In order for the crew of SYFY‘s The Ark to get to another star system, they’d need a spacecraft that can go long distances quickly, with a minimum fuel requirement. In the show, they solve that problem using an electrically powered ion drive engine, but in the real world we might solve it by sailing through space on waves made of sunlight.
On April 24, 2024, NASA launched its Advanced Composite Solar Sail System (ACS3, for short) into orbit, on a mission to test the next generation of solar sail spacecraft.
NASA’s Advanced Composite Solar Sail System Plans to Sail on Sunshine
Solar sails work similarly to traditional boat sails by catching external pressure to push an attached vessel. The difference in space is that the pressure comes from starlight instead of wind. Once a solar sail is deployed in space, photons from a nearby star (in this case, the Sun) hit the reflective surface of the sail and bounce back, transferring some of their momentum in the process.
The individual impact of each photon is small, but with a large enough sail you can collect enough light to push a payload without needing to carry fuel. Consequently, we can plan missions which go farther and cost less by taking fuel almost entirely out of the equation.
The sails themselves are incredibly thin, designed to be as lightweight as possible to avoid overloading the craft they are supporting, but they have to be supported. Adding a boom structure gives solar sails shape, but it also adds weight. NASA’s goal has been to develop a boom structure which can fold up compactly, add as little weight as possible to the overall mission, and still provide the structural support the sail needs. That’s the problem NASA hopes the ACS3 will solve.
For More on Solar Sails:
Billowing Spaceship Sails Could Capture Laser Light Like Wind
Soon, We May be Sailing Between the Planets on a Beam of Sunlight
Solar-Sailing CubeSate Concept Could Give Better Look at Weird Objects Like ‘Oumuamua
“Booms have tended to be either heavy and metallic or made of lightweight composite with a bulky design – neither of which work well for today’s small spacecraft. Solar sails need very large, stable, and lightweight booms that can fold down compactly. This sail’s booms are tube-shaped and can be squashed flat and rolled like a tape measure into a small package while offering all the advantages of composite materials, like less bending and flexing during temperature changes,” Keats Wilkie, the mission’s principal investigator, said in a statement.
A CubeSat built by NanoAvionics launched aboard an electron rocket from Launch Complex 1 in Māhia, New Zealand on April 24. The CubeSat is responsible for carrying the ACS3 during launch and to an orbit of about 600 miles (1,000 kilometers). Once there, it will unroll the booms and deploy the 800-square-foot solar sail. Once totally unfurled and in the right orientation, the ACS3 should be bright enough to see with the naked eye from the ground, roughly about as bright as the star Sirius.
All of that will be rolled up and tucked into a package about the size of your hand. The process of deploying the boom and sail will be captured from the CubeSat’s point of view, using cameras mounted to its exterior. Deploying the boom and sail is the primary purpose of the mission, but once it’s unfurled, mission controllers are going to put it through its paces. By angling the sail toward or away from the Sun, they expect to control how the spacecraft moves.
What engineers learn from this test mission will lay the groundwork for more ambitious missions in the future. The ACS3 boom structure could support a sail as large as 5,400 square feet and future versions could support truly massive sails as large as 21,500 square feet, roughly the size of a soccer field.
NASA suggests that similar boom structures might also be used in future missions on the Moon or Mars by providing structural support for crew habitats. If things go according to plan, these booms and others like them could be an all-purpose solution for space-based support structures from here to Proxima centauri.
Catch up with the crew of The Ark when they return for Season 2, on Peacock!
