The “Impossible” Tech Behind SpaceX’s New Engine

February 13, 2019 by Tom Nardi 92 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.

Continue reading “The “Impossible” Tech Behind SpaceX’s New Engine” →

Every Digital Clock Is Made Of Analog Components

February 12, 2019 by Brian Benchoff 8 Comments

In 2008, an art studio out of Stockholm released the ClockClock, a digital clock with an analog heart. The ClockClock used 24 individual analog clocks — hour and minute hands and all — to display time digitally. The world went crazy, Pinterest blew up, and everyone wanted a digital analog clock until the next interesting project distracted the masses.

This was ten years ago, and for a project that’s neck deep in stepper motors, timekeeping, and 3D printed parts, we haven’t seen a DIY project that puts these tools together to build a clone of the ClockClock. Until now, that is. [Wojtek] was inspired by the ClockClock and decided to make his own.

For the plastic bits, each of the 24 analog clocks are printed out of PLA. So far, it’s exactly what we would expect. The trick to the ClockClock is moving the hour and minute hand of each analog clock independently. This is done with a double shaft — just like a real clock — and two stepper motors. Each of the stepper motors are controlled by a single PCB in each analog clock with two 360° stepper drivers, a dual motor driver, and an ATMega328pb microcontroller. As a group, the individual analog clocks are controlled over I2C, with a single ‘satellite’ board serving as the master.

While there are a few details missing from this build, specifically how to attach the hands to the stepper motors, this is an amazing project. Someone finally built a ClockClock, and it didn’t cost thousands of dollars as the original did. You can check out some videos of the Analog/Digital clock below.

Continue reading “Every Digital Clock Is Made Of Analog Components” →

EF50: The Tube That Changed Everything

February 12, 2019 by Al Williams 32 Comments

From today’s perspective, vacuum tubes are pretty low tech. But for a while they were the pinnacle of high tech, and heavy research followed the promise shown by early vacuum tubes in transmission and computing. Indeed, as time progressed, tubes became very sophisticated and difficult to manufacture. After all, they were as ubiquitous as ICs are today, so it is hardly surprising that they got a lot of R&D.

Prior to 1938, for example, tubes were built as if they were light bulbs. As the demands on them grew more sophisticated, the traditional light bulb design wasn’t sufficient. For one, the wire leads’ parasitic inductance and capacitance would limit the use of the tube in high-frequency applications. Even the time it took electrons to get from one part of the tube to another was a bottleneck.

There were several attempts to speed tubes up, including RCA’s acorn tubes, lighthouse tubes, and Telefunken’s Stahlröhre designs. These generally tried to keep leads short and tubes small. The Philips company started attacking the problem in 1934 because they were anticipating demand for television receivers that would operate at higher frequencies.

Dr. Hans Jonker was the primary developer of the proposed solution and published his design in an internal technical note describing an all-glass tube that was easier to manufacture than other solutions. Now all they needed was an actual application. While they initially thought the killer app would be television, the E50 would end up helping the Allies win the war.

Continue reading “EF50: The Tube That Changed Everything” →

Security Engineering: Inside The Scooter Startups

February 12, 2019 by Brian Benchoff 62 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.

Continue reading “Security Engineering: Inside The Scooter Startups” →

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

February 11, 2019 by Dan Maloney 85 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?

Continue reading “Automate The Freight: Amazon Tackles The Last Mile Problem On Wheels” →

Oops… Britain Launched A Satellite, But Who Remembers It?

February 7, 2019 by Jenny List 40 Comments

Did you know Britain launched its first satellite after the program had already been given the axe? Me neither, until some stories of my dad’s involvement in aerospace efforts came out and I dug a little deeper into the story.

I grew up on a small farm with a workshop next to the house, that housed my dad’s blacksmith business. In front of the workshop was a yard with a greenhouse beyond it, along one edge of which there lay a long gas cylinder about a foot (300mm) in diameter. To us kids it looked like a torpedo, and I remember my dad describing the scene when a similar cylinder fell off the side of a truck and fractured its valve, setting off at speed under the force of ejected liquid across a former WW2 airfield as its pressurised contents escaped.

Everybody’s parents have a past from before their children arrived, and after leaving the RAF my dad had spent a considerable part of the 1950s as a technician, a very small cog in the huge state-financed machine working on the UK’s rocket programme for nuclear and space launches. There were other tales, of long overnight drives to the test range in the north of England, and of narrowly averted industrial accidents that seem horrific from our health-and-safety obsessed viewpoint. Sometimes they came out of the blue, such as the one about a lake of highly dangerous liquid oxidiser-fuel mix ejected from an engine that failed to ignite and which was quietly left to evaporate, which he told me about after dealing with a cylinder spewing liquid propane when somebody reversed a tractor into a grain dryer.

Bringing Home A Piece Of History

The remains of the Black Arrow first and second stages, taken from the Skyrora promotional video.

My dad’s tales from his youth came to mind recently with the news that a privately-owned Scottish space launch company is bringing back to the UK the remains of the rocket that made the first British satellite launch from where they had lain in Australia since crashing to earth in 1971. What makes this news special is that not only was it the first successful such launch, it was also the only one. Because here in good old Blighty we hold the dubious honour of being the only country in the world to have developed a space launch capability of our own before promptly abandoning it. Behind that launch lies a fascinating succession of forgotten projects that deserve a run-through of their own, they provide a window into both the technological and geopolitical history of that period of the Cold War.

Continue reading “Oops… Britain Launched A Satellite, But Who Remembers It?” →

Arduino Enters The Cloud

February 7, 2019 by Al Williams 61 Comments

Love it or hate it, for many people embedded systems means Arduino. Now Arduino is leveraging its more powerful MKR boards and introducing a cloud service, the Arduino IoT Cloud. The goal is to make it simple for Arduino programs to record data and control actions from the cloud.

The program is in beta and features a variety of both human and machine interaction styles. At the simple end, you can assemble a dashboard of controls and have the IoT Cloud generate your code and download it to your Arduino itself with no user programming required. More advanced users can use HTTP REST, MQTT, Javascript, Websockets, or a suite of command line tools.

Continue reading “Arduino Enters The Cloud” →