Started by graduate students from the California Institute of Technology in the late 1930s, the Jet Propulsion Laboratory (JPL) was instrumental in the development of early rocket technology in the United States. After being tasked by the Army to analyze the German V2 in 1943, the JPL team expanded from focusing purely on propulsion systems to study and improve upon the myriad of technologies required for spaceflight. Officially part of NASA since December of 1958, JPL’s cutting edge research continues to be integral to the human and robotic exploration of space.
For longtime friend of Hackaday Ara “Arko” Kourchians, getting a job JPL as a Robotics Electrical Engineer was a dream come true. Which probably explains why he applied more than a dozen times before finally getting the call to join the team. He stopped by the Hack Chat back in August of 2019 to talk about what it’s like to be part of such an iconic organization, reminisce about some of his favorite projects, and reflect on the lessons he’s learned along the way.
It seems like whenever the topic of rocket science comes up, the conversation quickly shifts to that of rocket fuels. As discussed in the excellent [Scott Manley] video below the break, there are many rocket fuels that can be found in some way, state, or form at your local grocery or liquor store. The video itself is a reaction to some college students in Utah who caused an evacuation when the rocket fuel they were cooking up exploded.
[Scott] himself theorizes that the fuel they were cooking was Rocket Candy, a volatile mix of sugar and potassium nitrate that is known to go Kaboom on occasion. And as it turns out, the combination might not even be legal in your area because as much as it can be used as rocket fuel, it can also be used for other things that go boom.
So, what else at your local megamart can be used to get to orbit? [Scott] talks about different kinds of alcohols, gasses, cleaners- all things that can be used as rocket fuel. He also talks about all of the solid reasons you don’t want to do this at home.
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.
We’re delighted to see the progress on [Foaly]’s 3D-printed Cortex 2 rocket, and the latest build log is full of beautiful pictures and design details. Not only is this rocket jam-packed with an efficiency of electronics and smart design, but it almost seems out to single-handedly prove that 3D-printing is far from the novelty some think it is.
There is so much going on in the Cortex 2 that it simply wouldn’t be possible to do everything it does without the ability to make one’s own parts exactly to specification. In fact, there is so much going on that cable management is its own challenge.
Everything in the build log is interesting, but the design of the parachute system is of particular note. [Foaly]’s original Cortex rocket met it’s end when the parachute failed to deploy, and Cortex 2 is determined to avoid that fate if it can. For the parachute and any cords and anchors, a careful layout maximizes the chances of a successful deployment without anything tangling, but there are some extra features as well. The panel covering the parachute is mounted with the help of four magnets, which are mounted with opposing polarities. This provides an initial repulsing force when the door is unlocked by a servo, which should help wind immediately rush in to the opening to blow the panel away. The recovery system even has its own dedicated microcontroller and can operate autonomously; even if software for everything else crashes, the parachute will still get deployed. Locking connectors for all cables also ensure that acceleration forces don’t dislodge any contacts.
Everything about the rocket looks great, and the amount of work that has gone into the software is particularly evident. The main controller even has an interactive pre-flight checklist, which is a fantastic feature.
Liquid-fuelled rocket engine design has largely followed a simple template since the development of the German V-2 rocket in the middle of World War 2. Propellant and oxidizer are mixed in a combustion chamber, creating a mixture of hot gases at high pressure that very much wish to leave out the back of the rocket, generating thrust.
Humans love combusting fuels in order to do useful work. Thus far in our history, whether we look at steam engines, gasoline engines, or even rocket engines, all these technologies have had one thing in common: they all rely on fuel that burns in a deflagration. It’s the easily controlled manner of slow combustion that we’re all familiar with since we started sitting around campfires. Continue reading “Japanese Rocket Engine Explodes: Continuously And On Purpose”→
Rocket engines are great for producing thrust from fire and fury, but they’re also difficult to make. They require high-strength materials that can withstand the high temperatures involved. [Integza], however, has tried for a long time to 3D print himself a working rocket engine. His latest attempt involves printing an aerospike design out of metal.
The project relies on special metal-impregnated 3D printer filaments. The part can be printed with a regular 3D printer and then fired to leave just the metal behind. The filament can be harsh, so [Integza] uses a ruby nozzle to handle the metal-impregnated material. Processing the material requires a medium-temperature “debinding” stage in a kiln which removes the plastic, before a high-temperature sintering process that bonds the remaining metal particles into a hopefully-contiguous whole. The process worked well for bronze, though was a little trickier for steel.
Armed with a steel aerospike rocket nozzle, [Integza] attempts using the parts with his 3D printed rocket fuel we’ve seen before. The configuration does generate some thrust, and lasts longer than most of [Integza]’s previous efforts, though still succumbs to the intense heat of the rocket exhaust.
Overall, though, it’s a great example of what it takes to print steel parts at home. You’ll need a quality 3D printer, ruby nozzles and a controllable kiln, but it can be done. If you manage to print something awesome, be sure to drop us a line. Video after the break.
Getting started with model rocketry is relatively cheap and easy, but as you move up in high power rocketry, there are a few hoops to jump through. To be able to buy rocket motors larger than H (160 N·s / 36 lbf·s impulse) in the US, you need to get certified by the National Association of Rocketry. The main requirement of this certification involves building, flying, and recovering a rocket with the specific motor class required for the certification level. [Xyla Foxlin] had committed to doing her Level 2 certification with a couple of friends, thanks to the old procrastination monster, was forced to build a rocket with only 5 days remaining to launch data.
For Level 2 certification, the rocket needs to fly with a J motor, which is capable of producing more than 640 N·s of impulse. Fortunately [Xyla] had already designed the rocket in OpenRocket, and ordered the motor and major body, nosecone, and parachute components. The body was built around 2 sections of 3″ cardboard tubes, which are covered in a few layers of fiberglass. The stabilizing fins were laser cut from cheap plywood and were epoxied to the inner tube which holds the motor and passes through the sides of the outer tube. The fins are also fibreglassed to increased strength. For a unique touch, she covered the rocket with a real wood veneer, with the rocket’s name, [Fifi], inlaid with darker wood. The recovery system is a basic parachute, connected to the rocket body with Kevlar rope.
[Xyla] finished her rocket just in time for the trek out to the rocket range. She successfully did the certification flight and recovered [Fifi] in reusable condition, which is a requirement. There was nothing groundbreaking about [Fifi], but then again, reliability the main requirement. You don’t want to do a certification with a fancy experimental rocket that could easily fail. Continue reading “A High Power Wood Rocket In 5 Days”→