I’ve periodically uploaded videos of some of my rocket launches during the past year (with more to come soon, of course). Generally, my YouTube videos don’t get a ton of views. Most of them have maybe 50 or 60 views; some of the more interesting ones have about 600-700. But one video seems to have really taken off – no pun intended.
What’s fascinating to me about this is: why? This is just a twelve second video clip of a rocket launch. It’s the Darkstar Extreme rocket that I built earlier this year, and this particular flight is on a K-535 motor, a common and standard workhorse motor. This video is not very different from several others that I’ve uploaded recently. Yet suddenly and without warning, the views started to dramatically increase: as of when I’m writing this, it’s topped 94,000 views.
As a nice side effect, it’s caused my YouTube channel to gain a bunch of new subscribers. Some sizeable fraction of people who casually see this clip want to subscribe – my total number of subscribers has risen from about 30 to over 170 in the past week or so. This is awesome, from my perspective.
I’m just not sure what accounts for this sudden interest. YouTube provides some analytics and it looks like most traffic (82 percent) is coming from YouTube Shorts, which is something new YouTube rolled out: a vertical video format that’s basically meant to compete with TikTok.
Another 13 percent of viewers are finding this through their suggested videos. Very few people are finding the video by using specific search terms (e.g. rocket launch).
But it’s still mysterious: why this particular video when I have several similar ones? Why now?
If anyone has any suggested explanations, I’d definitely be interested, since I’m still relatively new to this and figuring out how it all works!
Just to follow up on my last post, I wanted to provide some additional information and the actual flight data, and briefly explain what this all means, especially for all those folks reading this who are not familiar with anything related to rockets or flight computers. And for anyone who has significant experience flying rockets, you may find the below information interesting as well, without any explanation!
As a starting point: a flight computer is basically a very small circuit board that you put inside your rocket, and it has a bunch of neat built-in gadgets to measure exactly how high the rocket went, and how fast, and what interesting events happened when. I’ll explain more below.
This is the relevant flight data for the flight I mentioned in my last post, which went over one mile high:
So what does all of this mean?
First of all, it means that the rocket flew to a maximum height of about 7,579 ft – you can see this in “maximum height.” This measurement is made by a barometer taking air pressure readings in the flight computer, starting at ground level on the launch pad, and then many times while it’s in flight. There’s also a GPS chip on this flight computer and you can see it also independently measures the height using GPS, but I’m just going to assume the lower value is more likely correct.
The flight computer also records the maximum speed, which in this case was 904 feet per second (fps), which is equivalent to Mach 0.8, or a little bit slower than the speed of sound.
The total flight time was 145 seconds (just over two minutes), and there’s a further breakdown of how long the rocket spent going up and then coming back down.
The graph is even more intuitive:
This reflects the same data described above. The black line is the easiest to understand: it represents the rocket’s actual height over time. As is generally the case (unless you experience a catastrophic failure), the rocket zooms off the launch pad extremely rapidly and hits a maximum height early (here, just over 7,500 ft, as you can see from the black units to the left side), and then after parachutes deploy, it descends more slowly.
The red line is speed (extremely high at first and then plummets quickly), and the orange or gold line is acceleration. Both of these units are off to the right side of the graph.
It’s definitely fun to build and fly a rocket, but with modern flight computers and the ability to record all kinds of really precise data, you can really geek out on this stuff. How high can I fly? How fast can my rocket go? Is it descending at the right speed, or do I need a bigger (or smaller) parachute next time? This can really help refine your building and flying skills through a trial and error process, because you have access to reliable data. And needless to say, this can also help you find your rocket if you lose it because it lands really far away out of sight. In that situation, you’ll find the GPS coordinates onboard to be incredibly useful!
The National Association of Rocketry (“NAR”) has established a “Rocket Science Achievement Award” program, which currently has three categories of awards:
- Mile Marker
- Faster Than Sound, and
- Data Downlink.
The awards are pretty straightforward: to achieve Mile Marker, you need to fly a rocket to at least 1 mile (5,280 ft), and you can get additional awards for 2 or 3 miles, or as many as you’d like, in one-mile increments. To achieve Faster Than Sound, you just have to fly a rocket at a speed that is Mach 1.0 or higher. And the Data Downlink award involves real-time telemetry for data beyond just basic altitude and acceleration.
For any of these awards, you have to have documentation of the flight data, including a copy of the data file from a commercial flight computer. If you submit this documentation and it’s accepted, you’ll be awarded a high quality printed certificate and your name will be added to the NAR website, which is pretty cool.
I recently achieved the Mile Marker award when I flew my Darkstar Extreme rocket to 7,579 ft AGL. I plan on even higher flights in the future, of course, and I’d like to try to achieve an award in each of the three categories that NAR established. The data downlink one should be the most interesting and will require a bit of creativity.
In case you’re interested, the award page is here!
You may have noticed a few recent changes to the website, and there are more in the works. I just thought I’d take a moment to explain some of the things that I’ve been doing.
First, the website now has a new domain, “improbableventures.org,” instead of the original wordpress domain, “improbableventures.home.blog.” Either one will work and you’ll be directed to the same website, but getting a custom domain was the appropriate next step.
Similarly, we created a banner for the website last year, and it’s gone through several iterations. We’re still playing around with it and are looking forward to unveiling a new logo soon, as well.
And on that note, you may ask: who is “we”? Improbable Ventures is growing, with two new members of the team. We’ll roll out a more formal announcement with additional info soon, but wanted to give everyone a preview of where Improbable Ventures is headed, and what we’ll be doing in the near future! Our team will be:
- Posting more YouTube videos to our channel, detailing high power rocket construction;
- Designing and building a high-altitude two-stage rocket, capable of flying to 100,000 ft;
- Developing our own flight computer;
- Machining aluminum parts, and building an all-aluminum rocket;
- Designing and testing a liquid fuel rocket engine;
And some additional top secret projects to be announced later!
My previous high power rocket builds have been relatively slow. Don’t get me wrong – I generally don’t procrastinate, and once I get excited about a rocket project, I dive in and don’t come up for air until it’s complete.
But my techniques are far from perfectly efficient, and there’s often a substantial amount of long-curing epoxy, and then waiting for it to cure. And then… repeat. Each cure takes hours or even needs to wait overnight, and I’m doubly and triply reinforcing everything to make sure it’s sufficiently strong. Plus I’ve only built a few larger high power rockets so far and I was inevitably much slower in the beginning.
With this L3 Fusion build, however, I was able to move at a much more rapid pace. One big reason was using a fast-curing 12 minute epoxy. You just mix the resin and hardener and get to work. With a 12 minute cure, it’s amazing how quickly you can build!
That being said, for purposes of filming every step, this was still a marathon build session. It took a couple days of nonstop construction, even though the steps themselves are pretty simple and there was nothing that I hadn’t done before. At least, in principle. The “marathon” aspect was only because of filming and trying to make the most efficient use of our time.
We did have a few minor technical difficulties. Despite an excellent studio setup with a camera and tripod, external microphone, bright lights, and so on, there were several long stretches where we captured excellent video but the audio was completely missing. This meant we had to go back and figure out what went wrong with the microphone (troubleshooting this was much more difficult than you might think) and then re-shoot some of the steps. This turned out to have a silver lining, though, because the second time through I was substantially less inept than my initial attempts. Still inept, that is, but less so.
All in all, this was a really cool project, an awesome rocket build, and a successful video shoot. As soon as we’re done with the editing and have a final product, SBR will share the video on its YouTube channel (and I’ll share it as well, on my channel). In the meantime, if you’re looking to embark on your L3 certification, I highly recommend that you consider this L3 Fusion rocket!
Once I completed my level 2 certification, I had been spending a lot of time thinking about what, exactly, I should build for my level 3 project. And more generally, how should I approach it?
Cardboard or fiberglass?
I’ve built both cardboard and fiberglass rockets, and each has advantages depending on what you’re trying to achieve. I had initially assumed any L3 project would need to be fiberglass, and I’d been looking at some very large and very heavy rockets.
Fiberglass is more durable than cardboard, and is the strongest building material aside from metal. It won’t change size based on fluctuations in temperature, and it won’t swell up or get ruined if wet. This is particularly important since the rocket parts need to slide over each other using couplers. But the primary drawback of fiberglass is that it’s really heavy.
Cardboard (especially when properly reinforced with epoxy) is still durable but more lightweight, and that is a key characteristic when you are trying to defy gravity and launch something into the air. A cardboard rocket will go a lot higher than a fiberglass rocket on the same motor.
While agonizing over this fundamental choice, a solution appeared, from out of nowhere.
Deus ex machina
I had previously met and worked with Scott Binder, the owner of Scott Binder Rocketry (“SBR”), creator of the Fusion Rocket, as well as high power rocket motors and accessories. Scott’s shop is located in Walla Walla, Washington. His flagship rocket is the Fusion, but he’s recently been developing a new, larger version of the Fusion that is specifically for L3 certification – and long story short, I agreed to do some beta testing on this rocket.
In addition to building the rocket and using it for my L3 cert, I am going to create a video tutorial with Scott for the construction of this rocket, from start to finish. I’ll link to that as soon as it’s ready.
The L3 Fusion itself is roughly 90 inches in length and a 5.5 inch diameter. With a 75mm motor mount tube, it’s capable of flying an M motor, and I plan to fly it on an Aerotech M1297 for the cert flight. The great part about cardboard is that this rocket only weighs about 22 lbs fully loaded, and it should come close to 10,000 ft. at apogee on the M1297.
The electronics bay will have two RRC3 altimeters, each powered by a 9V battery, and will use omni-directional black powder charges for separation and deployment of the parachutes during flight. The drogue chute is 24 inches and the main chute is 84 in. Descent should be less than 20 feet per second under the main chute.
There are more details forthcoming, but right now I’m excited to dive into this L3 project! I need to begin putting together a comprehensive document describing the rocket, with a lot of technical information. Later, once I begin building, I’ll include a lot of detail about the construction process and materials, with plenty of photos documenting the build step by step. And much later, once it’s complete, the most exciting part: flight!
More to come soon!