NASA’s Composite Solar Sail System (ACS3) will deploy an apartment-sized sail from a microsatellite to Earth orbit by mid-2022.
Sail technology has been used in space before, the most recent being the Planetary Society’s LightSail 2 mission which spent two years in orbit. Similar to a sailboat propelled by the wind blowing through its sails, solar sails use the pressure of sunlight to generate propulsion, thereby eliminating the need for traditional rocket fuel, according to a June 23 announcement from NASA. The data collected by the new mission will help inform the design of future larger-scale systems, finding asteroids, tracking solar activity, or powering the communication system of astronauts in deep space. .
ACS3 has been in development since 2018. In 2020, NASA chose the company NanoAvionics to build the satellite bus. NanoAvionics is a subsidiary of a consortium of Vilnius University, which built the LituanicaSAT-1 satellite which sent the first Lithuanian message into space in 2014.
The new mission will deploy composite solar sails, showing that ultralight, high-strength materials can reduce mass and launch costs on future missions. The fully tensioned sail will be supported by 4 piers and will extend 9 m sideways. While the ACS3 solar sail is relatively small, NASA claims that the composite solar sail technology can reach the size of a basketball court (500 m2). For this reason, composite pillar technology is at the heart of the mission.
The composite pillar was an idea from a project at NASA’s Langley Research Center, which sought to learn how to deploy large systems, including solar sails, on small satellites. According to NASA, the mast is made from a carbon fiber reinforced polymer material, which makes it 75% lighter than standard metal poles and less susceptible to thermal warping. This will be the first mission where pillars, sails and composite deployment systems will be used together in orbit.
This composite material can ride on small vehicles, but is still strong and super light when unfolded, NASA said. The navigation system will include advanced mast mounting equipment, which will minimize the risk of entanglement.
While solar sail technology is in its infancy, potential benefits include extended mission times, as chemical and electric propulsion have limited fuel availability. Mission leaders will also examine how the sail propulsion function works when changing the spacecraft’s orbit, in preparation for missions further from Earth.
