2.08.2021
The National Oceanic and Atmospheric Administration’s (NOAA’s) Geostationary Operational Environmental Satellite (GOES)-East/17 has suffered another major issue while in orbit, as NOAA aims to replace the problematic satellite with GOES-T. GOES-17 is the second satellite in NOAA’s GOES-R program, a replacement to the aging GOES-N satellites.
The GOES satellite constellation is NASA, NOAA’s weather constellation to provide 24/7 weather observation of the US.
Current GOES program
After deploying its solar array, it began a multi-day maneuver using its onboard LEROS-1c engine, and successfully placed itself into a geostationary orbit (GEO) — at which point it was renamed GOES-16. After completing a year of on-orbit testing and inspections, it was moved into its operational location in the GOES-East position.
A little over a year later, in March 2018, GOES-S launched on an Atlas V 541 and successfully made it to GEO, being renamed GOES-17, and began its year of on-orbit testing; however, this is when its first of many issues began. In May 2018, the Advanced Baseline Imager (ABI) instrument started to encounter performance issues with its cooling system.
The ABI is the GOES’s primary instrument for imaging Earth’s weather, oceans, and environment. While this issue did not delay GOES-17 service start time, it did cause delays for the next satellite in line, GOES-T. Due to the issue, GOES-T was delayed for over a year as the satellite required disassembly to replace its own ABI instrument. It is schedule to launch no earlier than January 8, 2022.
Launch of the GOES-R/16 satellite. Credit: United Launch Alliance
GOES-U, the last satellite in the GOES-R program, was not far enough along in construction to be adversely affected by the needed change and is scheduled to launch in 2024 without a delay from this issue.
During investigations, NOAA discovered that the ABI heat pipe was not transferring heat correctly to the satellite’s radiators due to a blockage in the pipes causing a restricted flow of coolant to the ABI and thus causing it to overheat. NOAA adjusted the instrument’s operations and conducted more testing, leading to a new cooling timeline.
L3Harris, the manufacturer of the ABI, redesigned the instrument for the GOES-T and GOES-U satellites. The new design uses less complicated hardware configurations that eliminate the filters that are susceptible to debris.
After the investigation, NOAA sent a software update to GOES-17 to fix its coolant system. During the software update, the satellite experienced a memory error that caused it to shut down. It was reactivated, and no damage was found on the ABI. After this, GOES-17 finally entered operation in the GOES-West position. As a precaution, GOES-14 and GOES-15 were reconfigured as backups for the GOES-16 and 17 satellites.
Newer issues for GOES-17 began on the early morning of July 22, 2021, after its onboard computer triggered the flight computer to enter “safe-mode.” This caused all of GOES-17’s instruments to shut down, and the satellite was temporarily out of commission. NOAA ground teams quickly began recovery operations, and by the following day the satellite was returned to normal.
Photo of the GOES-R ABI instruments. Credit: Lockheed Martin
The initial findings of the most-recent GOES-17 anomaly point to a memory bit-error found in the spacecraft computer. This latest anomaly will not cause any lasting effects to the GOES-17/West satellite, but the NOAA team recalibrated its instruments nonetheless. The ABI and magnetometer were the first two instruments to be restored.
Due to the continued issues with the GOES-17/West satellite, NOAA aims to replace it with GOES-T next year.
Future of GOES
GOES-T is the next-in-line satellite in the GOES-R program. It is based on the A2100 satellite bus, a Lockheed Martin offering for Medium Earth Orbit and GEO satellites, and has been used for military and commercial missions like the GPS-IIIsatellites, Arabsat 6A, and the Mobile User Objective System (MUOS) satellite constellation.
In August 2020, the satellite bus for GOES-T was completed with the new ABI instrument. The A2100 satellites are produced and tested at the Lockheed Martin Waterton Facility in Colorado. The satellite started final testing, to ensure it can survive the harsh environments of launch and space, shortly after it was completed and is set to finish testing in September.
These tests are also designed to verify the redesigned ABI instrument.
While the ABI is one of the main instruments mounted on the nadir, Earth-facing side of the GOES platforms, it is not the only one. The second scientific instrument mounted here is the Geostationary Lightning Mapper (GLM). GLM will monitor Earth for sudden, visual events to help build a map for lightning activity.
GOES-T undergoing vibration testing. Credit: Lockheed Martin
A second set of instruments are mounted on the satellite’s solar panel to track the Sun. The first is the Solar Ultraviolet Imager (SUVI), which operates in the extreme ultraviolet, capturing full images of the sun to monitor eruptions, solar flares, and changes to the surface.
The second instrument on the solar array is the Extreme Ultraviolet and X-Ray Irradiance Sensors (EXIS) that monitors specific spectral bands in the light coming from the sun.
Joining those two are the Space Environment In-Situ Suite, consisting of four sensors that will take readings of the space environment around the satellite and a newly upgraded magnetometer, GMAG. Built by the NASA Goddard Space Flight Center, the magnetometer will measure magnetic field variations associated with space weather.
Once testing for GOES-T is complete, Lockheed will deliver the satellite to the Kennedy Space Center, likely using a Lockheed C-5M Super Galaxy cargo aircraft. After arriving at KSC, it will be unpacked and transferred to the Astrotech Space Operations facility, where it will be loaded with fuel and undergo final testing and encapsulation.
Once all pre-launch operations are complete, GOES-T will launch on an Atlas V 541 no earlier than January 8, 2022 at 16:33 EST / 21:33 UTC from SLC-41. It will follow a near-identical flight path as GOES-17 and will move itself into GEO. GOES-T, to be renamed GOES-18 once in GEO, will complete the same on-orbit testing as well.
As soon as that testing is complete, GOES-18 will replace GOES-17 at the GOES-West position. GOES-T/18 will work in tandem with GOES-16/East in capturing high-resolution coverage of storm systems, lightning, wildfires, coastal fog, and other hazards affecting the western U.S.
GOES-U’s SUVI. Credit: Lockheed Martin
In the following years, the final GOES-R satellite, GOES-U, will sport an additional instrument, the Compact Coronagraph. Provided by the Naval Research Laboratory, it will be used to image the Sun’s corona to help detect and characterize coronal mass ejections.
In July 2019, GOES-U underwent mating of its system and core module, connecting its “brain” and “body” together. Once completed, it will undergo the same testing as the other GOES-R series satellites.
Past of GOES
The GOES satellite program traces its history to the 1960s when NASA began the Applications Technology Satellite (ATS) program to test weather satellites in GEO. Six satellites were launched in the ATS program, the first in 1966. With five of the six satellites, based on the spin-stabilized Hughes’ HS-306 satellite bus, three successfully reached orbit and two were unsuccessful.
ATS-1 was the first in the program, launching in December 1966. It was successfully launched on an Atlas-Agena and would operate for 12 years. ATS-2 was launched in April 1967, but due to a failure with the Agena upper stage, failed to reach its intended orbit and was decommissioned six months later.
ATS-3 was successfully launched to GEO in November 1967, where it completed communications testing and provided images for meteorological studies. It was decommissioned at the same time as ATS-1. ATS-4 followed in August 1968 but was left in a low Earth orbit and burned up in the atmosphere.
ATS-5 was the last of the original satellites; it successfully reached GEO but began a flat spin after firing its apogee kick motor. It recovered but was rotated in the wrong direction. Nevertheless, it was able to complete many of its objectives and was retired after 15 years in 1984.
ATS-6 undergoing testing. Credit: NASA
The success of the first five satellites led to the last satellite in the ATS program.
A sixth satellite, ATS-6, was successfully launched on a Titan-3(23)C rocket in May 1974. The ATS-6 satellite used a brand new type of satellite bus, the ATS-6 bus, to test several new technologies, including ion engines, three-axis stabilized platforms, and communications. The success of the early ATS program led to the start of a new weather satellite program: the Synchronous Meteorological Satellite (SMS) program.
The first five of the satellites of this program were nearly identical. SMS 1 was launched in May 1974 by a Delta 2914 rocket, and successfully reached GEO and began operations. In February 1975, SMS 2 was successfully launched and also began operations.
With the success of the two SMS satellites, NASA and NOAA started a joint program, based on the SMS program, for operating weather satellites in GEO. This new joint satellite constellation would be called GOES. With this, the final three planned SMS satellites took on the new designations of GOES-1 through 3.
GOES-1 launched in October 1975 on a Delta 2914 and successfully began its own operations. GOES-2 followed two years later in June 1977 with GOES-3 joining another year later. Both GOES-2 and GOES-3 were retired in 1993 but were reactivated in 1995 as communication satellites.
GOES-2 was used to allow communication in the Pacific Ocean before being retired for the last time in May 2001. GOES-3 was also used for communications in the Pacific but was retired in June 2016, after a full 38 years in operation.
GOES-4 through 7 were the first satellites built specifically as part of the GOES program. GOES-4 through 6 were launched in 1980, 1981, and 1983, respectively, but this new generation of satellites started a trend of issues. GOES-G (using the before-launch letter designation — numbers are only assigned after successful insertion to GEO) was launched in May 1986 but was lost during first stage ascent after a premature engine shut down. GOES-G was supposed to replace the problematic GOES-5 satellite.
Artist impression of SMS-1 thru GOES-3. Credit: NOAA
GOES-5 had issues with its visible and infrared atmospheric sounder (VAS) that caused NOAA and NASA to shut down the instrument. GOES-6 was moved to help replace GOES-5. Later GOES-1 and 4 were reactivated to help replace GOES-5 while a replacement was launched. The last satellite in the first GOES generation, GOES-7, was successfully launched in February 1987 and successfully reached orbit; it was retired after 25 years in 2012.
The second generation of satellites started with GOES-8 in 1994. These five satellites were based on the SSL-1300 satellite bus. GOES-8 and 9 were launched in 1994 and 1995 on an Atlas-1. However, both satellites had nearly identical issues.
A design fault with its motor winding on its imager and sounder instrument caused one of two sets of the motors to fail. If both sets were lost, the instrument would be inoperable. It was found that the glossy potting compound the windings were encased with would expand and contract in extreme temperatures, causing wires to break apart. This was fixed with the next satellite, GOES-10.
Another failure on both satellites occurred with their momentum wheels. On GOES-8, one of the wheels failed, but on GOES-9 both wheels suffered issues. GOES-8 operated until 2004 while GOES-9, with both wheels having issues, caused more power to be used than expected, and images were returned back with noise. This led NOAA to place GOES-9 in storage and replace the satellite with GOES-10. GOES-9 was then used by Japan from 2003 to 2005 and was retired in June 2007.
GOES-10 was launched in April 1997 by an Atlas-1 after undergoing changes caused by the GOES-8 and 9 issues. It was launched successfully but also encountered many issues during in-orbit testing. Just days into checkouts, its main solar array became stuck and couldn’t face the sun. Two months later, the satellite was flipped North-South and the solar array was commanded to rotate in the opposite direction then normal. The fix worked and allowed the solar array to track the sun. GOES-10 was used as a backup satellite until December 2009 when it was retired due to fuel exhaustion.
GOES-10 in final launch preparation. Credit: NASA
GOES-11 was launched on an Atlas IIAS in May 2000 and successfully reached orbit and completed in-orbit testing. It was used as an on-orbit backup until its retirement in December 2011.
GOES-12 joined the fleet in July 2001. In December 2007, during three orbital adjustment maneuvers, it began to leak propellant and was shut down before being recovered. This happened again in 2008 and 2009 and led to GOES-10 and GOES-13 stepping in for weather coverage. In 2009, GOES-10 was replaced by the GOES-13 and retired in 2013.
GOES-12 was the last satellite in the second GOES generation with generation three based on the Boeing 601 satellite bus beginning with GOES-13, which was launched on a Delta IV in May 2006. Issues began six months after launch when a solar flare damaged the satellite’s solar X-ray imager.
In September 2012, the satellite started sending back blurry images and was placed on standby while GOES-14 took its place. The issue was traced to aging lubricant in the sounder system. After fixing the issue, GOES-13 was put back into service before being hit by a micrometeoroid in 2013. The impact event caused it to enter safe mode; however, no major damage was detected.
In 2017, it was put into storage. Its sounder malfunctioned again in 2018 and had to be turned off before it was transferred to the U.S. Space Force in 2019 and renamed to :Electro-optical Infrared Weather System Geostationary (EWS-G1).
The last two satellites in the third generation are the GOES-14 and GOES-15 satellites. The two satellites were launched on a Delta IV rocket and both successfully reached orbit where they have served as on-orbit backups. A fourth third-generation satellite, GOES-Q, was an option but was canceled in 2004.
Quelle: NS