Propellant estimation with height

[sharpedge]

Hi ya...Does any one knw of any equation to estimate the amount of propellant burn per height climb for a spcaecraft?..doing some spacecraft review.

Cheers.

 

[pstuckey]

Weight.propellant=Weight.initial*(1-exp(-deltaV/g*Isp))

Note this equation does not account for atmospheric drag or varying g.

Peter

 

[sharpedge]

Thank you Peter, I duly appreciate your respose. My other question is how do I estimate the weight of the space craft?, from the equation you posted i wld have to knw what the space craft weight is. Is here any equation out there to estimate the weight of space craft as we do have for aircrafts?.

Also how can you relate the amount of propellant burn to the height ascent? any equation that relates the two together like we have for aircraft.( i.e. specific thrust and range)

Cheers.

 

[pstuckey]

I don't have an answer for your first question.

The answer to your second question is deltaV. For instance liftoff from Earth to LEO might be a deltaV of ~7-10 km/s (depending on the launch site and final orbit). Earth to GEO would be higher, ~12 km/sec (including transfer orbit and plane change maneuvers).

Peter