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.
No mentioning of BS.space?
Thank you. I was wondering too
I’ll assume you mean https://bps.space/ – yeah – that guy seems to be a better youtuber than a rocket builder. His videos are highly enjoyable, but seems to milk things for views. Guess that’s the day and age we live in.
Pay people for views, get people milking views
A dude with a degree in music production working as a wedding videographer gets inspired to learn about rocketry, learns to code, learns about control algorithms, learns about CAD/CAM, designs his own flight computers, designs and tests thrust vectoring motor mounts, designs and tests solid rocket throttling scheme, learns to machine parts, designs and builds motor test stand, formulates and tests solid rocket propellant, gets high power rocket certification, learns CFD, learns about transonic and supersonic aerodynamics, designs, builds and integrates all major components of a high performance rocket – so you can shit on the fact that he makes entertaining videos and shows his failures. Bravo.
-Slow- -clap-
Amen brother.
https://www.youtube.com/watch?v=SH3lR2GLgT0
Wow, nice achievement. Cool project!
That is quite the achievement and that kid is definitely going places
Is it amazing that they are doing this with solid rocket engines or is it just my lack of rocket knowledge?
It is amazing. Because with solid motors you have no throttle control at all, it’s just fire and let it burn out.
I’m not sure if you are even allowed to make any other type of engine for hobby purposes.
You can, but at that point your choices are a) toxic/dangerous hypergolics (i.e. RFNA) that get really expensive really fast and you need to deal with hazmat concerns/etc that are non-trivial even for large companies or b) Cryogenic, e.g. liquid oxygen, liquid methane, etc. That and liquid fuel injection into a combustion chamber is non-trivial (mixing, injector spacing/sizing), as are the pumps to deliver the fuel at a sufficient rate. And if you want to post any of that to youtube, you’re going to start running into export restrictions if you’re in the US as well, as I believe (I could be wrong here) turbopump fuel delivery systems are export controlled for the simple reason of because missiles.
Hybrid rockets are also an option, as far as I know. Obtaining some types of solid rocket fuels, as well as liquid oxidizers such as nitrous oxide, shouldn’t be too troublesome in the US (may be different elsewhere).
What about those CO2 cartridges you use to inflate bike tires? Heavy, but rate adjustable and you only need propulsion for the last few seconds.
Yeah hypergolics are incredibly disgusting, would be a blessing for the descent motor to be something relatively wholesome like aluminum oxide or some other solid fuel
Throttleable solids are actually a thing. Aerojet (pre-AJR) tested one back in the 60s (https://www.aerospaceprojectsreview.com/blog/?p=3763) where throttling and shutoff was achieved via a moveable nozzle throat plug. Simple shutoff-and-restart can be achieved via a rear plug vent (drop internal pressure to ambient/vacuum and combustion stops until the casing is resealed and reignited). Then there’s the more boring throttle method of multiple independent grains that can be fired sequentially to give you PWM-like throttling (used by the Dragon missile to steer in flight).
I’m amazed by this too.
yeah my first thought from the headline was ‘well, sure, why not, once you invent a throttle-able engine of course you could eventually get it to land’. why shouldn’t one person in a garage replicate at small scale the early work of armadillo aerospace? doing it with those standard solid motors is a totally different game!
Nope, it’s quite amazing to not only do all the requisite math and engineering for this but also make it account for a propulsion system you can’t throttle or turn off.
The complementary filter bit is a good reminder about trying simpler options before diving in to a complex solution to a problem. If I was facing the altitude error issue, I’d probably go straight down the rabbit hole of system id and kalman filters. The designer saved himself a ton of time and heartache by just using a simple option and seeing if it worked well
Very impressive for a high-schooler!! (or even a non-high schooler) Extra impressive for doing it with a solid rocket motor with no throttle control! Kudos young man!!
The Chinese space program is still trying to make their SpaceX clone work. This kid did it on his own. Great job for him.
SpaceX should hire him straightaway
I think Boeing needs the help more than SpaceX!
This is without question the most impressive accomplishment by someone his age I have ever seen. He climbed a cliff NASA has not climbed. I strongly suspect that when he retires, long after I’m gone, he will be listed in history alongside Goddard and Von Braun.
The range of things he had to master is huge. Perhaps the most impressive part is he did it on a budget that was far less than a week’s wages for a single member of Musk’s team.
Wow!
Technically NASA has landed retrorockets successfully on multiple planets, just not Earth.
https://www.youtube.com/watch?v=GcEddXYU-Pg
Whatabout this?
Tangentially related .. my son was is a model rocket club in high school. I was a co-sponsor of the club (I’m a teacher). At one of the meetings, my son starts talking about how it would be cool to design and build a guidance system for his rocket…
We dissuaded him of the idea.
Are there any legal restrictions on speech in Kapoor’s country that might penalize him for publicly sharing his designs and experiences? Securely anonymizing photographs and videos is very difficult (especially outdoors, but even indoors), and he also seems to have shared a significant amount of other personally identifiable information.
This video could be a fake generated with help of AI. The rocket seems unreal. Has anyone prooved that it is real?