GOES-17 Post-Launch Testing and Transition to Operations

Transition to Operations Plan

December 20, 2018

GOES-17 began drifting from its current location of 89.5 degrees west longitude to its GOES West operational location of 137.2 degrees west longitude on October 24, 2018. The satellite completed drift on November 13, 2018 and arrived at its final operational location of 137.2 degrees west. The change from 137.0 to 137.2 has been made for operational efficiency and to minimize impacts from other geostationary satellites.

Following two days of calibration activity, all instruments resumed data distribution on November 15, 2018. GOES-17 continues to operate from the 137.2 degrees west longitude position but the transition to operations as NOAA’s GOES West satellite will be delayed until January 2019. GOES-17 will go into operations as GOES West during the week of January 7, 2019. At that time, the GOES-15 Low Rate Information Transmission (LRIT) will be disabled.

Recently, the satellite’s main instrument, the Advanced Baseline Imager, or ABI, experienced an error that resulted in degraded infrared imagery. This anomaly was not due to the ongoing loop heat pipe issue. After an engineering investigation, it was determined that a recent update to software that controls the ABI cryocooler system (which pumps heat away from the instrument’s detectors to cool them to their required operating temperatures) experienced a memory error. This caused the cryocooler to shut down which led to a series of events through November 25, 2018. The cryocooler operation has been restored and there has been no additional degraded imagery as a result of this issue.

ABI engineers are testing a permanent software fix that should conclude in January 2019. Upon successful confirmation of the fix, the operational declaration to GOES West should occur soon after. In the meantime, the previously scheduled ABI calibration activities have resumed.

GOES-15 is now operating at 128 degrees west longitude (to eliminate radio frequency interference with GOES-17). GOES-15 (at 128 west) and GOES-17 (at 137.2 west) will operate in tandem for at least six months to allow for assessment of the performance of GOES-17 as the GOES West operational satellite.

Summary of Cooling System Issue

During post-launch testing of the GOES-17 ABI instrument, an issue with the instrument’s cooling system was discovered. The loop heat pipe (LHP) subsystem, which transfers heat from the ABI electronics to the radiator, is not operating at its designed capacity. The consequence of this is that the ABI detectors cannot be maintained at their intended temperatures under certain orbital conditions. This is preventing adequate cooling for some of the infrared (IR) channels on the instrument during parts of the night, leading to partial loss of ABI imagery.

Infrared signals with long wavelengths can be swamped by infrared light emitted by warm parts of the imager, degrading the signal. Cooling the detectors reduces this thermal “noise” in observations. During nighttime hours, the sun heats up the ABI detectors faster than they can be cooled. The detectors become warmer than they’re designed to operate, and they begin to radiate at temperatures closer to the wavelengths they’re attempting to detect from the Earth. Eventually, local emissions and dark current noise overwhelm the signal from the Earth, and the channels saturate, meaning a useful signal is not available. Channel availability will also fluctuate seasonally depending on the amount of solar radiation absorbed by the instrument.

A great deal of progress has been made to optimize the performance of the GOES-17 data and the instrument is currently projected to deliver 97% of the data it was intended to provide. GOES-17 is observing with more channels, at a higher resolution, and with more rapid refresh than what is available from the current GOES West satellite. NOAA is confident the GOES constellation will continue to meet the operational needs of the National Weather Service and forecasters across the nation.

GOES-17 will move into operational service in late 2018 and will operate in tandem with GOES-15 for an extended period of time to enable user evaluation.

Latest Status

October 3, 2018

The Independent Review Team (IRT) provided its final GOES-17 ABI cooling system anomaly outbrief on October 3, 2018. The investigation concluded that the most likely cause of the thermal performance issue is foreign object debris (FOD) blocking the flow of the coolant in the loop heat pipes. A series of ground-based tests introducing FOD into test pipes support FOD as the most likely cause. A second potential cause, mechanical failure, was investigated and deemed unlikely.

The IRT recommended changes to the design of the ABI radiators for GOES-T and GOES-U to decrease the chance of future cooling system anomalies. The new design utilizes a simpler hardware configuration and ammonia loop heat pipes instead of propylene. Redesign efforts are underway and the Critical Design Review is scheduled to take place in December.

Previous Status Updates

Show/Hide (below) all status updates on the GOES-17 ABI cooling system issue.

October 2, 2018

NASA and NOAA have appointed a Mishap Investigation Board to investigate an instrument anomaly aboard the GOES-17 weather satellite currently in orbit. During post-launch testing of the satellite’s Advanced Baseline Imager (ABI) instrument, it was discovered that the instrument’s infrared detectors cannot be maintained at their required operating temperatures under certain seasonal and orbital conditions ,resulting in a loss of approximately three percent of the instrument’s availability over the course of a year. This loss exceeds a key design requirement. NASA and NOAA senior leadership have determined the need to convene the mishap investigation board, which will work to determine the root or proximate cause of the anomaly and identify actions to prevent occurrences on future satellites. The board will begin its work as soon as possible.

August 28, 2018

GOES-17 Advanced Baseline Imager (ABI) data was declared “Beta” mature on August 27, 2018, following its Peer Stakeholder - Product Validation Review. The ABI data was released through GOES Rebroadcast (GRB) on August 28, 2018. Please see the Data Flow to Users section of this webpage for additional information.

August 27, 2018

This week, NOAA will begin releasing GOES-17 Advanced Baseline Imager (ABI) “beta” level data and imagery – data that are still preliminary and not yet fully ready for use – to forecasters and scientific partners. This is an important step in making sure that GOES-17 is ready to do its job of providing timely, accurate data for weather forecasting and environmental monitoring. By distributing this data to the larger NOAA and partner community, we are providing NOAA and the community of users the opportunity to understand the ABI data quality and to prepare to use the data operationally.

August 8, 2018

The team that is working on optimizing the GOES-17 ABI performance has been successful at finding techniques that increase the available observing time of the infrared channels. These include increasing the operating temperature of the infrared detectors and cyrocoolers, decreasing the detector integration time, and changing the spacecraft attitude to minimize solar heat load on ABI.

Channel availability will fluctuate seasonally depending on the amount of solar radiation absorbed by the instrument. During the instrument’s “cool” seasons (near the summer and winter solstice), all channels are expected to be available 24 hours per day. During the instrument’s “warm” seasons (before and after the vernal and autumnal equinox), experts estimate 7 channels (bands 1-7) will be available 24 hours per day and the other 9 channels (bands 8-16) will be saturated and images will be degraded or unusable 2-6 hours per night. These estimates are preliminary and are still being refined. The warmest part of the instrument’s season is coming up in early September and performance estimates will need to be confirmed through observation during that time.

NOAA shared the first infrared imagery from GOES-17 on August 8, 2018. The 16-panel images below show data from the ABI’s 16 bands. The upper image was taken on July 29, 2018 at 0932 UTC, during the time of maximum detector temperatures for that date. The lower image was taken on the same date at 1802 UTC, during the time of “cool” detectors. These images show that unsaturated data is currently available 24 hours per day, even during the “hottest” part of the night.

Experts have identified four likely causes for the issue. A series of ground-based tests using spare and engineering unit ABI hardware is underway to help understand the loop heat pipe behavior and isolate the specific root cause. Additionally, analytical models of the loop heat pipes have been made to simulate launch and on-orbit conditions and predict the LHP behavior under varying conditions.

NOAA and NASA are also evaluating design modifications for the ABI that will fly on GOES-T and GOES-U to ensure that cooling system performance is not an issue moving forward.

July 27, 2018

NOAA has shared new information on efforts to resolve the technical issues impacting the performance of the GOES-17 Advanced Baseline Imager (ABI), predicting all of the ABI spectral channels will be available for the majority of the day. The ABI, the primary instrument onboard the satellite, has experienced trouble with its cooling system during the orbital check-out phase of GOES-17's six instruments. The other five instruments are performing normally.

The cooling system of the ABI is not functioning properly. Currently the loop heat pipe subsystem, which transfers heat from the ABI electronics to the radiator, is malfunctioning. This is preventing adequate cooling for some of the infrared (IR) channels on the instrument during parts of the day, leading to partial loss of ABI imagery.

Experts have identified four likely causes for the issue and have recommended a set of ground tests to further isolate the specific root cause. Based on these initial findings, NOAA and NASA are evaluating design modifications for the ABI that would fly on GOES-T and GOES-U. The team of experts have also pinpointed different operating procedures to improve the availability of the IR channels. This will allow the ABI spectral channels to be available for the majority of the day.

The availability of the imagery will vary during different times of the year. Initial estimates predict that 13 of the 16 channels will be available the full 24 hours during "cool seasons" (near the summer and winter solstice), with the other three channels available for 20 hours. During "warm seasons" (before the vernal and autumnal equinox), they estimate 10 channels will be available for 24 hours, another 3 will be available for 20 hours, and 3 will be available for approximately 12 hours. Through adjustments in operating procedures and software and algorithm changes, experts hope to revise these estimates as we head into the fall "warm season" for the satellite. After operation through the hot season, estimates of channel availability will be finalized.

NOAA’s operational geostationary constellation -- GOES-16, operating as GOES-East, GOES-15, operating as GOES-West and GOES-14, operating as the on-orbit spare -- continues to remain healthy and monitoring weather across the nation each day.

July 24, 2018

Teams of experts continue to work to understand the exact nature of the GOES-17 cooling system anomaly, determine the capacity of the instrument in its compromised state, and maximize its operational utility. These teams are making great progress and the ABI is demonstrating improved performance from initial observations. The team that is working on optimizing the GOES-17 ABI performance has been successful at finding techniques that increase the available observing time of the infrared channels. The root cause independent review team has narrowed down the number of possibilities to a few likely causes. A series of ground-based tests using spare and engineering unit ABI hardware is underway through September to try to isolate the specific root cause. This team has also recommended design modifications for the GOES-T and GOES-U ABIs to ensure we do not experience the cooling system issue moving forward.

We still plan to move GOES-17 into operational service in late 2018. Even during the checkout phase, GOES-17 is observing with more channels at a higher resolution with more rapid refresh than what we have with the current GOES-West satellite. Listen to audio from the July 24, 2018, GOES-17 ABI media call. Learn more about the role of loop heat pipes in the cooling system issue in this fact sheet.

May 23, 2018

The GOES-R Program is currently addressing a performance issue with the cooling system encountered during commissioning of the GOES-17 Advanced Baseline Imager (ABI) instrument. The cooling system is an integral part of the ABI and did not start up properly during the on-orbit checkout.

A team of experts from NOAA, NASA, the ABI contractor team and industry are investigating the issue and pursuing multiple courses of possible corrective actions. The issue affects 13 of the infrared and near-infrared channels on the instrument. At this time, we do not believe that the three channels with the shortest wavelengths, which includes the visible channels, are significantly affected.

NOAA’s operational geostationary constellation -- GOES-16, operating as GOES-East, GOES-15, operating as GOES-West and GOES-14, operating as the on-orbit spare -- is healthy and monitoring weather across the nation each day, so there is no immediate impact from this performance issue.

If efforts to restore the cooling system are unsuccessful, alternative concepts and modes will be considered to maximize the operational utility of the ABI for NOAA's National Weather Service and other customers. An update will be provided as new information becomes available.

Path Forward

The anomaly investigation teams plan to provide findings and recommendations in fall of 2018. These include recommendations for the following: modifications to the GOES-T and GOES-U ABIs to address the loop heat pipe issue, operation of GOES-17 to maximize mission performance, and best constellation options for incorporating GOES-17, including potential changes to the operational usage of other assets.

NOAA plans to move GOES-17 into operational service in late fall of 2018. Preparations are underway to operate GOES-17 in tandem with GOES-15 for an extended period of time to enable user evaluation.

Data Flow to Users

The GOES-17 ABI Level 1b (L1b) and Cloud and Moisture Imagery (CMI) data was declared “Beta” validated on August 27, 2018, following the Beta Maturity Peer Stakeholder – Product Validation Review. The data was released through GOES Rebroadcast (GRB) on August 28, 2018.

NOAA's GOES-17 satellite has not been declared operational and its data are preliminary and undergoing testing. Users receiving these data through any dissemination means (including, but not limited to, PDA and GRB) assume all risk related to their use of GOES-17 data and NOAA disclaims any and all warranties, whether express or implied, including (without limitation) any implied warranties of merchantability or fitness for a particular purpose.

The ABI L1b and CMI data products are calibrated and geo-located radiances of the 16 ABI bands over the Full Disk (FD) of the Earth, the Continental United States (CONUS) region, the Mesoscale (MESO) regions, and certain instrument calibration and engineer data. Beta maturity is defined by the following:

• Initial calibration applied (L1b);
• Rapid changes in product input tables / algorithms can be expected;
• Product quick looks and initial comparisons with ground truth data not adequate to determine product quality;
• Anomalies may be found in the product and the resolution strategy may not exist;
• Product is made available to users to gain familiarity with data formats and parameters (via GRB);
• Product has been minimally validated and may still contain significant errors; and
• Product is not optimized for operational use.

Beta users bear all responsibility for inspecting the data prior to use and for the manner in which the data are utilized. Persons desiring to use the GOES-17 ABI Beta maturity L1b products for any reason, including but not limited to scientific and technical investigations, are encouraged to consult the NOAA ABI calibration scientists for feasibility of the planned applications.

Known issues being investigated include the following:

1. An anomaly with the ABI Loop Heat Pipe (LHP) prevents the instrument cooling system from maintaining sufficiently cool temperatures during certain parts of the day and year. Data quality will fluctuate seasonally depending on the amount of solar radiation absorbed by the instrument. During the instrument’s “cool” seasons (near the summer and winter solstice), all channels are expected to be nominal 24 hours per day. During the instrument’s “warm” seasons (before and after the vernal and autumnal equinox), experts estimate 7 channels (Bands 1-7) will be of nominal quality 24 hours per day and the other 9 channels (Bands 8-16) will be degraded and images will be of reduced quality or unusable 2-6 hours per night. These estimates are preliminary and are still being refined. The warmest part of the season is coming up in early September and performance estimates will need to be confirmed through observation during that time.
2. Significant stray light exists for VNIR channels approximately one hour before and after satellite local midnight for approximately forty days during the eclipse season before the vernal (spring) equinox and after the autumnal (fall) equinox, and may exist in other days of the year.
3. Stray light exists for Band 7 approximately one hour before and after satellite local midnight for approximately forty days during the eclipse season before the vernal (spring) equinox and after the autumnal (fall) equinox. The intensity of the stray light is less than the requirements, but may affect certain applications.
4. Band 1 radiances may be brighter on the west end than on the east end by 1% or more.
5. Band 4 radiances are about 7% darker, and Band 5 radiances are about 7% brighter than commonly accepted values from comparable satellites products. These may be due to error in the gains of these channels so the bias is larger for brighter scenes.
6. Band 2 is brighter than commonly accepted values by up to 10%.
7. There are periodic infrared calibration anomalies (PICA) present in the data that can be seen as regular and repeating pulses in infrared brightness temperatures. The infrared calibration may produce an error with a periodicity depending on timeline.
8. There are periodic infrared calibration anomalies (PICA) present in the data that can be seen as regular and repeating pulses in infrared brightness temperatures. The infrared calibration may produce an error with a periodicity depending on timeline.
9. Image striping may occur across all 16 channels.

Contacts for specific information on the ABI data:

Fred Wu (L1b) xiangqian.wu@noaa.gov
Tim Schmit (CMI) tim.j.schmit@noaa.gov

There will be occasional interruptions to the flow while various post-launch tests occur and those interruptions will be communicated through the GRB forum distribution list.

A notification will be sent when the data is considered Provisionally Mature and suitable for operational use after further testing and validation.

Contact information for further information: NOAA Office of Satellite and Product Operations (OSPO) User Services at SPSD.UserServices@noaa.gov

See the OSPO General Satellite Messages webpage for this and other satellite related messages.

DATA QUALITY FLAGS

The GOES-17 ABI Level 1b (L1b) and Cloud and Moisture Imagery (CMI) Peer Stakeholder-Product Validation Review is scheduled for August 27, 2018. If the L1b products achieve Beta maturity level at that review then GOES-17 ABI L1b products will be added to the GOES Rebroadcast (GRB) radiofrequency stream as soon as August 28. All of the GOES-17 ABI L1b products including channels degraded by the ABI cooling system anomaly will be distributed via GRB. Since ABI channels 8-16 could be degraded during parts of the day, the pixels that are impacted will be flagged during the data quality control (QC) check. The Data Quality Flags (DQF) are added to the metadata during product generation processing in the ground system and included in the L1b radiance product transmitted on GRB. There are no near-term changes in the ground system planned for the data quality flags so the GOES-R Product Definition and Users’ Guide (PUG) Volume 4 is the reference. The DQF values are as follows:

DQF value 0 represents a pixel that passed the QC check and is labeled: good_pixel_qf

DQF value 1 represents a pixel that conditionally passed the QC check because it has some usable data and it is labeled: conditionally_usable_pixel_qf

DQF value 2 represents a pixel that failed the QC check because the pixels values are out of range and it is labeled: out_of_range_pixel_qf

DQF value 3 represents a pixel that had no values probably because the data was missing and it is labeled: no_value_pixel_qf

Early checks indicate users will see DQF=2 when the affected infrared (IR) channels are saturated.

The metadata in the ABI Level 1b radiances product provides statistical and other properties of the product image and supports diagnosis of algorithm anomalies. Specific metadata includes:

• Number of good and conditionally usable, and missing pixels.
• Number of saturated and undersaturated pixels.

The percentages of pixels assigned to each DQF value are also included in the product.

Data Sharing Guidance

Below is the guidance for sharing GOES-17 images, plots, data files, and publications.

IMAGE & PLOT FILES

Once the official NOAA/NASA release for an instrument has been distributed, you may share instrument images/plots (not data files) from GOES-17, however acquired or processed. These posts must contain the caveat: “GOES-17 Preliminary, Non-Operational Data.” Data files may not be distributed until after the data has reached “Provisional” maturity.

DATA FILES

Once an instrument’s data has reached Provisional maturity, you may share data files. All data or image postings should STILL state: “GOES-17 Preliminary, Non-Operational Data”. Data are only considered operational once Provisional maturity is attained AND GOES-17 is in the operational GOES-West assignment. These dates are subject to change in conjunction with testing and validation schedule changes.

PUBLICATIONS

If you are submitting a paper to be published, you may include pre-Provisional instrument data/images/plots as long as it will not be published until after Provisional validation is declared for that instrument. Exercise caution in publishing data regarding anomalies or artifacts as there are ongoing updates to the product quality.

"Sharing" includes methods such as posts on social media, showing or sending to friends/family, retaining on insecure drives, speaking to the press or media (whether direct or indirect), posting on blogs, posting electronic versions of presented presentations or papers, etc. This list is not exhaustive-- if you have a specific concern, see contact info below.

These restrictions apply only to instrument data/images/plots and do not apply to spacecraft or ground system engineering data.

IMPORTANT:

NOAA's GOES-17 satellite has not been declared operational and its data are preliminary and undergoing testing. Users receiving these data through any dissemination means (including, but not limited to, PDA and GRB) assume all risk related to their use of GOES-17 data and NOAA disclaims any and all warranties, whether express or implied, including (without limitation) any implied warranties of merchantability or fitness for a particular purpose.

If you have any questions about this policy, reach out to kathryn.mozer@noaa.gov, elizabeth.kline@noaa.gov, or kevin.fryar@noaa.gov.

Frequently Asked Questions

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Additional Information

• ABI Bands Quick Information Guides
• Loop Heat Pipe Fact Sheet
• OSPO Satellite Messages
• Contact OSPO User Services