Upcoming space mission to test drag sail pulls rocket back to Earth

A rocket enters space with a tarpaulin. The goal? For the tug of war to bring the rocket back to Earth, it appears as the thousands of pieces of spacecraft in Earth’s lower orbit.

The tow rope, developed by engineers from Purdue University, will be on board a Firefly Aerospace rocket that is expected to launch in November from Vandenberg Air Force Base in California.

This sail and six other “Dedicated Research and Education Accelerator Mission” (DREAM) loadloads fly at the Alpha launch of Firefly Aerospace, the company’s first flight for launched cars.

“High-value orbits around the Earth are being silenced,” said David Spencer, a Purdue adjunct associate professor of aerospace and astronomy and the mission manager for the Mars Sample Return campaign at NASA’s Jet Propulsion Laboratory.

“If we do not remove satellites or other launched auto parts from orbit, we will eventually kill high-used orbits for other space systems,” he said. “Drag sailing technology is designed to launch with a host spacecraft as a launch vehicle and deploy at the end of the host car’s mission. The drag delivered through the Earth’s atmosphere will accelerate the car’s deorbit . “

Named “Spinnaker3”, this tug of war is not the first to be launched into space. But it is one of the first to be large enough to debug the upper stage of a launched car. The launch of the Firefly Alpha will target an orbital altitude of about 200 miles, but the Spinnaker3 towbar is capable of delivering orbital capacity of orbital altitude of 400 miles or more.

This is thanks to 3 meter long carbon fiber trees (hence the “3” in the name) that pull a sail with an area of ​​194 square feet.

The sail itself is made of a shiny transparent material, a fluorinated polyimide called CP-1, produced by the company NeXolve. The material is designed to counteract degradation of monatomic oxygen in an empty earth orbit.

Purdue spaceship laboratory Anthony Cofer led the design and testing of the tow rope assembly.

“This sailboat has bombs like a sailboat does, but sailing through space is very different. The towbars have to be extremely lightweight, and they have to be stacked in a tight volume,” Cofer said. “Once deployed, the seal must maintain its integrity throughout the deorbit phase, which can take months or years.”

Launches of cars and other spaceships typically deorbit on their own with propellant, but these propulsion needs limit the payload that a launched car can bring to space. Drag sails use atmospheric towing to get the job done, save valuable fuel and reduce the overall mass of the car.

U.S. space vehicles are required to orbit within 25 years after completion of mission. If a satellite or launch vehicle becomes inoperable, it cannot use the propellant to make deorbit. A tow rope helps passive spacecraft to penetrate, even when it is unusable or out of propellant.

The launch of the Firefly Aerospace Alpha will be a test of how well the prototype Spinnaker3 helps deorbit the stage for launched cars.

“A lot of things could have debilitated on their own in about a hundred years, but that’s not doing us any good. We want to speed up that debilitating with a tow rope,” said Arly Black, a Purdue Ph.D. candidate in aeronautics and astronautics, who performed system tests and performance analysis for Spinnaker3.

“Overwhelmed with predictive atmospheric conditions for November, the Firefly Aerospace’s launch vehicle was able to deerbit on its own at a low altitude of about 200 miles within 25 days. Using Spinnaker3, the deorbitation process could be shortened to 15 days.”

Deorbit without a sail in 25 days is already a reasonable time for low altitudes, Black said, but as launch height increases, deorbit time also increases, which increases the chance of collision with other objects. Accelerating this deorbit time with a drag sail would make a big difference.

Spinnaker3 is a prototype for a dragline product line developed by Vestigo Aerospace LLC, a start-up company founded by Spencer. The idea is to develop tugs of various sizes and boom lengths, depending on the type of spacecraft. The technology is licensed by the Purdue Research Foundation. Spencer has partnered with the Purdue Foundry to develop startup business models.

The product line also includes a Spinnaker1 sail, which has 1 meter long bombs designed to orbit smaller satellites such as CubeSats used for space exploration.

Spencer directed the year-long development of Spinnaker3 by students, faculty, and staff at Purdue’s Space Flight Projects Laboratory. The development of drag seals also included contributions from 18 students for students and students as part of a course on space flight projects.

Lab tests of Spinnaker3 at Purdue completed in the spring. A team at California Polytechnic State University, San Luis Obispo, contributed an avionics unit that provides power and communication for the charge, as well as imaging capabilities that allow photos of the sail to land to be transferred after deployment.

Vestigo Aerospace has partnered with Purdue for a NASA Phase I SBIR award and was recently awarded a two-year Phase II research to advance tugboat technology. The Purdue lead researcher for the SBIR is Alina Alexeenko, a professor at the School of Aeronautics and Astronautics.