Plan a simplified lunar transfer assuming you start in a geo transfer orbit.
This will result in the moon crashing into the spacecraft from behind. ------------------------------------------------------------------------ See also Constant, SS2O ------------------------------------------------------------------------
Contents
%------------------------------------------------------------------------------- % Copyright 1998 Princeton Satellite Systems, Inc. % All rights reserved. %------------------------------------------------------------------------------- hPerigee = 400; % km. Reasonable for Ariane rPerigee = hPerigee + Constant('Earth radius mean'); rGeoApogee = 42167; rLunarApogee = 384400; mu = Constant('mu earth');
Semi major axes of the two ellipses
%------------------------------------
aGeo = 0.5*(rPerigee + rGeoApogee);
aLunar = 0.5*(rPerigee + rLunarApogee);
vGeoTransfer = sqrt(mu*(2/rPerigee - 1/aGeo));
vLunarTransfer = sqrt(mu*(2/rPerigee - 1/aLunar));
deltaV = vLunarTransfer - vGeoTransfer;
Assume 20 N monopropellant hydrazine engines
%--------------------------------------------- iSp = 200; % sec mPayload = 50; % kg structuralFraction = 0.2; % Ratio of structural mass to fuel mass thrustTotal = 40; % 2 20 N engines [mFuel, mTotal, mStructure] = SS2O( iSp, mPayload, structuralFraction, deltaV ); burnDuration = deltaV*1000*mTotal/thrustTotal; disp('A simple coplanar lunar transfer') disp('--------------------------------') fprintf('Structural Fraction = %12.2f\n',structuralFraction) fprintf('Structure Mass = %12.2f kg\n',mStructure) fprintf('Payload Mass = %12.2f kg\n',mPayload) fprintf('Fuel Mass = %12.2f kg\n',mFuel) fprintf('Total Mass = %12.2f kg\n',mTotal) fprintf('Delta V = %12.4f km/sec\n',deltaV ) fprintf('Total Thrust = %12.2f N\n',thrustTotal) fprintf('Specific Impulse = %12.2f sec\n',iSp) fprintf('Burn Duration = %12.2f min\n',burnDuration/60) %--------------------------------------
A simple coplanar lunar transfer -------------------------------- Structural Fraction = 0.20 Structure Mass = 4.56 kg Payload Mass = 50.00 kg Fuel Mass = 22.78 kg Total Mass = 77.33 kg Delta V = 0.6843 km/sec Total Thrust = 40.00 N Specific Impulse = 200.00 sec Burn Duration = 22.05 min