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NASA Wants to Make a Mobile Water Factory on the Moon

Water has long been the limiting factor for humans in space. But now, NASA is developing a rover that can make water on the Moon. Such a capability will be necessary for any serious attempt at the permanent settlement of Mars, or any other long-term space voyage. If successful, it will inaugurate a new, critical area in space exploration, where resources from other worlds can be harnessed and used.

Presently, everything we use in space is made on Earth. Consider the big, visible parts of human exploration of the solar system, rockets like the Space Launch System (SLS), under construction and set for its maiden voyage in 2018. There’s also the Orion capsule, tested previously and set to fly atop SLS (without astronauts). Then there’s work on habitats: Scientists are currently working on manufacturing artificial habitats for the International Space Station, but soon will be working on one for the Martian surface. A huge part of this kind of pioneering the solar system, however, concerns not just what we bring to other worlds, but what we leave behind. The Lunar Resource Prospector is the first big step in striking that balance.

IN-SITU RESOURCE UTILIZATION

The real problem of colonization is mass. It's very expensive to send something to space, and the heavier it is, the more it costs. It takes hundreds of kilograms on the launch pad to put a single kilogram on the surface of Mars, and Martian settlers will need many, many metric tons of commodities to survive. Practically speaking, they can't take everything they will need from Earth. To colonize the solar system, they will have to learn how to use the resources of the solar system.

The good news is that everything in the solar system is a potential resource for settlers. In-situ resource utilization, or ISRU, is the concept of mining resources on other worlds and turning them into useful commodities, as well as recycling waste created on other worlds. (Waste conversion solves two problems: It creates new useful things and eliminates garbage. The ISS dumps its garbage, allowing it to burn up in the atmosphere. But surface dwellers on Mars won't have such a convenient disposal service.)

Energy is an important part of ISRU, and from a settlement perspective, energy is very cheap. The Sun is a giant fusion reactor in the sky, after all, and to harness it, all pioneers need are a few solar panels that they bring from home. Those panels will provide energy for a very long time—energy that can be used for ISRU.

Mars is the most likely current spot for future human settlement, so consider what resources might be available there: Settlers could extract oxygen from Mars's soil, known as regolith. Water could be extracted from volatiles in the soil, essentially baking them off. There is also carbon dioxide in the Martian atmosphere. Combine carbon with electrolyzed water and settlers can make methane, which could be used as fuel.

Settlers won't need to take building material to Mars; they could easily glue soil together and make bricks. Metals could also be extracted from Martian regolith to build things. Because Mars is rich with carbon, hydrogen, and oxygen, settlers could even make plastic. What would they build first? Probably greenhouses, for starters. Growing crops for food will also be useful for water purification and oxygen generation.

For ISRU to be most effective, planning will begin long before humans leave Earth. NASA's provisional plans see ISRU projects beginning 480 days before astronauts launch. Machines already on Mars will be put to work before settlers even arrive, extracting resources and storing them cryogenically. Water will need to be waiting for humans to drink. Oxygen and inert gasses would need to be ready for instant use in a habitat. An ascent vehicle would be fueled with methane propellant and ready from day one in the event of an emergency.

Even the propellant to get to Mars in the first place could be extracted off-world. The moon's equatorial region yields an abundance of oxygen, and its poles an abundance of water. Engineers could harness that to make rocket propellant, which would be much cheaper to bring from the Moon than launching it from Earth.

ISRU is an obvious approach to exploration and settlement, but so far, it’s been theoretical: No one has ever tried this on a planetary scale. When we go to Mars, it won’t be for a casual visit, it will be for pioneering. The long-term goal is independence from Earth.

LUNAR RESOURCE PROSPECTOR

One of the first serious ISRU proposals is the Lunar Resource Prospector. The project is in early development and will be NASA's first soft landing on the Moon since the 1970s. The spacecraft is a small rover, and as its name suggests, it will prospect the lunar surface, studying its composition with an emphasis on finding water.

Scientists will choose its landing site carefully. Potential sites must be in sunlight, as the spacecraft is solar powered, and it must have a direct line of sight for communications with the Earth. (It does not presently use orbital assets as relays.) The terrain must be traversable, and data collected by such spacecraft as the Lunar Reconnaissance Orbiter will have to suggest where there is hydrogen present in the subsurface, and where subsurface temperatures support the presence of water. Moreover, the landing site must be close to at least one of the moon's permanently shadowed regions. (There are areas on the moon that have not seen sunlight in billions of years; water is known to exist in such places.) Moreover, the orbit of the Moon and shifting launch windows on Earth mean that different landing sites must be chosen for different times of the year, and that if a launch slips, a backup landing site is ready to go. Sometimes the prospector will target the north pole of the Moon, and sometimes the south pole.

The lander itself is a pallet design—a flatbed from which the rover would roll once it has landed. It would immediately orient its solar panels toward the sun. Because of the rover's relatively small size, the sun provides more than enough energy for its operation, especially when compared with Curiosity on Mars, which is big enough that it needs to be powered by a radioisotope thermoelectric generator. "The rover that we're going to go on is a little bit smaller than a golf cart," James Smith, lead system engineer of the primary payload for the rover, told mental_floss earlier this year. "It's not a MSL [Mars Science Laboratory] sized-rover, but it's much bigger than Pathfinder."

Once the science mission gets underway, a neutron spectrometer on the rover will look for signatures of hydrogen in the lunar subsurface. (Think of a metal detector, only for hydrogen.) This might originate from water, but might also be found in hydrated minerals, or be solar-implanted hydrogen. A drilling instrument will bring regolith material to the surface for quick inspection by a near infrared spectrometer. "A cool thing about this," Jacqueline Quinn, an environmental engineer at Kennedy Space Center, told mental_floss, "is that we're going to get a meter sample, and that's never been done robotically."

The instrument can also grab material and deliver it to an onboard oven. The oven is a sealed system, and through heating can drive off the water. A quantifying spectrometer system can determine the precise amount of water present in the lunar dirt. That water is also imaged and those images are sent back to Earth. For the first time, humans will see video of water extracted on another world.

The rover itself is nimble and engineered to traverse up to a 15-degree slope and not tilt over. The moon's light gravity is an additional engineering challenge. "We have to have equal and opposite forces in one-sixth G," says Quinn. "We have to have enough mass to counter our drilling—otherwise we'll do beautiful doughnuts in the surface. We don't want to do that."

The Lunar Resource Prospector is designed to be launch-vehicle independent. SLS would be an optimal rocket for the mission, and the timing is just right, but the spacecraft's "mass to translunar injection" is such that it can fly on anything from a SpaceX Falcon 9 rocket and up. If all goes well, the mission will launch in the 2020s, and we’ll finally get a chance to see what in-situ resource utilization looks like in practice.

Original image
iStock // Ekaterina Minaeva
technology
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Man Buys Two Metric Tons of LEGO Bricks; Sorts Them Via Machine Learning
May 21, 2017
Original image
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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iStock
Animals
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Scientists Think They Know How Whales Got So Big
May 24, 2017
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iStock

It can be difficult to understand how enormous the blue whale—the largest animal to ever exist—really is. The mammal can measure up to 105 feet long, have a tongue that can weigh as much as an elephant, and have a massive, golf cart–sized heart powering a 200-ton frame. But while the blue whale might currently be the Andre the Giant of the sea, it wasn’t always so imposing.

For the majority of the 30 million years that baleen whales (the blue whale is one) have occupied the Earth, the mammals usually topped off at roughly 30 feet in length. It wasn’t until about 3 million years ago that the clade of whales experienced an evolutionary growth spurt, tripling in size. And scientists haven’t had any concrete idea why, Wired reports.

A study published in the journal Proceedings of the Royal Society B might help change that. Researchers examined fossil records and studied phylogenetic models (evolutionary relationships) among baleen whales, and found some evidence that climate change may have been the catalyst for turning the large animals into behemoths.

As the ice ages wore on and oceans were receiving nutrient-rich runoff, the whales encountered an increasing number of krill—the small, shrimp-like creatures that provided a food source—resulting from upwelling waters. The more they ate, the more they grew, and their bodies adapted over time. Their mouths grew larger and their fat stores increased, helping them to fuel longer migrations to additional food-enriched areas. Today blue whales eat up to four tons of krill every day.

If climate change set the ancestors of the blue whale on the path to its enormous size today, the study invites the question of what it might do to them in the future. Changes in ocean currents or temperature could alter the amount of available nutrients to whales, cutting off their food supply. With demand for whale oil in the 1900s having already dented their numbers, scientists are hoping that further shifts in their oceanic ecosystem won’t relegate them to history.

[h/t Wired]

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