NASA’s Advanced Composite Solar Sail System (ACSSS) has reached a significant milestone—its booms and sail are now fully deployed, harnessing the pressure of sunlight to propel the spacecraft through the solar system. Much like a test pilot navigating a new aircraft, NASA is currently testing how well the sail performs in space. The spacecraft was tumbling before deployment, and now engineers are working to bring it under control using solar sail power.

Solar sails operate by using the pressure exerted by sunlight to generate low levels of thrust. As photons strike the sail’s surface, they transfer momentum to the spacecraft, causing it to accelerate gradually. Though the thrust is minimal, it can accumulate over time, making solar sails an incredibly efficient method of propulsion for small spacecraft on long-duration missions. This technology first saw success in 2010 when the Japan Aerospace Exploration Agency (JAXA) deployed the IKAROS (Interplanetary Kite-craft Accelerated by Radiation of the Sun) solar sail.

The ACSSS, developed by NASA, builds on these earlier innovations by using lighter and more flexible composite materials for its booms and sail, aiming for more efficient deep space exploration. NASA hopes to prove the viability of this technology for low-thrust missions, including asteroid rendezvous and other deep-space objectives. ACSSS currently orbits Earth at an altitude of 500 to 600 kilometers.

Initially launched without attitude control, the spacecraft began tumbling in space. Now that the sail is deployed, NASA’s team is analyzing its behavior and preparing to stabilize the spacecraft using sail power. They will also study how the sail adjusts the spacecraft’s orbit, gathering valuable data from images and telemetry to understand how well the boom and sail technologies are functioning.

The next phase of testing will involve assessing the flight handling and dynamics of the ACSSS. So far, the mission is progressing smoothly, with successful deployment and initial operations.

For sky watchers, the highly reflective sail makes the spacecraft easily visible to the naked eye as it passes overhead. NASA has even updated its app to provide notifications when the spacecraft is visible from your location. The public is encouraged to track the sail and share their photos using the hashtag #SpotTheSail.

With ongoing tests and future demonstrations, NASA’s ACSSS could pave the way for more sustainable and efficient space exploration, bringing the dream of solar sail propulsion closer to reality.

By Impact Lab