A Guide To CubeSat Mission And Bus Design

April 28, 2026 by Al Williams 9 Comments

If you mention the word bus, you might think of public transportation or, more likely for us, a way to connect things together. But in the satellite world, the bus is the part of a vehicle that supports the payload but isn’t itself the payload. Typically, that means the electric power system, propulsion, radios, and thermal control, among other systems. If you are designing a CubeSat, you will want to read A Guide to CubeSat Mission and Bus Design by [Frances Zhu].

The Creative Commons-licensed book has twelve chapters, ranging from systems engineering — that is, defining what you want to do — to analyzing structures, handling power, setting up communications, and more. Of particular interest to us was the chapter on command and data handling. The final chapters cover software, system integration, and there’s even a chapter on Ethics.

If you want to build a CubeSat or just want to learn more about how satellites actually work, this is a great read. There are videos and other features, too. If you don’t like reading in your browser, you can download an EPUB, PDF, or MOBI near the top of the page.

There are many resources for the want-to-be CubeSat builder. You can even start with an open source design.

Hackaday Links: July 13, 2025

July 13, 2025 by Dan Maloney 8 Comments

There’s interesting news out of Wyoming, where a coal mine was opened this week. But the fact that it’s the first new coal mine in 50 years isn’t the big news — it’s the mine’s abundance of rare earth elements that’s grabbing the headlines. As we’ve pointed out before, rare earth elements aren’t actually all that rare, they’re just widely distributed through the Earth’s crust, making them difficult to recover. But there are places where the concentration of rare earth metals like neodymium, dysprosium, scandium, and terbium is slightly higher than normal, making recovery a little less of a challenge. The Brook Mine outside of Sheridan, Wyoming is one such place, at least according to a Preliminary Economic Assessment performed by Ramaco Resources, the mining company that’s developing the deposit.

The PEA states that up to 1,200 tons of rare earth oxides will be produced a year, mainly from the “carbonaceous claystones and shales located above and below the coal seams.” That sounds like good news to us for a couple of reasons. First, clays and shales are relatively soft rocks, making it less energy- and time-intensive to recover massive amounts of raw material than it would be for harder rock types. But the fact that the rare earth elements aren’t locked inside the coal is what’s really exciting. If the REEs were in the coal itself, that would present something similar to the “gasoline problem” we’ve discussed before. Crude oil is a mixture of different hydrocarbons, so if you need one fraction, like diesel, but not another, like gasoline, perhaps because you’ve switched to electric vehicles, tough luck — the refining process still produces as much gasoline as the crude contains. In this case, it seems like the coal trapped between the REE-bearing layers is the primary economic driver for the mine, but if in the future the coal isn’t needed, the REEs could perhaps be harvested and the coal simply left behind to be buried in the ground whence it came.

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38C3: Save Your Satellite With These Three Simple Tricks

December 30, 2024 by Elliot Williams 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.

Libre Space Foundation Aims To Improve Satellite Tech

October 22, 2024 by Bryan Cockfield 27 Comments

There’s no shortage of movies, TV shows, and books that show a dystopian future with corporations run amok in outer space with little or no effective oversight. Dune, The Expanse, and The Dispossessed spring to mind as predicting different aspects of this idea, but there are plenty of other warnings throughout sci-fi depicting this potential future. One possible way of preventing this outcome is by ensuring that space is as open-sourced as possible and one group, the Libre Space Foundation (LSF), is working towards this end. Their latest is a project with Ondsel to develop and model a satellite deploying mechanism using almost entirely open source software.

The LSF had already designed the PICOBUS satellite launcher system that flew to space in 2022 and deployed a number of CubeSats, but the group needed more information about how the system would perform. They turned to Ondsel to help develop a multi-body dynamics (MBD) solver, managing simulations with mass-spring-damper models. The satellite launcher includes a large constant-force spring that pushes the CubeSats out of the device once the door is opened, and the model can now simulate their paths in space without gravity. The team will launch their next set of satellites sometime next year on an RFA-ONE rocket.

The LSF maintains a huge database of their open source space projects, including this one, on their GitLab page. Although it might seem like small potatoes now, the adoption of open source software and hardware by space-fairing entities can help further the democratization of low Earth orbit.

Thanks to [johnad] for the tip!

Hackaday Links: September 3, 2023

September 3, 2023 by Dan Maloney 16 Comments

Right-to-repair has been a hot-button topic lately, with everyone from consumers to farmers pretty much united behind the idea that owning an item should come with a plausible path to getting it fixed if it breaks, or more specifically, that you shouldn’t be subject to prosecution for trying to repair your widget. Not everyone likes right-to-repair, of course — plenty of big corporations want to keep you from getting up close and personal with their intellectual property. Strangely enough, their ranks are now apparently joined by the Church of Scientology, who through a media outfit in charge of the accumulated works of Church founder L. Ron Hubbard are arguing against exemptions to the Digital Millennium Copyright Act (DMCA) that make self-repair possible for certain classes of devices. They apparently want the exemption amended to not allow self-repair of any “software-powered devices that can only be purchased by someone with particular qualifications or training or that use software ‘governed by a license agreement negotiated and executed’ before purchase.

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Discussing The Finer Points Of Space-Worthy Software

July 17, 2023 by Tom Nardi 28 Comments

At the dawn of the Space Race, when computers were something that took up whole rooms, satellites and probes had to rely on analog electronics to read from their various sensors and transmit the resulting data to the ground. But it wasn’t long before humanity’s space ambitions outgrew these early systems, which lead to vast advancements in space-bound digital computers in support of NASA’s Gemini and Apollo programs. Today, building a spacecraft without an onboard computer (or even multiple redundant computers) is unheard of. Even the smallest of CubeSats is likely running Linux on a multi-core system.

As such, software development has now become part an integral part of spacecraft design — from low-level code that’s responsible for firing off emergency systems to the 3D graphical touchscreen interfaces used by the crew to navigate the craft. But as you might expect, the stakes here are higher than any normal programming assignment. If your code locks up here on Earth, it’s an annoyance. If it locks up on a lunar lander seconds before it touches down on the surface, it could be the end of the mission.

To get a bit more insight into this fascinating corner of software development, we invited Jacob Killelea to host last week’s
Software for Satellites Hack Chat. Jacob is an engineer with a background in both aero and thermodynamics, control systems, and life support. He’s written code for spacecraft destined for the Moon, and perhaps most importantly, is an avid reader of Hackaday.

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Democratizing Space, One Picosatellite At A Time

June 28, 2023 by Tom Nardi 50 Comments

There was a time when putting an object into low Earth orbit was the absolute pinnacle of human achievement. It was such an outrageously expensive and complex undertaking that only a world superpower was capable of it, and even then, success wasn’t guaranteed. As the unforgiving physics involved are a constant, and the number of entities that could build space-capable vehicles remained low, this situation remained largely the same for the remainder of the 20th century.

But over the last couple of decades, the needle has finally started to move. Of course spaceflight is still just as unforgiving today as it was when Sputnik first streaked through the sky in 1957, but the vast technical improvements that have been made since then means space is increasingly becoming a public resource.

Thanks to increased commercial competition, putting a payload into orbit now costs a fraction of what it did even ten years ago, while at the same time, the general miniaturization of electronic components has dramatically changed what can be accomplished in even a meager amount of mass. The end result are launches that don’t just carry one or two large satellites into orbit, but dozens of small ones simultaneously.

To find out more about this brave new world of space exploration, we invited Nathaniel Evry, Chief Research Officer at Quub, to host last week’s DIY Picosatellites Hack Chat.

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