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NASA

5 Bold Proposals For Cleaning Up Space Junk

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NASA

Since the Russians put Sputnik in orbit in 1957, a heavy amount of space junk, from old satellites to nuts and bolts, has clogged up the orbit around Earth; as of February 2011, there were 10 million pieces of man-made debris in space, according to the Sydney Morning Herald. This puts us in real danger of something scientists call the Kessler Syndrome: Low Earth orbit becomes so crowded with artifical satellites and other trash that collisions occur, generating more pieces of debris that will in turn cause more collisions, creating a domino effect that could hinder space exploration. 

Larger pieces of space junk can be tracked and sometimes avoided—the International Space Station (ISS) can change orbit to get around debris—but even smaller pieces, which are eventually pulled into Earth's atmosphere and burn up, are dangerous when moving at these speeds in space. According to Popular Mechanics, a paint chip moving at hypervelocity is capable of punching a 0.025 centimeter hole in a U.S. satellite

Scientists are seeing evidence of the Kessler Syndrome—orbital debris is on track to triple by 2030—and are on the hunt for solutions to our space junk problem. Various nations have put forward clean-up plans that range from practical to Star Trek levels of ambition. Here are five ideas.

1. Robots

The Defense Advanced Research Projects Agency (DARPA), an agency of the U.S. Defense Department that develops and funds technology used by the military, plans to refurbish and recycle lifeless satellites that are floating around in space—with robots.

DARPA’s Phoenix program hopes to scavenge the space debris by using robots that tag along on commercial satellite launches and attach themselves to defunct satellites. From there, the robots will collect parts, particularly antennas, which can be re-used to craft a communications network for the military at low cost.

Here’s how they’re hoping it will work: Nanosatellites, known as a satlets, will be carried in PODS (Payload Orbital Delivery System) that will piggyback into space on a larger commercial satellite being sent into orbit. Once in space, the PODS would rendezvous with another type of salvaging spacecraft (NASA calls this a “tender”) launched into orbit, that will then navigate it to the dead satellite. The tender and PODS stay together from then on. This is when the robot will go to work, using robotic arms to remove an antenna and installing the satlets into the antenna. This creates the new communications network.

The agency is planning the first Phoenix mission for 2015 and is targeting 140 dead satellites for repurposing.

2. Kamikaze Space Janitors

CleanSpaceOne—a proposed satellite from scientists in Switzerland—will go into space as a single-capture mission, grabbing debris and heading back to Earth’s atmosphere, where both the CleanSpaceOne and its collection will burn up on re-entry. Switzerland will build many of the CleanSpaceOne satellites to send into space one after the other. The first mission is one of nostalgia: The space janitor will retrieve the first satellite Switzerland ever launched, Swisscube.

In a video, the director of the Swiss Space Center, Volker Gass, said the amount of space junk is getting out of hand. “Something has to be done about this problem. Collisions between satellite and debris are bound to happen. There’s going to be an avalanche effect, and more satellites are going to be destroyed,” Gass said.

This big clean-up plan is also set to launch in 2015.

3. Fishing Nets

In 2011, it was reported that The Japan Aerospace Exploration Agency teamed up with Nitto Seimo, a manufacturer of fishing nets, to build and deploy a giant net that will sweep up space junk in Earth’s orbit.

It won’t be bringing the mess back to Earth, though. The plan is to stretch the thin metal net into space, collecting waste as it moves along for several weeks. After the journey, an electric charge to the net will draw it back toward Earth, burning up both the net and its contents upon entering the atmosphere. (Details for how the net will be guided to gather trash and avoid things we might actually want in orbit are not available.)

Nitto Seimo has spent six years developing the net, which sounds like something out of science fiction.

4. Galactic Garbage “Trucks”

The European Space Agency has a plan, too. Their initiative just isn’t as far-fetched as the others.

According to the ESA, space junk has increased by 50 percent in the past five years, and they’re afraid of future collisions—those by debris alone and those between debris and a working satellite or active mission. The agency wants to tackle the problem directly by sending out missions dedicated to removing litter.

In 2015, the ESA has plans to launch ATVs (Automated Transfer Vehicles), which are unmanned cargo freighters equipped with optical sensors that could be able to detect orbiting trash, gather it, and return it to Earth.

5. Lasers

NASA just wants to use lasers. But they don’t want to zap the garbage and destroy it—they want to nudge debris out of the way.

The debris in space moves at incredibly fast speeds and is extremely dangerous to shuttles, the space station, and satellites. The agency wants to avoid using a laser that would explode any objects, which would only create a bigger mess of smaller (and therefore harder to track) pieces.

Ideally, the laser—which would cost an relatively inexpensive $1 million—would be mounted on one of Earth’s poles, where the atmosphere is thinner. During a launch or to avoid a collision, NASA would send pulses of photo pressure to gently prod objects out of the way.

So far, NASA has only floated this idea; actually building the laser would require international cooperation.

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iStock // Ekaterina Minaeva
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Man Buys Two Metric Tons of LEGO Bricks; Sorts Them Via Machine Learning
May 21, 2017
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iStock // Ekaterina Minaeva

Jacques Mattheij made a small, but awesome, mistake. He went on eBay one evening and bid on a bunch of bulk LEGO brick auctions, then went to sleep. Upon waking, he discovered that he was the high bidder on many, and was now the proud owner of two tons of LEGO bricks. (This is about 4400 pounds.) He wrote, "[L]esson 1: if you win almost all bids you are bidding too high."

Mattheij had noticed that bulk, unsorted bricks sell for something like €10/kilogram, whereas sets are roughly €40/kg and rare parts go for up to €100/kg. Much of the value of the bricks is in their sorting. If he could reduce the entropy of these bins of unsorted bricks, he could make a tidy profit. While many people do this work by hand, the problem is enormous—just the kind of challenge for a computer. Mattheij writes:

There are 38000+ shapes and there are 100+ possible shades of color (you can roughly tell how old someone is by asking them what lego colors they remember from their youth).

In the following months, Mattheij built a proof-of-concept sorting system using, of course, LEGO. He broke the problem down into a series of sub-problems (including "feeding LEGO reliably from a hopper is surprisingly hard," one of those facts of nature that will stymie even the best system design). After tinkering with the prototype at length, he expanded the system to a surprisingly complex system of conveyer belts (powered by a home treadmill), various pieces of cabinetry, and "copious quantities of crazy glue."

Here's a video showing the current system running at low speed:

The key part of the system was running the bricks past a camera paired with a computer running a neural net-based image classifier. That allows the computer (when sufficiently trained on brick images) to recognize bricks and thus categorize them by color, shape, or other parameters. Remember that as bricks pass by, they can be in any orientation, can be dirty, can even be stuck to other pieces. So having a flexible software system is key to recognizing—in a fraction of a second—what a given brick is, in order to sort it out. When a match is found, a jet of compressed air pops the piece off the conveyer belt and into a waiting bin.

After much experimentation, Mattheij rewrote the software (several times in fact) to accomplish a variety of basic tasks. At its core, the system takes images from a webcam and feeds them to a neural network to do the classification. Of course, the neural net needs to be "trained" by showing it lots of images, and telling it what those images represent. Mattheij's breakthrough was allowing the machine to effectively train itself, with guidance: Running pieces through allows the system to take its own photos, make a guess, and build on that guess. As long as Mattheij corrects the incorrect guesses, he ends up with a decent (and self-reinforcing) corpus of training data. As the machine continues running, it can rack up more training, allowing it to recognize a broad variety of pieces on the fly.

Here's another video, focusing on how the pieces move on conveyer belts (running at slow speed so puny humans can follow). You can also see the air jets in action:

In an email interview, Mattheij told Mental Floss that the system currently sorts LEGO bricks into more than 50 categories. It can also be run in a color-sorting mode to bin the parts across 12 color groups. (Thus at present you'd likely do a two-pass sort on the bricks: once for shape, then a separate pass for color.) He continues to refine the system, with a focus on making its recognition abilities faster. At some point down the line, he plans to make the software portion open source. You're on your own as far as building conveyer belts, bins, and so forth.

Check out Mattheij's writeup in two parts for more information. It starts with an overview of the story, followed up with a deep dive on the software. He's also tweeting about the project (among other things). And if you look around a bit, you'll find bulk LEGO brick auctions online—it's definitely a thing!

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Nick Briggs/Comic Relief
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What Happened to Jamie and Aurelia From Love Actually?
May 26, 2017
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Nick Briggs/Comic Relief

Fans of the romantic-comedy Love Actually recently got a bonus reunion in the form of Red Nose Day Actually, a short charity special that gave audiences a peek at where their favorite characters ended up almost 15 years later.

One of the most improbable pairings from the original film was between Jamie (Colin Firth) and Aurelia (Lúcia Moniz), who fell in love despite almost no shared vocabulary. Jamie is English, and Aurelia is Portuguese, and they know just enough of each other’s native tongues for Jamie to propose and Aurelia to accept.

A decade and a half on, they have both improved their knowledge of each other’s languages—if not perfectly, in Jamie’s case. But apparently, their love is much stronger than his grasp on Portuguese grammar, because they’ve got three bilingual kids and another on the way. (And still enjoy having important romantic moments in the car.)

In 2015, Love Actually script editor Emma Freud revealed via Twitter what happened between Karen and Harry (Emma Thompson and Alan Rickman, who passed away last year). Most of the other couples get happy endings in the short—even if Hugh Grant's character hasn't gotten any better at dancing.

[h/t TV Guide]

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