Elon Musk’s Starlink internet project involved the launch of 49 satellites on February 4, 2022, the majority of which burnt up in the atmosphere a few days later. A geomagnetic storm brought on by the Sun is what led to this malfunction that cost more than $50 million USD.
When space weather impacts and interacts with the Earth, geomagnetic storms develop. Electrons, protons, and other particles are sent into space as a result of variations in the Sun. I research the risks that space weather poses to space-based assets and how scientists may enhance space weather models and predictions to mitigate these risks.
Space weather causes a number of intricate processes to start when it hits Earth, which may be quite problematic for anything in orbit. And professionals like me are attempting to better comprehend these dangers and protect satellites from them.
Why does space weather occur?
A constant stream of charged particles are constantly being released into space by the Sun. The term for this is solar wind. The solar magnetic field is also carried by the solar wind. Localized oscillations on the Sun can occasionally send extremely powerful bursts of particles in a specific direction. A geomagnetic storm results if Earth is struck by the heightened solar wind produced by one of these occurrences while on its course.
The two most frequent sources of geomagnetic storms are solar wind that escapes via coronal holes in the Sun’s outer atmosphere and coronal mass ejections, which are explosions of plasma from the Sun’s surface.
The strength of the geomagnetic storm depends on how quickly the solar wind or plasma is emitted from space and arrives to Earth. The average speed of solar wind is 900,000 mph (1.4 million kph). Strong solar events, though, can cause winds to blow up to five times as quickly.
A coronal mass ejection in September 1859 led to the biggest geomagnetic storm ever recorded.
In some severe situations, the electrical surges in telegraph lines that were created as the mass of particles struck Earth literally set telegraph equipment on fire, shocking the operators and shocking the public. According to research, the damage caused by a geomagnetic storm of this size on Earth today would be close to $2 trillion.
A protective magnet
Any living form unlucky enough to come into close contact with solar emissions, particularly the solar wind, would be in grave peril. Thankfully, the magnetic field of Earth provides a lot to shield people from harm.
As solar wind reaches Earth, it initially collides with the magnetosphere. Plasma consisting of electrons and ions is present in this area around the Earth’s atmosphere. The planet’s powerful magnetic field controls it.
In some severe situations, the electrical surges in telegraph lines that were created as the mass of particles struck Earth literally set telegraph equipment on fire, shocking the operators and shocking the public. According to research, the damage caused by a geomagnetic storm of this size on Earth today would be close to $2 trillion.
The majority of the energy from the normal amount of solar wind may be absorbed by the magnetosphere. It can, however, become overloaded and leak extra energy into the upper atmosphere of Earth near the poles during intense storms. Fantastic aurora occurrences are caused by this energy redistribution toward the poles, but it also alters the upper atmosphere, which may be hazardous to spacecraft.
Risks to orbiting objects
Geomagnetic storms can endanger orbiting satellites that regularly provide services to people on the ground in a number of different ways.
The atmosphere warms up and stretches higher as a result of absorbing energy from magnetic storms. The thermosphere, a layer of the atmosphere that stretches from about 50 miles (80 kilometers) to about 600 miles (1,000 km) above the surface of the Earth, has a much higher density as a result of this expansion. More drag results from higher density, which might be problematic for satellites.
This same circumstance is what caused the SpaceX Starlink satellites to be destroyed in February. Falcon 9 rockets are used to deliver Starlink satellites into low-earth orbit, usually between 100 and 200 kilometers (60 miles) above the planet’s surface. The satellites then steadily overcome the drag and lift themselves to their ultimate height of about 350 miles using onboard engines (550 km).
While still in extremely low-Earth orbit, the most recent group of Starlink satellites ran through a geomagnetic storm. The satellites’ engines were unable to cope with the greatly increased drag, and they started to slowly plummet toward Earth before exploding in the atmosphere.
One risk that space weather presents to space-based objects is drag. Strong geomagnetic storms cause a considerable increase in high-energy electrons in the magnetosphere, which implies that more electrons will enter a spacecraft’s shielding and build up within its electronics. Electronics can be damaged by the discharge of this accumulation of electrons, which is like a miniature lightning strike.
The output signal from electrical devices can also be affected by penetrating radiation or charged particles in the magnetosphere, even during minor geomagnetic storms. Any component of a spacecraft’s electronics system may have problems as a result of this phenomena, and if a mistake affects a crucial component, the entire satellite may malfunction. Small mistakes are frequent and typically easy to correct, but complete failures do occur, albeit rarely.
Finally, geomagnetic storms can interfere with satellites’ radio communications with Earth. Radio waves are a key component of several communications technology, including GPS. Engineers account for this distortion when designing communication systems since radio signals are always slightly distorted by the environment.
Radio waves’ path through the ionosphere, the charged counterpart of the thermosphere that occupies nearly the same height range, will shift during geomagnetic storms. During geomagnetic storms, the calibrations set up for a calm atmosphere are incorrect.
For instance, this makes it challenging to latch onto GPS signals and can cause the placement to be off by a few meters. GPS location inaccuracies of a few meters are just intolerable for many businesses, including aviation, marine, robotics, transportation, agriculture, and the military. Accurate location will also be necessary for autonomous driving systems.
How to be safe against space weather
The operation of many aspects of the contemporary world depends heavily on satellites, and safeguarding space assets against space weather is a key topic of research.
By protecting electronics from radiation or using materials that are more radiation-resistant, some of the dangers can be reduced. But in the face of a strong geomagnetic storm, there is only so much shielding that can be done.
If storms could be correctly predicted, it would be feasible to secure satellites and other assets in advance by turning off delicate electronics or reorienting the satellites to be safer. Although geomagnetic storm modeling and forecasting have substantially improved over the past few years, the predictions are frequently off.
The National Oceanic and Atmospheric Administration had issued a warning that a geomagnetic storm was “likely” to happen the day before or the day of the February Starlink launch following a coronal mass ejection. However, the job was carried out.