RainCube Spreads Its Umbrella

There are times when a mechanism comes to your attention that you have to watch time and time again, to study its intricacies and marvel at the skill of its designer. Sometimes it can be a complex mechanism such as a musical automaton or a mechanical loom, but other times it can be a device whose apparent simplicity hides its underlying cleverness. Such a moment came for us today, and it’s one we have to share with you.

RainCube is a satellite, as its name suggests in the CubeSat form factor and carrying radar instruments to study Earthly precipitation. One of the demands of its radar system is a parabolic dish antenna, and even at its 37.5 GHz  that antenna needs to be significantly larger than its 6U CubeSat chassis.

The unfolding parabola in action.
The unfolding parabola in action.

It is the JPL engineers’ solution to this problem that is the beautiful mechanism we want to show you. The parabola is folded within itself and tightly furled round the feedhorn within the body of the satellite. As the feedhorn emerges, first the inner sections unfurl and then the outer edge of the parabola springs out to form the dish antenna shape. Simultaneously a mechanism of simplicity, cleverness, and beauty, one we’d be very proud of if it were our creation.

There is nothing new in collapsible parabolas used in spacecraft antennas, petal and umbrella-like designs have been a feature of some of the most famous craft. But the way that this one has been fitted into such a small space (and so elegantly) makes it special, we hope you’ll agree.

[via space.com]

HFSat and The All-HF Amateur Radio Satellite Transponder

One facet of the diverse pursuit that is amateur radio involves the use of amateur radio satellites. These have a long history stretching back to the years shortly after the first space launches, and have been launched as “piggy-back” craft using spare capacity on government and commercial launches.

Though a diverse range of payloads have been carried by these satellites over the years, the majority of amateur radio satellites have featured transponders working in the VHF and UHF spectrum. Most often their links have used the 2m (144 MHz) and 70cm (430MHz) bands. A few have had downlinks in the 10m (28MHz) band, but this has been as far as they have ventured into the HF spectrum.

A new cubesat designed and built by trainees at the US Naval Academy promises to change all that, because it will feature an all-HF transponder with a 15m (21MHz) uplink and a 10m downlink. To that end it will carry a full size 10m wire dipole antenna. The 30KHz wide transponder is an inverting design intended to cancel out the effects of Doppler shift. In their write-up they provide a fascinating description of many aspects of cubesat design, one which should be of significant interest beyond the world of amateur radio.

If the subject of amateur radio in space interests you, have a look at our series on the matter, first covering the OSCAR satellites, and then our recent feature on its use in manned missions.

[via Southgate ARC]

Hackaday Links: September 25, 2016

So you like watching stupid stuff? Here you go, a scene from Bones that tops the infamous ‘IP backtrace with Visual Basic’ or ‘four-handed keyboard’ scenes from other TV shows. Someone hacked the bones by embedding malware in a calcium fractal pattern. Also, when she uses the fire extinguisher, she doesn’t spray the base of the fire.

Raspberry Pi! You have no idea how good the term Raspberry Pi is for SEO. Even better is Raspberry Pi clusters, preferably made with Raspberry Pi Zeros. Here’s a Raspberry Pi hat for four Raspberry Pi Zeros, turning five Raspberry Pis into a complete cluster computer. To be honest and fair, if you’re looking to experiment with clusters, this probably isn’t a bad idea. The ‘cluster backplane’ is just a $2 USB hub chip, and a few MOSFETs for turning the individual Pis on and off. The Zeros are five bucks a pop, making the entire cluster cost less than two of the big-boy sized Pi 3s.

Do you think you might have too much faith in humanity? Don’t worry, this video has you covered.

Hacking on some Lattice chips? Here’s a trip to CES for you. Lattice is holding a ‘hackathon’ for anyone who is building something with their chips. The top prize is $5k, and a trip to next year’s CES in Vegas, while the top three projects just get the trip to Vegas. If you already have a project on your bench with a Lattice chip, it sounds like a great way to wait an hour for a cab at McCarran.

UPSat. What’s an upsat? Not much, how about you? The first completely open source hardware and software satellite will soon be delivered to the ISS. Built by engineers from the University of Patras and the Libre Space Foundation, the UPSat was recently delivered to Orbital ATK where it will be delivered to the ISS by a Cygnus spacecraft. From there, it will be thrown out the airlock via the NanoRacks deployment pod.

The Voyager Golden Record is a message in a bottle thrown into the cosmic ocean and a time capsule from Earth that may never be opened. Now it’s a Kickstarter. Yes, this record is effectively Now That’s What I Call Humanity volume 1, but there are some interesting technical considerations to the Voyager Golden Record. To the best of my knowledge, no one has ever tried to extract the audio and pictures from this phonographic time capsule. The pictures included in the Golden Record are especially weird, with the ‘how to decode this’ message showing something like NTSC, without a color burst, displayed on a monitor that is effectively rotated 90 degrees counterclockwise from a normal CRT TV. Want to know how to get on Hackaday? Get this Golden Record and show an image on an oscilloscope. I’d love to see it, if only because it hasn’t been done before by someone independent from the original project.

Modest Motor Has Revolutionary Applications

Satellites make many of our everyday activities possible, and the technology continues to improve by leaps and bounds. A prototype, recently completed by [Arda Tüysüz]’s team at ETH Zürich’s Power Electronics Systems Lab in collaboration with its Celeroton spinoff, aims to improve satellite attitude positioning with a high speed, magnetically levitated motor.

Beginning as a doctoral thesis work led by [Tüysüz], the motor builds on existing technologies, but has been arranged into a new application — with great effect. Currently, the maneuvering motors on board satellites are operated at a low rpm to reduce wear, must be sealed in a low-nitrogen environment to prevent rusting of the components, and the microvibrations induced by the ball-bearings in the motors reduces the positioning accuracy. With one felling swoop, this new prototype motor overcomes all of those problems.

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GNU Radio for Space (and Aircraft)

GOMX-3 is a CubeSat with several payloads. One of them is a software defined radio configured to read ADS-B signals sent by commercial aircraft. The idea is that a satellite can monitor aircraft over oceans and other places where there no RADAR coverage. ADB-S transmits the aircraft’s ID, its position, altitude, and intent.

The problem is that ADS-B has a short-range (about 80 nautical miles). GOMX-1 proved that the signals can be captured from orbit. GOMX-3 has more capability. The satellite has a helical antenna and an FPGA.

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OzQube-1: A Tiny Australian Satellite

Over the last couple of decades we have become used to the possibility of launching a satellite into orbit no longer being the exclusive preserve of superpowers. Since the first CubeSats were launched over a decade ago a myriad others have followed, and scarcely a week passes without news of another interesting project in this area.

OzQube-1 is just such a satellite, designed for imaging of the Southern Hemisphere, and it’s the brainchild of Australian [Stuart McAndrew]. He’s posted significant details of its design: it’s a PocketQube, at 50mm cubed, an eighth the volume of a CubeSat, and its main instrument is a 2 megapixel camera with a 25mm lens. Images will be transmitted to earth as slow-scan digital video via the 70cm amateur band, the dipole antenna being made from a springy tape measure which will unfurl upon launch. Attitude control is passive, coming from a magnet aligned to ensure the camera will be pointing Earthwards as it passes over the Southern Hemisphere. The project has a little way to go yet, but working prototypes have been completed and it has a Gofundme campaign under way to help raise the money for a launch.

There are plenty of Cubesat and other small satellite builds to be found on the web, here at Hackaday we’ve covered a significant number of them. Many of them are the fruits of well-funded university departments or other entities with deep pockets, but this one comes from a lone builder from Western Australia. We like that, and we wish OzQube-1 every success!

After The Prize: SatNOGS Builds Satellites

When Hackaday announced winners of the 2014 Hackaday Prize, a bunch of hackers from Greece picked up the grand prize of $196,418 for their SatNOGS project – a global network of satellite ground stations for amateur Cubesats.

upsat-integration-test-1The design demonstrated an affordable ground station which can be built at low-cost and linked into a public network to leverage the benefits of satellites, even amateur ones. The social implications of this project were far-reaching. Beyond the SatNOGS network itself, this initiative was a template for building other connected device networks that make shared (and open) data a benefit for all. To further the cause, the SatNOGS team set up the Libre Space Foundation, a not-for-profit foundation with a mission to promote, advance and develop Libre (free and open source) technologies and knowledge for space.

Now, the foundation, in collaboration with the University of Patras, is ready to launch UPSat – a 2U, Open Source Greek Cubesat format satellite as part of the QB50 international thermosphere research mission. The design aims to be maximally DIY, designing most subsystems from scratch. While expensive for the first prototype, they hope that documenting the open source hardware and software will help kickstart an ecosystem for space engineering and technologies. As of now, the satellite is fully built and undergoing testing and integration. In the middle of July, it will be delivered to Nanoracks to be carried on a SpaceX Dragon capsule and then launched from the International Space Station.

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