NASA is testing a solar sail system that uses solar energy to propel spacecraft through space.
The world’s most advanced solar sail spacecraft began its journey at 6:32 AM on April 24 when it launched on Rocket Lab’s Electron rocket from Launch Complex 1 in Mahia, New Zealand. This is one of two payloads in the Beginning Of The Swarm mission. Although it is only the size of a microwave, NASA’s Advanced Composite Solar Sail System (ACS3) can deploy its thin plastic sail in about 25 minutes, spreading over an area of 80m2 with a 7-meter-long tensioned mast. This is not the first solar sail launched into space, but its tensioned mast made from an ultra-lightweight composite polymer material and its specially designed compact configuration mark an important advancement that makes the system lighter and more stable, according to Popular Science.
Simulation of the ACS3 spacecraft moving through space. (Photo: NASA).
Currently in a solar synchronous orbit 966 million kilometers from Earth, ACS3 is set to deploy in the coming weeks and demonstrate technology that can power deep space missions without using rocket fuel after launch. By harnessing the pressure emitted by solar energy, the thin sail can propel the spacecraft at extremely high speeds, similar to a sailing boat. Engineers have previously demonstrated this principle, but NASA’s new project will specifically test the design promising to be constructed from flexible composite polymer materials reinforced with carbon fibers.
After deployment, the tensioned masts serve as the sailboat’s masts, keeping the sail taut to collect solar energy. What makes the ACS3’s tensioned mast special is how it is compactly folded. The solar sail’s tensioning system needs to be rigid enough to withstand temperature fluctuations, yet durable enough to last through long missions. However, large-scale solar sails will be quite large. NASA is currently planning to design sails over 500m2, equivalent to a basketball court. These sails will require extremely long tensioned masts that cannot fit within the payload bay of a rocket.
To address this issue, NASA coiled the tensioned mast made from composite material into a large envelope-sized package. When ready, engineers will use a pulling system similar to a tape dispenser to deploy the mast, minimizing the risk of getting stuck. Once set up, the tensioned mast will keep the thin solar sail taut while onboard cameras capture the entire process.
NASA hopes this project will allow them to evaluate the new solar sail design while measuring how its thrust affects the low orbit of the small spacecraft. Engineers will also assess the durability of the new composite tensioned mast, which is 75% lighter and less prone to deformation than any previous solar sail prototypes.
After the initial flight and a two-month estimated subsystem testing phase, ACS3 will conduct tests on raising and lowering the orbit of a CubeSat satellite over several weeks. If the ACS3’s solar sail and tensioned mast system is successful, NASA will scale up the design enough to enable travel within the Solar System.
