A small cube satellite designed to demonstrate a practical, low-cost method to cut down on space debris has been built by students at Brown University.
Current estimates suggest there are over 100 million pieces of space junk orbiting the Earth, ranging from debris the size of a penny to an entire rocket booster.
The number of satellites in low-Earth orbit (LEO) is also expected to increase dramatically over the next few years, which is raising concerns that involuntary collisions between operational payloads and space debris could occur in orbit.
The student-made cube satellite was built on a shoestring budget using off-the-shelf supplies available at most hardware stores, including 48 Energizer AA batteries.
Called SBUDNIC, the prototype was blasted into space on Elon Musk’s SpaceX rocket last May as part of the Transporter 5 ridesharing mission and was designed to tackle the growing issue of space junk. For that purpose, the students added a plastic drag sail made from Kapton polyimide to understand the effect this could have on atmospheric re-entry.
About five years ahead of schedule, the small cube satellite re-entered the Earth’s atmosphere sometime on Tuesday 8 August or immediately after, and burned up high above Turkey after 445 days in orbit.
The sail popped open like an umbrella upon deployment at about 520 kilometres, well above the orbit of the International Space Station (ISS), and helped push the satellite back down to Earth more quickly than anticipated.
“We were trying to prove that there are ways of deorbiting space junk after mission life has ended that are not super costly,” said Selia Jindal, a Brown University graduate and one of the project leads.
“This showed that we can do that. We were successfully able to deorbit our satellite so that it’s no longer taking up space in Earth’s orbit. More importantly, the project really helped to show that there are significant plans we can put in place to combat the space junk problem that are cost-effective.”
According to Nasa, there are now more than 27,000 pieces of what it calls orbital debris or space junk being tracked by the Department of Defense’s Space Surveillance Network.
In a worst-case scenario, a satellite exploding in orbit could set off a chain reaction that hits a number of other satellites as well, closing off that orbit until all the debris falls back to Earth.
“There are companies that are trying to solve this problem of space junk with concepts such as space tow trucks or nets in space that could capture space junk and take them out of orbit,” said Dheraj Ganjikunta, SBUDNIC’s lead program manager.
“What’s amazing about SBUDNIC is that it is magnitudes less [expensive] than any of those solutions. Rather than taking junk out of space after it becomes a problem, we have this $30 drag device you can just throw onto satellites and radically reduce how long they’re in space.”
Most satellites remain in orbit for an average of 25 years or more after they have served their purpose. To help combat this, the Federal Communications Commission adopted a new five-year rule in 2022 for deorbiting satellites.
Last year, a study calculated that there is now a 10 per cent chance of space debris killing one or more people over the next decade as it falls from the sky.
Source: E&T
