GOES logo GOES-L UPDATE last updated 12 June 2006


GOES-11 was kept in cold on-orbit storage at 104 W during 2000-2006. It was revived at least once per year for orbit adjustment. GOES-11 will have had 2 years of on-ground storage and 6 years of on-orbit storage before becoming operational. This on-orbit storage is not "free", since the same amont of fuel must be used to maintain orbit inclination over the equator. In addition, radiation damage and other simple aging effects are unavoidable.

Post-launch testing was more uneventful than any of the previous satellites in the series. After launch and geo-stationing in 2000, there was at least 10 years worth of station-keeping fuel on board. During on-orbit storage, there were no significant concerns with the instruments or spacecraft.

On 16 May 2006, GOES-11 failed to power on its sensor data transmitter side A, a communications box which formats and transmits the raw instrument data to the ground. Two fuses for side A were tripped. On 19 May, the redundant sensor data transmitter side B was successfuly turned on.

In May-June 2006, GOES-11 was revived to replace GOES-10 as GOES-WEST at 135W.

In 2008, one of the two batteries on GOES-11 failed, leaving it with just enough power to get safely through spring and fall eclipses with most of the equipment turned off.

Topic: GOES-10 to GOES-11 Transition Plan  - Update #5
Message Issued: June 12, 2006, 0140 UTC
Satellites Impacted: GOES-10 and GOES-11
Products Impacted: GOES-10 and GOES-11 Imager and Sounder Data and
Associated Products including AWIPS
Date/Time of Initial Impact: GVAR Switch from GOES-10 to GOES-11 on June
21, 2006, GOES-11 Direct Operations on June 28, 2006.

***GOES-11 is scheduled to replace GOES-10 as the GOES-West operational
spacecraft on June 21, 2006***
(GVAR switch from GOES-10 to GOES-11 on June 21. GOES-11 GVAR to be
flowed through GOES-10 until June 28)

This message is to provide additional information on a planned
transition from GOES-10 to GOES-11 as the operational GOES-West
spacecraft.  Characteristics of the Imager and Sounder are similar from
GOES-10 to GOES-11 (except GOES-10 is currently operating in a Yaw Flip
mode).  Additional information can be found at: 
http://www.osd.noaa.gov/Gvar/gvardownload.htm ). Ground equipment may
require adjustments to satellite id.

Position locations of GOES-11 are contained at the end of this message.

The plans developed are intended to cause as few disruptions to all
users who need to acquire the GOES-11 GVAR signal via a ground antenna.

An up to date synopsis:

(1) GOES-11 was taken out of Z-axis storage and is currently being moved
to the 135 degrees West position.

(2) GOES-11 GVAR startup (for testing and calibration purposes) on May
25, 2006 with short Full Disk imaging (19 minute scans) at XX:00 and
XX:30, with CONUS soundings at XX:01.

(3) As GOES-11 arrives close to 135 degrees West (on June 21, 2006),
GOES-11 data will be flowed through GOES-10 communication links, thus,
GOES-11 data is operational but received through GOES-10 downlink. Users
point to GOES-10 to receive GOES-11 data. At this point GOES-11 data are
considered operational, but should significant problems occur, GOES-10
data can be reestablished quickly. The GOES-West schedule at:
http://www.ssd.noaa.gov/PS/SATS/GOES/WEST/sched.html will begin on
GOES-11 on June 19, 2006. Details of this event:
- June 19 at 21:45 UTC - GOES-11 begins West imaging schedule.
- June 21 at 19:00 UTC - GOES-11 starts to flow data through GOES-10
(GVAR switch). GOES-10 begins executing a Housekeeping only schedule.

(4) As GOES-11 is within 1 degree of GOES-10 (on June 28, 2006), will
turn off GOES-10 signal, and acquire GOES-11 data directly from GOES-11,
not GOES-10.  Users should not need to repoint their antenna, as the two
satellites are very close. (GOES-11 stop maneuver scheduled for June 28
at 03:07 UTC)

(5) Switch ancillary communication services (DCS, LRIT, EMWIN, SAR) from
GOES-10 to GOES-11, on or about June 28, 2006.

(6) Pending the successful PLT and checkout of GOES-N (launched May 24,
2006), and successful arrival of GOES-11 at 135 degrees West, GOES-10
will be moved to 60 degrees West at a rate of 0.6 degrees per day for
South American support in October 2006. (GOES-10 drift start maneuver
scheduled for June 30 at 00:00 UTC)

These intricate steps are necessary to provide a continuous flow of
data, with minimal impact to users. There should be no need to readjust
antenna unless there is a desire to acquire GOES-11 data prior to
GOES-11 becoming operational.

Position Locations for GOES-11:

Date Time(UTC) Lat  Lon  
60612      0  0.36N 120.09W
60612 120000  0.36S 120.28W
60613      0  0.36N 121.05W
60613 120000  0.36S 121.24W
60614      0  0.36N 122.00W
60614 120000  0.37S 122.20W
60615      0  0.37N 122.96W
60615 120000  0.37S 123.16W
60616      0  0.37N 123.92W
60616 120000  0.37S 124.12W
60617      0  0.37N 124.88W
60617 120000  0.37S 125.08W
60618      0  0.37N 125.84W
60618 120000  0.37S 126.03W
60619      0  0.37N 126.80W
60619 120000  0.37S 126.99W
60620      0  0.37N 127.76W
60620 120000  0.37S 127.95W
60621      0  0.37N 128.72W
60621 120000  0.38S 128.90W
60622      0  0.38N 129.67W
60622 120000  0.38S 129.85W
60623      0  0.38N 130.62W

Contact Information:
Brian Hughes
Satellite Services Division
301-763-8051 x106
See http://www.ssd.noaa.gov/PS/SATS/messages.html  for this and other
satellite related messages.
See http://www.ssd.noaa.gov  for full GOES scanning schedules.

First GOES-11 Images

Public relations stories about the GOES-L launch on 3 May 2000

Prelaunch photo of the GOES-11 spacecraft (0.4 MByte JPG)

NOAA Press Release

SOCC Statement

GOES-11 Status

On August 15, 2000, at approximately 06:16 Z, the GOES-11 spacecraft was
successfully placed in the Z-Axis Precession (ZAP) storage mode. Flight
data shows that the actual major axis and desired spin-up rates were
extremely close to those predicted. The initial maximum nutation cone was
approximately 2.5 degrees, indicating a good spin maneuver and an accurate
mass property prediction from the spacecraft manufacturer, SS/L. The
target angular velocity magnitude was 0.7 deg/sec and 0.698 deg/sec was

Further analysis will reveal long term attitude and thermal stabilization
performance, but it is expected to be excellent. Ranging results show
that GOES-11 is now located at 104.2 deg W longitude with a West drift rate
of 0.01 deg/day. The GOES-11 orbit will turn around at 106.7 deg W
longitude in July 2001. The event marks the 7th ZAP storage maneuver for
the GOES constellation and a further validation of the robustness of the
storage mode design.

Significant Events Timeline

Launch                                                May 3

Circularize Orbit                                     May 3--May 21
    AMF 1          May 5
    AMF 2          May 7
    AMF 3          May 9
    AAM            May 11
    Trim 1         May 18
    Trim 2         May 19
    Trim 3         May 21

    Mag boom and final SA deployment                  May 12
    Dipole Estimation                                 May 13
    Momentum Wheel turn-on and Solar Sail Deployment  May 14-15
    Cooler Cover deployment                           June 10

GOES-L becomes GOES-11                                May 11

Imager/Sounder Initialization                         May 14

First Official Image                                  May 17 at 1900 UTC

Sounder and Imager Outgassing                         May 12--June 9

Instrument Contamination Avoidance                    May 14-20

Start-ups and functional tests                        May 12--June 9
    X-Ray Sensor (XRS) Turn on           May 16
    Safehold Mode Characterization       May 21
    Communications Testing               May 22--June 7
    Solar Array Drive stepping tests     May 25-27
    Earth Sensor Characterization        May 28--June 9

System Performance and Operational Testing (SPOT)     June 10--July 23

Station Maneuvers                                     June12-14
    North/South Stationkeeping Maneuver  June 12
    East/West Stationkeeping Maneuver    June 14

NOAA Science Testing                                  July 24--August 13

Enter Z-Axis Precession (ZAP) storage mode            August 14-15

Spacecraft Hand-over to NOAA                          August 16

Spacecraft Configuration

As of 21 May 2000:

 AOCE 1 on
 DIRA 1 (gyros) on
 Coarse Analog Sun Sensor (CASS) 1 on
 Digital Sun Sensor (DSS) 1 on
 Earth Sensor (ES) 1 on
 Magnetometer 1 on
 X-Ray Sensor on

 Magnetometer boom-released-locked
 Solar Array fully deployed
 Solar Array Drive Electronics side 1 on
 Solar Array Run Mode
 Trim Tab at 10 degrees
 Solar Sail fully deployed

Control mode and Actuators
 Normal on-orbit L1Mode (earth pointing)
 Momentum Wheels 1 and 2 @2900 RPM and Reaction Wheel off
 Main Spacecraft Thruster Isolated

Telemetry Transmitters
 CDA A transmitter on
 DSN A transmitter on
 DSN B transmitter off
 Command Units 1 and 2 in secure mode

 Power AMPs A and C on (for thermal heating)
 Sensor data transmitter on

 Imager/Sounder Outgas heaters on High

 Imager & Sounder on and scan functional


1) Notch Filter 2 Occurred May 12.
An upgrade to the attitude control software designed to minimize resonances between the spacecraft and solar panel did not work properly. (It will remain disabled until further notice)

2) Sounder Filter Wheel Back-EMF anomaly occurred May 18.
Sounder FW current and un-powered winding voltage showed YH TLM violation. Sounder FW current and voltage problems were corrected by cycling the Sounder electronics ON. Both current and voltage went back to the nominal values.

3) AOCS FMT change anomaly occurred May 18.
When commanded to switch to FMT 126, FMT 126 was not received. The problem was isolated to the Santiago ground network station and their operation method for energizing the 16 kHz sub-carrier just before a command up-link and dropping it immediately after the command is sent.

4) Attitude Deviation on June 16.
An attitude fluctuation of 0.01 degree was observed in yaw (east-west). The cause is not yet understood.


In mid-1998, the GOES-L spacecraft completed thermal-vac testing at Space Systems/Loral in Palo Alto, California. GOES-L was shipped to Cape Canaveral in mid-December 1998. There were no significant issues with the spacecraft and instruments, which were stored at the Cape for 18 months.


Imager SN06 was constructed and tested at ITT in Fort Wayne, Indiana. It was shipped to SS/L for integration onto the spacecraft in August 1997.


Sounder SN06 has been constructed and tested at ITT in Fort Wayne, Indiana. It was shipped to SS/L for integration onto the spacecraft in August 1997.

Launch Saga

After being assembled and tested during 1997-98, GOES-L was to be launched in the spring of 1999 and used to replace GOES-8 in 2000.

The expected launch date was 15 March 1999, but then it was moved up to 15 May 1999 to accomodate another launch.

The expected launch date was then moved to 23 May 1999, due to concern about the second stage rocket.

The GOES-L May launch was then put on hold throughout the summer of 1999 due to a spate of rocket failures in similar second stage rockets.

The rockets were cleared for use in August of 1999, and GOES-L was re-scheduled for mid-November 1999 and then mid-December 1999.

The late 1999 launches which were both pre-empted by other launches.

In January 2000, GOES-L was given a firm launch data of 3 May 2000.

However, a Shuttle launch during the last week of April 2000 was delayed by weather. It could have pre-empted the GOES-L launch in the first week of May. Fortunately, GOES-L was given the green light on April 29th.

Finally, GOES-L did launch sucessfully on 3 May 2000, at 3:07 am EDT, just 40 minutes after the planned launch time of 2:27 am.

After about 3 months of post-launch checkout at 104W, NOAA put GOES-11 into on-orbit cold storage in mid-August 2000.

We hoped that NOAA would use GOES-L to perform continuous rapid scans of the south Atlantic and Caribbean during the Y2K hurricane season, before being turned off.

back to the GOES Project page