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The Challenges of Building a Colony on Mars

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In this series, mental_floss will examine the engineering problems associated with humanity’s most extreme endeavors, from mining asteroids to colonizing the ocean, and explain how engineers plan to solve them.

“Twenty years from now you will be more disappointed by the things you didn’t do than by the ones you did. So throw off the bowlines, sail away from the safe harbor, catch the trade winds in your sails. Explore. Dream. Discover.” – Not Mark Twain (regardless of what Virgin Galactic would have you believe).

If you’re going to settle Mars, there are a couple of questions that you have to answer straightaway: 1. Where? 2. How? 3. Who? That third question is especially difficult to answer—building a colony on Mars isn’t like discovering some Polynesian island and building a hut. Mars doesn’t want you there, and will be doing everything it can think of to keep you away. And if you do plan to go there, you shouldn’t expect to come back. You should, in fact, probably expect a confined life of loneliness, misery, disease, and starvation before you eventually descend into madness and death. Jack Torrance is likely the best-case scenario. Personally, my money’s on a colony of Reavers.

But all of that assumes a Martian colony can actually be built. Let’s start with the basic problems associated with moving to Mars.

Weathering the Weather

The average temperature on Earth is 61 degrees Fahrenheit (with wide variations, obviously). The average temperature on Mars is -80 degrees. But here’s the real challenge: A warm summer day on Mars might hit 71, which is pretty nice. Maybe wear jeans and carry along a light jacket. But that same warm summer day will plunge to -100 degrees come nightfall, with 100 percent humidity going into the following morning. (I’m going with’s numbers here.) So even though we have lots of experience (relatively speaking) living at research stations in Antarctica, it’s not exactly a 1:1 comparison. (Average temperature in Antarctica: -34.4 degrees, with no 170-degree swings.) The point is, if you’re building a house on Mars, you need to build one that neither braises nor freezes the Reavers inside.

We should also talk about the weather. The Butterfly Effect aside, when there’s a sandstorm in Dubai, your average New Yorker doesn’t change her dinner plans. Mars is a little different, though, with dust storms that engulf the entire planet. So in addition to moderating temperature, your shelter needs to be pretty durable. When it’s humidity-caked in red dirt, it’s not like you can just find someone on Angie’s List to pressure wash the siding.

And those are only the trivial problems. 

The Radiation Problem

In 2001, NASA sent a particle energy spectrometer to Mars to study the red planet’s radiation. This was called the Mars Radiation Environment Experiment, or MARIE. The device found that the surface of Mars has two and half times the radiation that you’d get at the International Space Station, and that’s not even counting the solar proton events, which come without warning and really bombard the place. “Wait a minute,” you say. “Why don’t we worry about solar proton events here on Earth? I mean we share the same sun!” Good question. When the protons of an SPE hit Earth, the magnetosphere pulls them to the poles, and the ionosphere (just below the magnetosphere) handles the rest. This is called polar cap absorption, and is one of the many reasons why Earth is a wonderful place indeed. Mars, lacking a magnetosphere, offers no such protection. How much of a problem is this, human-life-wise? After a series of solar flares in 2003, MARIE was damaged and rendered inoperable. If the sun is frying the machines on Mars designed to measure such solar salvos, imagine what it will do to humans. So, cancer: CHECK.

Power Issues

Even the dust storms are more than an annoyance. See, if we’re going to live on Mars, we’re going to need a reliable source of electricity. Because of the temperatures, lack of natural resources, incompatible atmosphere, etc., life support systems are really, really important. In six words: If the power fails, you die.

There are few more reliable sources of power than the sun, right? (Well, there’s nuclear power, but present political opposition has effectively removed that from the table.) The problem with solar panels is that those planetary dust storms can reduce sunlight by 99 percent. Uh-oh. Suddenly, your greenhouses aren’t growing vegetables and your solar cells aren’t charging very well. Your water-recycling and air filtration and temperature regulation systems are in jeopardy. You’re living off of reserve power and reserve supplies. Better hope the storm ends before the batteries do.

Conquering the Atmosphere

Another thing. Human beings have evolved very nicely for long, comfortable lives on Earth. We developed to enjoy the air, the sun, the land, the microbes, the gravity. We’re biologically equipped to survive a good 70 years on terra firma, and some of us much longer.

Not so much on Mars, though. The Martian atmosphere is thin. Really thin. A guy named George Armstrong did some research and determined that there exists an altitude at which the boiling point of water is 98.6 degrees. You might recognize that temperature as the happy result on a thermometer—unless you’re at the Armstrong Limit. Then it’s a really sad result because your bodily liquids will begin to boil. Tears, saliva, the lining of your lungs, etc. (Your blood is OK, as is your interior water, so to speak. Skin is an excellent protectant.) The atmospheric pressure of Mars is well over the Armstrong Limit. That means you’re confined to the colony. If you want to take a stroll, you’re confined to a space suit. “Well fine,” you say, “I’ll just wear a space suit.”

Getting Around

That’s a smart thing to do. But that suit is also pretty limiting. When you land on Mars, you won’t be climbing mountains and planting very many flags. You’ll have a small radius of travel, and that’s it for the foreseeable future. Are you familiar with the color brown? Because that’s all you’re going to see on Mars. “Well I’ll just saddle up one of those rovers,” you say, “and zip around to see the sights.”

This might not be the most effective means of travel. It’s taken the NASA rover Opportunity a full decade to travel a total of 23.94 miles. In six years, rover Spirit traveled 4.8 miles. Rover Curiosity is expected to travel a minimum of 12 miles. Rover Sojourner traveled 330 feet. None of this is to diminish the extraordinary engineering that was required to build, deploy, and operate the rovers. Those things are nearly indistinguishable from magic and have advanced human knowledge immeasurably. But they also offer a little perspective on what the best of our efforts can do. None of these rovers would have been able to finish a marathon in less than 10 years, if they could finish one at all. So it’s not as though we’ve established a proof of concept for a Martian freeway.

Getting There At All

One more point concerning our frail bodies: Consider that the ride from Earth to Mars takes about six months when the planets are close. At a compounding loss of 1 percent bone density per month, which is what you’re going to get in zero gravity, you’re looking at brittle bones before you even touch the Martian surface. Likewise muscle atrophy. A recent study by NASA found that even our steely-eyed astronauts, disciplined and no strangers to physical fitness on Earth and in space, lost significant calf muscle volume, peak power, and force-velocity characteristics over six-month stays on the International Space Station. We’re talking significant decreases in the 30% range, all around, even while engaging in a pretty serious exercise regimen. Try moving into a new house while you have pneumonia. That’s about what it’s going to feel like when you get to Mars.

Taken together, all of this probably makes temporary human settlement on Mars—let alone permanent colonies—sound impossible. But it’s not. In the next entry we’ll take a look at what engineers have up their sleeves to counter the problems of Martian settlement, and why it really can become a reality.

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iStock // Ekaterina Minaeva
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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Library of Congress
10 Facts About the Tomb of the Unknown Soldier
May 29, 2017
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Library of Congress

On Veterans Day, 1921, President Warren G. Harding presided over an interment ceremony at Arlington National Cemetery for an unknown soldier who died during World War I. Since then, three more soldiers have been added to the Tomb of the Unknowns (also known as the Tomb of the Unknown Soldier) memorial—and one has been disinterred. Below, a few things you might not know about the historic site and the rituals that surround it.


Wikimedia Commons // Public Domain

To ensure a truly random selection, four unknown soldiers were exhumed from four different WWI American cemeteries in France. U.S. Army Sgt. Edward F. Younger, who was wounded in combat and received the Distinguished Service Medal, was chosen to select a soldier for burial at the Tomb of the Unknowns in Arlington. After the four identical caskets were lined up for his inspection, Younger chose the third casket from the left by placing a spray of white roses on it. The chosen soldier was transported to the U.S. on the USS Olympia, while the other three were reburied at Meuse Argonne American Cemetery in France.


One had served in the European Theater and the other served in the Pacific Theater. The Navy’s only active-duty Medal of Honor recipient, Hospitalman 1st Class William R. Charette, chose one of the identical caskets to go on to Arlington. The other was given a burial at sea.


WikimediaCommons // Public Domain

The soldiers were disinterred from the National Cemetery of the Pacific in Hawaii. This time, Army Master Sgt. Ned Lyle was the one to choose the casket. Along with the unknown soldier from WWII, the unknown Korean War soldier lay in the Capitol Rotunda from May 28 to May 30, 1958.


Medal of Honor recipient U.S. Marine Corps Sgt. Maj. Allan Jay Kellogg, Jr., selected the Vietnam War representative during a ceremony at Pearl Harbor.


Wikipedia // Public Domain

Thanks to advances in mitochondrial DNA testing, scientists were eventually able to identify the remains of the Vietnam War soldier. On May 14, 1998, the remains were exhumed and tested, revealing the “unknown” soldier to be Air Force 1st Lt. Michael Joseph Blassie (pictured). Blassie was shot down near An Loc, Vietnam, in 1972. After his identification, Blassie’s family had him moved to Jefferson Barracks National Cemetery in St. Louis. Instead of adding another unknown soldier to the Vietnam War crypt, the crypt cover has been replaced with one bearing the inscription, “Honoring and Keeping Faith with America’s Missing Servicemen, 1958-1975.”


The Tomb was designed by architect Lorimer Rich and sculptor Thomas Hudson Jones, but the actual carving was done by the Piccirilli Brothers. Even if you don’t know them, you know their work: The brothers carved the 19-foot statue of Abraham Lincoln for the Lincoln Memorial, the lions outside of the New York Public Library, the Maine Monument in Central Park, the DuPont Circle Fountain in D.C., and much more.


Tomb Guards come from the 3rd U.S. Infantry Regiment "The Old Guard". Serving the U.S. since 1784, the Old Guard is the oldest active infantry unit in the military. They keep watch over the memorial every minute of every day, including when the cemetery is closed and in inclement weather.


Members of the Old Guard must apply for the position. If chosen, the applicant goes through an intense training period, in which they must pass tests on weapons, ceremonial steps, cadence, military bearing, uniform preparation, and orders. Although military members are known for their neat uniforms, it’s said that the Tomb Guards have the highest standards of them all. A knowledge test quizzes applicants on their memorization—including punctuation—of 35 pages on the history of the Tomb. Once they’re selected, Guards “walk the mat” in front of the Tomb for anywhere from 30 minutes to two hours, depending on the time of year and time of day. They work in 24-hour shifts, however, and when they aren’t walking the mat, they’re in the living quarters beneath it. This gives the sentinels time to complete training and prepare their uniforms, which can take up to eight hours.


The Tomb Guard badge is the least awarded badge in the Army, and the second least awarded badge in the overall military. (The first is the astronaut badge.) Tomb Guards are held to the highest standards of behavior, and can have their badge taken away for any action on or off duty that could bring disrespect to the Tomb. And that’s for the entire lifetime of the Tomb Guard, even well after his or her guarding duty is over. For the record, it seems that Tomb Guards are rarely female—only three women have held the post.


Everything the guards do is a series of 21, which alludes to the 21-gun salute. According to

The Sentinel does not execute an about face, rather they stop on the 21st step, then turn and face the Tomb for 21 seconds. They then turn to face back down the mat, change the weapon to the outside shoulder, mentally count off 21 seconds, then step off for another 21 step walk down the mat. They face the Tomb at each end of the 21 step walk for 21 seconds. The Sentinel then repeats this over and over until the Guard Change ceremony begins.