An increase in solar activity has resulted in the early re-entry of three CubeSats from Curtin University's Binar Space Program. These small satellites, which operated at low Earth orbit, were designed to last for at least six months. However, due to intensified solar conditions, they were destroyed within two months, significantly shortening their scientific mission.
CubeSats like Binar-2, 3 and 4 are particularly vulnerable to space weather impacts because they lack propulsion systems that could counteract the heightened atmospheric drag caused by solar activity. The satellite programme had launched Binar-1 in 2021 during relatively low solar activity, which allowed it to complete a full year in orbit.
The Science Behind Solar Activity
As per a report by The Conversation, solar activity, which includes phenomena such as solar flares, sunspots and solar wind, follows an 11-year cycle driven by the Sun's magnetic field. Known as “solar cycle 25,” this phase has shown unexpected activity levels, currently over 1.5 times higher than projected. This has impacted not only the Binar satellites but also large-scale operations like the Starlink constellation and the International Space Station, both of which require continuous adjustments to counter increased drag.
Impact of Space Weather on Satellites and Earth
Increased solar activity generates higher levels of ionising radiation and charged particles. This can damage sensitive satellite electronics, disrupt radio communications and increase radiation exposure for astronauts. The intensified solar conditions have also expanded the Earth's atmosphere outward, leading to increased drag for satellites in low Earth orbit. This affects many smaller satellites, which lack the capability to adjust their altitude.
The recent solar activity has also created more visible auroras, with these atmospheric light displays appearing closer to the equator than seen in decades.
Future Considerations for Space Missions
Despite current challenges, solar activity is expected to decline gradually, reaching a minimum by 2030. This pause may offer more favourable conditions for future missions. In response to current conditions, work has commenced on future Binar missions, which may benefit from a more predictable space weather environment.
