Validity of the Mandal Diagrams

Howedar · Post by **Howedar** » 2003-12-16 11:45pm

Durandal wrote:
Howedar wrote: You are taking a given acceleration for an ISD, and it's max speed, then using that to find the mass of fuel needed to get to top speed. However, this is based on an effective exhaust velocity that you seem to have arbitrarily chosen. If we are willing to accept an exhaust velocity of, say, 99.99999c, the mass of propellant (when at rest) should be vastly less.
As the ejecta velocity increases linearly, its kinetic energy increases exponentially. In other words, it takes a lot more energy.

Naturally.