NASA is gearing up to launch an improved spacecraft equipped with a solar sail at the end of this month. Scheduled for April 24, the launch of the ADVANCED COMPOSITE SOLAR SAIL SYSTEM spacecraft will incorporate new lightweight dimensional composites.
Solar sails operate on a surprisingly simple concept. Unlike other technologies that may require metaphors for explanation, solar sails work on principles similar to sailing boats on Earth.
The key difference lies in the propulsion method: while sailing boats rely on wind to move through water, solar sails navigate through space in a vacuum using solar wind – a stream of plasma composed mainly of protons and electrons continuously emitted by the sun at varying speeds and densities. This allows the solar sail to maneuver similarly to ships in the atmosphere, adjusting its course by moving in the direction of the solar wind.
One notable challenge for solar sails is their low acceleration due to the minimal pressure exerted by the solar wind on the relatively small surface area comparable to a sheet of paper. However, solar sails do not require traditional fuel and can potentially accelerate indefinitely. The main hurdle lies in designing a spacecraft that is light enough to carry a sufficiently large sail.
The sail itself is relatively straightforward, with Mylar films demonstrating effectiveness since the 1960s. The primary complication arises in developing the necessary rods to maintain the sail’s position. According to Kitsa Wilki, lead researcher at NASA Langley Research Center, the sail’s sides will feature tubes that can be compressed and rolled up like a tape measure, providing the benefits of composite materials such as reduced bending and deformation during temperature changes.
The upcoming mission will utilize a new flexible polymer-carbon composite rod alongside a twelve-unit (12U) Cubesat constructed by Nanoavionics. Following its launch by Rocket Lab from the Mahia Launch Complex in New Zealand, the spacecraft will be placed into a sun-synchronous orbit approximately 600 miles above the Earth’s surface. The sail will unfurl in about 25 minutes, covering an area of 860 square feet (80 m²), with the rod extending from the size of an arm to 23 feet (7 m) in length. Once deployed, the sail will help adjust the spacecraft’s orbit by manipulating its angle relative to the solar wind.
If the demonstration mission proves successful, it could pave the way for more ambitious projects, including solar sails with an area of up to 21,500 square feet (2000 m²) – nearly