Tracking Satellites With A Commodore PET

October 29, 2020 by Chris Lott 17 Comments

A recent writeup by Tom Nardi about using the 6502-based NES to track satellites brought back memories of my senior project at Georgia Tech back in the early 80s. At our club station W4AQL, I had become interested in Amateur Radio satellites. It was quite a thrill to hear your signal returning from space, adjusting for Doppler as it speeds overhead, keeping the antennas pointed, all while carrying on a brief conversation with other Earth stations or copying spacecraft telemetry, usually in Morse code.

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Hackaday Links: September 27, 2020

September 27, 2020 by Dan Maloney 15 Comments

Hardly a week goes by without a headline screaming about some asteroid or another making a close approach to Earth; it’s only by reading the fine print that we remember what an astronomer’s definition of “close” means. Still, 2020 being what it is, it pays to stay on top of these things, and when you do the story can get really interesting. Take asteroid 2020 SO, a tiny near-Earth asteroid that was discovered just last week. In a couple of weeks, 2020 SO will be temporarily captured into Earth orbit and come with 50,000 km near the beginning of December. That’s cool and all, but what’s really interesting about this asteroid is that it may not be a rock at all. NASA scientists have reverse-engineered the complex orbit of the object and found that it was in the vicinity of Earth in late 1966. They think it may be a Centaur booster from the Surveyor 2 moon mission, launched in September 1966 in the runup to Apollo. The object will be close enough for spectral analysis of its. surface; if it’s the booster, the titanium dioxide in the white paint should show up loud and clear.

Lasers are sort of forbidden fruit for geeks — you know you can put an eye out with them, and still, when you get your hands on even a low-power laser pointer, it’s hard to resist the urge to shine it where you shouldn’t. That includes into the night sky, which as cool as it looks could be bad news for pilots, and then for you. Luckily, friend of Hackaday Seb Lee-Delisle has figured out a way for you to blast lasers into the night sky to your heart’s content. The project is called Laser Light City and takes place in Seb’s home base of Brighton int he UK on October 1. The interactive installation will have three tall buildings with three powerful lasers mounted on each; a smartphone app will let participants control the direction, shape, and color of each beam. It sounds like a load of fun, so check it out if you’re in the area.

We got an interesting story from a JR Nelis about a quick hack he came up with to help his wife stay connected. The whole post is worth a read, but the short version of the story is that his wife has dementia and is in assisted living. Her landline phone is her social lifeline, but she can’t be trusted with it, lest she makes inappropriate calls. His solution was to modify her favorite cordless phone by modifying the keypad, turning it into a receive-only phone. It’s a sad but touching story, and it may prove useful to others with loved ones in similar situations.

We pay a lot of attention to the history of the early computer scene, but we tend to concentrate on computers that were popular in North America and the UK. But the Anglo-American computers were far from the only game in town, and there’s a new effort afoot to celebrate one of the less well-known but still important pioneer computers: the Galaksija. Aside from having a cool name, the Yugoslavian Z80 computer has a great story that will be told in documentary form, as part of the crowdsourced Galaksija project. The documentary stars our own Voja Antonic, who was key to the computer’s development. In addition to the film, the project seeks to produce a replica of the Galaksija in kit form. Check out the Crowd Supply page and see if it’s something you’re willing to back.

There’s an interesting new podcast out there: the Pick, Place, Podcast. Hosted by Chris Denney and Melissa Hough, it comes out every other week and is dedicated to the electronic assembly industry. They’ve currently got eight episodes in the can ranging from pick and place assembly to parts purchasing to solder paste printing. If you want to learn a little more about PCB assembly, this could be a real asset. Of course don’t forget to make time for our own Hackaday Podcast, where editors Mike and Elliot get together to discuss the week in hardware hacking.

Eavesdropping On Satellites For Fun And Profit

August 20, 2020 by Dan Maloney 8 Comments

Geosynchronous satellites, girdling the Earth from their perches 36,000 km above the equator, are remarkably useful devices. Depending on where they’re parked, they command views of perhaps a third of the globe at a time, making them perfect communications relays. But as [James Pavur] points out in his DEF CON Safe Mode talk, “Whispers Among the Stars”, geosynchronous satellite communication links are often far from secure.

[James], a D. Phil. student in Systems Security at Oxford University, relates that his exploits rely on the wide areas covered by the downlink signals from the satellites, coupled with security as an afterthought, if it was even thought of at all by satellite service providers. This lackadaisical approach let him use little more than a regular digital satellite TV dish and a tuner card for a PC — off-the-shelf stuff that you’d really have to try hard to spend more than $300 on — to tap into sensitive information.

While decoding the digital signals from satellites into something parseable can be done with commercial applications, [James] and his colleagues built a custom tool, GSExtract, to pull data from the often noisy signals coming down from on high. The setup returned an amazing bounty of information, like maritime operators relaying the passport information of crew members from ship to shore, point-of-sale terminal information from cruise ships in the Mediterranean, and in-flight entertainment systems in jet airliners. The last example proved particularly alarming, as it revealed an exploitable connection between the systems dedicated to keeping passengers content and those in the cockpit, which clearly should not be the case.

We found [James’] insights on these weaknesses in satellite communications fascinating, and it’s well worth the 45 minutes to watch the video below and perhaps try these exploits, which amount to side-channel attacks, for yourself.

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Drone Buoy Drifts Along The Gulf Stream For Citizen Science

August 13, 2020 by Dan Maloney 26 Comments

It may be named after the most famous volleyball in history, but “Wilson” isn’t just a great conversationalist. [Hayden Brophy] built the free-drifting satellite buoy to see if useful science can be done with off-the-shelf hardware and on a shoestring budget. And from the look of the data so far, Wilson is doing pretty well.

Wilson belongs to a class of autonomous vessels known as drifters, designed to float along passively in the currents of the world’s ocean. The hull of [Hayden]’s drifter is a small Pelican watertight case, which contains all the electronics: Arduino Pro Trinket, GPS receiver, a satellite modem, and a charger for the LiPo battery. The lid of the case is dominated by a 9 W solar panel, plus the needed antennas for GPS and the Iridium uplink and a couple of sensors, like a hygrometer and a thermometer. To keep Wilson bobbing along with his solar panel up, there’s a keel mounted to the bottom of the case, weighted with chains and rocks, and containing a temperature sensor for the water.

Wilson is programmed to wake up every 12 hours and uplink position and environmental data as he drifts along. The drifter was launched into the heart of the Gulf Stream on August 8, about 15 nautical miles off Marathon Key in Florida, by [Captain Jim] and the very happy crew of the “Raw Deal”. As of this writing, the tracking data shows that Wilson is just off the coast of Miami, 113 nautical miles from launch, and drifting along at a stately pace of 2.5 knots. Where the buoy ends up is anyone’s guess, but we’ve seen similar buoys make it all the way across the Atlantic, so here’s hoping that hurricane season is kind to Wilson.

We think this is great, and congratulations to [Hayden] for organizing a useful and interesting project.

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A Hybrid Helical Antenna For The Es’hail-2 Geosynchronous Repeater

August 4, 2020 by Dan Maloney 14 Comments

Amateur radio operators like to say that working a contact in space can be done with a simple handheld transceiver and a homemade antenna. And while that’s true, it’s true only for low Earth orbit satellites such as the ISS. If you want to reach a satellite in geosynchronous orbit it’ll take a little more effort, and this dual-feed helical “ice cream cone” antenna could really help.

Until recently, the dream of an amateur radio repeater in geosynchronous orbit remained out of reach, but that changed with the launch of the Qatari satellite Es’hail-2 last year. Since then, hams from Brazil to Thailand have been using the repeater, and UK-based [Tech Minds] has been in the thick of the action. The antenna he presents is a hybrid design, needed because of the 2.4-GHz band uplink and 10-GHz downlink on the satellite, also known as QO-100. Both require a largish dish antenna, with the downlink requiring a low-noise block downconverter (LNB) and feed horn. The uplink side of [Tech Minds]’ antenna is a helical design, with three-and-a-half turns of heavy copper wire and a tuning section of copper strapping that attaches directly to an N-type connector. The helix is just the right size for the feed horn of an LNB for the downlink side, nestled in a hole in the helical antenna’s aluminum reflector disc. There are 3D-printed parts to support everything, plus a cone-shaped radome to keep it all safe from the elements.

It looks like a great design, but sadly, North American and East Asian hams can only dream about building one, since QO-100 is below the horizon for us. We’re jealous, but we’re still glad the repeater is up there. Check out this article for more on how Es’hail-2 got the first geosynchronous ham repeater.

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Help Thrust Open Source Satellites To The Next Level

June 21, 2020 by Jenny List 12 Comments

To place a satellite in orbit satisfactorily it is necessary not only to hitch a ride on a rocket, but also to put it in the right orbit for its task, and once it is there, to keep it there. With billions of dollars or roubles of investment over six decades of engineering behind them the national space agencies and commercial satellite builders solved these problems long since, but replicating those successes for open source microsatellites still represents a significant engineering challenge. One person working in this field is [Michael Bretti], who is doing sterling work with a shoestring budget on open source electric thrusters for the smallest of satellites, and he needs your help in crowdfunding a piece of equipment.

Beware suspiciously cheap eBay vacuum pumps!

As part of his testing he has a vacuum chamber, and when he places a thruster inside it he has to create a space-grade vacuum . This is no easy task, and to achieve it he has two pumps. The first of these, a roughing pump, is a clapped-out example that has clearly reached the end of its days, and it is this that he needs your help to replace. His GoFundMe page has a modest target of only $4,200 which should be well within the capabilities of our community in reaching, and in supporting it you will help the much wider small satellite community produce craft that will keep giving us interesting things from space for years to come.

We’ve mentioned his work before here at Hackaday, and we hope that in time we’ll have a chance to look in more detail at his thrusters. Meanwhile you can follow along on Twitter.

Thanks [Bruce Perens K6BP] for the tip.

Hackaday Links: April 26, 2020

April 26, 2020 by Dan Maloney 15 Comments

Gosh, what a shame: it turns out that perhaps 2 billion phones won’t be capable of COVID-19 contact-tracing using the API that Google and Apple are jointly developing. The problem is that the scheme the two tech giants have concocted, which Elliot Williams expertly dissected recently, is based on Bluetooth LE. If a phone lacks a BLE chipset, then it won’t work with apps built on the contact-tracing API, which uses the limited range of BLE signals as a proxy for the physical proximity of any two people. If a user is reported to be COVID-19 positive, all the people whose BLE beacons were received by the infected user’s phone within a defined time period can be anonymously notified of their contact. As Elliot points out, numerous questions loom around this scheme, not least of which is privacy, but for now, something like a third of phones in mature smartphone markets won’t be able to participate, and perhaps two-thirds of the phones in developing markets are not compatible. For those who don’t like the privacy-threatening aspects of this scheme, pulling an old phone out and dusting it off might not be a bad idea.

We occasionally cover stories where engineers in industrial settings use an Arduino for a quick-and-dirty automation solution. This is uniformly met with much teeth-gnashing and hair-rending in the comments asserting that Arduinos are not appropriate for industrial use. Whether true or not, such comments miss the point that the Arduino solution is usually a stop-gap or proof-of-concept deal. But now the purists and pedants can relax, because Automation Direct is offering Arduino-compatible, industrial-grade programmable controllers. Their ProductivityOpen line is compatible with the Arduino IDE while having industrial certifications and hardening against harsh conditions, with a rich line of shields available to piece together complete automation controllers. For the home-gamer, an Arduino in an enclosure that can withstand harsh conditions and only cost $49 might fill a niche.

Speaking of Arduinos and Arduino accessories, better watch out if you’ve got any modules and you come under the scrutiny of an authoritarian regime, because you could be accused of being a bomb maker. Police in Hong Kong allegedly arrested a 20-year-old student and posted a picture of parts he used to manufacture a “remote detonated bomb”. The BOM for the bomb was strangely devoid of anything with wireless capabilities or, you know, actual explosives, and instead looks pretty much like the stuff found on any of our workbenches or junk bins. Pretty scary stuff.

If you’ve run through every binge-worthy series on Netflix and are looking for a bit of space-nerd entertainment, have we got one for you. Scott Manley has a new video that goes into detail on the four different computers used for each Apollo mission. We knew about the Apollo Guidance Computers that guided the Command Module and the Lunar Module, and the Launch Vehicle Digital Computer that got the whole stack into orbit and on the way to the Moon, but we’d never heard of the Abort Guidance System, a backup to the Lunar Module AGC intended to get the astronauts back into lunar orbit in the event of an emergency. And we’d also never heard that there wasn’t a common architecture for these machines, to the point where each had its own word length. The bit about infighting between MIT and IBM was entertaining too.

And finally, if you still find yourself with time on your hands, why not try your hand at pen-testing a military satellite in orbit? That’s the offer on the table to hackers from the US Air Force, proprietor of some of the tippy-toppest secret hardware in orbit. The Hack-A-Sat Space Security Challenge is aimed at exposing weaknesses that have been inadvertantly baked into space hardware during decades of closed development and secrecy, vulnerabilities that may pose risks to billions of dollars worth of irreplaceable assets. The qualification round requires teams to hack a grounded test satellite before moving on to attacking an orbiting platform during DEFCON in August, with prizes going to the winning teams. Get paid to hack government assets and not get arrested? Maybe 2020 isn’t so bad after all.