Figuring out LEO possibility

[Tomato3017]

Hello,

I am trying to build a stack using UCD and am trying to figure out if a certain rocket has enough thrust to take the payload to LEO. Is there any kind of equations I can use if I know the Thrust and Total mass of the stack?

Also is there any way to determine how quickly a TLI-like stage of a rocket will go through its delta-v? The reason I ask this is because if it add's the dV too slowly I won't be able to reach my target orbit/escape in 1 burn and will have to do multiple ejection burns which I still haven't figured out how to do correctly.

Thanks for your time!

 

[Bj]

figure out if a certain rocket has enough thrust to take the payload to LEO. Is there any kind of equations I can use if I know the Thrust and Total mass of the stack?

From Earth to LEO, it is around 9.3 - 10 km/s according to wiki

To calculate this, you can use the (basic/easy)Tsiolkovsky rocket equation

For any such maneuver (or journey involving a number of such maneuvers):

where:
m0 is the initial total mass, including propellant.m1 is the final total mass.ve is the effective exhaust velocity. (

where Isp is the specific impulse expressed as a time period)

is delta-v.

Then your second question was;

Also is there any way to determine how quickly a TLI-like stage of a rocket will go through its delta-v?

Ok see Specific Impulse

Out of time, but somehow that relates to burn time




Oh yea and to calc hohmann transfer

Therefore the delta-v required for the Hohmann transfer can be computed as follows (this is only valid for instantaneous burns):

,

, where r1 and r2 are, respectively, the radii of the departure and arrival circular orbits; the smaller (greater) of r1 and r2 corresponds to the periapsis distance (apoapsis distance) of the Hohmann elliptical transfer orbit.
Whether moving into a higher or lower orbit, by Kepler's third law, the time taken to transfer between the orbits is:

(one half of the orbital period for the whole ellipse), where

is length of semi-major axis of the Hohmann transfer orbit.

 

[Urwumpe]

Also note: You can calculate the dV of a multistage rocket as sum of all logical stages (which means: all phases of constant structural mass). The following stages are included in the burn-out mass of the current state. For example dropping a fairing is ending a logical stage, shutting down a engine not.