Solar storms hasten fall of Australian satellites ahead of time
Unpredictable solar activity is causing satellites to fall to Earth. Intense solar phenomena contributed to the untimely conclusion of the mission of three Australian Binar satellites, prompting experts to revisit space weather forecasts and their impact on technology.
14 November 2024 08:02
Last week, three Australian satellites from the Binar program, managed by Curtin University, re-entered Earth's atmosphere ahead of schedule, where they disintegrated. Their mission lasted only two months, even though it was initially planned for six months. The Binar-2, 3, and 4 satellites were not the only casualties of heightened solar activity—the recent increase in solar phenomena is causing difficulties for satellite operators worldwide, as reported by The Conversation.
What is happening on the Sun?
The solar cycle, lasting around 11 years, is marked 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 streams of charged particles, increases. Though this cycle is understood, accurately forecasting solar activity remains challenging due to the Sun's complex processes, leading to often imprecise predictions.
The current phase, known as solar cycle 25, has surprised scientists with a level of activity 50% higher than expected. Recently, it has been accompanied by stunning auroras visible much closer to the equator than usual. High solar activity poses additional risks to satellites, astronauts, and radio communications, necessitating more precise space weather forecasts.
Space weather describes phenomena originating outside our atmosphere, primarily from the Sun, affecting Earth. Increased solar activity results in more solar flares and a stronger solar wind, increasing the flow of charged particles that can harm satellite electronic systems. These phenomena also increase atmospheric resistance for satellites in low Earth orbit, causing a faster descent.
Low orbits include the International Space Station and Starlink satellites, which can adjust their positions using propulsion systems. However, university satellites like Binar CubeSats typically lack these capabilities and rely entirely on space weather conditions.
According to scientific forecasts, solar activity is expected to decline and may reach a minimum by 2030, indicating less challenging conditions for future missions. The Binar program will continue developing future satellites, likely encountering more favourable circumstances.
