Three-Stage Thrust Vectoring Model Rocket With Tiny Flight Computers

September 5, 2021 by Danie Conradie 23 Comments

Flying a thrust-vectoring rocket can be a challenge, and even more so if you stack multiple stages and a minimalist flight computer on top of it all. But [Joe Barnard] is not one to shy away from such a challenge, so he built a three stage actively guided rocket named Shreeek.

[Joe] is well known for his thrust-vectoring rockets, some of which have came within a hair’s breadth of making a perfect powered landing. Previous rockets have used larger, more complex flight computers, but for this round, he wanted to go as small and minimalist as possible. Each stage of the rocket has its own tiny 16 x 17 mm flight computer and battery. The main components are a SAM21 microcontroller running Arduino firmware, an IMU for altitude and orientation sensing, and a FET to trigger the rocket motor igniter. It also has servo outputs for thrust vector control (TVC), and motor control output for the reaction wheel on the third stage for roll control. To keep it simple he omitted a way to log flight data, a decision he later regretted. Shreeek did not have a dedicated recovery system on any of the stages, instead relying on its light weight and high drag to land intact

None of the four launch attempts went as planned, with only the first two stages functioning correctly in the test with the best results. Thanks to the lack of recorded flight data, [Joe] had to rely on video footage alone to diagnose the problems after each launch. Even so, his experience diagnosing problems certainly proved its worth, with definitive improvements. However, we suspect that all his future flight computers will have data logging features included.

Continue reading “Three-Stage Thrust Vectoring Model Rocket With Tiny Flight Computers” →

So How Does A Rocket Fly Sideways, Anyway?

September 1, 2021 by Tom Nardi 43 Comments

It’s often said that getting into orbit is less about going up, and more about going sideways very fast. So in that sense, the recent launch conducted by aerospace startup Astra could be seen as the vehicle simply getting the order of operations wrong. Instead of going up and then burning towards the horizon, it made an exceptionally unusual sideways flight before finally moving skyward.

As you might expect, the booster didn’t make it to orbit. But not for lack of trying. In fact, that the 11.6 meter (38 feet) vehicle was able to navigate through its unprecedented lateral maneuver and largely correct its flight-path is a testament to the engineering prowess of the team at the Alameda, California based company. It’s worth noting that it was the ground controller’s decision to cut the rocket’s engines once it had flown high and far enough away to not endanger anyone on the ground that ultimately ended the flight; the booster itself was still fighting to reach space until the very last moment.

There’s a certain irony to the fact that this flight, the third Astra has attempted since their founding in 2016, was the first to be live streamed to YouTube. Had the company not pulled back their usual veil of secrecy, we likely wouldn’t have such glorious high-resolution footage of what will forever be remembered as one of the most bizarre rocket mishaps in history. The surreal image of the rocket smoothly sliding out of frame as if it was trying to avoid the camera’s gaze has already become a meme online, arguably reaching a larger and more diverse audience than would have resulted from a successful launch. As they say, there’s no such thing as bad press.

Naturally, the viral clip has spurred some questions. You don’t have to be a space expert to know that the pointy end of the rocket is usually supposed to go up, but considering how smooth the maneuver looks, some have even wondered if it wasn’t somehow intentional. With so much attention on this unusual event, it seems like the perfect time to take a close look at how Astra’s latest rocket launch went, quite literally, sideways.

Continue reading “So How Does A Rocket Fly Sideways, Anyway?” →

Beeping The Enemy Into Submission

April 17, 2018 by Christian Trapp 45 Comments

In July 1940 the German airforce began bombing Britain. This was met with polite disagreement on the British side — and with high technology, ingenuity, and improvisation. The defeat of the Germans is associated with anti-aircraft guns and fighter planes, but a significant amount of potential damage had been averted by the use of radio.

Night bombing was a relatively new idea at that time and everybody agreed that it was hard. Navigating a plane in the dark while travelling at two hundred miles per hour and possibly being shot at just wasn’t effective with traditional means. So the Germans invented non-traditional means. This was the start of a technological competition where each side worked to implement new and novel radio technology to guide bombing runs, and to disrupt those guidance systems.

Continue reading “Beeping The Enemy Into Submission” →