Tech Hidden In Plain Sight: Cruise Control

July 8, 2021 by Al Williams 29 Comments

The advent of the microcontroller changed just about everything. Modern gadgets often have a screen-based interface that may hide dozens or hundreds of functions that would have been impractical and confusing to do with separate buttons and controls. It also colors our thinking of what is possible. Imagine if cars didn’t have cruise control and someone asked you if it were possible. Of course. Monitor the speed and control the gas using a PID algorithm. Piece of cake, right? Except cruise control has been around since at least 1948. So how did pre-microcontroller cruise control work? Sure, in your modern car it might work just like you think. But how have we had seventy-plus years of driving automation?

A Little History

A flyball governor from a US Navy training film.

Controlling the speed of an engine is actually not a very new idea. In the early 1900s, flyball governors originally designed for steam engines could maintain a set speed. The idea was that faster rotation caused the balls would spread out, closing the fuel or air valve while slower speeds would let the balls get closer together and send more fuel or air into the engine.

The inventor of the modern cruise control was Ralph Teetor, a prolific inventor who lost his sight as a child. Legend has it that he was a passenger in a car with his lawyer driving and grew annoyed that the car would slow down when the driver was talking and speed up when he was listening. That was invented in 1948 and improved upon over the next few years.

Continue reading “Tech Hidden In Plain Sight: Cruise Control” →

Electric Land Speed Racing Can Be Lightning Fast

July 8, 2021 by Zoe Skyforest 4 Comments

Land speed racing is a pursuit of ultimate speed above all else. Most cars typically run on huge, flat salt pans, and racers run flat out for miles in a straight line, attempting to push their machines to the limit. Like most motorsports, the history of land speed racing has traditionally been centred around internal combustion, but electric racers have long been out there chasing land speed records as well.

The Need For Speed

At the most famous land speed trials, such as Bonneville’s Speed Week, speed runs take place over miles and miles of open salt, with timing traps along the way to determine competitor’s speeds. These tracks are long enough that acceleration is of little concern, which is of great benefit to electric runners. Additionally, only one or two runs is required to set a record. This means that heavy batteries aren’t always needed, as the distance a competitor must travel is short, and even if the batteries are heavy, it doesn’t excessively affect top speed.

With an eye to that, land speed competitors in electric classes are typically classified into weight classes. This is due to the fact that bigger, heavier battery packs can deliver more current, and thus potentially have a performance advantage over lighter vehicles. Thus, typical classes run by most salt flats competitions involve the E1 class, which allows for vehicles under 1100 lbs, the E2 class, for vehicles up to 2200 lbs, and the E3 class, which is for anything 2200 lbs and above. The FIA also publish their own set of classes, again separated by weight, though to a much more granular degree.

Procedures for setting records vary depending on the venue and the record in question. Local records at salt venues like El Mirage can typically be broken with a single run faster than the standing record, while Bonneville Speed Week competitors must set a higher average speed across two runs on two consecutive days. FIA records differ again, and are perhaps the most stringent, requiring competitors to set a faster average across two runs in opposite directions, set within an hour of each other, to attempt to minimise the effect of wind on the result. Things can sometimes get confusing, as many FIA records, for example, are set at the Bonneville salt flats, but not actually in Speed Week competition or by Speed Week rules. Continue reading “Electric Land Speed Racing Can Be Lightning Fast” →

What’s Chia, And Why Is It Eating All The Hard Drives?

July 7, 2021 by Tom Nardi 102 Comments

At this point the average Hackaday reader is likely familiar with so-called “Proof of Work” (PoW) cryptocurrencies, such as Bitcoin, Ethereum, and Dogecoin. In the most basic of terms, these cryptocurrencies allow users to earn money by devoting computational power to the network. Unfortunately, it’s well past the point where your standard desktop CPU is moving enough bits to earn anything worthwhile. Individuals looking to turn a profit have therefore resorted to constructing arrays of high-end graphics cards for the express purpose of “mining” their cryptocurrency of choice.

These miners, combined with ongoing chip shortages, have ravaged the GPU market. Anyone who’s looked at building or upgrading a computer recently will know that new video cards are in short supply, and even old models that would otherwise be considered budget options, are commanding outrageous prices. In an effort to appease their core customers, NVIDIA has even introduced cryptocurrency-specific cards that lack video output. The hope was that professional miners would buy these Cryptocurrency Mining Processors (CMPs) instead of the traditional video cards, freeing up the latter for purchase by gamers. But due to the limited availability and relatively high cost of CMPs, they’ve done little to improve the situation.

Now if you don’t use your computer for gaming, this probably seems like a distant problem. You could even be forgiven for thinking of this as little more than two largely frivolous pursuits at loggerheads with each other. After all, in a community that still holds decades-old Thinkpads as the high water mark in portable computing, a certain ambivalence about cutting edge video cards is perhaps to be expected.

But there’s a new form of cryptocurrency on the rise which threatens more than just the hardcore gamers. With “Proof of Space” (PoS) cryptocurrencies, it’s not about having the fastest CPU or the highest number of GPUs; the commodity being traded is storage space, and the player with the most hard drives wins.

Continue reading “What’s Chia, And Why Is It Eating All The Hard Drives?” →

TerraPower’s Natrium: Combining A Fast Neutron Reactor With Built-In Grid Level Storage

July 6, 2021 by Maya Posch 66 Comments

Most new nuclear fission reactors being built today are of the light water reactor (LWR) type, which use water for neutron moderation into thermal neutrons as well as neutron capture. While straightforward and in use since the 1950s in commercial settings, they are also essentially limited to uranium (U-235) fuel. This is where fast neutron reactors are highly attractive.

Fast neutron reactors can also fission other fissile elements, covering the full spectrum of neutron cross sections. TerraPower’s Natrium reactor is one such fast reactor, and it’s the world’s first fast reactor that not only targets commercial use, but also comes with its own grid-level storage in the form of a molten salt reservoir.

The upshot of this is that not only can these Natrium reactors use all of the spent LWR fuel in the US and elsewhere as their fuel, but they should also be highly efficient at load-following, traditionally a weak spot of thermal plants.

TerraPower and its partners are currently looking to build a demonstration plant in Wyoming, at the site of a retiring coal plant. This would be a 345 MWe (peak 500 MWe) reactor.

Continue reading “TerraPower’s Natrium: Combining A Fast Neutron Reactor With Built-In Grid Level Storage” →

The Trouble With Hubble: Payload Computer Glitch Stops Science At The Space Observatory

July 2, 2021 by Dan Maloney 21 Comments

The Hubble Space Telescope’s remarkably long service life and its string of astonishing contributions to astronomy belie its troubled history. Long before its launch into low Earth orbit in 1990, Hubble suffered from design conflicts, funding and budgetary pressures, and even the death of seven astronauts. Long delayed, much modified, and mistakenly sent aloft with suboptimal optics, Hubble still managed to deliver results that have literally changed our view of the universe, and is perhaps responsible for more screensaver and desktop pictures than any other single source.

But all of that changed on June 13 of this year, when Hubble suffered a computer glitch that interrupted the flow of science data from the orbiting observatory. It’s not yet clear how the current issue with Hubble is going to pan out, and what it all means for the future of this nearly irreplaceable scientific asset. We all hope for the best, of course, but while we wait to see what happens, it’s worth taking the opportunity to dive inside Hubble for a look at its engineering and what exactly has gone wrong up there.

Continue reading “The Trouble With Hubble: Payload Computer Glitch Stops Science At The Space Observatory” →

Could Airships Make A Comeback With New Hybrid Designs?

July 1, 2021 by Zoe Skyforest 101 Comments

Airships. Slow, difficult to land, and highly flammable when they’re full of hydrogen. These days, they’re considered more of a historical curiosity rather than a useful method of transport.

Hybrid Air Vehicles are a UK-based startup working to create a modern take on the airship concept. The goal is to create cleaner air transport for short-hop routes, while also solving many of the issues with the airship concept with a drastic redesign from the ground up. Their vehicle that will do all this goes by the name of Airlander 10. But is it enough to bring airships back to the skies?

A Hybrid Technology

Airlander 10 seen taking off during its first flight.

The Airlander 10 is not a lighter-than-air craft like traditional airships. Instead, the vehicle uses the buoyancy from its helium envelope to create only 60-80% of its lift. The rest of the left is generated aerodynamically by air passing over the eliptical shape of the airship’s body. This lift can also be further augmented by two diesel-powered ducted fans on the sides of the airship, which can pivot to assist with takeoff and landing. Two further fixed ducted fans on the rear provide the primary propulsion for the craft.

The hybrid approach brings several benefits over the traditional airship model. Chief among them is that as the Airlander 10 is heavier than air, it need not vent helium throughout flight to avoid becoming positively buoyant as fuel burns off, nor does it need to vent helium to land. However, it still maintains the capability to loiter for incredibly long periods in the sky as it needs to burn very little fuel to stay aloft. Reportedly, it is capable of five days when manned, and even longer durations if operated in an unmanned configuration. Using helium for lift instead of solely relying on engine thrust and wings means that it is much more fuel efficient than traditional fixed-wing airliners. The company’s own estimates suggest the Airlander 10 could slash emissions on short-haul air routes by up to 90%. The gentle take-off and landing characteristics also mean the vehicle doesn’t require traditional airport facilities, making it possible to operate more easily in remote areas, on grass, sand, or even water. Continue reading “Could Airships Make A Comeback With New Hybrid Designs?” →