Technicians working on the NOAA-funded solar sail membrane. [Credit: Applied Aerospace & Defense]
Like wind propelling a sailboat through the water, solar sail technology is taking NOAA’s observational capabilities a step closer to the sun.
Through a Joint Venture partnership with NASA Marshall Space Flight Center in Huntsville, Ala., and Applied Aerospace & Defense, a private sector partner also based in Huntsville, NOAA funded $4.2 million dollars for a state-of-the-art solar sail membrane that can be attached to a satellite and allow space weather instruments to travel closer to the sun than ever before.
By allowing instruments to travel closer to the sun, solar sails can help NOAA’s Space Weather Prediction Center (SWPC) issue earlier warnings for solar storms, providing better protection to critical systems such as power grids, aviation and astronauts in space.
Sailing on Sunlight
The solar sail membrane is an ultra-thin, highly reflective, and lightweight material called polyimide, which is coated with aluminum. It is designed to harness solar radiation pressure for propellant-free spacecraft propulsion. Acting like a reflective mirror, the sail captures momentum from sunlight to generate continuous, low-thrust acceleration.
This solar sail is the largest ever manufactured. When fully deployed, the membrane will cover 17,792 square feet (1,653 square meters), which is equivalent to roughly four basketball courts placed side by side.
An artist's concept of NASA's Advanced Composite Solar Sail System spacecraft. [Credit: NASA/Aero Animation/Ben Schweighart]
How Does It Work?
Solar sail technology allows a spacecraft attached to the sail to move using sunlight alone. Much like how the wind can propel a sailboat, light from the sun can essentially “push” a spacecraft equipped with a reflective solar sail.
Sunlight is composed of particles called photons. When photons strike and bounce off the sail, they transfer momentum, gradually accelerating the spacecraft. This eliminates the need for rocket propellant and enables the spacecraft to travel indefinitely.
The solar sail membrane can be packed inside a space roughly the size of a microwave oven during launch. Once in space, lightweight carbon fiber booms unroll from the spacecraft to form rigid tubes that support the ultra-thin reflective sail. When fully deployed, the sail structure forms a square measuring more than 133 by 133 feet. By adjusting the sail’s angle relative to the sun, the spacecraft can change its position.
Expanding NOAA’s Space Weather Capabilities
Solar sail propulsion could allow NOAA to position future space weather observatories closer to the sun than current missions. Observations from this vantage point would give NOAA’s Space Weather Prediction Center additional lead time to detect and forecast geomagnetic storms. Earlier warnings help NOAA protect the nation against these storms, which pose threats to satellite systems, electric power grids, and other critical infrastructure affected by space weather events.
NOAA’s SOLAR-1 observatory depicted safeguarding the nation against solar storm impacts. [Credit: NOAA]
NOAA and NASA's Space Technology Mission Directorate (STMD) are currently exploring the possibility of using the newly manufactured solar sail in a joint demonstration mission called the Space Storm Solar Sail Sentinel (S5). The mission would showcase solar sail propulsion technology and evaluate whether the technology can support earlier detection of space weather events that can affect Earth. Discussions are ongoing, and funding for the S5 project has yet to be confirmed.