Update #8: From Nov. 4, 2024 (19:00 UTC) to Nov. 10, 2024 (19:00 UTC), the NOAA-20 and NOAA-21 satellites are using Troll station, instead of McMurdo, for their Southern Hemisphere downlinks of Stored Mission Data (SMD). Because of Troll's more northerly location, a few times per day it will be unable to receive data from these satellites: thus SMD from the approximate time periods listed below will be delayed by a half-orbit (50 minutes).
Update #7: The third outage of the McMurdo ground station, originally scheduled for Oct. 29 - Nov. 2, 2024, has been postponed by 6 days. Thus the NOAA-20 and NOAA-21 satellites will downlink Stored Mission Data (SMD) to Troll station (instead of McMurdo) from Nov. 4, 2024 (1900z) to Nov. 10, 2024 (1900z).
During this time period, SMD from NOAA-20 and NOAA-21 will be delayed by a half-orbit (50 minutes) when the satellites miss Troll station, 3 or 4 times per day. An update to this notice will detail the timing of those delays.
Update #6: On Friday, Oct. 11, NOAA-21 data from some or all the half-orbits indicated below may incur delays well in excess of the 50 minutes estimated in the original Notice.
(rev 9944) 2024-10-11, 04:41 to 05:32 UTC
(rev 9945) 2024-10-11, 06:21 to 07:12 UTC
(rev 9946) 2024-10-11, 08:01 to 08:51 UTC
This is because NOAA-21's current onboard schedule calls for data downlinks via the Tracking and Data Relay Satellite System (TDRSS) on Oct. 8 and 11, intended to avert the expected 50-minute delay. On Oct. 8, these TDRSS contacts were unsuccessful, but resulted in incomplete downlinks at the Svalbard ground station, with data replay / recovery on subsequent Svalbard passes. This may also happen on Oct. 11.
NOAA-20 had no TDRSS data downlinks scheduled, so its data incurred only the expected half-orbit (50 minute) delays on Oct. 8 at the previously indicated times. This half-orbit delay is still expected for NOAA-20 data at the following times on Oct. 11:
(rev 35736) 2024-10-11, 03:47 to 04:37 UTC
(rev 35737) 2024-10-11, 05:27 to 06:18 UTC
(rev 35738) 2024-10-11, 07:07 to 07:58 UTC
(rev 35739) 2024-10-11, 08:47 to 09:38 UTC
During the final McMurdo outage (Oct. 29 - Nov. 2), neither NOAA-21 nor NOAA-20 will have TDRSS data downlinks scheduled; so their data will be delayed by only a half-orbit, 3 or 4 times per day when they miss Troll station. An update to this Notice will supply the timing of those delays.
Update #5 - Correction to Update #4: All NOAA-21 Stored Mission Data (SMD) from rev 9905 was processed, recovered, and distributed to IDPS on Oct. 8. However, IDPS did not receive the data from NOAA-21 observations between 07:36z and 08:00z (part of rev 9903) on Oct. 8. IDPS will not recover this data. Portions of this data may be available from Direct Readout sites.
Update #4: All NOAA-21 Stored Mission Data (SMD) has been processed, recovered and distributed to IDPS.
Update #3: NOAA-21 Stored Mission Data (SMD) rev. 9905 was not received due to antenna issues. Data expected to be recovered on the next upcoming Troll rev. 9905.
Update #2: NOAA-21 Stored Mission Data (SMD) passes may incur ~3 hour delays on the days and times detailed below.
Update #1: NOAA-20 and NOAA-21 Stored Mission Data (SMD) from nighttime (descending) passes may incur half-orbit (~50 minute) delays on the days and times detailed below.
Topic: Intermittent delays expected in NOAA-20 and NOAA-21 Science Mission Data
Date/Time Issued: November 04, 2024 2007Z
Product(s) or Data Impacted: All Science Mission Data from NOAA-20 and NOAA-21 descending (nighttime) passes
Date/Time Initial Impact: October 07, 2024 0000Z J/Day 281
Date/Time of Expected End: November 2, 2024 0000Z J/Day 327
Length of Event: 26 days
Details/Specifics of Change: Between Oct. 7, 2024, and Nov. 1, 2024, about 4 times per day, Science MIssion Data (SMD) from the descending (nighttime) passes of the NOAA-20 and NOAA-21 satellites may incur delays of about 50 minutes, due to maintenance at the McMurdo (Antarctica) ground station. An update will be made to this notice when further SMD delay dates and times are available.
This will NOT have any effect on
SMD from ascending (daytime) passes of NOAA-20 and NOAA-21;
Any SMD from the S-NPP satellite; or
Any High-Rate Data (HRD) / Direct Broadcast.
User feedback and questions should be directed to John Evans, LEO Data Operations Manager, NESDIS/OSPO/SPSD <john.d.evans@noaa.gov>