There was an interesting phenomenon that happened in September when Starlink launched 49 new satellites. The satellites were successfully deployed by the rocket, but as the satellites were being maneuvered to reach the final orbital slots there was a geomagnetic storm that caused 38 of the satellites to fall back to earth.
Space storms happen when radiation affects the magnetosphere that surrounds the earth. This is a band of particles that are held close to the planet due to the earth’s magnetic field. A geomagnetic storm occurs when there is an exchange of energy from outer space to the orbiting particles. The biggest storms are caused by mass ejections of particles and energy that occur during large solar flares. These solar flares release radiation and highly charged particles into space, which during a storm, interface with the magnetosphere.
It is the charged particles from the storms that manifest in the Aurora Borealis or northern lights. The extra energy from the storms can also play havoc with GPS and other space-based communications. The earth’s atmosphere keeps most of the radiation from solar flares away from the planet, but strong storms can wreak havoc with radio communications and can even produce feedback in long-haul electric wires that can disrupt the power grid.
During a geomagnetic storm, energy is pushed from the particles in the magnetosphere to the upper reaches of the ionosphere. This can temporarily increase the heat and the intensity of the ionosphere, which is what happened to the satellites. They met unexpected resistance that the tiny thrusters on the small satellites were unable to overcome.
Scientists have been looking at ways to better predict solar flares and the ensuing storms. In this case, with a warning, the satellite launch would have been delayed until the storm had passed. It’s a big challenge to predict the size and location of solar flares. The sun has an eleven-year cycle for the period of the heaviest solar flare activity, but a solar flare can erupt at any time.
Scientists around the world have been studying the sun using NASA’s Solar Dynamics Observatory. Scientists in China have had some success by tracking changes in the magnetic field of the sun, particularly in how that manifests in changes on the sun’s surface. They say that the temperature temporarily drops on the surface of the sun in the area where flares are coming. They have predicted several solar flares within 48 hours of an eruption. They have a long way to go for this to be accurate. Even when we get to the point of successfully predicting solar flares, it’s an even bigger challenge to predict if the particles from the flare will hit the earth. The worse impacts come when our planet is in the direct path of the ejected particles.
Tracking space weather matters since we are becoming reliant on space technologies. We’ve all incorporated GPS and satellite weather into our daily routines. We use space monitors for scientific research, to study farm fields, and to keep an eye on the various militaries around the planet. And suddenly, we have a lot of people using satellites for broadband. It was costly to Starlink to lose most of the satellites from a launch. But the potential damage from space storms is going to increase dramatically as we use space more and more. Starlink alone keeps talking about having 30,000 broadband satellites.
It’s not hard to picture the impact of losing these technologies for a few days up to a week. How many of you still carry an atlas in your car in case GPS doesn’t work? Businesses of all types plan outdoor work based on weather predictions that use data gathered by satellites. And having multi-day broadband outages can be devastating, particularly for rural businesses or people working from home. Space technology has become everyday technology, but it’s too easy to take for granted and to assume it will always work.
This reminds me of an article I read some years back buried in the back pages of the Wall St Journal about how the USNA had stopped teaching celestial navigation. It seems to me that skills like that could be very important in the future.