Read about rocket propulsion | 8 Discussions | Page 1

  1. granzer

    Why variable geometry nozzles are not used on rocket engines

    Why is it that variable geometry nozzles, like those found on jet engine(iris nozzles), are not used as rocket nozzle to provide better altitude compensation?
  2. G

    I 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...
  3. T

    Exhaust velocity of a fire extinguisher

    < Mentor Note -- thread moved to HH from the technical physics forums, so no HH Template is shown > Hey, For our project we have to think of an experiment that can kind of simulate a rocket. We decided to use a fire extinguisher on a kart, since its mass constantly changes (same with a rocket)...
  4. M

    B Laser thrusters

    I just had this thought while watching a video about the EM drive...basically using 2 lasers to bounce them off prisms inside an object to push the craft through space at a small but constant acceleration....could someone explain why this would not work?...please see attached image :)
  5. Carlos PdL SdT

    Airflow speed into vacuum

    I have a weird question here. At what speed does air flow from a pressurized container at one atm into vacuum (rupture in ISS for example). I was watching the Martian and I wanted to see how much deltaV Mark Wattney can get by puncturing his suit, so I did my homework and saw that the spacesuit...
  6. F

    B Newton's 3rd law & rocket propulsion (detailed explanation)

    I had someone ask me how rockets are able to accelerate in space and my initial answer was that the rocket fuel combusts and is heated into an energetic gas, the gas is accelerated out of the back of the rocket (i.e. the rocket exerts a force on the gas), then according to Newton's 3rd law, the...
  7. E

    How rockets take curved paths in space (absent gravity)

    This might have been answered before but it's something that has been bothering me. A rocket in space will move in a straight line. If I apply thrust, it still moves in a straight line unless I apply the thrust in a different direction. So unless I have rocket nozzles attached to the side...
  8. RAHIL008

    Why can't a rocket continue to travel without fuel?

    By Newton's first law of motion, every object will continue to be in state of movement or rest, until acted upon by external force. Now, why can't a rocket continue to travel after it was initially thrusted (do not know if its right word) by fuel ? like a satellite that is set in orbit with some...