Echo – Landing Test #4

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Thanks for the data, Jonny!


  1. Timothy Deneffe

    Excited to see what you come up with. You have serious talent. Great job!

  2. Scott Manly

    Man! I keep scoring on the prize for the first person to watch your video all the way through!
    That, or you still think I am Scott Manley.
    (Neither this post, nor my channel are frauds. I just happen to spell my name the right way. =P)

  3. Asteris Mpampos

    It actually looks like the failed SpaceX droneship landing when it run out of fuel (besides the X-plosion)

  4. Chris MacKay

    It’s awesome to see the improvements in each video, very satisfying.

  5. Oliver Von arx

    I really hope this fly got a SERIOUS warning ⚠️ !!! 😜🤣👌

  6. Simon Williams

    Good luck my friend. Love these kind of one man projects.

  7. EngieBot V.1

    Tbh you look like elon and zuck had a baby
    Not an insult. I like these videos

  8. jim hough

    Maybe land the boosters/ core on a baseball diamond? Maybe that tall grass is catching on the legs at horizontal a little? Don’t know the dry mass of these things. Just an observation.

  9. G Malone

    Totally enjoying the progress and development process. And thanks for the somewhat technical explanations. Feel free to get a bit more techie, i.e. make us stretch. The lack of throttle control is such a key factor. Amazing that you’ve gotten so close to a soft upright landing.

  10. gmcjetpilot

    These model rocket engines are not throttle-able. Amazing you can control this. Great stuff.

  11. CapApollo

    why dont you adapt a flight controller like the Matek F405-STD that have barometer , faster F4 micro and data logging

  12. 771

    “It’s a lot easier to balance a broom stick with one hand than it is to balance a pencil” – Jeff Bezos

  13. GiantGerman

    An idea i have for you. I see your working on the RCS system too. If you need an assist with the landing, you could use the residual gas as a retro thruster. Almost like how the Soyuz capsule has retro thrusters for landing. But you could either rapidly fire the gas retro thruster or just release at a constant rate for a more precise, constant, and soft landing.

  14. Zach Bimson

    if you haven’t already, would you consider making a breakdown video to ease the learning curve/ introduction to your videos? almost like a dictionary of terms/ phrases used? cheat sheet as it were… wouldn’t expect it to be super basic nor would I need it to be but it could be really helpful to getting more people onboard with a better understanding of the more technical aspects of the videos in the past and future! Great work and thanks for sharing

  15. Charles Huse

    Great work. Maybe separate the gyros some. 1 at the tail and 1 at the nose. The greater the distance between them, the more accurate the measurement sent to the main processor and the more accurate the control response. Also, while the fixed vanes near the nose assist in your vertical orientation during descent, making them steerable via inputs from the upper gyro (along with tying the gimbled nozzle to the lower gyro) should eliminate the vast majority of the tilt in any direction, as well as minimizing lateral drift.
    I would suggest the addition of a gps unit linked into the gyros, but units that small and that accurate are limited to military usage for the time being.

  16. Detc0re

    A channel that shows content before intro/ads/10min rambling… respect



  18. Storm Silvawalker

    I would suggest that you try removing that last 10cm by allowing for impact to occur with a little bit of velocity remaining with a sub-power engine (with some very small landing pins on the legs)
    This would remove the control the thrust vectoring has after landing but it could not take back off so thats a win and would look great on video

  19. Uriah Siner

    Would dropping it from higher offer more time to passively stabilize so you can use the LIDAR without having to worry about tipping too much?

  20. Albert Farah

    Could you improve your altitude measurements by cross-referencing barometer data with simulation data during tests, then fine-tuning the simulation?

  21. C Rodriguez

    Honestly think you need just a slight amount of more weight…perhaps lead or tungsten penny or quarter on the landing leg tips.

  22. Ed Minchau

    Shouldn’t you be using curved fins, like you would on the final rocket? Ideally, you should be using the same fins that you’d be using on the final rocket, but you could just have fixed curved fins for the test vehicle. On the other hand, using flip-out fins might impart a rotation along the vertical axis as they unfold, and you’ll definitely want to test for that.
    Also, try reverse-biased LEDs as your SRB ignitors. If they’re hooked up backwards, instead of lighting up they’ll let out their magic blue smoke on the millisecond timescale.
    Finally, other people have suggested shock absorbers on the legs, which is a good idea. Having six legs instead of four would also help with the landing stability.

  23. Random Electronics and Displays

    About the drift and hover on touchdown, to what extend do ground effects influence that?
    And what is the ratio between the forces involved and the mass of the rocket?

  24. Perpel P. Pleater

    Why are you adding complexity with pop out fins and center of mass shifting (and multistage for relanding?) instead of just doing an initial iteration of going up (engine and fins on bottom) then allow the drop to flip the rocket and a separate motor in the top to do the land?
    So, just rocket up -> fall and allow flip with fins up and the heavier unspent engine down -> land

  25. K Francis

    Use aluminum foil, folded up on itself. Construct a strut attachment that deploys with the opening of each leg. As a mechanical engineer myself, if you’d like, I can design a simple to construct and lightweight configuration for you. No charge.

  26. JM Studios

    Pulling a musk
    Remember it took him years to land his first falcon nine booster. Keep trying!

  27. Scriptminer

    What you’re doing is amazing!! Love watching these regular updates, it will be great to see it work!!

  28. Xenon 5

    Nearly perfect landing, congratulations!

  29. Unfinished Sentenc

    I love you, you’ll get it next time!

  30. Thom L

    This was so close! Great job! Cant wait to see what’s next!

  31. LabRatMatt

    I recently learned from my work with model rockets that kinematic equations are not sufficient to model the trajectory of a rocket at any extended path along its trajectory. Kinematic equations are actually based on truncated Taylor series approximation of Newton’s laws of motion, and are not accurate enough, even with an infinite number of terms, to model a system with varying mass or drag. While the error is negligable in many cases, it seems that it is subtantial enough in your case to affect the rocket as it descends the last few inches. Tweaking your physics-based altitude algorithm might be adjustment needed to land the rocket exactly on the ground

  32. Marek Ryń

    Hi! Amazing job. Did you consider to use laser distance sensors for measuring altitude of the rocket during landing stage? This way you can trigger whole landing sequence more precisely.

  33. Saint Chablo

    I’d make those landing legs slightly longer to decrease pressure during landing and also increase stability. so you have a higher increase in landing the rocket.
    The grass is literally the only place you can land, so I would buy some thin material to cover the grass so it lands evenly on the ground.

  34. Laura Harris

    Wow, what an impressive effort! You clearly know what you’re talking about and present your work really well. : )

  35. Antalz

    Could you not print the landing legs in a more flexible filament, like PETG or ASA? You could also add TPU feet, which should also be able to dissipate some energy.

  36. ben

    Never thought I would see this on such a small scale! Amazing work!!

  37. kn m

    Off-road radio controlled car
    Oil damper
    If you put it on the foot of a rocket, it may not bounce

  38. Ben brazier

    When I first saw the rocket get dropped and fire up then slow down to a stop surrounded by smoke, I thought you had stuck it perfectly! So close, I cant wait to see the the rocket launch and landing tests. Brilliant project, I am rooting for you buddy…

  39. Hesynergy

    Congrats kiddo! How bout some shocks? Crush core…would be lighter…

  40. Meghashyam Malur

    I know it’s not practical, but what about a solid and flat landing pad… Once the the vehicle gets more accurate with lateral movement

  41. cokeandtwirl

    Fascinating! Love all the software stuff. Looking forward to the day you can say: LANDED IT!

  42. Darin Morgan

    Really cool project. Thanks a bunch for sharing it with us. Just side note though. I cant believe I had to go through 4 videos to get to one landing. Man this droned on for for EVER!

  43. Steen Jansdorf

    Deploy landing gear BEFORE igniting landing burn!
    – Simple thing works >8+D~

  44. TOEIC L&R

    Amazing…Its amazing that you can control rocket with “solid fuel”…!!!

  45. Aaron Tyler

    Idk about you but…
    “I’m running out of whiteboard jokes”

  46. Alexander Assies

    Congratulations, I love to see the progress you are making! keep it up, next time perfect landing? Fingers crossed!

  47. Gene Lomas

    Dude!! So close, I reckon you’ll land it next time for sure..
    Have you considered making a landing platform.. this might mitigate the bounce.. but then your only challenge would be to target said platform from 30 meters up.. (lidar??) ;)
    Looking forward to the next episode..
    Cheers from Australia :)

  48. ZayneTech

    Nice job Joe!
    Try replacing the current fins with some thicker ones that also are more aerodynamic.

  49. Hamza Abdullah

    Hey Joe, if it is really you ❤️ the comments..Please tell me (this might be a stupid question) how far off is the software for Thrust Vector Control from a one for a full-size rocket. Or rather how much if any can you scale the rocket and use the same software and procedures. Thanks.

  50. cαm

    I am the guy that you and Tim meme’d on twitter about the consistency of the burns. GG. For real tho, I think it would be crazy if you had a permanent range where you could set up fixed cameras and do some mocap/3d spatial mapping – imagine the data overload that could provide.

  51. K van der Veen

    You can always try to reduce drift in attitude and position estimation with better filtering, however with the sensors that you are using you can’t avoid having some drift (namely given your sensors your system is not observable). To avoid position drift you could maybe use optical flow with a down facing camera, but maybe you can reduce the drift enough with just filtering.

  52. daniel letterman

    Thanks and congratulations on the progress !!
    Serious question. Could you include some drop tests from a height where the acceleration is approximate to the expected acceleration prior to engine cut off ? And could this be done at the launch/landing site ? This would be to observe the expected bounce from the landing gear, as well as any “reflection” of the landing rocket from the grassy surface.
    Watching this landing, in that environment, makes it easy to believe that out of 5 drops from about 60 cm (2 feet), might result in at least 2 topples (technical term) of the equipment.
    This may already be tried in an earlier video, if so, never mind.
    Keep up the amazing work !!

  53. Warren Terrell

    Try dampeners for the landing legs

  54. Roy Ramírez

    turn off guidance system when legs are deployed, after the vibration occurs, turn on sys again

  55. Advaith s

    Use a plain surface u genius!!

  56. Slide100

    Awesome job Joe!
    As far as igniters go, maybe get together with ElementalMaker. He did igniters on his channel. Maybe more consistent if you make them yourself.

  57. SunnyWorld

    I think you got this. But i think you need to add more weight into the rocket. I think it is too light. When it drops on the ground it bounce and fall. Maybe you can add more weight into lower part of the rocket and it helps to stabilize the rocket after the first touch down.

  58. Nathan Telles-Langdon

    Just curious,
    What is your monthly budget to spend on your rockets?

  59. Gabriel DeVault

    Amazing work! I would suggest servos for vehicle release and landing gear deployment. Much more precise timing and control available, and it’s probably no more difficult… Keep it up!

  60. Kent Hansen

    I’m running out of whiteboard jokes….
    Naaah… Keep up the good work, you are so close !! … I hope all the best for it to succeed, and although I don’t understand much about rockets… ;)

  61. Filmemacher

    But is it possible? Aren’t the motors to unrepeatable and allways have a slightly diffrent power?
    edit; Just noticed you talked about it.
    Generally in R/C you can expect 5% error. But after testing, those motors have arpund 1-2%.
    Much bigger problem is setting them off

  62. spieltmit

    Amazing drawing on the board in the background by the way – dude I admire you and your work a lot! Keep it up!

  63. Ruzaini Roosfa

    Thank you for calling it a UAV instead of a drone.

  64. weiqiang yang

    You are so good at explaining things!

  65. Tom George

    Hi Joe. Great video.
    Knowing when you deploy the landing gear, can you mute or increase the dampening of the gyro signal for that short instant?

  66. Matthew Newman

    Why do you look suspiciously like Elon Musk?

  67. pinatown

    “I’m out of whiteboard jokes”

  68. Karin Herrmann

    I think the rocket will get into a Spin with those fins 2:42 . I love your content.

  69. Jake Biddlecome

    Definitely just realized you have been putting jokes on the whiteboard. Now i’ll have to rewatch all your previous vids!
    And damn good job on that landing – dunno how you have the brain power to solve all these physics issues, especially with high tolerance equipment/environment.

  70. yako

    You definitely need a new type of thrust. Those rocket motors don’t have control.

  71. Josh Gaughan

    Hey Joe I see you’re running out of whiteboard jokes

  72. Bryant Patterson

    Modify the landing legs so that they ABSORB the shock,
    Roger Garrett is on the right track

  73. chicky

    What if you eject the motor vertically through the airframe upon touchdown? Motor retention could be actuated slightly before or at touchdown (TVC System would need to be vertical obviously). Motor ignition could occur at some moment slightly later than you’re currently running, to guarantee you’ve got motor impulse remaining to stick the landing.
    It seems you’re more inclined to software side tweaks. Also my suggestion would require structural modifications that could prove unrealistic (clear space through the rocket forward of motor retention)

  74. Diego Emusici

    I think that you need to upgrado those landing legs, My reaction to the test: oh jesus crist that was close!!!

  75. Kit Sandham

    Could you use multiple lower powered engines to balance rocket motor variability?
    9 is a nice number!

  76. Kalamazoo Permaculture

    use tiny syringes as struts, that would dampen the landing gear on deployment and add impact absorption on touchdown. (coat the inside of the syringes with mineral oil to reduce the static friction coefficient)

  77. Nicolas Hoffmann

    Amazing to see the progress your making! Keep up the great work you have one of the most interesting channels on all of YouTube!

  78. Canaan Winthrop

    Magnets on the feet and a steel landing platform!

  79. MrXxplmx13

    Damn I hope this goes well
    Edit: Darn, That was soooo close! You’ll get it next time.

  80. Atmoventus

    Hi Joe,
    you should contact ST Microelectronics about their latest LSM6DSOX Sensor. They are one of the best IMUs I found on the open market.

  81. Romain Poirier

    Awesome, your so close !
    Do you take into account the change in mass while the motor is burning in your motor ignition timing calculation? Because 13cm sound like the result of the rocket descelerating to much at the end of the burn ^^.
    Anyway, congratulation !

  82. Ahmed Bafagih

    Cant believ your pulling this off. What’s next Backyard fusion energy.

  83. No Brand YT User

    Wow I’m such a better person because of watching this video. What a wonderful experience it was to sit through all roughly 17 minutes of it. I‘ll never be the same and I feel bad for everyone who didn’t watch the whole thing.

  84. David Sebesta

    “I’m out of whiteboard jokes.”
    -Joe’s Whiteboard

  85. Air Command Rockets

    Very well done Joe. That was so close on such a difficult surface. If that thing had your RCS it would have probably stood upright. Best of luck with the next tests.

  86. The Exoplanets Channel

    This video is a *master piece*

  87. Saul Reynolds-Haertle

    Sensor fusion! Slap a kalman filter on everything and it’ll probably fix a bunch of your sensor issues.
    Right now you’re using only one of your sensors at a time and cutting between them as you change flight regimes, accepting the downsides of each in turn. You don’t have to do this – there’s math that will let you throw all of your measurements into a single state estimate and gain something that’s close to having the best features of both sensors. The accelerometers continuously recalibrate the gyros, the gyros provide high-resolution angular measurements, the barometer keeps the accelerometer’s altitude information from drifting, and the accelerometers provide high-resolution altitude information. You can even manually tune the amount of noise you expect from each signal over what time scales.
    Sensor fusion also works with multiple sensors *of the same kind*. I’m impressed with the performance you’re getting given how slowly you’re observing your sensors; when I did humanoid robotics we wanted to be measuring important sensors at multiple kilohertz. But buying more expensive single sensors isn’t necessarily the only way to improve measurement frequency. You can also mount multiple low-quality sensors and throw them all into the update step of your filter. Even if you measure them all at the same time it’ll probably help you reject some vibration. The real win would be sampling them out of phase, which would give you a better chance of capturing large transients like the shock you get from dropping the legs.
    I apologize if this is something you’re already doing, or if you’ve already rejected these features because they don’t fit into project scope or available computational resources. I only watched this video and looked around on your website for a few minutes. But the part where you’re cutting between sensors entirely makes me hope that this will at least provide some paths for improvement. Good luck!

  88. Sidney King

    Joel, could you use hobby shocks like what is on RC cars for landing? They can absorb very well hard landings. Just a thought.
    Good job on your progress!

  89. elliolibasti

    “These are model rockets, like, you can´t take it too seriously” – Says the guys landing them with solids😂

  90. Timmie Siew

    Great work Joe…I have a suggestion or two…
    Unlike you, I’m not a rocket scientist but I think the landing surface is possibly another contributing factor for the vehicle tipping over…
    So, why not design a portable firm landing surface…
    Idk what is the proper term but getting a working retro system that would aid in orientation of the vehicle and possibly eliminate the sliding issue….
    Finally, for the legs, would a shock absorption system help to eliminate the bounce also. ..
    May your skies be always blue and Godspeed in you endeavors….

  91. Pauls Welt

    Congratulations to this nearly perfect landing!
    Greetings from Germany 🇩🇪

  92. Michael Skrzynski

    I teach an aerospace engineering class to high school students. We just watched this video, and they lost their minds!

  93. IceBox

    omg joe, you are so damn close to sticking it, I cant wait to see the next test!

  94. Hamza Abdullah

    So you ran out of whiteboard jokes

  95. Thomas Degenhardt

    This was so close I thought you landed it when I saw your tweet 👏🚀

  96. Jairo Leal

    “These are model rockets. You can’t take it too seriously” 😂

  97. *Insert stupid serial number here.*

    Witeboard in the backround:

  98. Roger Garrett

    Modify the landing legs so that they ABSORB the shock of landing rather than bounce back from the shock.

  99. Dustin Penner

    This is just an elaborate job application to SpaceX.


    Just as a reminder, this video was sponsored by CRAP. Concerned Rocketeers Against Parachutes. To become a CRAP yourself, go to

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