by Even small solar flares can have huge impacts on the environment around Earth, space weather experts have learned after SpaceX lost 40 brand new satellites in February after launching into a “mild” geomagnetic storm. In a new study, a team of researchers outlines how to correct weather forecasts in space in the future, to prevent companies from steering their craft into such “treacherous waters.”
At the end of January this year, a burst of hot magnetized plasma erupted from the Sun direction Soilcausing space weather forecasters from the U.S. National Oceanic and Atmospheric Administration’s (NOAA) Space Weather Prediction Center (SWPC) to issue a mild geomagnetic storm warning.
At the same time, SpaceX engineers were preparing a batch of 50 star link internet satellites for launch on the company’s Falcon 9 rocket ship. They saw the space again alarm and ran the data through a model of Earth’s upper atmosphere, in which they were about to place their spacecraft. The analysis suggested the area was safe, but when the missile fired the payload at an altitude of 220 miles, all hell broke loose. The thin air around the spacecraft behaved differently than ground controllers expected, and 38 of the new satellites quickly headed back toward Earth instead of climbing to their operational orbit 340 miles (550 km) above the planet.
Related: Planned NASA mission to the ‘ignorosphere’ could improve space weather forecasts
The geomagnetic storm was quickly identified as the culprit of the mishap, and a new study by SpaceX and NOAA experts has now revealed that had SpaceX followed NOAA’s additional resources, the company might have changed its mind about that fateful launch .
Last year, NOAA launched the so-called Whole Atmosphere Model (WAM), in which processes are modeled the Earth’s atmosphere all the way up to an altitude of 600 km, well above the troposphere where terrestrial weather occurs. The model includes the thermosphere, the second highest layer of Earth’s atmosphere, where thin, diffuse gases create drag that slows satellites down.
When space weather hits, the thermosphere swells, temporarily increasing the density of the thin air. The study showed that during that geomagnetic storm, air density at altitudes between 125 and 250 miles (200 and 400 km) increased by 50% to 125%. For satellites orbiting at speeds approaching 20,000 mph (28,000 km/h), such an increase in density would feel like suddenly running into a very strong wind.
Since the accident, SpaceX has been working with NOAA to help improve space weather forecasting for satellite operators, Tzu-Wei Fang, a space scientist at the SPWC and lead author of the new study, told Space.com in a statement. previous conversation.
The company has even started providing data on its low-Earth orbit satellites to the agency to improve the model, as NOAA is currently struggling with a lack of measurements from the critical region, Fang said.
“This study demonstrates the benefits that can come from government-industry collaboration,” Fang said in a pronunciation (opens in new tab). “The free exchange of model and satellite data and the close interaction between SWPC and the Starlink team have enabled us to identify the quantitative impact of space weather events on these satellites, helping us to quickly prioritize our tasks to improve our space weather models. and design to improve operational products that will better meet the needs of modern aerospace.”
SpaceX isn’t the only satellite operator to have run into problems due to space weather. Earlier this year, the European Space Agency said its Swarm satellites, which monitor Earth’s magnetic field, had been Sinking 10 times faster since December 2021 than in other years since its launch in 2013. The reason for this is increasing solar activity as the sun moves towards the peak of its power solar cyclethe 11-year cycle of ebb and flow in the generation of sunspots and outbursts. In addition, the current solar cycle appears to be much more active than space weather forecasters predictedand it comes after a long quiet period.
Experts warn that the current period of disturbed space weather comes at a time when a much higher number of small satellites are being launched into low Earth orbit than during previous solar cycle peaks. Many of these new satellites are simple cubesats with no onboard propulsion. Increased atmospheric resistance due to space weather can therefore significantly shorten the time the spacecraft can remain in orbit to perform their missions.
The study concluded that it is “critical for SWPC to establish appropriate alerts and warnings based on [air] density predictions to guide users in avoiding satellite losses due to drag and to aid in collision avoidance calculations.”
Other teams have warned that, in the case of very severe solar storms, the changes in drag could be so great that the speeds and altitudes of orbiting satellites would change so much that computer algorithms that generate warnings when two objects, satellites or space debris, collide touch. too close together would become completely inaccurate.
It would take several weeks to come back all junk and cubesats and synchronize the catalog with reality. During that time, operators would not receive accurate collision avoidance warnings and the risks of devastating collisions while in orbit would increase significantly.
Severe solar storms can also wreak havoc on Earth, causing power outages and disrupting GPS and radio signals. While such powerful solar storms don’t happen often, they can sometimes appear with little warning.
The study (opens in new tab)published in AGU’s Space Weather magazine, was published on November 2.
Follow Tereza Pultarova on Twitter @TerezaPultarova. follow us on Twitter @Spacedotcom and further Facebook.
