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.

Continue reading “GNU Radio for Space (and Aircraft)”

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.

Continue reading “After The Prize: SatNOGS Builds Satellites”

Flying The Infinite Improbability Drive

Not since the cold fusion confusion of 1989 has the pop science media industry had a story like the EmDrive. The EmDrive is a propellantless thruster – a device that turns RF energy into force. If it works, it will revolutionize any technology that moves. Unlike rocket motors that use chemicals, cold gas, ions, or plasma, a spacecraft equipped with an EmDrive can cruise around the solar system using only solar panels. If it works, it will violate the known laws of physics.

After being tested in several laboratories around the world, including Eagleworks, NASA’s Advanced Propulsion Physics Laboratory, the concept of a device that produces thrust from only electricity is still not disproven, ridiculed, and ignored. For a device that violates the law of conservation of momentum, this is remarkable. Peer review of several experiments are ongoing, but [Paul] has a much more sensational idea: he’s building an EmDrive that will propel a cubesat.

Make no mistake, our current understanding of the universe is completely incompatible with the EmDrive. The idea of an engine that dumps microwave energy into a metal cone and somehow produce thrust is on the fringes of science. No sane academic physicist would pursue this line of research, and the mere supposition that the EmDrive might work is irresponsible. Until further peer-reviewed experiments are published, the EmDrive is the fanciful dream of a madman. That said, if it does work, we get helicarriers. Four EmDrives mounted to a Tesla Roadster would make a hovercar. Your grandchildren would only see Earth’s sun as a tiny speck in the night sky.

This isn’t [Paul]’s first attempt to create a working propellantless thruster. For last year’s Hackaday Prize, [Paul] built a baby EmDrive. Unlike every other EmDrive experiment that used 2.4GHz microwaves, [Paul] designed his engine to operate on 22 to 26 GHz. This means [Paul]’s is significantly smaller and can easily fit into a cubesat. If it works, this cubesat will be able to maintain its orbit indefinitely, fly to the moon and back, or go anywhere in the solar system provided the solar panels get enough light.

While [Paul]’s motivations in creating a citizen science version of the EmDrive are laudable, Hackaday.io’s own baby EmDrive does not display the requisite scientific rigor for a project of this magnitude. Experimental setups are ill-defined, graph axes are unlabeled, and there is not enough information to properly critique [Paul]’s baby EmDrive experiments.

That said, we can’t blame a guy for trying, and the EmDrive is still an active area of research with several papers under peer review. [Paul]’s plan of putting an EmDrive into orbit is putting the cart several miles ahead of the horse, but it is still a very cool project for this year’s Hackaday Prize.

The HackadayPrize2016 is Sponsored by:

A $1000 Tiny Personal Satellite

If you ever read any old magazines, you might be surprised at how inexpensive things used to be. A U.S. postage stamp was six cents, a gallon of gas was $0.34, and the same amount of milk was $1.07. Everything is relative, though. The average household income back then was under $8,000 a year (compared to over $53,000 a year in 2014). So as a percentage of income, that milk actually cost about seven bucks.

The same is true of getting into orbit. Typical costs today just to get something into orbit has gone from–no pun intended–astronomical, to pretty reasonable. Lifting a pound of mass on the Space Shuttle cost about $10,000. On an Atlas V, it costs about $6,000. A Falcon Heavy (when it launches) will drop the cost to around $1,000 or so. Of course, that’s just the launch costs. You still have to pay for whatever you want to put up there. Developing a satellite can be expensive. Very expensive.

Continue reading “A $1000 Tiny Personal Satellite”

32C3: So You Want to Build a Satellite?

[INCO] gave this extremely informative talk on building a CubeSat. CubeSats are small satellites that piggyback on the launches of larger satellites, and although getting a 10 cm3 brick into orbit is cheap, making it functional takes an amazing attention to detail and redundant design.

[INCO] somehow talks through the entire hour-long presentation at a tremendous speed, all the while remaining intelligible. At the end of the talk, you’ve got a good appreciation for the myriad pitfalls that go along with designing a satellite, and a lot of this material is relevant, although often in a simpler form, for high altitude balloon experiments.

satellite_2-shot0002CubeSats must be powered down during launch, with no radio emissions or anything else that might interfere with the rocket that’s carrying them. The satellites are then packed into a box with a spring, and you never see or hear from them again until the hatch is opened and they’re pushed out into space.

[INCO] said that 50% of CubeSats fail on deployment, and to avoid being one of the statistics, you need to thoroughly test your deployment mechanisms. Test after shaking, being heated and cooled, subject to low battery levels, and in a vacuum. Communication with the satellite is of course crucial, and [INCO] suggests sending out a beacon shortly after launch to help you locate the satellite at all.

satellite_2-shot0003Because your satellite is floating out in space, even tiny little forces can throw it off course. Examples include radiation pressure from the sun, and anything magnetic in your satellite that will create a torque with respect to the Earth’s magnetic field. And of course, the deployment itself may leave your satellite tumbling slightly, so you’re going to need to control your satellite’s attitude.

Power is of course crucial, and in space that means solar cells. Managing solar cells, charging lithium batteries, and smoothing out the power cycles as the satellite enters the earth’s shadow or tumbles around out of control in space. Frequent charging and discharging of the battery is tough on it, so you’ll want to keep your charge/discharge cycles under 20% of the battery’s nominal capacity.

mpv-shot0001In outer space, your satellite will be bombarded by heavy ions that can short-circuit the transistors inside any IC. Sometimes, these transistors get stuck shorted, and the only way to fix the latch-up condition is to kill power for a little bit. For that reason, you’ll want to include latch-up detectors in the power supply to reset the satellite automatically when this happens. But this means that your code needs to expect occasional unscheduled resets, which in turn means that you need to think about how to save state and re-synchronize your timing, etc.

In short, there are a ridiculous amount of details that you have to attend to and think through before building your own CubeSat. We’ve just scratched the surface of [INCO]’s advice, but if we had to put the talk in a Tweet, we’d write “test everything, and have a plan B whenever possible”. This is, after all, rocket science.

Hackaday Links: November 8, 2015

[Burt Rutan] is someone who needs no introduction. Apparently, he likes the look of the Icon A5 and is working on his own version.

Earlier this week, the US Air Force lost a few satellites a minute after launch from Barking Sands in Hawaii. This was the first launch of the three stage, solid fueled SPARK rocket, although earlier versions were used to launch nuclear warheads into space. There are some great Army videos for these nuclear explosions in space, by the way.

[Alexandre] is working on an Arduino compatible board that has an integrated GSM module and WiFi chip. It’s called the Red Dragon, and that means he needs some really good board art. The finished product looks good in Eagle, and something we can’t wait to see back from the board house.

The Chippocolypse! Or however you spell it! TI is declaring a lot of chips EOL, and although this includes a lot of op-amps and other analog ephemera (PDF), the hi-fi community is reeling and a lot of people are stocking up on their favorite amplifiers.

[Jeremy] got tired of plugging jumper wires into a breadboard when programming his ATMega8 (including the ‘168 and ‘328) microcontrollers. The solution? A breadboard backpack that fits right over the IC. All the files are available, and the PCB can be found on Upverter.

In case you haven’t heard, we’re having a Super Conference in San Francisco later this week. Adafruit was kind enough to plug our plug for the con on Ask an Engineer last week.