satellite

187 Articles

38C3: Save Your Satellite With These Three Simple Tricks

December 30, 2024 by 11 Comments

BEESAT-1 is a 1U cubesat launched in 2009 by the Technical University of Berlin. Like all good satellites, it has redundant computers onboard, so when the first one failed in 2011, it just switched over to the second. And when the backup failed in 2013, well, the satellite was “dead” — or rather sending back all zeroes. Until [PistonMiner] took a look at it, that is.

Getting the job done required debugging the firmware remotely — like 700 km remotely. Because it was sending back all zeroes, but sending back valid zeroes, that meant there was something wrong either in the data collection or the assembly of the telemetry frames. A quick experiment confirmed that the assembly routine fired off very infrequently, which was a parameter that’s modifiable in SRAM. Setting a shorter assembly time lead to success: valid telemetry frame.

Then comes the job of patching the bird in flight. [PistonMiner] pulled the flash down, and cobbled together a model of the satellite to practice with in the lab. And that’s when they discovered that the satellite doesn’t support software upload to flash, but does allow writing parameter words. The hack was an abuse of the fact that the original code was written in C++. Intercepting the vtables let them run their own commands without the flash read and write conflicting.

Of course, nothing is that easy. Bugs upon bugs, combined with the short communication window, made it even more challenging. And then there was the bizarre bit with the camera firing off after every flash dump because of a missing break in a case statement. But the camera never worked anyway, because the firmware didn’t get finished before launch.

Challenge accepted: [PistonMiner] got it working, and after fifteen years in space, and ten years of being “dead”, BEESAT-1 was taking photos again. What caused the initial problem? NAND flash memory needs to be cleared to zeroes before it’s written, and a bug in the code lead to a long pause between the two, during which a watchdog timeout fired and the satellite reset, blanking the flash.

This talk is absolutely fantastic, but may be of limited practical use unless you have a long-dormant satellite to play around with. We can nearly guarantee that after watching this talk, you will wish that you did. If so, the Orbital Index can help you get started.

Handheld Satellite Dish Is 3D Printed

December 23, 2024 by 11 Comments

Ham radio enthusiasts, people looking to borrow their neighbors’ WiFi, and those interested in decoding signals from things like weather satellites will often grab an old satellite TV antenna and repurpose it. Customers have been leaving these services for years, so they’re pretty widely available. But for handheld operation, these metal dishes can get quite cumbersome. A 3D-printed satellite dish like this one is lightweight and small enough to be held, enabling some interesting satellite tracking activities with just a few other parts needed.

Although we see his projects often, [saveitforparts] did not design this antenna, instead downloading the design from [t0nito] on Thingiverse. [saveitforparts] does know his way around a satellite antenna, though, so he is exactly the kind of person who would put something like this through its paces and use it for his own needs. There were a few hiccups with the print, but with all the 3D printed parts completed, the metal mesh added to the dish, and a correctly polarized helical antenna formed into the print to receive the signals, it was ready to point at the sky.

The results for the day of testing were incredibly promising. Compared to a second satellite antenna with an automatic tracker, the handheld 3D-printed version captured nearly all of the information sent from the satellite in orbit. [saveitforparts] plans to build a tracker for this small dish to improve it even further. He’s been able to find some satellite trackers from junked hardware in some unusual places as well. Antennas seem to be a ripe area for 3D printing.

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Photo manipulation of Skynet-1A hovering a planet

Britain’s Oldest Satellite On The Move: A Space Curiosity

November 11, 2024 by 9 Comments

Space and mystery always spark our curiosity, so when we stumbled upon the story of Skynet-1A, Britain’s first communication satellite from 1969, we knew it was worth exploring. The BBC recently highlighted its unexpected movement across the sky – you can check out their full coverage here. The idea that this half-century-old hunk of metal mysteriously shifted orbits leaves us with more questions than answers. Who moved Skynet-1A, and why?

Launched just months after the Apollo 11 Moon landing, Skynet-1A stood as a symbol of Cold War innovation, initially placed above East Africa to support British military communications. But unlike the silent drift of inactive satellites heading naturally eastward, Skynet-1A defied orbital norms, popping up halfway across the globe above the Americas. This wasn’t mere chance; someone or something had made it fire its thrusters, likely in the mid-1970s.

Experts like Dr. Stuart Eves and UCL’s Rachel Hill suggest the possibility of control being temporarily transferred to the US, particularly during maintenance periods at the UK’s RAF Oakhanger. Still, the specifics remain buried in lost records and decades-old international collaborations. Skynet-1A’s journey serves as a stark reminder of the persistent challenges in space and the gaps in our historical data.

Looking for more space oddities? Hackaday has some interesting articles on space debris. You can read the original BBC article here.

A Lesson In RF Design Thanks To This Homebrew LNA

November 4, 2024 by 7 Comments

If you’re planning on working satellites or doing any sort of RF work where the signal lives down in the dirt, you’re going to need a low-noise amplifier. That’s typically not a problem, as the market is littered with dozens of cheap options that can be delivered in a day or two — you just pay your money and get to work. But is there a case to be made for rolling your own LNA?

[Salil, aka Nuclearrambo] thinks so, and he did a nice job showing us how it’s done. The first step, as always, is to define your specs, which for [Salil] were pretty modest: a low noise figure, moderate gain, and good linearity. He also wanted a bandpass filter for the 2-meter amateur radio band and for weather satellite downlinks, and a bias-tee to power the LNA over the coax feedline. The blog post has a detailed discussion of the electrical design, plus some good tips on PCB design for RF applications. We also found the discussion on bias-tee design helpful, especially for anyone who has ever struggled with the idea that RF and DC can get along together on a single piece of coax. Part 2 concentrates on testing the LNA, mostly using hobbyist-grade test gear like the NanoVNA and tiny SA spectrum analyzer. [Salil]’s tests showed the LNA lived up to the design specs and more, making it more than ready to put to work with an RTL-SDR.

Was this more work than buying an LNA? Absolutely, and probably with the same results. But then again, what’s to learn by just getting a pre-built module in the mail?

A Look Inside A Canadian Satellite TV Facility

October 31, 2024 by 5 Comments

If you’ve ever wondered what goes on in the ground facilities of a satellite TV operation, you could go banging on the doors or your local station. You’d probably get thrown out in short order. Alternatively, you could watch this neat little tour from [saveitforparts].

The tour takes us through a ground facility operated by the Canadian Broadcasting Corporation and Radio Canada in Montreal. The facility in question largely handles CBC’s French language content for the Canadian audience. We’re treated to a look at the big satellite dishes on the roof, as well as the command center inside. Wall to wall screens and control panels are the order of the day, managing uplinks and downlinks and ensuring content gets where it needs to go. Particularly interesting is the look at the hardcore hardware for full-strength transmission to satellites. The video also includes some neat trivia, like how CBC was the first broadcaster to offer direct satellite TV to customers in 1978.

We’ve seen [saveitforparts] tackle some interesting satellite hardware teardowns before, too.

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Teardowns Show Off Serious Satellite Hardware

October 18, 2024 by 14 Comments

As hackers, we’re always pulling stuff apart—sometimes just to see what it’s like inside. Most of us have seen the inside of a computer, television, and phone. These are all common items that we come into contact with every day. Fewer of us have dived inside real spacey satellite hardware, if only for the lack of opportunity. Some good gear has landed on [Don]’s desk over the years though, so he got to pulling it apart and peering inside.

[Don] starts us off with a gorgeous… box… of some sort from Hughes Aircraft. He believes it to be from their Space & Communications group, and it seems to have something to do with satellite communications work. Externally, he gleans that it takes power and data hookups and outputs RF to, something… but he’s not entirely sure. Inside, we get a look at the old 90s electronics — lots of through hole, lots of big chunky components, and plenty of gold plating. [Don] breaks down the circuitry into various chunks and tries to make sense of it, determining that it’s got some high frequency RF generators in the 20 to 40 GHz range.

Scroll through the rest of [Don]’s thread and you’ll find more gems. He pulls apart a microwave transmitter from Space Micro — a much newer unit built somewhere around 2008-2011. Then he dives into a mysterious I/O board from Broad Reach, and a very old Hughes travelling wave tube from the 1970s. The latter even has a loose link to the Ford Motor Company, believe it or not.

Even if you don’t know precisely what you’re looking at, it’s still supremely interesting stuff—and all very satellite-y. We’ve seen some other neat satellite gear pulled apart before, too. Meanwhile, if you’ve been doing your own neat teardowns, don’t hesitate to let us know!

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Hackaday Links: September 29, 2024

September 29, 2024 by 16 Comments

There was movement in the “AM Radio in Every Vehicle Act” last week, with the bill advancing out of the US House of Representatives Energy and Commerce Committee and heading to a full floor vote. For those not playing along at home, auto manufacturers have been making moves toward deleting AM radios from cars because they’re too sensitive to all the RF interference generated by modern vehicles. The trouble with that is that the government has spent a lot of effort on making AM broadcasters the centerpiece of a robust and survivable emergency communications system that reaches 90% of the US population.

The bill would require cars and trucks manufactured or sold in the US to be equipped to receive AM broadcasts without further fees or subscriptions, and seems to enjoy bipartisan support in both the House and the Senate. Critics of the bill will likely point out that while the AM broadcast system is a fantastic resource for emergency communications, if nobody is listening to it when an event happens, what’s the point? That’s fair, but short-sighted; emergency communications isn’t just about warning people that something is going to happen, but coordinating the response after the fact. We imagine Hurricane Helene’s path of devastation from Florida to Pennsylvania this week and the subsequent emergency response might bring that fact into focus a bit.

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