Screenshot from ULA Webcast of the launch of GOES-T
Mission Rundown: ULA - Atlas V 541 - GOES-T
Written: November 25, 2022
Dude. It’s a weather satellite
United Launch Alliance (ULA) has launched the Geostationary Operational Environmental Satellite (GOES)-T advanced weather satellite for the US National Oceanic and Atmospheric Administration (NOAA). GOES-T launched on an Atlas V 541 from Space Launch Complex (SLC)-41 from Cape Canaveral Space Force Station (CCSFS). The launch took place on March 1, 2022, at 4:38 PM EST (21:38 UTC).
Two pilots with a restored F-86 Sabre took this photo of the GOES-T launch from SLC-41. Squirrel
GOES-T is the third satellite in the GOES-R satellite series, the 19th overall GOES satellite, and the second Atlas V launch of 2022. Following the launch, GOES-T will become GOES-18 and will be stationed in the GOES-West position, replacing GOES-17.
The attachment of four side-mounted solid rocket boosters (SRBs) to the Atlas first stage will generate three-quarters of the energy necessary at liftoff to power the vehicle on to a complex, seven-hour flight. The core Atlas V booster will do the remaining 25%.
At T-7 minutes, the final Go/No-Go poll is conducted. Once the poll is complete and authorization to proceed received, the countdown resumes at T-4 minutes.
The RD-180 engine ignites at T-2.7 seconds. At T+1 second, the four GEM-63 boosters ignite and the Atlas V lifts off the pad. At T+5.3 seconds, the Atlas begins a pitch and roll maneuver to reach the proper flight profile while minimizing the loads on the rocket.
The four GEM-63 boosters burn out 94 seconds into the flight and are released 24 seconds later. This must be done to secure a safety distance from shore for rocket disposal.
With the rocket out of the atmosphere, payload fairing jettison occurs at T+3 minutes 30 seconds followed by Atlas engine shutdown at T+4 minutes 22 seconds.
Six seconds later, the Atlas separates from the Centaur, and 10 seconds after that, the Centaur main RL-10C-1 engine ignites.
NOTAM hazard areas where Atlas V 541 will drop off SRB boosters, fairings and 1st stage
Just under eight minutes after Centaur’s ignition, the rocket reached its initial parking orbit. Centaur then begins an approximately 11-minute coast to a point directly over the equator.
Centaur then reignites to boost the apogee to around the GEO altitude of 36,000 km. The centaur burns for five minutes. After the burn it begins a long-duration coast phase.
After three hours, Centaur burns for a third and final time. This burn raises the perigee close to 8,900 km and lowers the inclination to 9.4 degrees. After a final two-minute coast, GOES-T separates from Centaur in 35,286 km by 8,876.7 km at a 9.4-degree inclination.
Following separation from the Centaur, GOES-T will begin an orbit-raising operation that will be completed on March 23. Once in GEO, GOES-T will be renamed GOES-18 and will be in the 89.5-degree and 136.2-degree locations for its on-orbit testing. This testing will make sure the spacecraft and instrument systems are ready for operations.
The upper stage Centaur’s RL-10C-1 engine depletes its last reserves of propellant to lift itself into a graveyard orbit some 38 655 km away from earth. The remaining gasses and fuel vapors will be vented at apogee in order to raise the perigee just a little.
The Centaur’s propellant tanks must be empty to avoid exploding like a rotting toad in the sunlight. At least three upper stage Centaur’s weren't purged and exploded in 10-15 large pieces of space debris.
The GOES-T Payload
GOES has its roots in the 1960s with the Applications Technology Satellite (ATS) program. ATS was NASA’s program to test satellites in Geostationary orbit (GEO) that could be used to observe the weather. The six satellite program was successful and led to the Synchronous Meteorological Satellite (SMS) Program.
The SMS program was NASA’s operational program having real time weather observations of the US. NOAA later became involved with the program, and it was renamed GOES. Since then, NASA and NOAA have continued to work together on the GOES program.
Despite issues seen with previous satellites while in orbit, the GOES program has successfully allowed for continuous observations for nearly 47 years.
The GOES-R program became operational with the GOES-R satellite, launched in November 2016. The GOES satellites, despite having individual letter and number designations, are also referred to by their program name, which is taken from the first GOES in that new series. GOES-R was the first of the GOES-R program, of which GOES-T is a part.
Its twin, GOES-S, was launched on an Atlas V 541 in March 2018 and successfully made it to GTO. It later moved to GEO where it began its testing. However, in May 2018, its Advanced Baseline Imager’s (ABI’s) cooling system started having performance issues due to a blockage of a coolant line.
For the whole GOES-R program, the ABI is the primary instrument for imaging Earth. The performance issues on GOES-S, now named GOES-17, did not impede its entering service. However, the GOES-T satellite was delayed for over a year to fix the issues with the ABI instrument. Reprogramming of coolant procedures.
GOES-T is the latest satellite in the GOES-R program. Like the other three in the series, the satellite is based on the Lockheed Martin A2100 satellite bus. The A2100 is Lockheed Martin’s offering for medium Earth orbit and GEO satellites. Since its introduction, the A2100 has been used for both military and commercial missions.
For the GOES-R program, the satellites have a dry mass of 2,857 kg. Fully fueled, each masses 5,192 kg and will have a lifetime of around 15 years.
The ABI instrument is mounted on the nadir, Earth-facing side of the GOES platforms. ABI is a multi-channel passive imagining radiometer designed to observe the Earth and its weather activity.
A second scientific instrument, Geostationary Lightning Mapper (GLM), is also mounted on the nadir side of GOES. GLM will monitor Earth for sudden, visual events to help build a map for lightning activity.
The second set of instruments is 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 surface changes.
The second instrument on the solar array is the Extreme Ultraviolet and X-Ray Irradiance Sensors (EXIS) that monitor specific spectral bands in the light coming from the sun.
Two years after GOES-T’s launch, the final GOES-R satellite, GOES-U will be launched with an additional instrument, the Compact Coronagraph (CCOR) provided by the Naval Research Laboratory.
The CCOR will work with NOAA's Space Weather Follow-On-L1 (SWFO-F1) to observe the solar activity. SWFO-L1 will launch on Falcon 9 in 2025.
Graphic image of GOES-T keeping a keen eye on weather conditions on Earth and the Sun. Source
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 NASA’s Goddard Space Flight Center, the magnetometer will measure magnetic field variations associated with space weather.
Testing is expected to be completed on January 3, 2023, with GOES-18 will be declared operational. Then GOES-18 will then drift to the GOES-West position with GOES-17 being transitioned to a backup satellite.
Graphic of the GOES-R series spacecraft locations. They hover over America. Not the World. link
The Atlas V rocket
The Atlas V core in use for this mission is AV-095. First launched in August 2002 on the Hotbird-6 telecommunication mission, Atlas V has since launched 91 times, with a nearly spotless record. After GOES-T, there are built 24 remaining Atlas V launches before its retirement in favor of the upcoming Vulcan rocket.
Atlas V is a two-stage liquid-fueled rocket. The first stage booster is a single-engine stage utilizing a Russian-built RD-180 engine. The RD-180 generates 3,828 kN of thrust with a specific impulse of 337 seconds. This stage is 32.5 meters in length, 3.81 meters in diameter, uses RP-1/LOX, and burns for about four minutes.
For the initial part of the flight, the first stage can support up to five GEM-63 solid rocket boosters. These boosters, first introduced on the NROL-101 mission in November 2020, are manufactured by Northrop Grumman and are smaller versions of the GEM-63XL boosters set to launch on Vulcan. Each booster generates 1,652 kN and burns for about 94 seconds. This mission will use four boosters.
The second stage is the Centaur, a hallmark of the Atlas family that was first used in 1962. Since then, the Centaur has evolved into the Common Centaur used today. To power the stage, an Aerojet Rocketdyne RL10C-1 engine is used to place its payload(s) into its final orbit. The RL10 engine is historic, having been used over several generations of rocket families and has been produced over 500 times.
The RL10C-1 uses liquid hydrogen and liquid oxygen to generate 101.8 kN of thrust with a specific impulse of 449 seconds. It has a 842 second - 14 minute burn time at full thrust. Centaur is also where the Atlas V rocket’s avionics systems are housed. Centaur is 3.05 meters in diameter and 12.6 meters in length.
Encapsulating both the Centaur upper stage and the GOES-T satellite is the payload fairing. Seen with the ULA rockets, a four or five-meter fairing can be used to better suit a customer’s needs. The five-meter fairings used on the GOES-T mission are manufactured from RUAG space.
To show what variant of the rocket is used on a given mission, ULA uses a three-digit number. The first digit denotes the diameter of the payload fairing, the second indicates the number of solid rocket motors, and the third represents the number of RL10 engines on the Centaur upper stage.
On GOES-T, the Atlas V was a 541, meaning a five-meter fairing with four GEM-63 boosters and a single RL10C-1. Using the Atlas V 541 allows ULA to put GOES-T into an optimized GTO that can place the satellite closer to its final orbit and therefore allows for less fuel consumption. This will help extend GOES-T’s operational lifetime.
