# What is Rocketry: Definition and 17 Discussions

High-power rocketry is a hobby similar to model rocketry. The major difference is that higher impulse range motors are used. The National Fire Protection Association (NFPA) definition of a high-power rocket is one that has a total weight of more than 1,500 grams (3.3 lb) and contains a motor or motors containing more than 125 grams (4.4 oz) of propellant and/or rated at more than 160 Newton-seconds (40.47 lbf·s) of total impulse, or that uses a motor with an average thrust of 80 newtons (18 lbf) or more.

View More On Wikipedia.org
1. ### Rocket Science Enthusiast Seeks Guidance and Help from Aerospace Graduates

Summary:: Looking for people who can guide me in what I want to pursue I am a 15 year old and I am an enthusiast. I have been fascinated by rocket science and I have been learning some advanced rocket science principles from the past year. I have a few Ideas for Launch Vehicles and would like...
2. ### Trouble with fluid thermodynamics and nuclear thermal rockets

Summary:: In need of help determining the exhaust velocity of a rocket nozzle given temperature and propellant molar mass Greetings and salutations! My name is Robert DeVries, world builder extraordinaire. I have come with questions in search of answers. So for the last few days I've been...
3. ### How to model a rocket equation from the derivative of momentum?

I am using the derivative of momentum (dp/dt) with Newton’s 3rd Law with the gravitational force of Earth. F - [Force of gravity on rocket] = dp/dt F - (G * m_e * m_r / r2 ) = v * dm/dt + ma F = Force created by fuel (at time t) G = Gravitational Constant m_e = Mass of Earth m_r = Mass of...
4. ### Maximizing rocket velocity - shoot fuel at once, or slowly?

I stumbled upon a 3-year old article from Wired that poses this question on rockets: Suppose I have two rockets with a mass M and fuel mass m. Rocket A shoots all the fuel at once (again, like a nuclear propulsion engine) with a fuel speed of u and rocket B shoots two blobs of fuel—first a shot...
5. D

### Finding the Coefficient of Drag for Partial Parachutes

Hey Guys, I'm on a rocket team at my university and we are attempting to figure out the force of opening acting on some of our parachutes. Typically this is done using the following equations, in particular, the one in the top right corner. This is where our trouble begins. In the Recovery...
6. S

### I Steps in designing a rocket

110kg sounding rocket that runs on apcp im trying to understand the steps to building this rocket what equations do i use to find nozzle parameters and estimated burn time etc. initial surface area for the fuel block is 5020cm^2 burn rate is .6 to 1.2mm a second fuel weight is 100kg gamma for...
7. ### Have we been able to land a rocket upright?

just an odd question that passed through my mind when i was watching a SpaceX youtube vid have we (as in humans)ever gotten a rocket to land on the ground with the nose up and the thrusters down (the same position the rocket took of in)?
8. ### Rocket meaning - definition

I was wondering if there is an actual definition given by a recognised organisation over what is meant by the word "rocket". In case there is not, I wanted to reflect upon what do we really mean when we say rockets.
9. ### Soyuz-2.1a Rocket Launch

Onboard Camera Soyuz-2.1a Rocket Launch
10. ### Rocket: Learn Rocket Science for NASA Student Launch Initiative

Hi! So I'm a college student and I was looking at trying to get together a group to compete in NASA's student launch initiative. However I don't really know anything about rocketry and don't know where to start. I'm currently studying mechanical engineering and planning on emphasizing in...
11. ### Why buy new model rocket engines?

Hi I was wondering why are model rocket engines disposable after one use? Is it because it is more economically feasible to buy a new model rocket engine than to repair a used one because the process of using a model rocket engine always ruins it? Also, if it is the case that model rocket...
12. ### Do I Need a License for Horizontal Thrust Rocket Tests?

If your rocket is of a certain power range you need a certain license. My question is of you need these license's if you are only doing horizontal thrusts tests and never actually launching it vertically into the air?
13. ### Amateur Rocketry in Orbit

Has an amateur rocket ever made it into orbit?
14. ### Goddard development of rocketry science?

what did Goddard research and test in the development of rocketry science?
15. ### Help with Newtons 2nd applied to Rocketry

This is a direct quote from nasa.gov. I understand everything up until the last equation. Can it not be written like F = mdot(v2-v1) ? Also, this equation F = d(mv)/dt is the same as this F = (m dot * V)e - (m dot * V)0 ? Or no? I understand Mass x Velocity is momentum and they want the...
16. ### Can CO2 canisters be used to power a water rocket?

Heya. Let's say I want to build a water rocket and I want to pressurise it with a 12 or 16 g CO2 canister used for powering airguns. I want to calculate the optimal size of the pressure tank, and I want to predict the thrust of this device at various nozzle diameters. So here's the...
17. ### Specific Heat Ratio - Rocketry

Hello, I know that the Specific Heat Ratio when referring to the gass(es) comming out the back of a rocket engine is the ratio of the specific heats at a constant pressure/volume and then what I am trying to do is use that to help me solve for what the theoretical force I can expect from the...