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In Space, No One Can Hear You Explode: The Byford Dolphin Incident

February 15, 2019 by 42 Comments

“It wouldn’t happen that way in real life.” One of the most annoying habits of people really into the “sci” of sci-fi is nitpicking scientific inaccuracies in movies. The truth is, some things just make movies better, even if they are wrong.

What would Star Wars be without the sounds of an epic battle in space where there should be no sound? But there are plenty of other examples where things are wrong and it would have been just as easy to get them right — the direction of space debris in the movie Gravity, for example. But what about the age-old trope of explosive decompression? Some movies show gross body parts flying everywhere. Others show distressed space travelers surviving in space for at least brief periods.

It turns out, dropping pressure from one atmosphere to near zero is not really good for you as you might expect. But it isn’t enough to just make you pop like some meat balloon. You are much more likely to die from a pulmonary embolism or simple suffocation. But you are a meat balloon if you experience a much greater change in pressure. How do we know? It isn’t theoretical. These things have happened in real life.

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The Problem With Self-Driving Cars: The Name

February 14, 2019 by 97 Comments

In 1899, you might have been forgiven for thinking the automobile was only a rich-man’s toy. A horseless carriage was for flat garden pathways. The auto was far less reliable than a horse. This was new technology, and rich people are always into their gadgets, but the automobile is a technology that isn’t going to go anywhere. The roads are too terrible, they don’t have the range of a horse, and the world just isn’t set up for mechanized machines rolling everywhere.

This changed. It changed very quickly. By 1920, cars had taken over. Industrialized cities were no longer in the shadow of a mountain of horse manure. A highway, built specifically for automobiles, stretched from New York City to San Francisco. The age of the automobile had come.

And here we are today, in the same situation, with a technology as revolutionary as the automobile. People say self-driving cars are toys for rich people. Teslas on the road aren’t for the common man because the economy model costs fifty thousand dollars. They only work on highways anyway. The reliability just isn’t there for level-5 automation. You’ll never have a self-driving car that can drive over mountain roads in the snow, or navigate a ball bouncing into the street of a residential neighborhood chased by a child. But history proves time and time again that people are wrong. Self-driving cars are the future, and the world will be unrecognizable in thirty years. There’s only one problem: we’re not calling them the right thing. Self-driving cars should be called ‘cryptocybers’.

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The “Impossible” Tech Behind SpaceX’s New Engine

February 13, 2019 by 83 Comments

Followers of the Church of Elon will no doubt already be aware of SpaceX’s latest technical triumph: the test firing of the first full-scale Raptor engine. Of course, it was hardly a secret. As he often does, Elon has been “leaking” behind the scenes information, pictures, and even video of the event on his Twitter account. Combined with the relative transparency of SpaceX to begin with, this gives us an exceptionally clear look at how literal rocket science is performed at the Hawthorne, California based company.

This openness has been a key part of SpaceX’s popularity on the Internet (that, and the big rockets), but its been especially illuminating in regards to the Raptor. The technology behind this next generation engine, known as “full-flow staged combustion” has for decades been considered all but impossible by the traditional aerospace players. Despite extensive research into the technology by the Soviet Union and the United States, no engine utilizing this complex combustion system has even been flown. Yet, just six years after Elon announced SpaceX was designing the Raptor, they’ve completed their first flight-ready engine.

The full-flow staged combustion engine is often considered the “Holy Grail” of rocketry, as it promises to extract the most possible energy from its liquid propellants. In a field where every ounce is important, being able to squeeze even a few percent more thrust out of the vehicle is worth fighting for. Especially if, like SpaceX, you’re planning on putting these new full-flow engines into the world’s largest operational booster rocket and spacecraft.

But what makes full-flow staged combustion more efficient, and why has it been so difficult to build an engine that utilizes it? To understand that, we’ll need to first take a closer look at more traditional rocket engines, and the design paradigms which have defined them since the very beginning.

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Security Engineering: Inside the Scooter Startups

February 12, 2019 by 56 Comments

A year ago, ridesharing scooter startups were gearing up for launch. Workers at Bird, Lime, Skip, and Spin were busy improving their app, retrofitting scooters, and most importantly, figuring out the logistics of distributing thousands of electronic scooters along the sidewalks of the Bay Area. These companies were gearing up for a launch in early summer, but one company — nobody can remember exactly who — decided to launch early. First mover advantage, and all. Overnight, these scooter companies burst into overdrive, chucking scooters out of panel vans onto the sidewalk simply to keep up with the competition.

The thing about San Francisco, and California in general, is that it’s a very direct democracy masquerading as a representative government. Yes, there are city council members and a state legislature, but the will of the people will rule. No one liked tripping over the scooters littering the sidewalks, so the scooters ended up at the bottom of a lake. Or in trees. Or in the trash. In time, city permits were issued, just like a hot dog cart or any other business operating on a public sidewalk, and the piles of electric scooters disappeared. Not before hundreds of scooters were vandalized, that is.

It’s still early in the electric scooter rental startup space, but if there’s one company leading the pack, It’s Bird. they’re getting the most press, the CEO was formerly at Lyft and Uber (which explains the press), and they’ve raised nearly a half Billion dollars in funding (which explains the press). Bird is valued at two Billion dollars, and it’s one of four major ridesharing scooter startups. Pets.com had nothing on this.

Despite how overvalued you think a scooter startup might be, they’re still a business, and they’re ruled by the bottom line. Bird has grown a lot in the past year, and with that comes engineering challenges. The Bird scooters must be more resistant to vandalism. The Bird scooters must be harder to steal. Above all else, they must remain in service longer. This is the teardown of how Bird managed to improve their bottom line and engineer a better scooter.

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Automate the Freight: Amazon Tackles the Last Mile Problem On Wheels

February 11, 2019 by 82 Comments

We’ve been occasionally exploring examples of what could be the killer application for self-driving vehicles: autonomous freight deliveries, both long-haul and local, as well as some special use cases. Some, like UAV delivery of blood and medical supplies in Kenya, have taken off and are becoming both profitable and potentially life-saving. Others, like driverless long-haul trucking, made an initial splash but appear to have gone quiet since then. This is to be expected, as the marketplace picks winners and losers in a neverending quest to maximize return on investment. But the whole field seems to have gotten a bit sleepy lately, with no big news of note for quite a while.

That changed last week with Amazon’s announcement of Scout, their autonomous delivery vehicle. Announced first on Amazon’s blog and later picked up by the popular and tech press who repeated the Amazon material almost verbatim, Scout appears at first glance to be a serious attempt by Amazon to own the “last mile” of delivery – the local routes that are currently plied by the likes of UPS, FedEx, and various postal services. Or is it?

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The Deep Space Energy Crisis Could Soon Be Over

February 8, 2019 by 34 Comments

On the face of it, powering most spacecraft would appear to be a straightforward engineering problem. After all, with no clouds to obscure the sun, adorning a satellite with enough solar panels to supply its electrical needs seems like a no-brainer. Finding a way to support photovoltaic (PV) arrays of the proper size and making sure they’re properly oriented to maximize the amount of power harvested can be tricky, but having essentially unlimited energy streaming out from the sun greatly simplifies the overall problem.

Unfortunately, this really only holds for spacecraft operating relatively close to the sun. The tyranny of the inverse square law can’t be escaped, and out much beyond the orbit of Mars, the size that a PV array needs to be to capture useful amounts of the sun’s energy starts to make them prohibitive. That’s where radioisotope thermoelectric generators (RTGs) begin to make sense.

RTGs use the heat of decaying radioisotopes to generate electricity with thermocouples, and have powered spacecraft on missions to deep space for decades. Plutonium-238 has long been the fuel of choice for RTGs, but in the early 1990s, the Cold War-era stockpile of fuel was being depleted faster than it could be replenished. The lack of Pu-238 severely limited the number of deep space and planetary missions that NASA was able to support. Thankfully, recent developments at the Oak Ridge National Laboratory (ORNL) appear to have broken the bottleneck that had limited Pu-238 production. If it pays off, the deep space energy crisis may finally be over, and science far in the dark recesses of the solar system and beyond may be back on the table.

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Eight Years of Partmaking: A Love Story for Parts

February 8, 2019 by 8 Comments

Over my many years of many side-projects, getting mechanical parts has always been a creative misadventure. Sure, I’d shop for them. But I’d also turn them up from dumpsters, turn them down from aluminum, cut them with lasers, or ooze them out of plastic. My adventures making parts first took root when I jumped into college. Back-in-the-day, I wanted to learn how to build robots. I quickly learned that “robot building” meant learning how to make their constituent parts.

Today I want to take you on a personal journey in my own mechanical “partmaking.” It’s a story told in schools, machine shops, and garages of a young adulthood spent making parts. It’s a story of learning how to run by crawling through e-waste dumps. Throughout my journey, my venues would change, and so would the tools at-hand. But that hunger to make projects and, by extension, parts, was always there.

Dear partmakers, this is my love letter to you.

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