ESA tackles space debris problem with ‘angel wings’ for satellites

As futuristic as this sounds, space real estate is booming. Major corporations and scientific research organizations are actively competing to send satellites into orbit for extraordinary reasons — developing a free Internet connection; improving GPS systems; climate change monitoring; even analyzing Albert Einstein’s trippy general relativity equations.

But as humanity continues to advance technologically, experts are increasingly concerned about a major problem: We’ve found a new part of the universe to pollute. As of 2021, NASA said, more than 27,000 pieces of orbital debris, or “space junk,” were in our planet’s gravitational tides — and since then, SpaceX alone has sent hundreds of satellites there.

When they’re done with their equipment, scientists usually just wait for things in Earth’s orbit to start coming out of orbit and eventually burn up in our atmosphere. However, this natural process can take a very (very) long time.

So, hoping to pave a cleaner future for our space dreams, the European Space Agency announced the reinforcing promise of its innovative aluminum-coated sail prototype. This device can drive a satellite into orbit and help it out of orbit at any time.

The concept is called the Drag Augmentation Deorbiting System, or ADEO, braking sail — and in late December, the smallest of its kind completed its last successful demo mission since the program’s groundbreaking mission in 2018.

A silver space sail is seen with a shining star in the background.

An artist’s impression of ESA’s prototype brake sail concept.


How does it work?

In fact, ESA folded the 3.5-square-meter (38-foot) sail until it fit into what essentially looks like a 10-centimeter (4-inch) jack-in-the-box package. Scientists then attached the part to a privately built spacecraft, the ION satellite carrier. ION was launched on June 30, 2021 via a Falcon 9 rocket.

Then, in December 2022, the sail was deployed to showcase a silvery polyamide membrane attached to four carbon-reinforced arms arranged in an X-shape. That increased what’s known as the satellite carrier’s atmospheric surface drag, which refers to a force generated by atoms near the top of the atmosphere moving opposite to the relative motion of something in low Earth orbit. You can think of resistance as friction, but with air.

With such an amplified drag effect, the spacecraft began to lower its orbital altitude at an accelerated rate, hastening the satellite’s eventual demise: burning up in Earth’s atmosphere.

“The ADEO-N sail will allow the satellite to re-enter in about a year and three months, when it would otherwise have re-entered in four to five years,” said Tiziana Cardone, an ESA structural engineer who oversaw the project. a statement.

Earth can be seen in the distance from the perspective of the ION satellite.  Covering most of the screen is part of the breaking space sail.

A camera image of the ION satellite after it unfurled its sail.


For a beautiful mental image of it all, ESA thinks of the silver sail as the satellite’s “angel wings”, helping to gently float it to its death. The official name of ADEO’s latest mission was, appropriately, “Show Me Your Wings.”

Going forward, the agency says this sail can also be scaled up or down, depending on what kind of satellite it’s connected to.

“The largest variety can be as large as 100 square meters and take up to 45 square meters [minutes] to deploy,” the agency said in a press release. “The smallest sail is just 3.5 square meters and deploys in just 0.8 seconds!”

Passive towing systems like this are not exactly a new concept. According to NASA, such devices represent the most “common deorbit device” for low-Earth orbiting satellites, and offer an advantage because they are quite easy to handle and pack super compact.

But what is notable about ESA’s recent achievement with ADEO is that it seems to be working extremely well, in line with widespread efforts to reduce the huge problem of space junk. For example, last year the Federal Communications Commission passed a new “five-year rule” for deorbiting satellites, compared to the previous 25 years, and ESA itself has a major initiative to tackle space pollution.

“We want to introduce a zero-waste policy, which means that if you put a spacecraft into orbit, you have to dispose of it,” Josef Aschbacher, ESA’s director general, said in a statement last year.