Updated 04/03/2025
Due to the uniquely severe potential of the ongoing Critical Weather Day (CWD), the transition of the GOES-19 satellite to the operational GOES-East position has been postponed. This delay ensures uninterrupted, critical weather monitoring during this period. The transition is now scheduled to occur no earlier than April 7, 2025, at 1510 UTC, which is after the current CWD declaration has concluded. Currently GOES- 16 and GOES-19 are in a co-location orbit.
This transition will necessitate a temporary cessation of the GRB, High Rate Information Transmission (HRIT) and Emergency Managers Weather Information Network (EMWIN), SAR and DCS broadcast. Specifically, a 10-minute service interruption, spanning 15:00 to 15:10 UTC, will occur during the switchover from GOES-16 to GOES-19 data dissemination.
GOES-16/19 Transition and Relocation Timeline
Key Events and Timeline:
- April 1, 2025:
- GOES-16: In co-location configuration at 75.5°W. X-Band and S-Band downlinks operational.
- GOES-19: Arrives at 75.2°W, instruments resume operation. X-Band and L-Band downlinks operational post-drift. NOTE SAR/DCS/HRIT/EMWIN will not be available on GOES-19 until April 4th at @1500UTC ~ GOES-16 will still be providing that data.
- (X-band here refers to Raw Data Downlink, and L-band to Tracking, Telemetry, and Control (TT&C), not the AUX COM services at L-band i.e. not to the GRB, SAR,DCPR,HRIT/EMWIN downlinks. See the GOES Data Book page 9.2)
- April 1 – April 4, 2025:
- GOES-16: Continues co-location configuration at 75.5°W with X-Band and S-Band downlinks.
- GOES-19: Post-Drift Product Checkout at 75.2°W. X-Band and L-Band downlinks operational.
- April 3, 2025:
- GOES-19: Operational Transition Readiness Review (OTRR).
- April 7, 2025:
- GOES-16: X-Band downlink shut down, instruments powered off. End of GOES-16 GRB Broadcast.
- GOES-19: Declared operational GOES-East. GOES-19 GRB broadcast and nominal distribution commence. SAR/DCS/HRIT/EMWIN services transitioned to GOES-19.
- During the April 4th transition period, GOES East DCS users should expect a short message data outage of roughly thirty minutes as operations are transferred between spacecraft.
- GOES-16: Begins drift to 105°W. Drift using Low Thrust Rockets (LTRs) with a maximum rate of ~0.5°/day.
- June 7, 2025:
- GOES-16: Arrives at 105°W, and enters storage mode.
- GOES-17: Will relocate to 89.5°W (storage location) after confirmation of GOES-16 arrival.
Summary:
This timeline outlines the transition of operational duties from GOES-16 to GOES-19, culminating in GOES-19 becoming the operational GOES-East satellite on April 4th. Following this transition, GOES-16 will begin a controlled drift to its storage location at 105°W, subsequently triggering the relocation of GOES-17.
Key Technical Details:
- Co-location: A period where two satellites operate in close proximity for transition purposes.
- GRB: Goes Rebroadcast.
- SAR/DCS/HRIT/EMWIN: Specific data and service transmissions.
- LTR: Low Thrust Rocket.
- X-Band, S-Band, L-Band: Specific radio frequency bands used for satellite communications.
- TT&C: Tracking, Telemetry and Control
GOES-16/19 Service Transition Timeline: (04/07) NOTE THE CHANGE FROM THE 4th!
This document delineates the anticipated timeline for the transition of GOES Rebroadcast (GRB) and auxiliary communication services from GOES-16 to GOES-19, scheduled for April 7th. All times are specified in Coordinated Universal Time (UTC).
Phase 1: GOES-16 GRB Service Deactivation and GOES-19 GRB Service Activation (15:00Z – 15:10Z)
- 15:00Z – 15:05Z:
- Command execution to mute GOES-16 Lightweight Transmitters (LTWT) 1 and 2.
- Resultant action: Cessation of GOES-16 GRB broadcast.
- 15:05Z – 15:10Z:
- Configuration and unmuting of GOES-19 LTWT 1 and 2.
- Resultant action: Commencement of GOES-19 GRB broadcast.
Phase 2: GOES-16 Auxiliary Communication Service Deactivation and GOES-19 Activation (15:10Z – 15:30Z)
- 15:10Z – 15:20Z:
- Deactivation of GOES-16 LTWT 3.
- Deactivation of GOES-16 Data Collection Platform Command Transmitter (DCPC) Tx1.
- Deactivation of GOES-16 Ultra-High Frequency Receiver (UHF) Rx1.
- Muting of GOES-16 LTWT 4.
- Resultant action: Discontinuation of GOES-16 High-Rate Information Transmission (HRIT), Emergency Managers Weather Information Network (EMWIN), Data Collection Platform Collection (DCPC), Data Collection Platform Reporting (DCPR), and Search and Rescue (SAR) services.
- 15:20Z – 15:30Z:
- Configuration and unmuting of GOES-19 LTWT 3.
- Activation and configuration of GOES-19 DCPC Tx1.
- Activation and configuration of GOES-19 UHF Rx1.
- Configuration and unmuting of GOES-19 LTWT4.
- Resultant action: Commencement of GOES-19 HRIT, EMWIN, DCPC, DCPR, and SAR services.
Service Specific Notes:
- GOES-16 DCPR and HRIT services will be offline during the 15:10Z – 15:20Z interval.
- GOES-19 DCPR and HRIT services will be online during the 15:20Z – 15:30Z interval.
Technical Terminology:
- GRB: GOES Rebroadcast.
- DCPC: Data Collection Platform Command.
- Tx: Transmitter.
- Rx: Receiver.
- UHF: Ultra-High Frequency.
- HRIT: High-Rate Information Transmission.
- EMWIN: Emergency Managers Weather Information Network.
- DCPR: Data Collection Platform Reporting.
- SAR: Search and Rescue.
Additional Info
The CCOR instrument requires a specific calibration, and because of this GOES-19 will execute bi-annual yaw maneuvers to facilitate calibration of the Compact Coronagraph (CCOR) instrument. These maneuvers, performed within a +/- 2 day window centered on the vernal and autumnal equinoxes (approximately March 20th and September 20th), will occur near Satellite Local Time (SLT) noon. Expect Environmental Satellite Processing Center (ESPC) notifications disseminated in advance and near the execution time. These yaw maneuvers will result in data and imagery of all product outages of up to 50 minutes .
Leap Second Adjustments
In the event that the Coordinated Universal Time (UTC) is adjusted for a leap second, GOES
spacecraft will be placed into a special housekeeping period at 0000 GMT on the day of the leap
second. A clock adjustment will be performed to compensate for this change in UTC over the
duration of the housekeeping period. Upon exit of the housekeeping period, the onboard clock
will be synchronized with UTC within specifications.
