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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 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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335 views

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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Issue with units for a rocket nozzle throat area problem

I'm working through How to Design, Build, and Test Small Liquid-Fuel Rocket Engines. The guide explains calculating a rocket nozzle throat area using Eq. (7): $$A_t = \frac{w_t}{P_t} \sqrt{\frac{R ...
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Calculating the height and width of a rocket for drag

While messing around with making a little rocket launch simulator, I seem to have hit a slight wall with finding the relevant information in order to calculate the width and height of the rocket for ...
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112 views

Is it possible to supply 47 tons of payload to the orbit with 5 tons of fuel?

There are 2 orbits: Circular orbit with 200km altitude Circular orbit with 800km altitude The space tug is already on the first orbit. Its dry mass is 960kg, the total mass of fuel is 5250 kg. It ...
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Trying To Understand This Characteristic Velocity To Force Problem

Having problems trying to solve part b of this problem. Rocket Propulsion Elements 8th - Chapter 2 A jet of fluid hits a stationary flat plate in the manner shown below. (a) If there is 50 kg of ...
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From the General Thrust Equation towards Tsiolkovsky, how to explain dropping these terms along the way?

The NASA Glen Research Center tutorial page Rocket Thrust Equation links to the General Thrust Equation page which starts with: Which transcribes into MathJax as: $ \ \ \ F = \dot{m}_\mathrm e ...
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631 views

Is it possible to calculate Max-Q without having to input an altitude

Is it possible to calculate max-q based on just upwards velocity instead of specially inputting a given altitude/air density? Based on this graph of Falcon 9 launches till MECO below "Air Pressure vs. ...
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Is there a maximum gravity limit for conventional rockets? [duplicate]

The "tyranny" of the Tsiolkovsky rocket equation means that more and more fuel is needed to reach higher delta-vs, and that the amount of fuel needed grows in greater than linear way. Does this mean ...
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How could asteroid 2013 ND$_1$$_5$ become a moon of Venus with the aid of rocket engines?

Notice: Although this question is similar to this one, it is different because asteroid 2012 XE$_1$$_3$$_3$ has a transitional path between Venus's Lagrangian points L5 point and L3 point, whereas ...
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Could asteroid 2012 XE$_1$$_3$$_3$ become a moon of Venus with the aid of rocket engines?

2012 XE$_1$$_3$$_3$ is an asteroid, classified as near-Earth object of the Aten group that is a temporary co-orbital of Venus. It is following a transitional path between Venus's Lagrangian points L$...
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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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1answer
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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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1answer
1k views

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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1answer
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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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239 views

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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1answer
741 views

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 ...
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Derivation of a variant of the Tsiolkovsky rocket equation which includes gravity

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, ...
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Is this a correct understanding of Tsiolkovsky's rocket equation?

When I graph the rocket equation, substituting arbitrary values for v(exhaust) and m1, so m0 because m1 - m0, the graph implies that increasing propellant mass past a certain point does not increase ...