Apollo 11 Trig Was Brief

In this day and age where a megabyte of memory isn’t a big deal, it is hard to recall when you had to conserve every byte of memory. If you are a student of such things, you might enjoy an annotated view of the Apollo 11 DSKY sine and cosine routines. Want to guess how many lines of code that takes? Try 35 for both.

Figuring out how it works takes a little knowledge of how the DSKY works and the number formats involved. Luckily, the site has a feature where you can click on the instructions and see comments and questions from other reviewers.

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Ask Hackaday: What Are Your Apollo Memories?

This month will mark the 50th anniversary of the Apollo 11 mission that brought to a successful conclusion the challenge laid down by President Kennedy only eight years earlier. Three men went to the Moon, two walked on it, and they all came back safely, in a dramatic eight-day display of engineering and scientific prowess that was televised live to the world.

If you’ve made more than 50 trips around the sun, chances are good that you have some kind of memories of the first Moon landing. An anniversary like this is a good time to take stock of those memories, especially for something like Apollo, which very likely struck a chord in many of those that witnessed it and launched them on careers in science and engineering. We suspect that a fair number of Hackaday readers are in that group, and so we want to ask you: What are your memories of Apollo?

A Real American Hero

My memory of the Moon landing is admittedly vague. I had just turned five the month before, hadn’t even started kindergarten yet, but I had already caught the space bug in a big way. I lived and breathed the space program, and I knew everything about the Mercury missions that were over by the time I was born, and the Gemini missions that had just wrapped up. Apollo was incredibly exciting to me, and I was pumped to witness the landing in the way that only a five-year-old can be.
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Books You Should Read: Sunburst And Luminary, An Apollo Memoir

The most computationally intense part of an Apollo mission was the moon landing itself, requiring both real-time control and navigation of the Lunar Module (LM) through a sequence of programs known as the P60’s. Data from radar, inertial navigation, and optical data sighted-off by the LM commander himself were fed into the computer in what we’d call today ‘data fusion.’

The guy who wrote that code is Don Eyles and the next best thing to actually hanging out with Don is to read his book. Don’s book reads as if you are at a bar sitting across the table listening to his incredible life story. Its personal, hilarious, stressful, fascinating, and more importantly for those of us who are fans of Hackaday, it’s relatable.

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Katherine Johnson: Computer To The Stars

In 1962, John Glenn sat in his capsule waiting for his rocket engines to light-up and lift him to space. But first, he insisted that Katherine Johnson double-check the electronic computer’s trajectory calculations. While that’s the dramatic version of events given in the recent movie, Hidden Figures, the reality isn’t very far off. Glenn wasn’t sitting on the launchpad at the time, but during the weeks prior to launch, he did insist that Johnson double-check the computer’s calculations.

So who is this woman who played an important but largely unknown part of such a well-known historical event? During her long life, she was a wife, a mother, an African-American, a teacher, and a human computer, a term rarely used these days. Her calculations played a part in much of early spaceflight and in 2015, she was awarded the Presidential Medal of Freedom by President Obama. She also has a building named after her at the Langley Research Center in Hampton, Virginia.

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Beyond A Boot Print: The Lasting Effect Of Apollo On Humanity

July 20th, 1969 was the day that people from Earth set foot on different soil for the first time. Here we are 48 years later, and the world’s space programs are — well — not very close to returning to the moon. If you aren’t old enough to remember, it was really amazing. The world was in a lot of turmoil in the 1960s (and still is, of course) but everyone stopped to look at the sky and listen to the sound of [Neil Armstrong] taking that first step. It was shocking in a good way and almost universally observed. Practically everyone in the world was focused on that one event. You can see some of that in the NASA video, below.

Space flight was an incredible accomplishment, but it paled in comparison with the push to actually landing a person on the moon and bringing them home safely. The effort is a credit to the ability of people to work together (on the order of thousands of minds) to overcome a difficult challenge. We can learn a lot from that alone, and it makes a compelling argument to continue taking on tough problems. Today, as we remember the Apollo landings, let’s take a moment to recognize what came of it beyond an iconic boot-print in the floury lunar soil.

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Don Eyles Walks Us Through The Lunar Module Source Code

A couple weeks ago I was at a party where out of the corner of my eye I noticed what looked like a giant phone book sitting open on a table. It was printed with perforated green and white paper bound in a binder who’s cover looked a little worse for the wear. I had closer look with my friend James Kinsey. What we read was astonishing; Program 63, 64, 65, lunar descent and landing. Error codes 1201, 1202. Comments printed in the code, code segments hastily circled with pen. Was this what we thought we were looking at? And who brings this to a party?

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Hackaday Links: July 20, 2012

Hey, it’s the 43rd anniversary of men first walking on the moon. Here’s some stuff we found to celebrate that. Fun trivia: for Apollo 11, [Neil] and [Buzz] didn’t go more than 200 feet from the LEM.

This is so incredibly sad

Remember Heathkit? A lot of cool kit-based electronics came from them. They’re out of business, but you can get all the Heathkit swag you can imagine from the repo man. A ton of stuff from the old Heathkit headquarters is being auctioned off in Byron Center, Michigan this Tuesday, July 24. Notable lots include a HE-Robot and a nice pair of o’scopes. If someone wants to pick up one of the catalog lots for us, we’d be thankful.

Troll Physics: ‘What is with this guy’ edition

We’ve seen [Fredzislaw]’s LED trickery before. The first time was a crazy 3 LED circuit, the reveal of which showed two AC power supplies in a battery connector. This time, [Fred] has two switches and an LED. Turn one switch on, the LED lights up. Turn that switch off and flip the other one, the LED still lights up. Turn both switches on, the LED goes off. Your guess is as good as ours.

Prototyping with a key fob remote

[Gary] wrote in to tell us about the dev board he’s been working on. It has either a PIC or AVR on the back side, broken out into 0.1 inch headers on the front. There’s a small solderless breadboard and an on-board RF link that uses a five-button key fob remote. Seems very useful, no matter what side of the PIC/AVR holy war you’re on.

Consumer Alerts: Software defined radio

Over on the RTLSDR subreddit, [photoscotty] bought this TV tuner dongle from Deal Extreme and received the inferior EZTV645 tuner. Unsurprisingly, Chinese manufacturers will just grab whatever is available, put it in an envelope, and ship it off on a slow boat from China. [photoscotty] is trying to return his dongle to DX, but until Sparkfun or Adafruit start selling these things (yes, there’s a market now get on it) you’ll have to be careful out there.

Wouldn’t this feel terrible against your skin all day?

[Colin] printed a watch band on his Makerbot. Apparently Shenzhen humidity didn’t play nicely with his nylon strap, so [Colin] made his own out of plastic. It’s flexible and has a neat looking clasp, as well as an awesome demo for what a 3D printer can actually do. Thingiverse files here.