# 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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### mass of propellant required + rocket equation

I'm doing some research for a class project and I have a questions about the use of the rocket equation to get the propellant mass required. If $m_1$ is the final mass, and $m_0$ is the initial mass, ...
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### Calculations needed to full-design a rocket

Suppose I want to put a cubesat in Titan's orbit (saturn's moon). and I want to calculate what rocket power I need, how do I calculate it? Where do I begin? total mass of the probe or delta-v needed? ...
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### What would the rocket equation look like for 4 ion thrusters?

If i have 4 ion thrusters(IFM Nano Thrusters), how would the rocket equation have to be done to calculate the total delta-v?
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### What would a human rocket be like to launch a human off Mimas?

In a comment on Is there a self-rounding celestial body from which an Olympian could jump into space? @jpa made a modest proposal. What if we stacked a bunch of athletes on top of each other and ...
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### Need help with 'Tsiolkovsky's Rocket Equation': What's the maximum weight of my rockets command module?

A civilization wants to transport a command module towards another planet that is passing by. Their planet has a radius of 6'800 kilometers and weighs about 9 × 10^24 kg. They have no stronger engines ...
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### Can I exclude coriolis effects if I express a rocket launch in an inertial reference frame for a rotating earth?

I am wondering if I can exclude coriolis effects and centrifugal forces if I calculate my position relative to an inertial reference frame with as origin the launch site at the moment of lift off. ...
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### In principle, could the oxygen tanks of an 'air breathing' rocket, be filled during ascent?

(Thinking of SABRE and it's heat exchanger). As I understand it, Skylon would take off with full oxygen tanks. Putting aside engineering difficulties, is there a thermodynamic reason why a hybrid ...
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### How much higher could g be before we couldn't launch rockets? [duplicate]

Obviously having a higher gravitational acceleration makes it harder to get rockets into orbit / escape. How much stronger could earths gravity be before we would no longer be able to do the sort of ...
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### Is there a general relativistic relativistic rocket equation?

I am not to familiar with rocket equations but I know that if you combine special relativity with classical mechanics you get "c" as a speed limit. Basically the closer you get to "c" the more you ...
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### Some exercise questions about Tsiolkovsky's Rocket Equation and Thrust Equation

I have found 6 of the question's answers, but I don't know they are correct. The last question about time of the burn I get negative result -0.42 seconds. Time could not be a negative value, so I ...
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### What are Mass Rate(∆v)/∆v, Mass Rate(Isp)/Isp and time of burn(MR)/MR graphs?

I have some problems about Tsiolkovsky's Rocket Equation and some graphs. Firstly, I didn't get what I can do with Rocket Equation formulas as seen below, Also, what these three graphs try to mean? ...
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### Lightest possible orbital rocket - being launched from high altitude

Iv'e been looking into micro-satellites launches on small rockets - from what I could find the lightest rocket to deploy a satellite into LEO is the SS-520-4 which had a weight of 2600kg. If ...
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### What do the axis labels mean in this plot (apparently from Sutton 8th edition)?

In the Analytical Graphics Inc. video Low-Thrust Space Trajectory Design and Optimization the speaker Pradipto Ghosh of AGI shows a slide at around 07:00 shown ...
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### Does a high staging number have diminishing returns? Is there a way to address that mathematically?

I was reading this question: Help me understand what Farside, a ten "stage" rockoon looked like? How was it configured? Comments link to Highest stage counts in actual launchers? but here ...
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### Cooling jacket calculation issue [duplicate]

I'm going through How to Design, Build, and Test Small Liquid-Fuel Rocket Engines. The reference explains how to calculate the water flow gap for the cooling jacket that surrounds the combustion ...
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### Saturn S-IVB math

https://en.m.wikipedia.org/wiki/Saturn_V https://physics.stackexchange.com/questions/88145/why-are-rockets-so-big/88163#88163 User Asad posted a graph based on rocket science. https://i.stack.imgur....
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### How much fuel is necessary to cause delta-v?

For a project, I need to calculate how much thrust and how much fuel I need for getting into LEO. What I know: Delta-V necessary ($\approx 9.4$ km/s) Dry (empty spacecraft mass) What I don't know: ...
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### Problem in finding Propellant Mass using Rocket equation where total mass includes components dependant on Propellant Mass

Formulation - $$e^{\Delta v/v_{exhaust}} - 1=mass_{fuel}/mass_{structure}$$ $\text{let } k=e^{\Delta v/v_{exhaust}} - 1$ $$\implies mass_{fuel}= k \times mass_{structure}$$ According to SMAD (...
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### At what gravity would the rocket equation mean “cannot reach orbit from the surface”? [duplicate]

I remember reading (a long time ago in a library far, far away...) that, if Earth's gravity were that much stronger, the rocket equation (?) would mean that it were impossible to actually reach orbit ...
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### How does the Rocket Equation work when you use boosters?

For simple rockets, using the rocket equation is simple enough. $$\Delta v = v_e ln\left(\frac{m_i}{m_f}\right) = I_{sp} \ g \ ln\left(\frac{m_i}{m_f}\right)$$ plug in full and empty weights and ...
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### What is the distribution of ∆V amongst different stages of rocket flight?

How is rocket energy (or fuel consumption) is distributed between gaining orbital velocity gaining orbital height fight aerodynamic drag
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### How much thrust needed to move 6,000 kg from LEO to Lunar Orbit?

I'm trying to see how much thrust in needed to move 6,000 kg (1 surplus LK lander) from low earth orbit to lunar orbit? Even better would be to know what is currently available (off the shelf) to do ...
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### Is this equation for NEP thrust correct?

I have bolded the part that I am most interested in checking, because I am not sure if the formula is valid. I have been using Excel to find the thrust, power, etc for a NEP mission. I have been ...
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### What is Characteristic Length in a rocket engine?

The characteristic length of a engine's combustion chamber $L^*$ is defined as the ratio of the chamber volume to nozzle throat area: $$L^*=\frac{V_{chamber}}{A_{throat}}$$ Would it be correct to ...
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### Understanding Von Braun's Math: Theoretical Isp

I've just read Wernher Von Braun's Project Mars: A Technical Tale, and I'm trying to understand the math in the back. I can follow some of what he's doing, but other parts I just can't tell where his ...
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### Tsiolkovysky's Rocket Equation

As we know the rocket equation, $$\Delta v = v_e \ln\left(\frac{m_i}{m_f}\right) = I_{sp} \ g \ \ln\left(\frac{m_i}{m_f}\right)$$ So do $I_{sp}$ and the mass ratio have an inverse relation, or is ...
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### “Oh-my-god” particle drive performance

One of theories behind the origin of the esoteric oh-my-god particle was that it's exhaust of an alien spaceship. There are other explanations, some quite plausible, but let us for the purpose of this ...
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### What is the relation between the rocket equation and work, energy and power?

Say, I'm given the data typical to the Rocket equation in its many variants: $\Delta v, I_{sp}, m_f, m_0, ρ, T$ (thrust) and the likes. And someone asks me "What's the horsepower of the space shuttle ...
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### Burn spare oxidizer or carry it along?

Okay. This is not directly related to actual space travel, but it is semi-related, and definitely a practical, actual problem I face. It's about Kerbal Space Program and SSTO spaceplanes. And I ...
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### Why do some rockets not ignite all their engines during liftoff? (GSLV MK3 LV)

As I understand it, a rocket should produce its maximum thrust on liftoff. As time progresses, the mass of the rocket will decrease, but since the engines produce the same thrust, the rocket will ...
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### What was the best late Nova rocket design among the request for proposals NASA received?

According to Wikipedia (https://en.wikipedia.org/wiki/Nova_%28rocket%29) the late Nova rocket was a "larger version" of the Saturn 5, meant to send manned missions to Mars. Some requests for proposals ...
The Tsiolkovsky rocket equation is derived for a rocket under no external forces. No drag, no gravity. $$\frac{\Delta v}{v_{exhaust}}=ln\frac{m_{initial}}{m_{final}}$$ While sometimes g appears, ...