A student project shows that sails can knock satellites out of orbit at record speed

A prototype satellite designed to test a deployable towsail to take satellites out of orbit appears to have met its goal, burning up on re-entry earlier this month after spending just 445 days in orbit.

SBUDNIC, an acronym chosen to be a play on “Sputnik”, was assembled by students at Brown University, Rhode Island, using low-cost, off-the-shelf commercial components. The CubeSat design features a drag sail made of Kapton polyimide film, with structural supports of thin aluminum tubes, which are deployed once the satellite is in orbit.

The goal of the project was to show a potential solution to the problem that low Earth orbit has become a graveyard for more defunct satellites that have reached the end of their lives. log previously detailed. If it proves successful, the idea is that future satellites could include a similar mechanism to help deorbit them at the end of their lives.

SBUDNIC was sent aboard the ship SpaceX 5 transporter It was launched in May last year as part of a payload that includes a number of other small satellites. Its sail opened like a parachute about 520 kilometers above the Earth’s surface, according to the project team, to create drag and cause its orbit to decay.

The project Seems it was successful In this regard, according to tracking data obtained by the team from the US Space Command. It noted that SBUDNIC was about 470 kilometers (292 miles) above Earth in early March, while other similarly sized satellites deployed in a similar orbit as part of the same mission were still at altitudes of 500 kilometers (310 miles) or more.

The CubeSat’s orbit deterioration accelerated with its decline, so that its last known altitude was only 146 kilometers (90 miles) on August 8, and shortly thereafter it was presumed destroyed by atmospheric burn-up.

Previous projections had indicated that the thruster would reduce SBUDNIC’s orbital lifetime from more than 20 years to less than 6.5 years, but in reality it was dropped by about a year and a quarter.

“We’ve been trying to prove that there are ways to get space junk out of orbit after the mission is over, and it’s not very expensive,” said Celia Jindal, one of the project leaders who graduated from Brown University this year. “This showed that we can do this. We have succeeded in deorbiting our satellite so that it does not take up space in Earth’s orbit.”

The sail concept is an order of magnitude less expensive than competing orbital waste treatment ideas such as space tow trucks or nets to catch waste and haul it out of orbit, according to Dheeraj Gangikunta, SBUDNIC’s principal program manager who graduated last year.

“Instead of taking junk out of space after it becomes a problem, we have a $30 hauling device that you can throw at satellites and radically reduce the time they stay in space,” Gangikunta said.

Of course, this would require future satellites to be designed to have a similar mechanism built into them, and thus not help with existing space junk, but presumably every little bit helps.

SBUDNIC was a 3U CubeSat, which means it was the size of three 10cm cubes connected together. It was based on a $10 Arduino system plus 65 AA lithium batteries and includes a variety of 3D printed parts produced with consumer grade printers. ®