TV Broadcasts from Outer Space

According to ARISS (Amateur Radio on the International Space Station), the ISS will be sending us images using slow-scan TV on April 11th in honor of Russian cosmonaut Yuri Gagarin’s birthday. Tune in and you’ll get to see 12 different commemorative images from space, and of course bragging rights that you directly received them with your radio setup.

For those who aren’t Ham radio types, slow-scan TV (SSTV) is a radio mode where the pixels in an image are sent by encoding the brightness and/or color as a tone, a lot like a modem, fax machine, or the data cassette tapes of yore.

The ISS uses PD-180 which is a color mode where each pixel’s red, green, and blue values are encoded in a pitch between 1500 and 2300 Hz. Each image takes just over three minutes to transmit, meaning you’ll have to track the ISS pretty well as it travels across the sky. But don’t fret, they send each message for around an hour, so you have a good chance to receive it. (We’ll be the first to admit that a frame rate of one frame in 187 seconds isn’t really “TV”, but that’s what they call it.)

SSTV’s use in the space program goes back even before the moon landing, but with modern software-defined radio setups, it all becomes a lot more convenient to receive. The ISS folks do this periodically as a service to the amateur radio community, so it’s a good time to try out your chops.

We’ve covered ARISS before, but Yuri’s birthday is always a good reason to celebrate the folks out there. And if you need a reminder of when to look up, this hack right here has you covered.

If you do receive some images, you can upload them to the ARISS Gallery.  Or you can just hit refresh to see them as others post them up.

Ask Hackaday: Help NASA With Their High Altitude Problem

image of hackaday logo on box at high altitude

Unless you’ve been living under a high voltage transformer, you’ve probably heard that NASA has grounded the Space Shuttle fleet. This makes getting stuff to and from the International Space Station slightly more difficult. With the growing need to get small experiments back to the surface quickly and safely, NASA is researching an idea they call Small Payload Quick Return, or SPQR (pdf warning). Basically, they toss the experiment out of the window, use drag to slow it down, and then use a High Altitude High Opening (HAHO) self guiding parafoil to steer the thing down to a predefined location on the surface.

Now, what we’re interested in is the self guided parafoil part, as it takes place in known hacker territory – around 100,000 feet. This is the altitude where most high altitude balloon experiments take place. NASA is throwing a bunch of money and brainpower to research this part of the system, but they’re having problems. Lots of problems.

Stick around after the break and see if you can help, and maybe pick up some ideas on how to steer your next High Altitude Balloon project back to the launch pad.

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Canadian Space Robot Will Repair Itself

The video above shows an animation of what the Canadian Space Agency hopes will be the first successful self-repair of the Mobile Servicing System aboard the ISS. The mobile servicing system is basically a group of several complicated robots that can either perform complicated tasks on their own, or be combined into a larger unit to extend the dexterity of the system as a whole.

The most recent addition to the servicing system is the Special Purpose Dexterous Manipulator, otherwise known as Dextre. Dextre is somewhat reminiscent of a human torso with two enormous arms. It is just one of the Canadian Space Agency’s contributions to the station. It was installed on the station in 2008 to perform activities that would normally require space walks. Dextre’s very first official assignment was successfully completed in 2011 when the robot was used to unpack two pieces for the Kounotori 2 transfer vehicle while the human crew on board the ISS was sleeping.

Dextre is constructed in such a way that it can be grabbed by the Canadarm2 robot and moved to various work sites around the Space Station. Dextre can then operate from the maintenance site on its own while the Canadarm2 can be used for other functions. Dextre can also be operated while mounted to the end of Canadarm2, essentially combining the two robots into one bigger and more dexterous robot.

One of the more critical camera’s on the Canadarm2 has started transmitting hazy images. To fix it, the Canadarm2 will grab onto Dextre, forming a sort of “super robot”. Dextre will then be positioned in such a way that it can remove the faulty camera. The hazy camera will then be mounted to the mobile base component of the Mobile Servicing System. This will give the ISS crew a new vantage point of a less critical location. The station’s human crew will then place a new camera module in Japan’s Kibo module’s transfer airlock. Dextre will be able to reach this new camera and then mount it on the Canadarm2 to replace the original faulty unit. If successful, this mission will prove that the Mobile Servicing System has the capability to repair itself under certain conditions, opening the door for further self-repair missions in the future.

The Pioneering Lifestyle in Low Earth Orbit

The first element of the International Space Station (ISS) launched over fifteen years ago, on November 20, 1998. For more than thirteen years at least two human beings have been continually living off the surface of our planet. Assembly of the Space Station is now complete. It is being utilized by its crews and scientists from around the world to execute its primary mission – scientific investigations that can only be accomplished in the microgravity environment of Low Earth Orbit (LEO). As with any structure, items age, wear out, or break and need to be repaired. What could be rather “simple” repairs on Earth can become much more complex in zero gravity. In some cases, “necessity becomes the mother of invention.”

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Observe a satellite’s Morse Code message today!

Niwaka1-satellite

If you live in the Eastern portion of the United States and the skies are clear you can see a student built satellite flashing LEDs in Morse Code today. But don’t worry. If you it’s cloudy or if you live elsewhere there are several other opportunities to see it in the coming days.

This is the Niwaka Fitsat-1. It was developed by students at the [Fukuoka Institute of Technology] and deployed from the International Space Station on October 4th. Included in the payload is an array of LEDs seen in the image above. On a set schedule these are used to flash a Morse Code message for two minutes at a time. That is what’s shown in the image on the upper right.

You can look up information on seeing Fitsat-1 in your own area using this webpage. All of the observation windows in our area require a pair of binoculars or better. We’re not sure if there is any case in which this can be seen by the naked eye.

[Thanks SWHarden and KomradBob]

Building a Yagi-Uda antenna

[Tommy Gober] built this Yagi-Uda antenna that has some handy design features. The boom is a piece of conduit with holes drilled in the appropriate places. The elements are aluminum arrow shafts; a good choice because they’re straight, relatively inexpensive, and they have #8-32 screw threads in one end. He used some threaded rod to connect both sides of the reflector and director elements. The driven elements are mounted offset so that a different machine screw for each can be connected to the appropriate conductor of the coaxial cable. The standing wave ratio comes in right where it should meaning he’ll have no trouble picking up those passing satellites as well as the International Space Station.