NASA’s Advanced Composite Solar Sail System is seen orbiting Earth in this 13-second exposure photograph, Monday, Sept. 2, 2024, from Arlington, Virginia. The mission team confirmed the spacecraft’s unique composite boom system unfurled its reflective sail on Thursday, accomplishing a critical milestone in the agency’s demonstration of next-generation solar sail technology that will allow small spacecraft to “sail on sunlight.” Just as a sailboat is powered by wind in a sail, a spacecraft can use the pressure of sunlight on a solar sail for propulsion. This technology demonstration serves as a pathfinder for future missions powered by solar sail technology. Photo Credit: (NASA/Bill Ingalls)