The solar sail of the LightSail-2 spacecraft has unfolded completely as planned. The crowdfunded small satellite has been launched to become the first spacecraft in orbit propelled solely by sunlight.
The Planetary Society, creator of LightSail-2, reports that the little cubesat now sails on sunlight. According to the organization the spacecraft has already completed a circle around the earth in ‘solar sail mode’ and all major systems indicate that there are no problems.
There are no photos for now of the deployed sail and the Planetary Society website is also showing problems. According to the organization communication performance may be lower than before due to the presence of the deployed solar sail and the orientation of the satellite while passing the ground station.
LightSail-2, which measures 11.3×11.3×48.7cm, has a sail of 32m², which captures photons from the sun. These bounce off the reflective surface of the sail, generating a little bit of momentum. This weak radiation pressure drives the satellite. The satellite was launched on June 25 with a Falcon Heavy rocket.
Light sails are a sustainable technology for powering satellites and this has also been used in the predecessor of LightSail-2. The first LightSail went into space in 2015, and although the makers temporarily lost communication with the craft shortly after launch, the mission was ultimately a success. In 2010, the Japanese space agency JAXA was the first organization to successfully demonstrate this concept with Ikaros. In principle, lasers can also be used with these light sails.
Incidentally, alternative techniques are also being developed to power spacecraft with solar sails. Finnish researchers have a plan to power nanosatellites via the protons in solar wind. An electrically charged aluminum wire with a length of twenty kilometers has to collect the protons. The idea is that when protons collide with the wire, the positively charged particles in the wire and the protons from the solar wind repel each other. The incoming protons then transfer their momentum, which provides the drive. The researchers want to use this for a fleet of nanosatellites that will investigate the asteroid belt between Mars and Jupiter.