Binary satellites reenter early due to high solar activity

An increase in solar activity has resulted in the early return of three CubeSats from Curtin University’s Binar Space Program. Operating in low Earth orbit, these small satellites were designed to last at least six months. However, due to intensifying solar conditions, they were destroyed within two months, significantly shortening their scientific mission.

CubeSats such as Binar-2, 3 and 4 are particularly vulnerable to space weather impacts because they lack propulsion systems to counteract the increased atmospheric drag caused by solar activity. The satellite program had launched Binar-1 in 2021 during relatively low solar activity, allowing it to remain in orbit for a full year.

The science behind solar activity

According to one report According to The Conversation, solar activity, which includes phenomena such as solar flares, sunspots and solar wind, follows an eleven-year cycle, driven by the sun’s magnetic field. This phase is known as ‘solar cycle 25’ and has shown unexpected activity levels, currently more than 1.5 times higher than expected. This has affected not only the Binar satellites, but also large-scale operations such as the Starlink constellation and the International Space Station, both of which require constant adjustments to counter increased resistance.

Impact of space weather on satellites and Earth

Increased solar activity generates higher levels of ionizing 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 Earth’s atmosphere outward, leading to increased drag for satellites in low Earth orbit. This affects many smaller satellites, which are unable to adjust their altitude.

Recent solar activity has also brought more visible auroras, with these atmospheric light shows appearing closer to the equator than we’ve seen in decades.

Future considerations for space missions

Despite current challenges, solar activity is expected to gradually decline and reach a minimum by 2030. This pause may provide more favorable conditions for future missions. In response to current conditions, work has begun on future Binar missions, which could benefit from a more predictable space weather environment.