Solar flare frenzy forces Australian satellites' fiery descent
Unpredictable solar activity is causing satellites to fall to Earth. Intense solar phenomena have contributed to the premature end of the mission for three Australian Binar satellites, prompting specialists to reevaluate space weather forecasts and their impact on technology.
5:14 PM EST, November 14, 2024
Last week, three Australian satellites from the Binar program, managed by Curtin University, prematurely entered Earth's atmosphere, where they burned up. Their mission concluded after only two months, despite originally being planned to remain in orbit for six months. The Binar-2, 3, and 4 satellites were not the only ones affected by high solar activity—the recent increase in solar phenomena is causing issues for satellite operators worldwide, as reported by The Conversation.
The solar cycle, which lasts approximately 11 years, is characterized by changes in the Sun's magnetic field. When solar activity reaches its peak, the frequency of phenomena such as sunspots, solar flares, and solar wind, or the stream of charged particles, increases. Although this cycle is known, accurately predicting solar activity is difficult—the processes on the Sun are complex, and forecasts are often imprecise.
The current phase of the cycle, known as solar cycle 25, surprised scientists with a level of activity that was 50% higher than predicted. In recent months, it has been accompanied by spectacular auroras visible much closer to the equator than usual. High solar activity poses additional threats to satellites, astronauts, and radio communications, necessitating greater precision in space weather forecasts.
Space weather refers to phenomena originating outside our atmosphere, mainly from the Sun, that affect Earth. Increased solar activity results in more solar flares and stronger solar wind, which increases the flow of charged particles that can damage satellite electronic systems. For satellites in low Earth orbit, atmospheric conditions also increase air resistance and cause a faster descent.
Low orbits include the International Space Station and Starlink satellites, which can adjust their position thanks to propulsion systems. However, university satellites, like Binar CubeSats, rarely have such capabilities and depend entirely on space weather conditions.
According to scientific forecasts, solar activity is expected to decrease and may reach a minimum by 2030, promising less challenging conditions for future missions. The Binar program continues to work on future satellites, which will likely encounter more favorable conditions.
