Maximum delta-v of a rocket engine

[yrjosmiel]

So I was browsing wikipedia when I encountered:

What does this exactly mean? How does one calculate for this?

<< Adding link to the table >> https://en.wikipedia.org/wiki/Spacecraft_propulsion#Table_of_methods

 

[mfb]

Find the exhaust velocity, then make reasonable assumptions about the dry mass fraction and use the rocket equation.

 

[yrjosmiel]

Find the exhaust velocity, then make reasonable assumptions about the dry mass fraction and use the rocket equation.

So it's more or less an estimate?

 

[mfb]

Sure.

 

[donpacino]

So it's more or less an estimate?

Something cool about engineer. A lot of "measurements" are really just estimates.

Look at gps guidance in your car.

 

[etudiant]

Note that tether propulsion does not conform to the rocket equation at all.
For hybrid rockets, the mass fraction is critical, as in most cases a solid fuel is burned using an injected oxidizer.
The fuel loses integrity once 80 or so percent have burnt, which kills the mass fraction.