Hello and Welcome! 4CRA is a small group of people that like to fly rockets. We've been meeting out in the desert to do just that since 2014.
What is High Power Rocketry? High Power Rocketry (HPR) is a class of rockets that are propelled by H motors (and up) and/or weigh more than 1500 grams (about 3.3lbs). The lowest power H class motor, the beginning level in the high power line of motors, has about 10 times more thrust/force than the Estes D12 motor you probably used during your introduction to model rocketry.
Here's the motor class schedule for HPR: (All figures in newton seconds of thrust/force)
H 160.01 to 320
I 320.01 to 640
J 640.01 to 1280
K 1280.01 to 2560
L 2560.01 to 5120
M 5120.01 to 10,240
N 10,240.01 to 20,480
O 20,480.01 to 40,960
For comparison, an Estes D12-5 has 17ns of thrust... and that large O motor at the end of the list produces up to 40,960 ns of thrust (that's 1,936 lbs)! Even a loaded porta-pottie would do 10K with one of those under it! https://youtu.be/et4UqrkknxQ
HP rockets also commonly fly with on-board flight computers (aka altimeters) that precisely control the ejection charges to push out one or two chutes. When a HP rocket flies with two parachutes, this configuration is called Dual Deployment (DD). DD works when the flight computer ignites a black powder charge that ejects a small (drogue) chute at apogee. This small chute minimizes the drift of a HPR falling from a high apogee flight. Later the computer fires a second black powder charge at a low altitude (normally around 700 to 1000 feet) to eject a large chute. This larger chute slows the rocket down to a more suitable descent rate for a damage free landing (usually around 15 to 20 fps). Altimeters also record data, such as, apogee altitude, maximum velocity, acceleration, air temperature, flight time, etc. too. More sophisticated flight computers include GPS data transmitted to your laptop during the flight for tracking purposes.
With the higher power rocket motors, many rocketeers have flown rockets that have exceeded 20,000' agl (above ground level). A few have breached our atmosphere and pushed into space! ( Take a look at THIS )
To fly high power rockets you must be certified. Fortunately, the certification is not only easy, but fun too. Please see our "Certification" page on this site to learn a bit about what's involved in gaining your certification. Just let us know when you ready to begin your certification process; Either I, or another member, will be more than happy to help you accomplish this.
Low and mid power model (Estes type) rocket enthusiasts are most welcome to become a part of our club too. We have many low/mid power contest events all of our members enjoy competing in!
Spectators Anyone that is interested in becoming certified to fly high power rockets is welcome. Everyone planning to attend a launch is required to read and follow our Safety Protocol. This page is located under the "Safety Protocol" tab (on this page in the upper left margin of this page).
Want to fly with us? Contact one of our officers on the Membership page about becoming a member or for a Guest Pass.
Patrick Bowers (4CRA Founder)
Our 4CRA Facebook page is where we "live" between launches. ( Access to 4CRA's facebook site is limited to members ONLY. )