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.


On Oct 7, there may be a scheduled outage at the McMurdo ground station, spanning 10/7 19:00 UTC to 10/8 19:00 UTC.  During that outage, the following revs will have limited or no visibility to the Troll downlink station, which will be covering for McMurdo, and thus the Southern Hemisphere data playback may be delayed until the subsequent Svalbard downlink. This may introduce a half-orbit delay to some data delivery at the following approximate times:

NOAA-21:
(rev 9901) 2024-10-8, 03:57 to 04:47 UTC
(rev 9902) 2024-10-8, 05:37 to 06:28 UTC
(rev 9903) 2024-10-8, 07:17 to 08:07 UTC
(rev 9904) 2024-10-8, 08:57 to 09:48 UTC

NOAA-20:
(rev 35694) 2024-10-8, 04:43 to 05:34 UTC
(rev 35695) 2024-10-8, 06:23 to 07:14 UTC
(rev 35696) 2024-10-8, 08:03 to 08:54 UTC

On Oct 10, there may be a scheduled outage at the McMurdo ground station, spanning 10/10 19:00 UTC to 10/11 19:00 UTC.  During that outage, the following revs will have limited or no visibility to the Troll downlink station, which will be covering for McMurdo, and thus the Southern Hemisphere data playback may be delayed until the subsequent Svalbard downlink. This may introduce a half-orbit delay to some data delivery at the following approximate times:

NOAA-21:
(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

NOAA-20:
(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 

Future McMurdo outages, on or near Oct 29 - Nov 3, may also result in data delivery delays, to be detailed in a subsequent update.

Topic: Intermittent delays expected in NOAA-20 and NOAA-21 Science Mission Data

 

Date/Time Issued: October 25, 2024 1741Z 

 
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>


Contact Information for Further Information: ESPC Operations at ESPCOperations@noaa.gov and 301-817-3880

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