Why is NOAA’s brand new billion dollar weather satellite going blind?


The first months of a very expensive satellite in space go very badly. The cooling system the multibillion-dollar device needs to properly observe the atmosphere failed to start, leaving the satellite partially blind.

Called GOES-17, the glitchy orbiter is a brand new satellite from the National Oceanic and Atmospheric Administration (NOAA). It is the second in an $11 billion family of four high-resolution, state-of-the-art weather satellites that NOAA has developed to replace the aging previous generation of geostationary sky observers: GOES-13. , GOES-14 and GOES-15. (GOES stands for Geostationary Operational Environmental Satellite.)

Each of the four satellites of this family has the power to observe the Earth’s atmosphere in unprecedented detail, with the potential to improve storm forecasting and other risk assessments. GOES-17’s twin, GOES-16, was launched in 2016 and is already operational, its imagers trained over a region stretching from the Americas to the west coast of Africa.

GOES-17, built to the same specifications as GOES-16, was launched in march with the task of monitoring weather conditions across the western United States and the Pacific Ocean. But, NOAA revealed in a May 23 statement, as the agency took steps to get the satellite online in orbit, a major problem arose. The satellite’s Advanced Baseline Imager (ABI) cooling system – GOES-17’s large eye for monitoring atmospheric winds – “did not start up properly”, and the imager spends about half the day blindly. [GOES-S: NOAA’s Next-Gen Weather Satellite in Photos]

The ABI is supposed to see light on 16 channels of the visible and infrared spectrum, NOAA engineers explained in a May 23 press call. But to see well, it must be very cold – 60 kelvins (minus 352 degrees Fahrenheit, or minus 213 degrees Celsius).

ABIs on GOES-16 and Japanese satellites Himawari-8 and Himawari-9, all built in the same factory as GOES-17 to the same specifications, all performed well in this task. But GOES-17’s cooling system seems to fail during the hottest part of its day: midnight. At this time, the ABI becomes so warm that 13 of these channels – all needed to map wind heights in the upper atmosphere – stop working. (However, three visible light channels continue to operate at the highest temperature.)

When geostationary satellites, which orbit about 22,000 miles (36,000 kilometers) up, swing on the other side of the Earth from the sun, they watch a dark Earth. But where they are in space, any cameras they have pointed at Earth will also point directly at the sun, which floods their internal components with its energy. GOES-17, three months into a six-month test period, failed to properly cool its ABI.

“As you can imagine, [troubleshooting the satellite] remotely 22,000 miles down, just looking at data from orbit is a challenge,” Steve Volz, NOAA deputy administrator for satellite and information services, said on the call. “But we are used to doing that. We have done that in the past. But it will take some time to determine what is causing this and if there are any similarities in any of the other instruments that we hadn’t noticed before.”

Engineers said the ABI problem is alarming, but it’s not yet an emergency. The ABI still operates about 12 hours a day, as do the other instruments on the satellite. Even if it turns out to be a total collapse, it won’t leave any immediate gaps in weather satellite coverage, engineers said. GOES-13 and GOES-14, although near the end of their lifespan, are still functioning and have enough fuel to fill the gap from GOES-17 until 2025. Similarly, the Japanese constellation Himawari straddles considerably the coverage area of ​​GOES-17.

Later, GOES-16 and GOES-17 will have two additional identical siblings still sitting on Earth. GOES-T was to be launched in 2020 and wait in orbit until GOES-16 or GOES-17 needed to be replaced. GOES-U, slated for launch in 2024, would replace the GOES-16 and GOES-17 that died second.

ABIs for both satellites have already been built, Pam Sullivan, NASA flight project manager for the GOES project, said on the call. This means that any flaws that sidelined GOES-17 could also affect newer satellites, but it’s not too late to fix either one. And in the future, it is likely that one of the two spacecraft will step in to replace GOES-17 – although perhaps a little sooner than expected.

Originally published on Live Science.


Comments are closed.