Model Rocket Nails Vertical Landing After Three-Year Effort

July 10, 2024 by Dan Maloney 30 Comments

Model rocketry has always taken cues from what’s happening in the world of full-scale rockets, with amateur rocketeers doing their best to incorporate the technologies and methods into their creations. That’s not always an easy proposition, though, as this three-year effort to nail a SpaceX-style vertical landing aptly shows.

First of all, hats off to high schooler [Aryan Kapoor] from JRD Propulsion for his tenacity with this project. He started in 2021 with none of the basic skills needed to pull off something like this, but it seems like he quickly learned the ropes. His development program was comprehensive, with static test vehicles, a low-altitude hopper, and extensive testing of the key technology: thrust-vector control. His rocket uses two solid-propellant motors stacked on top of each other, one for ascent and one for descent and landing. They both live in a 3D printed gimbal mount with two servos that give the stack plus and minus seven degrees of thrust vectoring in two dimensions, which is controlled by a custom flight computer with a barometric altimeter and an inertial measurement unit. The landing gear is also clever, using rubber bands to absorb landing forces and syringes as dampers.

The video below shows the first successful test flight and landing. Being a low-altitude flight, everything happens very quickly, which probably made programming a challenge. It looked like the landing engine wasn’t going to fire as the rocket came down significantly off-plumb, but when it finally did light up the rocket straightened and nailed the landing. [Aryan] explains the major bump after the first touchdown as caused by the ascent engine failing to eject; the landing gear and the flight controller handled the extra landing mass with aplomb.

All in all, very nice work from [Aryan], and we’re keen to see this one progress.

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How To Land A Model Rocket Vertically

June 21, 2023 by Jenny List 20 Comments

Perhaps most readers will remember when they saw the first SpaceX demonstration of a rocket stage landing vertically on the pad under control. It’s something of a shock to be reminded that their first suborbital demonstration “hops” were around a decade ago, and how quickly what was once so special has become commonplace. We’re now in the era of the more complex model rockets having the same capability, with [BPS.space] managing it last year, and now [TTS Aerospace] sharing a video showing how they achieved the same feat.

The basics of the system revolve around a directed rocket nozzle, but to make it work is a lot more complex than simply hooking up a flight controller and calling it good. The steps in arriving at a landable rocket are examined, with plenty of failures shown along the way. Even the legs are more complex than they might appear, having to combine lightness, ease of unfurling under the power of elastic, and enough strength and give to survive a rough landing.

Those of us from countries where model rocketry is a highly licensed activity can only look on in envy at these projects, and we look forward to seeing where this avenue leads next. We covered the [BPS.space] rocket last year, should you be interested.

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Launch And Track Your Model Rockets Via Smartphone

July 27, 2022 by Lewin Day 14 Comments

Building and flying model rockets is great fun. Eventually, though, the thrill of the fire and smoke subsides, and you want to know more about what it’s doing in the air. With a thirst for knowledge, [archy587] started building a project to monitor the vital stats of rockets in flight.

The project mounts an M0 Feather microcontroller board into the rocket, along with a 900 MHz LoRa transmitter and a GPS module. This allows the rocket’s journey to be measured and logged, and is particularly useful for when a craft floats off downrange during parachute recovery. There’s also a relay module onboard, which dumps power from a dedicated separate battery into the rocket motor igniter. This allows the rocket to be fired wirelessly.

On the ground, the setup uses an ESP32 fitted with another LoRa module to receive signals from the rocket. It’s designed to hook up to an Android smartphone over its USB-C port. This allows data received from the rocket to be displayed in an Android app, including the rocket’s GPS location overlaid on Google Maps.

Being able to remotely ignite your rockets and track their progress brings some high-tech cool to the launch pad. You’ll be upgrading your rockets with micro flight controllers and vectored thrust in no time. Just be sure whatever tech you’re using is compliant with the rules for model rocketry in your local area.

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Retrotechtacular: Junior Missile Men Of The 1960s

November 22, 2021 by Dan Maloney 30 Comments

Just like the imaginative kids depicted in “Junior Missile Men in Action,” you’ll have to employ a fair bit of your own imagination to figure out what was going on in the original film, which seems to have suffered a bit — OK, a lot — from multiple rounds of digitization and format conversion. [GarageManCave] tells us he found the film on a newsgroup back in the 1990s, but only recently uploaded it to YouTube. It’s hard to watch, but worth it for anyone who spent hours building an Estes model rocket and had that gut-check moment when sliding it onto the guide rail and getting it ready for launch. Would it go? Would it survive the trip? Or would it end up hanging from a tree branch, or lost in the high grass that always seemed to be ready to eat model rockets, planes, Frisbees, or pretty much anything that was fun?

Model rocketry was most definitely good, clean fun, even with the rotten egg stink of the propellant and the risk of failure. To mitigate those risks, the West Covina Model Rocket Society, the group the film focuses on, was formed in the 1960s. The boys and girls pictured had the distinct advantage of living in an area where many of their parents were employed by the aerospace industry, and the influence of trained engineers shows — weekly build sessions, well-organized range days, and even theodolites to track the rockets and calculate their altitude. They even test-fired rockets from miniature silos, and mimicked a Polaris missile launch by firing a model from a bucket of water. It was far more intensive and organized than the early rocketry exposure most of us got, and has the look and feel of a FIRST robotics group today.

Given the membership numbers the WCMRS boasted of in its heyday, and the fact that model rocketry was often the “gateway drug” into the hacking lifestyle, there’s a good chance that someone in the Hackaday community got their start out in that park in West Covina, or perhaps was even in the film. If you’re out there, let us know in the comments — we’d love to hear a first-hand report on what the club was like, and how it helped you get started.

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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.

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So Close To Landing A Model Rocket On Its Tail

November 27, 2020 by Danie Conradie 44 Comments

We’ve become so used to seeing SpaceX boosters land themselves back on the pad with clockwork reliability, that it’s easy to forget it took them a good number of attempts to get right. Inspired by SpaceX’s work, [Joe Barnard] of [BPS.Space] started working to replicate it at the model scale five years ago, with no engineering education or experience. On the latest attempt with a brand-new thrust vectoring Scout E rocket, he has gotten tantalizingly close to doing a controlled propulsive landing with a solid-fuel rocket motor.

We’ve all been thrilled to see the SpaceX rockets return to earth, landing elegantly on a floating pad. But those are liquid-fueled. The trick with a solid-fuel rocket motor is it can’t be throttled directly, which is a challenge when you need precision control to land. Thanks to [Joe]’s custom AVA flight computer and the remarkably consistent thrust curve of the Estes F15 black powder motors he used, it becomes a matter of igniting the descent motor at the right moment to make the vertical velocity zero at touchdown. However, [Joe] found that the time between sending the ignition signal and when peak thrust is reached was inconsistent, so he had to work around that. He did this by controlling how much of the thrust is spent in the vertical direction, by vectoring the motor side to side to spend some trust horizontally.

View from rocket of the ascent motor falling away immediately after being ejected

In this attempt, the rocket tipped over on landing due to excessive horizontal movement at touchdown. Joe tracked the cause down to a weak GPS signal caused by antenna position and a possible bug in the Kalman filter that fuses all the sensor data for position and velocity estimation. Thanks to incredibly detailed telemetry and logging done by the flight computer, data from every launch are used for future improvements. We are looking forward to the next flight in a few weeks, during which [Joe] plans to tune and test the control software, among other minor improvements.

Almost every single part of this rocket is a display of engineering ingenuity. The landing struts are designed to absorb as much impact as possible without bouncing while being light and quick to deploy. The ascent motor is ejected simply by moving the thrust vectoring mount to one of its extremes, allowing the descent motor to drop into place. The rocket also features a complete emergency abort system with a parachute, which can be activated manually, or by the flight computer if it calculates that landing isn’t feasible. We already covered [Joe]’s latest launch pad, which is a very interesting project all by itself.

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Advanced Model Rocket Flight Computer Reaching For The Stars

October 2, 2020 by Danie Conradie 15 Comments

When you’re building and launching a variety of advanced model rockets like [Joe Barnard], you don’t want to spend time building (and debugging) specialized flight computers for every rocket configuration. This challenge has led him to create AVA (All Vehicle Avionics), an impressive model rocket flight computer that he intends to use on all his future rockets.

All of [Joe]’s rockets feature active stabilization and guidance, and comprehensive telemetry using a variety of sensors. On the board there are three separate microcontrollers connected over I2C or SPI, each with its own micro USB port. The two smaller microcontrollers are both ATSAMD21s, also used on the Arduino Zero. The first is used for GPS and inertial navigation, and uses data from onboard and external sensors like the two IMUs (one is a backup), GPS and barometer to estimate the rocket’s position, velocity and attitude, The second is for telemetry, and it handles all external communications via a Bluetooth modem or long range 900 Mhz radio. The main processor (MPU) is a NXP MK20DX256 (also used on the Teensy 3.2), which receives data from the other microcontrollers and handles all the real-time operations and control outputs.

[Joe] gives a very detailed overview on the board, it’s capabilities, and the reasoning behind some of his design choices in the video after the break. Most of the sensors and microcontrollers were selected partly because of his experience with them. All three microcontrollers have Arduino bootloaders, also due to familiarity with the framework. AVA is the 12th in the line of flight computers [Joe] has built, and it is clear that a lot of work and hard-earned experience went into the design. Continue reading “Advanced Model Rocket Flight Computer Reaching For The Stars” →