Scientists have created a rocket that can take off into space with a tension sail. The goal is simple – for the tractor to return the rocket to Earth, preventing it from becoming like thousands of pieces of space debris in Earth’s lower orbit. The drag sail, designed by engineers at Purdue University, will be aboard the Firefly rocket, which is expected to launch in November from Vandenberg Air Force Base in California.
Valuable orbits around the Earth are becoming congested. If we do not remove satellites or other components of launch vehicles from orbit, then over time, highly utilized orbits will become unusable for other space systems. Drag sail technology is designed to be launched from the main spacecraft or launch vehicle and deployed at the end of the mission of the main vehicle. The resistance created by the Earth’s atmosphere will accelerate the vehicle’s de-orbit.
David Spencer, Associate Professor of Aeronautics and Purdue Astronautics
Called the “Spinnaker3,” this braking sail is among the first large enough to launch the booster block of a launch vehicle from orbit. The Firefly Alpha launch will target an orbital altitude of about 320 km, but the Spinnaker3 braking sail is capable of deorbiting from an orbit of 640 km or more. This is thanks to the 3m carbon fiber booms (hence the “3” in the name) that pull the 194 square feet sail.
The sail itself is made from a shimmery translucent material – CP-1 fluorinated polyimide, manufactured by NeXolve. The material is designed to resist decomposition by monoatomic oxygen in low Earth orbit.
Anthony Kofer, an engineer at the Purdue Spacecraft Laboratory, led the design and testing of the windsail assembly.
This towed sail has booms like a sailboat, but sailing in space is very different. The brake sail booms should be extremely light and should be placed in a small amount. Once deployed, the sail must maintain its integrity during the de-orbiting phase, which can take months or years.
Anthony Kofer, Purdue Spacecraft Laboratory Engineer
Booster rockets and other spacecraft usually go out of orbit on their own using propellant, but these fuel requirements limit the payload mass that the booster can deliver into space. Moving sails use the drag of the atmosphere to get the job done, saving valuable fuel and reducing the overall weight of the vehicle.
US spacecraft must leave orbit within 25 years of the completion of the mission. If a satellite or launch vehicle fails, they cannot use the fuel to de-orbit. A sailing sail passively helps a spacecraft to de-orbit even if it is not working or is out of fuel.
The launch of Firefly Aerospace Alpha will test how well the Spinnaker3 prototype is helping the launch vehicle stage de-orbit. After the tests, it will become clear how the device works, which will reduce the amount of space debris.