Got Oxygen? Future Mars Missions Are Relying On The MOXIE Of Perseverance

March 9, 2021 by Dan Maloney 31 Comments

The rule of thumb with planetary exploration so far has been, “What goes up, stays up.” With the exception of the Moon and a precious few sample return missions to asteroids and comets, once a spacecraft heads out, it’s never seen again, either permanently plying the void of interplanetary or interstellar space, or living out eternity on the surface of some planet, whether as a monument to the successful mission that got it there or the twisted wreckage of a good attempt.

At the risk of jinxing things, all signs point to us getting the trip to Mars reduced to practice, which makes a crewed mission to Mars something that can start turning from a dream to a plan. But despite what some hardcore Martian-wannabees say, pretty much everyone who goes to Mars is going to want to at least have the option of returning, and the logistical problems with that are legion. Chief among them will be the need for propellants to make the return trip. Lugging them from Earth would be difficult, to say the least, but if an instrument the size of a car battery that hitched a ride to Mars on Perseverance has anything to say about it, future astronauts might just be making their own propellants, literally pulling them out of thin air.

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Sea Level: How Do We Measure Global Ocean Levels And Do Rising Oceans Change That Benchmark?

March 8, 2021 by Adam Zeloof 34 Comments

Every summer you go down the shore, but lately you’ve begun to notice that the beach seems narrower each time you visit. Is that the sea level rising, or is the sand just being swept away? Speaking of sea levels, you keep hearing that they rise higher every year — but how exactly is that measured? After all, you can’t exactly use a ruler. As it turns out, there are a number of clever systems in place that can accurately measure the global sea level down to less than an inch and a half.

Not only are waves always rippling across the ocean’s surface, but tides periodically roll in and out, making any single instantaneous measurement of sea level hopelessly inaccurate. Even if you plan to take hundreds or thousands of measurements over the course of weeks or months, taking the individual measurements is still difficult. Pick a nice, stable rock in the surf, mark a line on it, and return every hour for two weeks to hold a tape measure up to it. At best you’ll get within six inches on each reading, no matter what you’ll get wet, and at worst the rock will move and you’ll get a damp notebook full of useless numbers. So let’s take a look at how the pros do it.

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The Rise And Fall Of The Fan Car

March 5, 2021 by Lewin Day 51 Comments

The advent of aerodynamic wings in motorsport was one of the most dramatic changes in the mid-20th century. Suddenly, it was possible to generate more grip at speed outside of altering suspension setups and fitting grippier tyres. However, it was just the beginning, and engineers began to look at more advanced ways of generating downforce without the drag penalty incurred by fitting wings to a racecar.

Perhaps the ultimate expression of this was the fan car. Mechanically complex and arguably dangerous, the technology offered huge downforce with minimal drag. However, the fan car’s time in the spotlight was vanishingly brief, despite the promise inherent in the idea. Let’s take a look at the basic theory behind the fan car, how they worked in practice, and why we don’t see them on racetracks today. Continue reading “The Rise And Fall Of The Fan Car” →

Using Phase Change Materials For Energy Storage

March 3, 2021 by Lewin Day 35 Comments

Renewable energy sources are becoming increasingly popular. However, such energy can be wasted if an excess is available when it’s not yet needed. A particularly relevant example is solar power; solar panels provide most of their output during the day, while often a household’s greatest energy use is at night.

One way to get around this problem is by storing excess energy so that it can be used later. The most common way this is done is with large batteries, however, it’s not the only game in town. Phase change materials are proving to be a useful tool to store excess energy and recover it later – storing energy not as electricity, but as heat. Let’s take a look at how the technology works, and some of its most useful applications. Continue reading “Using Phase Change Materials For Energy Storage” →

Rube Goldberg’s Least Complicated Invention Was His Cartooning Career

March 2, 2021 by Kristina Panos 27 Comments

The name Rube Goldberg has long been synonymous with any overly-built contraption played for laughs that solves a simple problem through complicated means. But it might surprise you to learn that the man himself was not an engineer or inventor by trade — at least, not for long. Rube’s father was adamant that he become an engineer and so he got himself an engineering degree and a job with the city. Rube lasted six months engineering San Francisco’s sewer systems before quitting to pursue his true passion: cartooning.

Rube’s most famous cartoons — the contraptions that quickly became his legacy — were a tongue-in-cheek critique meant to satirize the tendency of technology to complicate our lives in its quest to simplify them. Interestingly, a few other countries have their own version of Rube Goldberg. In the UK it’s Heath Robinson, and in Denmark it’s Robert Storm Petersen, aka Storm P.

Rube Goldberg was a living legend who loved to poke fun at everything happening in the world around him. He became a household name early in his cartooning career, and was soon famous enough to endorse everything from cough drops to cigarettes. By 1931, Rube’s name was in the Merriam-Webster dictionary, his legacy forever cemented as the inventor of complicated machinery designed to perform simple tasks. As one historian put it, Rube’s influence on culture is hard to overstate.

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World’s First EVTOL Airport Will Land This November

March 1, 2021 by Kristina Panos 51 Comments

We have to admit that flying cars still sound pretty cool. But if we’re ever going to get this idea off the ground, there’s a truckload of harsh realities that must be faced head-on. The most obvious and pressing issue might seem to be the lack of flying cars, but that’s not really a problem. Air taxis are already in the works from companies like Airbus, Rolls-Royce, and Cadillac, who premiered theirs at CES this year.

Where we’re going, we don’t need roads. But we do need infrastructure to support this growing category of air traffic that includes shipping drones that are already in flight. Say no more, because by November 2021, the first airport built especially for flying cars is slated to be operational in England.

British startup Urban Air Port is building their flagship eVTOL hub smack dab in the center of Coventry, UK, a city once known as Britain’s Detroit due to the dozens of automobile makers who have called it home. They’re calling this grounded flying saucer-looking thing Air One, and they are building it in partnership with Hyundai thanks to a £1.2 million ($1.65M) grant from the British government. Hyundai are developing their own eVTOL which they are planning to release in 2028. Continue reading “World’s First EVTOL Airport Will Land This November” →

Should I Use Wheels Or Tracks?

February 26, 2021 by Lewin Day 32 Comments

When it comes to dominating offroad performance, many people’s first thought is of tracked vehicles. Bulldozers, tanks and excavators all use treads, and manage to get around in difficult terrain without breaking a sweat. Today, we’re exploring just what makes tracked vehicles so capable, as well as their weaknesses.

It’s All About Ground Pressure

The various parts of a tank’s propulsion system.

Let’s first look at how tank tracks work. There are a huge variety of designs, with differences depending on application. Different trends have been followed over time, and designs for military use in combat differ from those used for low-speed construction machines, for example. But by looking at a basic tank track design, we can understand the basic theory. On tanks, the track or tread itself is usually made up of individual steel links that are connected together with hinges, though other machines may use rubber tracks instead. The tracks are wrapped around one or more drive wheels, often cogged, which directly pull on the track. On the bottom of the vehicle are the road wheels, which ride on top of the track where it lies on the ground. The weight of the vehicle is carried through the road wheels and passed on to the tread, spreading out the load across a broader area. Outside of this, the track system may also have one or more idler wheels used to keep the track taught, as well as return rollers to guide the track back around without touching the road wheels.

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