The Photo Lab That Flew To The Moon

August 2, 2018 by Dan Maloney 12 Comments

When planning a trip by car these days, it’s pretty much standard practice to spin up an image of your destination in Google Maps and get an idea of what you’re in for when you get there. What kind of parking do they have? Are the streets narrow or twisty? Will I be able to drive right up, or will I be walking a bit when I get there? It’s good to know what’s waiting for you, especially if you’re headed someplace you’ve never been before.

NASA was very much of this mind in the 1960s, except the trip they were planning for was 238,000 miles each way and would involve parking two humans on the surface of another world that we had only seen through telescopes. As good as Earth-based astronomy may be, nothing beats an up close and personal look, and so NASA decided to send a series of satellites to our nearest neighbor to look for the best places to land the Apollo missions. And while most of the feats NASA pulled off in the heyday of the Space Race were surprising, the Lunar Orbiter missions were especially so because of how they chose to acquire the images: using a film camera and a flying photo lab.

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Kepler Planet Hunter Nears End Of Epic Journey

July 31, 2018 by Tom Nardi 50 Comments

The Kepler spacecraft is in the final moments of its life. NASA isn’t quite sure when they’ll say their last goodbye to the space telescope which has confirmed the existence of thousands of exoplanets since its launch in 2009, but most estimates give it a few months at best. The prognosis is simple: she’s out of gas. Without propellant for its thrusters, Kepler can’t orient itself, and that means it can’t point its antenna to Earth to communicate.

Now far as spacecraft failures go, propellant depletion isn’t exactly unexpected. After all, it can’t pull into the nearest service station to top off the tanks. What makes the fact that Kepler will finally have to cease operations for such a mundane reason interesting is that the roughly $600 million dollar space telescope has already “died” once before. Back in 2013, NASA announced Kepler was irreparably damaged following a series of critical system failures that had started the previous year.

But thanks to what was perhaps some of the best last-ditch effort hacking NASA has done since they brought the crew of Apollo 13 home safely, a novel way of getting the spacecraft back under control was implemented. While it was never quite the same, Kepler was able to continue on with modified mission parameters and to date has delivered so much raw data that scientists will be analyzing it for years to come. Not bad for a dead bird.

Before Kepler goes dark for good, let’s take a look at how NASA managed to resurrect this planet hunting space telescope and greatly expand our knowledge of the planets in our galaxy.

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How—And Why—To Avoid Tolerance Stacking In Your Technical Drawings

July 25, 2018 by Cameron Coward 49 Comments

If you want to have your part designs fabricated, you’re going to need to provide the manufacturer with a technical drawing. Yes, 3D printers and many modern machine tools rely on toolpaths created from 3D models. But, there is a good chance the manufacturer will be recreating the 3D model in their own system, instead of using the one you provided. Or, they may use traditional manual machining and not touch a 3D model at all. More importantly, the technical drawing gives them vital information on how closely they need to adhere to your dimensions in order for you to accept the parts.

On a technical drawing, the dimension that you want is called the nominal. But, no manufacturing is ever perfect, so you have to allow some wiggle room in what you’ll accept. That wiggle room is called tolerance. Maybe your part could be a little longer than specified and it wouldn’t affect the functionality. Maybe it could be a little shorter—or either. Specifying a tolerance is necessary, because it tells the manufacturer exactly how much wiggle room you’re giving them.

But, tolerances can introduce unforeseen consequences if you’re not careful. The wiggle room provided by tolerances is absolutely necessary, but if you don’t use them properly you can easily end up with unusable parts, even if the manufacturer followed your instructions to the letter. That usually happens because you have multiple tolerances being added together, which is called tolerance stacking.

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Edwin Armstrong’s Battle For FM Radio

July 24, 2018 by Al Williams 50 Comments

Chances are you have at least one radio that can receive FM stations. Even though FM is becoming less used now with Internet and satellite options, it still is more popular than the older AM radio bands. FM was the brainchild of an inventor you may have heard of — Edwin Armstrong — but you probably don’t know the whole story. It could make a sort of radio-themed soap opera. It is a story of innovation, but also a story of personal vanity, corporate greed, stubbornness, marital problems, and even suicide. The only thing missing is a long-lost identical twin sibling to turn it into a full telenovela.

Early Days

Armstrong grew up in New York and because of an illness that gave him a tic and caused him to be homeschooled, he was somewhat of a loner. He threw himself into his interest in electric and mechanical devices. By 1909 he was enrolled in Columbia University where professors noted he was very focused on what interested him but indifferent to other studies. He was also known as someone more interested in practical results than theory. He received an electrical engineering degree in 1913.

Unlike a lot of college graduates, Armstrong didn’t go work for a big firm. Instead, he set up a self-financed independent lab at Columbia. This sounded good because it meant that he would own the patents on anything invented there. But it would turn out to be a two-edged sword.

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Learn To Count In Seximal, A Position Above The Rest

July 20, 2018 by Tucker Ervin 42 Comments

Believe it or not, counting is not special. Quite a few animals have figured it out over the years. Tiny honeybees compare what is less and what is more, and their brains are smaller than a pinky nail. They even understand the concept of zero, which — as anyone who has had to teach a toddler knows — is rather difficult to grasp. No, counting is not special, but how we count is.

I don’t mean to toot our own horn, but humans are remarkable for having created numerous numeral systems, each specialized in their own ways. Ask almost anyone and they will at least have heard of binary. Hackaday readers are deeper into counting systems and most of us have used binary, octal, and hexadecimal, often in conjunction, but those are just the perfectly standard positional systems.

If you want to start getting weird, there’s balanced ternary and negabinary, and we still haven’t even left the positional systems. There’s a whole host of systems out there, each with their own strengths and weaknesses. I happen to think seximal is the best. To see why, we have to explore the different creations that arose throughout the ages. As long as we’ve had sheep, humans have been trying to count them, and the systems that resulted have been quite creative, if inefficient.

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What To Expect When You’re Expecting – A Trademark

July 18, 2018 by Bob Baddeley 18 Comments

A trademark represents a brand, so it can be words like “Apple”, including made up words like “Kleenex”. It can be symbols, like the Nike swoosh. It can also be colors, like UPS brown, and even scents like the flowery musk scent in Verizon stores. Filing a trademark in the United States is surprisingly easy. With a couple hundred dollars and a couple hours, you can be well on your way to having your very own registered trademark and having the right to use the ® symbol on your mark. You don’t need a lawyer, but you should know some of the hangups you might run into. The USPTO has a fantastic primer on trademarks, but we’ll TL;DR it for you. Continue reading “What To Expect When You’re Expecting – A Trademark” →

Françoise Barré-Sinoussi: Virus Hunter

July 17, 2018 by Steven Dufresne 13 Comments

It was early 1983 and Françoise Barré-Sinoussi of the prestigious Pasteur Institute in Paris was busy at the centrifuge trying to detect the presence of a retrovirus. The sample in the centrifuge came from an AIDS patient, though the disease wasn’t called AIDS yet.

Barré-Sinoussi and Montagnier in 1983, Image source: Le Globserver

Just two years earlier in the US, a cluster of young men had been reported as suffering from unusual infections and forms of cancer normally experienced by the very old or by people using drugs designed to suppress the immune system. More cases were reported and US Centers for Disease Control and Prevention (CDC) formed a task force to monitor the unusual outbreak. In December, the first scientific article about the outbreak was published in the New England Journal of Medicine.

By May 1983, researchers Barré-Sinoussi and Luc Montagnier of the Pasteur Institute had isolated HIV, the virus which causes AIDS, and reported it in the journal Science. Both received the Nobel prize in 2008 for this work and the Nobel prize citation stated:

Never before have science and medicine been so quick to discover, identify the origin and provide treatment for a new disease entity.

It’s only fitting then that we take a closer look at one of these modern detectives of science, Françoise Barré-Sinoussi, and what led to her discovery.

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