On September 5, 2024, NASA released the first image of its giant solar sail, formally called the Advanced Composite Solar Sail System (ACS3), deployed in space. The image was captured by the spacecraft itself, which has been slowly tumbling in space since the sail was unfurled on August 29.
The sail is a large, thin membrane made of Mylar, a polyester film. It is about the size of a tennis court and is designed to capture the energy of sunlight and use it to propel a spacecraft through space. The sail is made up of three layers of Mylar, each with a different reflective coating. The outermost layer is coated with silver, which reflects sunlight well. The middle layer is coated with aluminum, which reflects heat. The innermost layer is coated with a special material that absorbs ultraviolet radiation.
The sail is attached to a small spacecraft called the CubeSat. The CubeSat is about the size of a toaster and is powered by solar panels. It is also equipped with a variety of sensors, including a camera, a magnetometer, and a gyroscope.
The CubeSat was launched into orbit on August 23, 2024. Once in orbit, it deployed the sail. The sail was initially unfurled in a flat configuration. However, it quickly began to curl up into a tube shape. This is because the sail is not perfectly rigid. It is made up of many small pieces of Mylar that are held together by thin threads. These threads can stretch and contract as the sail is exposed to the sun's heat and pressure.
The tumbling of the CubeSat is not a problem. In fact, it is expected to help the sail to generate more thrust. As the sail tumbles, it will present different angles to the sun. This will allow the sail to capture more sunlight and generate more thrust.
The ACS3 mission is a proof-of-concept mission. It is designed to demonstrate the feasibility of using solar sails to propel spacecraft through space. If the mission is successful, it could pave the way for the development of solar sail-powered spacecraft that could be used for a variety of missions, including exploring the solar system, searching for exoplanets, and delivering cargo to space stations.