I Can Fix The Space Station With A Metronome, A Metronome, A Metronome


If the space station were left to its own devices, the living quarters would get incredibly hot. There are computers, hardware, and six crew members, all generating heat that must be gotten rid of. To do this, there are two heat exchangers inside the station that take warm water, dump that heat to ammonia, and send that ammonia out to panels outside the station. On December 11, 2013, Loop A of the thermal control system shut down, putting the station one failure away from evacuation. Plans for a spacewalk were tabled, but the ground crew managed to fix this hardware failure by telling the astronauts to push buttons, a metronome, and a software patch.

The problem with Loop A of the Internal Thermal Control System was a flow control valve that regulated the amount of ammonia flowing through the heat exchange. Too much ammonia, and the station would be far too cold. Too little, and it would be too hot. This valve is electronically controlled and takes exactly 13 seconds to move from open to closed. The first attempt at fixing the problem was having ground crew send the command to open the valve and cut the power halfway through. This involved using a metronome app on a phone to send two commands 6.5 seconds apart. It worked, but not quite well enough.

The failure of the metronome technique led [Todd Quasny] to write a script to turn the ‘on’ and ‘off’ commands from the ground to the ISS with millisecond resolution. This meant the commands to control the valve could be sent with the right delay, but they weren’t received with the right delay. This is a problem that had to be fixed from the station’s computers.

To finally solve the problem, ISS software engineer [Steve Joiner] was called in to write a software patch for the thermal control system. This is spaceflight and writing software is a long a laborious process of testing and code reviews. Nevertheless, the team managed to write and upload a patch in just two days.

This patch gave controllers the ability to control the valve with a resolution of 100 milliseconds, good enough for very fine control of the thermal system, and all without requiring the massive amount of planning that goes into a spacewalk or resupply mission.

Ups to [Ed Van Cise] for this tip. If you’re curious about the headline….

Raspi Notifies You Of Space Station Passes


A few months years ago, [Liam] funded a Kickstarter for a small desk toy that would tell him when the International Space Station was overhead. [Liam] got a little tired of waiting, so he decided to build his own with a Raspberry Pi and an astronomical computation Python library.

The impressive part of this build is computing where an orbiting object is in the sky given the ISS’ orbital elements. For this, [Liam] is using PiEphem, a library that can compute the positions of the sun, moon, planets, asteroids, and Earth-orbiting satellites given a location and a time. Since the ISS orbital elements change every so often, his software is set up to download an update every week or so.

[Liam] developed a few versions of his space station detector, each with a different display. The simplest uses a few LEDs, either through a LedBorg, Blinkstick, or PiGlow to serve as a notification of when the ISS is overhead. Two more complicated versions use an LCD display or LED matrix to signal when the next ISS pass will occur.

Video demo below.

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Satellite tracking by shining a laser into space

[Shingo Hisakawa] sent in a tip for a for a neat little box called the Levistone that tracks the Internation Space Station with a laser. His video log goes though all the steps for this great little project.

[Shingo] originally planned to pull orbital data down from NORAD and send that to an ArduinoBT board with ethernet, GPS and compass modules. In the original plan, the Arduino would do the orbit calculations and point the laser using a few servos. There wasn’t much success with making an Arduino do all the work, so the an Android phone stood in for the GPS, compass and connection to the web. The duty of calculating the location of the ISS using GPS and orbital elements was moved onto the Amazon EC2 cloud. The final product looks great, even if it’s impossible to record the beam for the video.

With the ability to calculate the azimuth and elevation of the ISS from any point in the world, [Shingo] came up with SightSpaceStation, a neat mashup of his data and Google Maps. There are also iOS and Android apps for a nice piece of work in augmented reality. It’s a great project that would really compliment the ISS desk lamp we covered a few days ago.

ISS lamp tells you when to look up

[Nathan Bergey] came up with a really neat desk lamp that provides a visualization of when the International Space Station is overhead.

The lamp uses a Teensy board to light a few LEDs on the edge of a piece of plexiglass. Because the orbit of the ISS decays over time, the time that overhead passes will occur is unpredictable after a few months. A stand-alone satellite tracking lamp will eventually lose it’s accuracy, so [Nathan] needed to parse tracking data the internet. Since he couldn’t find an API to track the ISS, [Nathan] wrote a Python script to parse the data he found on Heavens Above. Everything on the computer runs in the Gnome panel and is passed to the Teensy over the USB connection. [Nathan] posted all of the code is posted on github.

It’s a really great build that provides a reminder that there are people in space, and we think this would be a great way to provide some notification of upcoming Iridium flares, or when it’s most likely to pick up some APRS packets.

Check out [Nathan]‘s demo of his ISS lamp after the break.

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Radio packets…from spaaaace!


[Bill Meara] was watching the International Space Station and the Shuttle Discovery pass overhead a few weeks ago, which rekindled an interest he gave up long ago – sending and receiving radio packets from space.

Years ago, he used to send APRS packets into space with a small rig powered by a 286 computer and HandiTalkie. These packets would drift off into space most of the time, but occasionally they would bounce back to Earth whenever the space station or PC Sat would fly by. The packets were often captured by other ham operators across the globe, who happened to be tuned to 145.825 MHz.

His interest renewed, he dug out his old HandieTalkie and Kantronics Terminal Node, aiming them towards the sky via an antenna situated in his back yard. When he returned 10 hours later, he found that he had collected all sorts of “space packets” from across the globe.

While not exactly a hack, it is definitely a neat exercise in ham radio operation. We can imagine slinging data packets off the space station would be an exciting experience for any budding operator (and OMs as well!)

Hackaday Links: December 7 2009

Ah the beauty of watching molten solder pull SMD components into place. Yeah, we’ve seen it before, but for some reason it never gets old.

The glory days of wardriving are certainly behind us but if you’re still hunting in certain areas for access points you can leave the laptop at home. A homebrew program called Road Dog can turn your PSP into a WiFi search device. You must be able to run custom code to use this app.

Ferrofluid is our friend. But having grown up watching the Terminator and Hellraiser movies we can’t help being a little creeped out by the effects seen in this movie.

Follow along with the NASA astronauts in this 20 minute HD tour of the international space station. It’s a cramped place to live but we can’t help thinking that it looks incredibly clean. After all, where would the dirt come from?

How are your woodworking skills?  Can you take a wooden block and turn it on a lathe until you have a lampshade 1/32″ thick? We’d love to see how these are made, but imagine the artist’s reaction when hours of labor are ruined by a minuscule amount of misplaced pressure on a carving tool. Patience, we’ll learn it some day!

This video from the past that is about the future of  travel does leave us wondering why our cars don’t have built-in radar for poor visibility? We’ve already realized the rear-view-mirror-tv-picture, but we’re going to need your help before the flying police/fire/ambulance-mobile is a common sight. Oh, the fun of seeing a high-tech push-button selector 3:30 into the video. Perhaps the touch-screen was a bit beyond the vision of the time.

Sometimes you have so many servants you need to find creative things for them to do. Only the most discriminating of the super-rich employ a person whose sole responsibility is to erase and redraw the hands of a clock each minute. This video is obviously a result of the global recession as the live time-keeper has been let go; a looping recording took his job!

Last time we checked in with [Marco Tempest] he was syncing video over multiple iPhones. Now he’s at it again with an augmented reality setup. A camera picks up some IR LEDs in a canvas and translates that into information for a video projector. We’d call this a trick, but it’s certainly not magic.