# Questions tagged [rocket-equation]

Equation stating that the change in velocity (delta-v) of a single stage rocket is equal to the exhaust velocity times the natural log of the ratio of final to initial mass, named after Russian scientist Konstantin Tsiolkovsky.

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### Is the momentum thrust of a liquid rocket engine in a static test fire the same as in flight?

Assuming vacuum exit conditions are matched by means of a suitable ejector mechanism, is the exhaust velocity of combustion products relative to static engine the same as that of a flying rocket ...
1 vote
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### Formula for Determining Time to Perform Delta-V Burn Given Propulsion System Parameters

Question is as stated. Determining how much delta-V one needs to change orbits is pretty straight forward with the rocket equation. However, I’d like to see if there’s a way to calculate delta-V from ...
161 views

### Calculating the propellant needed for a trip from LEO to Low Mars Orbit at constant acceleration of 1g

I’ve been trying to calculate how much propellant a spaceship from Earth /LEO/ to Mars /LMO/ at constant acceleration of 1g would need. Here’s the data given: dry mass mf=100 t; g=9,81 m/s^2; Isp=...
1 vote
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### What is the equation to find how much fuel you need to reach a velocity? [closed]

Theoretically, I need to launch a rocket, and I need to find how much fuel I need to reach a velocity however I do not know the equation.
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### What does ln mean in the Delta V equation?

I am working on a project for school and can't figure out what ln means in the Delta-V equation, as in Δv = VE * ln(ML / ME). I know that Δv is Delta V, VE is ...
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### What are the Specific heat ratios of fluorine, Isopropyl Alcohol and Uranium?

I needed to calculate thrust and velocities of a rocket engine and its exhaust and in order to do that, I needed the values of Specific heat ratio(k) of Fluorine and k of Uranium and Isopropyl Alcohol....
1 vote
103 views

### Tsiolkowsky including gravity and air drag

in the classical theory Tsiolkowsky is normally explained as: $\Delta v=v_{eff}*\text{ln}\frac{m_0}{m_b}$ Then the books say, for staying in LEO one need approx. $\Delta v=7.8$ km/s But what about ...
207 views

### Where do the numbers 101,972 and 3,600 come from in terms of Thrust-Specific Fuel Consumption (TSFC or SFC)?

Online, on sites such as Wikipedia's for Specific Impulse and Thrust-specific fuel consumption, there are these units: 101,972/x g/(kN·s) and 3,600/x lb/(lbf·hr) Perhaps 3600 comes from the number of ...
121 views

### How do you calculate thrust produced by a rocket engine?

I was planning on building a water-powered rocket. I also wanted to know how high my rocket might go. Could someone help me figure out, how to calculate thrust produced by a rocket engine?