Computer Rendering of Next Mach Muncher

...And updated information. I was wrong about the projected speed. If I leave the rocket the way it is (without adding weight to the nose, or payloads), it's predicted to go 1800 ft/s! I don't want it to shred or anything, so I will definitely do something about this.

Revisiting an Old Project...

I'm not giving out too many details just yet, but I will disclose that I'm improving my supersonic design. It should be able to withstand higher airspeeds, so the motor of choice will hopefully be the 137 N-sec G80, the most powerful single use model rocket motor available. If I'm brave, I might even build a payload bay for either an altimeter, an accelerometer, or a camera...

On the simulations, this model reaches a maximum velocity of 1,700 ft/s (almost mach 1.5). Scary, isn't it? It requires VERY different construction and design. My last experience has encouraged me to try again with even more ambition than before.

I'm going to write a new post on supersonic travel soon!

Success! (Sorta)

The good news is that the rocket (I always forget to name them) didn't shred in flight! The bad news is that it wasn't recovered successfully. I think that the ejection charge severed the shock cord and the rocket fell from 4000 feet. The streamer was still in the sky for a very long time, and eventually drifted out of sight.

Did we hear a sonic boom? Well, when it was first launched I was so surprised by the high acceleration that I forgot to listen for one. But when I played the video back, I thought I heard it--two muffled "POP's"--but I'm not sure. If what I'm hearing is the sonic boom, it didn't come exactly .3 seconds after ignition, so I don't think the acceleration was quite as high as the simulation on my computer indicated. The quality of the sound is not very good on YouTube videos. What do you think? Do you hear the sonic boom?

Edit: The sound I am hearing is at about 1:32 in the video.

Supersonic Rocket

I've been working nonstop on my supersonic project, and it's starting to take shape! I've had some great breakthroughs in design and some great ideas on how I can achieve a better flight.

The goal for this project is as follows: To build a rocket that flies faster than the speed of sound and creates an audible sonic boom, built strong enough to withstand such high airspeeds, and be recovered safely after flight.

I've put all my technical ability into this project so that it might survive the high pressures of a supersonic flight.

I am building two of them, and one of them I'm adding a payload bay to so that I can include an altimeter. Then I will be able to determine altitude, velocity, and time to apogee.



Rocket Specs:

Length: 20"
Liftoff mass: 8 oz.
Total impulse: 105 N-sec type "G" motor
Projected altitude: 4,000 ft.
Maximum velocity: 1,300 ft/sec (mach 1.16)

Yesterday I thought of a way I can better my chances of hearing the sonic boom. The reason you don't usually here a boom from a rocket is because the shock wave travels out horizontally on a lateral plane above your head. So my idea is to stand farther back from the rocket and tilt the launch pad a few degrees toward the spectators. I want to aim that shock wave right at us. I'm not sure that would help at all, but I'll try it.

The first launch will be ready anywhere from two weeks to four weeks from now.

Let's pray it holds together!

Current Project: Supersonic Travel

One of my current projects involves a paper tube, a "G" motor, and a big boom. Yep, I'm going to build a model rocket that creates a sonic boom.

However, that is easier said than done... Here is the beginning of my technical report on this project:

I have discovered that it isn’t hard to design a rocket to go supersonic. I’m guessing the most challenging part of this project would be building it to withstand high airspeeds, yet still light enough to go that fast. Thus, here is the goal of this project:

Goal—To build a rocket that flies faster than the speed of sound and creates an audible sonic boom, built strong enough to withstand such high airspeeds.

To Fly Faster Than the Speed of Sound

Model rocketry is probably the only
hobby that can travel faster than the speed of sound (mach 1). But you can’t just build any old model rocket and expect it to break the sound barrier. It has to be a sleek, lightweight, high-thrust rocket. I’ve had to tweak my design several times to get it just right, and I probably will tweak it now and then in the future. However, there are 4 essential design features:

Click here to read the rest of the article...

I hope to have it finished by July of this year, just in time for the Anoka County Fair. I'll be entering a few projects in the Aerospace category of 4H, hopefully this one included.

I am pretty excited about this project, and while I only have a vague design thus far, I hope to post some more information the farther along I get on it. I may post some pictures in the next month or two as well!