After testing, NOAA-NESDIS shut GOES-10 down in June 1998, planning to keep it as an "on orbit spare" until GOES-8 or GOES-9 failed, which they expected around the year 2000 AD.
However, right after NESDIS shut down GOES-K, GOES-J's (GOES-9's) momentum wheels threatened to fail, so GOES-K was called right back out of storage in on 9 July 1998, for a week of spin-up and a month of orbital drift from 105W to 135W during August 1998 to take over as GOES-WEST.
GOES-10 operated as GOES-WEST until 27 June 2006, and then was taken out of operational service becasue it was running low on station-keeping fuel.
Late in 2006, NOAA moved GOES-10 to 65W to devote dedicated scan time to covering South America, as part of the Global Earth Observation System of Systems (GEOSS). While moving GOES-10, NESDIS took continuous 1-minutes scans of the southern USA.
GOES-10 is out of inclination-keeping fuel, so the satellite no longer stays over the equator. Consequently, imagery has to be reprocessed to make it look like it comes from a geostationary satellite.
There is a scrapbook of GOES-10 Results on-line.
During the CONUS-scan test, GOES-10 realtime images were posted on the web server at GSFC, and at a NOAA site.
After the test, NOAA put together a report on the results.
After two months of analysis and testing, GOES-10 was flipped north-south on July 31, and the north-pointing solar array was commanded to rotate in the opposite direction. Ever since then, GOES-10 has successfully tracked the sun "counterclockwise" 24 hours per day.
Broadcasts of images and the remainder of the post-launch test program from the upside-down GOES-10 satellite required a rewrite of the ground system software by NOAA-NESDIS contractors in late 1997.
So, for the remainder of 1997, the post-launch team tested the on-orbit cold-storage mode known as ZAP (Zero Angular Precession). ZAP mode testing during the first two weeks of November were quite successful, with minor anomalies from the predicted attitude and temperatures.
On 13 January 1998, GOES-10 was taken out of hibernation. There were no significant problems during the the wakeup sequence, and the Imager and Sounder performed satisfactorily during the software shakedown in January and February 1998.
In March-April 1998, the GOES-10 Imager was used to take rapid scans on the United States.
In May 1998, GOES-10 was tuned up and tested for normal operations.
In June 1998, GOES-10 was shut down adn returned to ZAP mode to serve as an on-orbit spare for GOES-EAST or GOES-WEST.
NOAA declines to operate GOES-10 as a "StormSat" to watch for rapidly developing events.
If GOES-10 suddenly loses all power from the solar array, the satellite will have to be de-orbited (pushed a few hundred kilometers higher) before the batteries are exhausted.
On July 16, after weeks of discussion and ground testing, the GOES-10 solar array was driven in the reverse direction, resulting in irregular motion and a snap, so the test was halted. A backlash (snap) is not unusual or harmful for this motor being put into reverse.
On July 23, the solar array was driven 1.5 degrees in the reverse direction, resulting in a pause, then slow motion, and then normal motion for 5 minutes until the scheduled end of the test.
On both July 24 and 25, the solar array was driven 1.5 degrees in the reverse direction, resulting in normal motion for 6 minutes until the scheduled end of each test.
On both July 29, the solar array was driven 15 degrees in the reverse direction, resulting in normal motion during the 60 minute test.
The entire spacecraft was flipped over on July 31st. With the solar array pointing north, the motor is being run "counterclockwise", allowing continuous sun-tracking and full power. Small periodicities in the counter-rotating array suggest some minor gear damage.
On August 8, some visible test images were taken (inverted), with no apparent anomalies.
On August 20, the first infrared data were taken with the Imager and Sounder focal planes cooled down to 104 K, with all systems OK. Sensitivity was within 10% of prelaunch values for all detectors, a typical post-launch condition.
As of mid-November, there have been no further anomalies with the solar array, even during large angle slews to accomodate ZAP mode on-orbit storage.
The engineering analysis of the sticky solar array, issued in January 1998, was unable to conclusively identify the cause of the jam-up.
The Imager's optical surfaces were cleaned and checked just before launch to minimize scattered light.
On-orbit, the GOES-10 Sounder (aka SN05) is delivering brightness temperatures a few degrees colder than the corresponding observations from the GOES-8 and GOES-9 Sounders. The underlying cause for this calibration error is under investigation (mid-1998).
The launch was slipped one day due to a tornadic storm front passing through central Florida on April 24.
GOES-K spacecraft completed construction and testing at Space Systems/Loral in Palo Alto, California in early 1996, and it was through thermal-vac testing in Boeing's facility in Seattle in mid-1996. GOES-J was shipped to the launch site at Cape Canaveral, Florida on a C5A aircraft on 15 January 1996.
GOES-K was launched, deployed, and tested for 3 months on-orbit at 105W. Then, it was stored "sleeping" on-orbit, facing away from the Sun in what is called the ZAP mode (Z-Axis Precession, one rotation per year relative to the Earth, for storage on-orbit facing steadily away from the Sun). On-orbit storage avoids on-earth storage costs, post-storage testing, and the 12-month delay expected between NOAA's call-up and launch.
Unfortunately, NESDIS does not budget money and manpower to operate a 3-satellite GOES constellation.
EVENT DATE
Launch GOES-K April 25, 1997 (01:49 EDT = 0549 UTC)
rocket firings, separations, April 25
partial deploy solar panel, etc.
Circularize Orbit April 25 - May 12
Apogee Motor Firing #1 April 26
Apogee Motor Firing #2 April 29
Apogee Motor Firing #3 May 1
Apogee Adjust Maneuver May 3
GOES-K becomes GOES-10 May 3
Deployments May 4 - May 6
Magnetic boom May 4
Solar Array May 5
Magnetic dipole estimation May 5
Imager/Sounder initialization May 6
Momentum wheels spinup May 6
Solar Sail May 6
GOES-10 ready May 7 (on orbit, deployments complete)
Instrument scan mirror contam. avoid. May 4-12
Start-ups and functional tests May 7-15
Final Orbit Trim May 10-12
First official visible image May 13
Outgassing May 5-31
Start-ups and functional tests May 7-TBD
Imager priority mode interrupt test TBD
Boresight alignment tests June 10-13
Storage Mode Test-dynamics phase June 16-20
First official infrared image June 21
Storage Mode Test-thermal validation June 22-26
Performance Testing June 28-August 5
INR startup-Imager June 30-July 3
INR startup-Sounder July 5-7
INR spec. tests, psuedo-schedules July 8-26
NASA Science Testing (interrupts) July 22-24
NOAA Science testing July 27-August 6
On-orbit Storage preparation August 11-13
North/South Maneuver August 14
Ranging/orbit determination August 10-11
East/West Maneuver (if needed) August 10
Pre-Storage Planning Meetings August 11
Enter ZAP on-orbit storage August 12
ZAP Storage Up to 2 years from entry
________________________
*INR stands for "Imager Navigation and Registration"
**ZAP stands for "Z-Axis Precession"
These dates are subject to change based on actual launch date and success of post-launch engineering checkout, and assumption that GOES-8 and GOES-9 are operational.
Date: Tue, 2 Jun 1998 07:10:03 -0400 (EDT)
From: Charles Bengston (cbengsto@csc.com)
Subject: GOES-10 ZAP Mode Activation
MIME-Version: 1.0
GOES-10 was successfully placed into a Z-axis Precession (ZAP) mode at
approximately 4:00 am this morning (June 7). This maneuver sequence was
the last major milestone prior to NASA handing over GOES-10 operations to
NOAA, scheduled for June 5. The entire ZAP activation sequence was
executed with no problems. This sequence returned GOES-10 to ZAP mode
following 4 1/2 months of rigorous ground system and spacecraft
post-launch tests while the in an inverted mode due to the solar array
drive anomaly. GOES-10 will remain in ZAP mode at a 105 degree longitude
station location until call up by NOAA to replace the existing GOES-8 or
9 operational spacecraft. Below summarizes the key maneuver sequences and
results of the ZAP activiation sequence:
The GOES-10 spacecraft is currently in a stable spin around the major
principal axis spinning at approximately .75 deg/sec with a Sun coning
angle of approximately .5 degrees. Spacecraft ZAP re-spins are required
when coning angles approach a maximum of 20 degrees. At this initial
coning angle (based on predictions and the previous ZAP test) a re-spin
may not be required for as much as 60 days. The solar array remains
stopped at the commanded ZAP mode array position. Thermal parameters are
all currently within storage mode limits. Instrument baseplate and 4
mounting panel heaters have been turned on. Engineers will be closely
monitoring both thermal and dynamics stabilization over the next couple
days. Some key events and observations that occurred during the
activation were:
- Instruments were configured for standby mode and the Sounder
filter wheel was turned off. Filter wheel spin down time was
nominal (measured at approximately 100 seconds).
- Momentum wheels were spun down and turned-off while spacecraft
was in pitch earth acquisition mode.
- Two large angle solar array slews of 82 and 111 degrees in the
reverse direction were successfully performed. Solar array
potentiometer data was nominal throughout both slews with no
unexpected signatures observed (ADS data not available due to MDL
transmitter off). The second slew positioned the solar array
approximately 3 degrees off the predicted principal axis to 159.2
degrees. The 3 degree offset was required to allow for final
tweeking of the solar array in the reverse only direction to the
actual measured principal axis. Final solar array fine adjustments
will be performed over the next day.
- The XRPE temperature temporarily reached 60 degrees C (close to Qual
temperature) during the second solar array slew due to
sunlight on the back of the electronics. However, the temperature
rapidly dropped back to nominal values shortly following the slew
completion.
Ranging with the DSN will be conducted over the next couple of days to
determine spacecraft orbit and drift rates.
Reactivation of GOES-10 should take about 14 days, and movement to an operational slot 30 degrees away at a drift rate of 1 degree perday will require another 30 days. (A 45-day delay is a lot less than a 1-year delay to launch and commission a spare satellite stored on the ground.)
a. GOES-10 to be activated upon failure of either
the imager, sounder, or a critical, nonredundant control subsystem
(e.g., lose IMC) on either operational GOES.
b. Maneuver to operational station from 105W to begin as soon as possible,
based on satellite operational constraints.
c. Management (AA NESDIS in concert with AA NWS) to review call-up
decision at the time of failure to account for all possible contingencies.
In the event of a GOES-8/9 failure, GOES-10 images should be available within a few days while soundings and derived products would be on-line within 4-7 weeks.