In a nutshell: NASA announced it is prepared to launch a “next-gen” solar sailor into orbit. The Advanced Composite Solar Sail System (ACS3) is a newly designed satellite meant to test the deployment of the solar-powered propulsion system. The craft launches from New Zealand aboard Rocket Lab’s Electron rocket in April.
The ACS3 is super compact – about the size of a microwave oven. However, it has four retractable booms that unfurl and hold four triangular sails, making a diamond shape about half the size of a tennis court. It takes about 25 minutes for the sails to unfold.
NASA was rather vague about the composition of the materials that made up the new sail. NanoAvionics developed the booms using a new composite material of carbon fiber and flexible polymers. They are structurally stiffer than previous booms and lighter as well. It didn’t describe the composition of the sails, but presumably, they are improvements to prior designs, too.
“Seven meters of the deployable booms can roll up into a shape that fits in your hand,” said ACS3’s lead systems engineer Alan Rhodes. “The hope is that the new technologies verified on this spacecraft will inspire others to use them in ways we haven’t even considered.”
NASA’s primary objective for this mission is to test the booms. These extendable arms are similar to a ship’s mast and must withstand extreme conditions. Once the ACS3 successfully tests the booms and deploys the sail, NASA will perform several orbital maneuvers to see how well the sail functions.
Sailing a satellite in space is similar to sailing a boat on Earth. The primary difference is that a boat relies on air molecules pushing the sails, and a solar sailor relies on photons for propulsion. The ACS3’s sails use Newton’s Third Law of Motion to steer. As photons rebound from the material between the booms, slight angular adjustments push the craft in the opposite direction of the photons’ bounce.
The ACS3 will maintain a Sun-synchronous orbit at an altitude of about 600 miles. NASA claims the satellite will be visible from Earth if the lighting conditions are “just right.” That is to say that as long as you are viewing from an ideal location beneath it, the sunlight reflected off the sail should be as bright as the star Sirius.
If the mission goes well, this small CubeSat could lead to designs with sails as large as a basketball court. Light-driven space vehicles could provide a more efficient and potentially faster means of travel to the Moon, Mars, and other places within our solar system and beyond.
“The Sun will continue burning for billions of years, so we have a limitless source of propulsion. Instead of launching massive fuel tanks for future missions, we can launch larger sails that use ‘fuel’ already available,” said Rhodes. “We will demonstrate a system that uses this abundant resource to take those next giant steps in exploration and science.”