Last week, three small Australian satellites from Curtin University’s binar space program Reentered Earth’s atmosphere and burned up much earlier than expected, reducing valuable research opportunities. Launched with an initial life span of six months, these CubeSats – named Binar-2, Binar-3 and Binar-4 – lasted only two months in low Earth orbit (LEO), a condition characterized by intense solar radiation. This is due to activity that is challenging the satellite. operations in recent years.
Increase in solar activity, defying forecasts
According to a Live Science reportSolar activity has recently exceeded forecasts, recording levels one and a half times higher than estimated for the current solar cycle, known as solar cycle 25. This surge, marked by solar flares, sunspots and an increase in the solar wind, is caused by fluctuations in the Sun’s magnetic field, which reverses polarity approximately every 11 years. While solar cycles have been mapped, solar weather forecasting is still in its infancy, making accurate predictions challenging.
The impact of space weather on Earth has been significant. Intense auroras have been observed close to the equator, and the increased solar wind increases ionizing radiation, creating additional hazards for astronauts and high-altitude flights. Satellites in LEO, particularly satellites without thrusters or altitude adjustment systems, such as binar CubeSats, face constant drag that accelerates their orbital decay during periods of increased solar activity.
Impact on satellite missions
The early termination of the Binar CubeSat highlights the need for better space weather forecasting to support satellite operations. CubeSats, like Curtin’s program, are often used by universities for research and often lack the ability to counteract the increased atmospheric drag caused by space weather. Their sudden re-entry shows the risks faced by satellites during solar peaks.
Further binar missions are already in development, with launches planned for the late 2026s, when solar activity is expected to decline. As solar minimum conditions approach by 2030, the next generation of CubeSats can operate in a more stable space environment, allowing more long-term research efforts.