NASA's Advanced Solar Sailcraft Embarks on Mission
On April 24 at 6:32 AM, the world's most advanced solar sail spacecraft embarked on its journey, launching on a Rocket Lab Electron rocket from Launch Complex 1 in Mahia, New Zealand. Part of the Beginning Of The Swarm mission, NASA's Advanced Composite Solar Sail System (ACS3), despite being only the size of a microwave oven, can unfurl a thin plastic sail measuring 80 square meters, supported by 7-meter-long booms. While not the first solar sail to reach space, its ultra-lightweight, advanced composite polymer booms and compact stowing configuration represent a significant advancement, making the system both lighter and more stable, according to Popular Science.
Currently orbiting Earth in a sun-synchronous orbit at an altitude of 966 kilometers, ACS3 will deploy in the coming weeks, demonstrating technology that could power deep-space missions without using rocket propellant after launch. The thin sail captures the light pressure emitted by sunlight, propelling the spacecraft at high speeds, much like a sailboat. Engineers have demonstrated the principle before, but NASA's latest project will specifically test a promising design using flexible, carbon fiber-reinforced polymer composite materials.
Deployable Booms Enable Solar Sail Function
Once deployed, the booms act as the masts of a sailboat, keeping the sail taut to capture sunlight. What makes ACS3's booms unique is how they are packed. Booms for solar sails need to be both strong enough to withstand temperature fluctuations and durable to last the duration of a mission. However, large-scale solar sails become very large. NASA is currently planning designs for sails over 500 square meters, roughly the size of a basketball court. Such sails would require impractically long booms to fit inside a rocket's payload bay.
To address this issue, NASA has coiled the novel composite booms into a package about the size of a large envelope. When ready, engineers will use a deployment system similar to the core of a roll of Scotch tape to unravel the booms, minimizing the chance of snags. Once erected, the booms hold the thin solar sail in place, while onboard cameras capture the entire process.
Testing New Designs and Performance
NASA hopes the project will allow them to assess the performance of the new solar sail design and measure how its thrust affects the small spacecraft's orbit. Engineers will also evaluate the toughness of the new composite booms, which are 75% lighter and 100 times stiffer than any previous solar sail prototype.
After its initial checkout and approximately two months of subsystem testing, ACS3 will then embark on weeks-long demonstrations of raising and lowering the orbit of a CubeSat satellite. Should ACS3's sail and boom system prove successful, NASA may scale up the design to sizes capable of deep space travel within our solar system.