LightSail 2 changed its orbit only due to the pressure of the sun’s particles. Also because of the increasing solar activity, the mission is now over.

The solar sail in earth’s orbit (Image: Planetary Society)
After almost three and a half years in orbit, the LightSail 2 experimental satellite has now burned up. This was announced by the Planetary Society, which was responsible for the project. With this, the non-profit organization wanted to prove that the solar sail concept works as a form of propulsion for spaceships and is already usable. As hoped, the small satellite only changed its orbit on its way around the earth due to the power of solar radiation. The Planetary Society now speaks of a successful mission.
18,000 times around the world
The probe was launched in June 2019 aboard a SpaceX Falcon 9 rocket. After that, it orbited the Earth at a distance of 720 km, explains the Planetary Society. The extremely thin atmosphere there is still dense enough to slowly slow down satellites. However, after LightSail 2 unfolded its solar sail, they were able to significantly reduce this deceleration and even stop it completely at one point. This proved the functionality of the drive. But after 18,000 orbits and 8 million kilometers, it was over.
“LightSail 2 has vanished after more than three glorious years in the skies pioneering light propulsion,” said Planetary Society executive director Bill Nye. It has been proven “that we can defy gravity by raising a sail in space”. According to the company, the fact that the probe has now crashed is also due to the increased solar activity in recent months. The space probe is now gone, but the evaluation of the collected data continues. The sun sail had an area of 32 m².
Solar sails have been discussed for decades as an alternative to existing forms of propulsion for spaceships. Attached to the immense sails, they should then only be powered by the radiation pressure of the sun – or strong lasers. Although it is not very strong, it is said to be able to accelerate spaceships to immense speeds over longer periods of time. Recently, the concept gained momentum because the Israeli-Russian billionaire Yuri Milner is working on using this technology to send spacecraft in large numbers and in a comparatively short time to our neighboring star Alpha Centauri.