomy will ramp up during commissioning

- Exact phasing of autonomy functions will depend on results of pre-launch testing, mission readiness planning, and spacecraft, instrument, and science team recommendations

• On-orbit demonstration of the core functionality of the succeeding phase is a gate to entering next phase

• All autonomous functions are configurable per requirements, and can be scaled back/overridden as desired throughout the mission

• The phases shown below can be thought of as Crawl/Walk/Run

Ramping up Integrated Onboard Timeline Autonomy

Post-Launch/Early

LEOC

• RT Commanding and Ground Provided ATS

• Full Ground

Responsibility

On-Orbit Check- Out

• Autonomously Generated Integrated Onboard Timeline

• Ground Review and

Approval

Nominal Ops/Post- Commissioning

• Autonomously Generated Integrated Onboard Timeline

• Ground Review and

Interrupt

The information provided in this presentation is preliminary. LNEXT-MGMT-DESC-0028, January 2025 Update

• Nominal propulsive maneuvers will be highly optimized, to reduce the time between maneuver decision and execution, and to provide flexibility to the operations team

• The ground will request an interruption of the executing integrated activity timeline when a maneuver is needed

- The spacecraft will fill back in any interrupted imaging if a maneuver sequence is deleted/removed

• Frequent collision threats are expected during the life of the mission, which drives the need for increased optimization and rapid turnaround – allowing the FOT to wait as long as possible before committing to a burn

- The ground system will be able to plan and assess maneuver options for the FOT to select and command the spacecraft to execute

• Pre-loaded maneuver sequences will be available for selection by the FOT to execute a pre-determined range of in-track and retro maneuver options without the need to build and load a custom command sequence (TBD)

- Infrequent or highly specific propulsive maneuvers can still be built, tested, and loaded from the ground, as needed

Orbit Adjust Maneuver Approach

The information provided in this presentation is preliminary.

Ground

Collision Risk Assessment

Assess Maneuver

Options

Select Maneuver

Screen Maneuver(s)

Command Maneuver

Type/Size/Time

Interrupt Activity Timeline and

Execute Maneuver Spacecraft

• Each observatory will be capable of maintaining the safety of the spacecraft and instruments indefinitely, in the case of a long ground outage or major onboard anomaly

- This will include typical onboard fault management functions like power and thermal anomaly detection and responses (load shedding, maintaining power positive state, thermal stability, pointing keep out zone management, etc.)

- This could be utilized as part of commissioning, if needed, to manage resources and activities

• Each observatory will operate independently

- Satellites have no ability to communicate or coordinate with each other – all coordination is ground based

- Functionality for each observatory is not dependent on the others

• End of Life and Decommissioning

- Each observatory will carry 10+ years of consumables (fuel), with the goal of extended mission life and science operations

- USGS, in collaboration with NASA, will make the determination to decommission

- Each Landsat Next observatory will be disposed of in accordance with NASA and USGS policies, which includes controlled deorbit as the baseline

Other Important Observatory Highlights

The information provided in this presentation is preliminary. LNEXT-MGMT-DESC-0028, January 2025 Update

• LNext will follow the 7123.1 I&T approach (ie. Plan, TRR, Consent to Break, post test review, test report, etc.) and will take advantage, where possible, of tests and qualifications inherent in a multiple build program

- Eg. Certain qualification tests, on a case by case basis, will only need to be performed on one observatory

• The LNext Environmental Requirements Document (LNERD) defines the environmental testing for the program

• The generic I&T flow, at a high level, will be performed on:

- Instruments (the instruments will be delivered to S/C fully qualified)

- Spacecraft Bus

- Fully integrated Observatory

- Dispenser

- Mission Payload (integrated Observatories on Dispenser)

• NASA GSFC Gold Rules will be utilized. Key rules include:

- Power on-time for components and observatory tests

- Test Like You Fly (TLYF) and margin requirements

• TVAC will be performed on all Observatories to verify functional performance

• RF Compatibility testing (narrowband and wideband) will be performed on all Observatories

• RF Suitcase testing (wideband only) will be performed at all LGN Ground Stations

• Independent data validation will be performed by USGS throughout I&T and will include end-to-end data chain validation with the complete observatory and ground system (Photon to L1 products at EROS)

Mission Payload Integration and Test – Constellation Focus

The information provided in this presentation is preliminary. LNEXT-MGMT-DESC-0028, January 2025 Update

• The three LNext Observatories will be launched on the same launch vehicle, released in succession, and inserted directly into the operational orbit defined by the mission injection parameters

- Launch Services Program 5m fairing used as lower bounding case, for smallest fairing envelope

• The spacecraft vendor will provide the observatory deployment system (dispenser) - below are a couple of stack and dispenser configuration examples, based on study feedback.

Launch Configuration - Notional

The information provided in this presentation is preliminary. LNEXT-MGMT-DESC-0028, January 2025 Update

Example 3x stack/launch configuration from Canadian Space Agency RCM mission

Solar Arrays “in” Solar Arrays “out”

Solar Arrays “out” stack

• The three LNext Observatories will be launched on the same launch vehicle, released in succession, and inserted directly into the operational orbit defined by the mission injection parameters

• Each Observatory will autonomously enter safe hold after separation

- Each observatory may stay in safe hold configuration for an extended period of time due to constellation activation sequences

• Communication after separation will be staggered between the observatories due to the tightly spaced proximity of the three Observatories and expected communication overlap (notionally same center frequencies)

• The ground will assess each observatory health and safety and prioritize early activities based on observatory need

• Phasing to 120 degree separation will occur as part of the commissioning timeline

Launch, Deployment, and Early Orbit Notional Approach

The information provided in this presentation is preliminary.

Orbit Injection

Commissioning and Phasing

Operational Phasing

• The LNext Mission baseline, as documented in Level 2 requirements, is 100 days for commissioning – this includes all activities up to handover and transition of operations to USGS

• Each Observatory is commissioned independently and must got through full commissioning activities

- This means Observatory 2 and 3 cannot use Observatory 1 commissioning results to buy off requirements

- Some validation steps and on-orbit tests may only be done once, as appropriate, on a case-by-case basis

• Big picture phases (some activities can happen in parallel):

- Launch, separation, autonomous deployments, autonomous transition to safe hold – approx. first 3 hours

- Ground directed activities up to collision avoidance (COLA) propulsive maneuver enabling capability (Propulsion system checkout, Earth Pointing, etc.)

- S/C commissioning, calibration, phasing, and checkout activities

- LandIS instrument turn on, dryout, cooldown (TBD), calibration, and checkout activities

- On-orbit verification, validation, calibration, tuning, and testing

- Complete nominal DRC-18 cycle

• Perform and finalize documentation updates, on-orbit performance comparison to pre-launch baseline, trending and end of life prediction updates, and anomaly summary/report closeout

• Mission Reviews/Milestones: On-Orbit Acceptance Reviews (OAR) – Observatories, Instruments, Ground, etc.;

Post Launch Acceptance (PLAR); Mission Transition/Handover (MTHR)

Commissioning Approach

The information provided in this presentation is preliminary. LNEXT-MGMT-DESC-0028, January 2025 Update

Notional Commissioning Activities

The information provided in this presentation is preliminary.

Commissioning Phase NASA Accountable USGS Accountable

Operations Phase

COLA

enabling S/C Commissioning Instrument Dryout and

Commissioning DRC-18 Routine OpsO-1

O-2 O-3

O-1 O-2

O-3

O-1 O-2

O-3

Requirements Verification and Validation

Cal/Val, Special Activities, Final Orbit Phasing, Constellation Operations

On-Orbit Tests

Trending and Documentation Updates

Launch

~3hr

*Separation and Autonomous

Activation

~3d ~30d

On-orbit Acceptance Reviews (OAR):

• Observatories

• Instruments

• Ground

• etc.

Example Tests (TBD):

• Cross calibration with L8/L9

• Science parameter and compression tuning

• Autonomy crawl/walk/run tests

• Routine Maintenance tests

• Retransmit logic tuning

• Retro/Posigrade maneuver tests

Handover @ 100days

Post-Launch Acceptance

Review (PLAR)

Mission Transition Handover Review

(MTHR)

100d

Time post launch

Ground directed activities up to

Collision Avoidance enabling capability

• Mission Readiness is operations focused and validates the mission conops – it demonstrates the team, systems, products, and procedures are ready for a safe and successful launch and subsequent operations

• The mission readiness campaign follows the Gold Rules’ Test As You Fly (1.09) and Minimum Simulation (3.10) rules and is structured to successfully pass through key mission reviews (see NPR 7123.1 for more detail):

- Mission Operations Review (MOR), Flight Operations Review (FOR), and Operations Readiness Review (ORR)

- Flight Readiness Review (FRR) and Launch Readiness Review (LRR)

• Incremental approach concurrent with Observatory integration, testing, and launch preparations

- Flexible schedule, coordinated across the project, agencies, and vendor teams, that adapts to system maturity

• Fully integrated team participation, including NASA (Engineering and Mission Integration), USGS (Ground, Science, and Operations), Spacecraft vendor, Instrument vendor, Launch Services, and Flight Operations involved

- NASA leads and coordinates mission readiness activities and USGS leads ground readiness activities

- USGS provides core flight operations and operations readiness engineering teams

• Core tests include Network Readiness Tests (NRTs), Ground Readiness Tests (GRTs), Mission Readiness Tests (MRTs), and Mission Simulations

• Note: Observatory requirements verification is performed independent of MRTs

Mission Readiness Approach

The information provided in this presentation is preliminary. LNEXT-MGMT-DESC-0028, January 2025 Update

Simulator Key Highlights and Capability Summary

The information provided in this presentation is preliminary.

Simulator Key Highlights Description and functional details Command and Telemetry Simulation System (CTSS)

• Simple C&T functions

• Deployable internationally

• Simple, low fidelity system for simulating realistic spacecraft command and telemetry (C&T) responses with basic scripting capability

• Primarily used for ground station and ground system checkout activities

• Deployable to international partner ground stations with limitable command and telemetry database functions (ie. remove all but a no-op and acknowledgement for ITAR/CUI protection)

SoftSim • 100% software

• Runs S/C FSW only

• Has full environmental truth model

• Software based (emulated hardware) simulator of the Observatory

• High fidelity Spacecraft (executable/patchable flight software (FSW), modeled subsystems, and environmental truth model, etc.)

• Low fidelity LandIS (basic C&T only) capability

• Primarily used for spacecraft and ground procedure development, ground software development, and ground readiness tests

Observatory Operational Simulator (OOpS)

• Runs S/C and LandIS

FSW

• Has full environmental truth model

• Workhorse simulator for mission readiness and operations teams

• High fidelity observatory simulators (integrated LandIS Operational Sim (LOpS) with S/C Operational Sim (SOpS)) with flight like timing for all mission data elements

• Flight-like command and telemetry response, redundancy, subsystem models, timing, compression, and science data generation/flow

• Executes S/C and LandIS FSW, with ability to use and update as in flight

• Primary resource for operational process and procedure development, Mission Conops validation, constellation operations testing, and Mission Readiness tests and simulations

• Long term operational use: special activity testing, product updates, anomaly investigation, team training and proficiency, etc.

• The LNext simulators are intended to provide incrementally more capability as the flight and ground segment needs increase during the mission development, launch preparation, and operations phases

• LNext will also utilize interface simulators for interface verification:

• LandIS Interface Simulator (LIS) – Early Instrument to S/C interface checkout

• Launch Vehicle Interface Simulator (LVIS) – Mission Payload (Dispenser plus Observatories) to Launch Vehicle interface

• RF Suitcase – Realistic Ka-Band RF signal to Ground Station hardware (free-space and/or coax.)

GN

Development

MOC

Development

Ops Product Development

DPAS

Development

Ground Readiness Tests

Mission Readiness Test

Mission Sims and Rehearsals

Notional Mission Readiness Simulator Uses and Timeline

CTSS SoftSim OOpS RF Suitcase

Approx.

Start of

I&T

MRT

Campaign

Start

The information provided in this presentation is preliminary.

GRT

Campaign

Start

Launch

Note: Timeline not to scale

• LNext is taking a proactive, comprehensive security approach, and will be following all relevant NASA and DOI/USGS guidelines.

• Please see the Landsat Next Integrated Security Architecture Plan, LNEXT-SYS-PLAN-0023, for an overview of the LNext Mission protection and security approach, including references to other key mission security documents.

Mission Protection and Security Approach

The information provided in this presentation is preliminary. LNEXT-MGMT-DESC-0028, January 2025 Update

• Multi-satellite Operations Center Functions

- Telemetry and Command: real time activities, and routine operations

- Orbit/Flight Dynamics: orbit determination, ephemeris and event generation, and maneuver planning (orbit maintenance)

- Planning and Scheduling: contact, imaging, calibration, and all special activities to be executed by the Observatory

- Analytical Modeling: modeling and tools to verify current flight operations concepts and assess potential modifications

- Simulation: activity validation, anomaly support, training, product updates, etc

- Trending and Analysis: multi-mission, short-term, and long-term trending

- Configuration & State Management: manage observatory and ground

- Contact & Activity Orchestration: Plan, schedule, and manage all activities in support of lights out operations

• Ground Network (GN) Functions

- Provide the RF interfaces between the ground and Observatory

- S-Band interface for command and telemetry, and SSOH

- Ka-Band interface for the capture of mission data from the Observatory

- Mission data transfer to Landsat cloud

• Data Processing & Archive System Functions

- Generation of special collection requests, transmission to LMOC

- Interval assembly and accounting of mission data files received from the GN

- Ingest of mission data files to produce Level-0 intervals

- Storing and archiving the data and products (short-term and long-term storage)

- Level 1 and Level 2 product generation

- User discovery and access

- International Cooperator data and products exchange

- Ground system and science metric gathering and reporting

Ground Segment Architecture Summary

Notional Depiction Only

The information provided in this presentation is preliminary. LNEXT-MGMT-DESC-0028, January 2025 Update

• The GN is comprised of the ground stations, networks, and all other data routing capabilities within the Ground System

• Key functions are to provide RF communications between each observatory and the ground for telemetry, command, and science data return

- For telemetry, command, and stored state of health (SSOH) the GN provides the interface between the observatories and the MOC

- For science data return, the GN provides the interface between the observatories and the DPAS

• S-Band RF uplink (encrypted) and downlink communications allow for MOC communications with each observatory

• Ka-Band RF receive communications allow for science data return

- Science data return includes transfer of mission data files, including interleaved spacecraft and instrument ancillary data, and the volume table of contents (VTOC), for science data ingest, processing, and archival

- During a Ka-Band mission data downlink event, the ground station monitors the downlink and provides a status of mission data files that were successfully received by the ground following the end of the contact

- The Ground System uses this information to determine if retransmit commands are needed for specific science mission files

• Nominally 5-6 S-Band contacts (TBR) and 10-12 Ka-band contacts (TBD) per day per observatory are expected

• The LNext GN is anticipated to be a global network employing a combination of polar and mid-latitude stations to optimize science data return and minimize operational costs

- Alternative International Cooperator (IC) data flows based on downlink approach are in development

• The GN includes a cloud-based data routing capability for the transfer of science mission data from GN stations

- Separation of mission data into priority-based virtual channels allows for expedited delivery of priority data

• Stations will cache Ka-Band mission data received for at least 60-days (TBR) and S-Band data received for at least 7-days (TBR) to support continuity of operations, contingencies, and retransfers of data

Ground System – Ground Network (GN)

The information provided in this presentation is preliminary. LNEXT-MGMT-DESC-0028, January 2025 Update

• The MOC includes all ground-based assets needed to operate the LNext constellation, excluding the ground network, DPAS, LTAP generation, and retransmit decisions.

• MOC will support unattended (lights-out) operations for extended periods (days to weeks, TBR), and includes:

- Autonomous contacts with ground stations for downlink of housekeeping and mission data

- Autonomous contact changes/updates (due to station changes, new downlink needs, etc.) on ground and observatories

- Autonomous notification of staff for any observatory or instrument issue or concern

- Autonomous monitoring and reporting of MOC and GN (TBD) systems status, including notification of staff as required

• Managing all coordinated Ops activities, like coordinated image campaigns and coordinated maneuvers

- Each observatory only knows about itself, so planning and monitoring is done on the ground

• Mission operations includes a backup MOC (bMOC) – primary purpose of the bMOC is to maintain constellation health and safety, receive and process real-time telemetry, provide T&C capabilities, manage orbit and maneuver planning, and perform science data planning and scheduling functions to continue nominal operations.

• bMOC supports MOC resiliency in the event of critical failure

- bMOC will assume operations of the mission within 24 hours (TBR) of loss of the primary MOC and is capable of providing MOC functionality for at least 30 days

• Pre-launch support for all factory and launch site observatory test events

• Test environment and connections to simulators for operational activity tests, product updates, and validation needs

Ground System – Mission Operations Center (MOC)

The information provided in this presentation is preliminary. LNEXT-MGMT-DESC-0028, January 2025 Update

• Multi-Satellite Management, Planning, Scheduling, Testing, and Orchestration

- Contact Planning, Scheduling, and Deconfliction

- Attitude and orbit determination capabilities and event propagation

- Routine, special collection, and special activity request planning, constraint checking, deconfliction, verification, and loading

- Routine orbit maintenance and risk mitigation maneuver planning, testing, constraint checking, and validation

- Plan, schedule, and manage all routine contact activities, including routing and execution of retransmit requests from DPAS

- Load building, validation, and uplink

- Simulators for product testing, training, activity validation, anomaly investigations, or other engineering activities

• The system provides the engineering team the ability to confirm the observatories are imaging autonomously as defined in the LCR and SCR

- Spacecraft provides the full, 18 day, up to date onboard WRS-3 scene (Path/Row) plan for validation on the ground

- This imaging plan and deconfliction report is reconciled against the LCR/SCRs and the results are provided to the DPAS

• Autonomously review and validate the observatory provided 48 hour (TBD) integrated onboard timeline (IOT) and notify engineering of any issues, errors, or unexpected results

• The MOC plans, schedules, and manages all flight operation resources and constellation contact activities to support downlinking of mission data

- Includes mass storage and priority data based reprioritization,…