CoCalc Shared FilesASYS 631 - Spacecraft Engineering / Homework-Lab_02 / HW-Lab_02.sagews
Author: Jordan Ziegler
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################# Lecture Question 1 #################### Re = 6378.1366; #Radius of Earth in km a = 6828.; #Given semi-major axis in km Xd = 0.81; Xe = 0.57; Pe = 1150; Pd = 1150; P = (1.6586690213e-4)*a^(3/2); #P in minutes (from equation C-19 of SME) print 'The period is: ', P, 'minutes'; MAX_Te = P*arcsin(Re/a)/(RealField(30)(pi)); #From equation C-37 (a little confused on units here) print 'The maximum eclipse is: ', MAX_Te, 'minutes'; Td = P - MAX_Te; print 'Td: ', Td, 'minutes'; Psa = ((Pe*MAX_Te/Xe) + (Pd*Td/Xd))/(Td); print 'Psa: ', Psa;
The period is: 93.5836548213360 minutes The maximum eclipse is: 35.918249 minutes Td: 57.665406 minutes Psa: 2676.4275
################# Lecture Question 2 #################### Id = 0.72; theta = 23.5*2*RealField(30)(pi)/360; efficiency = 0.247; Po = efficiency*1353; print 'Po: ', Po; Pbol = Po*Id*cos(theta); print 'Pbol: ', Pbol, 'watts/m^2'
Po: 334.191000000000 Pbol: 220.66072 watts/m^2
################# Lecture Question 3 #################### Peol = Pbol*(1-.0375)^4; print 'Peol: ', Peol, 'watts/m^2';
Peol: 189.37733 watts/m^2
################# Lecture Question 4 #################### Asa = Psa/Peol; print 'Asa: ', Asa;
Asa: 14.132777
################# Lecture Question 5 #################### Num_Cycles = 4*(3.156e+7)/60/P; #Sidereal year in minutes divided by period print 'The number of cycles in 4 years: ', Num_Cycles;
The number of cycles in 4 years: 22482.5585623560
################# Lecture Question 6 #################### Capacity = Pe*(MAX_Te/60)/(0.3*0.85); print 'Capacity: ', Capacity;
Capacity: 2699.7377
################# Lecture Question 7 #################### pii = RealField(30)(pi); c=3e8; #Speed of light Gains = [10, 20, 30, 40, 50, 75]; G=10.; eta=0.55; freq = 450e6; #Frequency given lamda=c/freq; for j in range(6): #Using 16-9 and 16-11 print 'Size for a gain of', Gains[j], 'is', sqrt((1/eta)*10^(Gains[j]/10.))*c/(pii*freq), 'meters, with a beam width of', 21/((freq/(1e9))*sqrt((1/eta)*10^(Gains[j]/10.))*c/(pii*freq));
Size for a gain of 10 is 0.90485194 meters, with a beam width of 51.573815 Size for a gain of 20 is 2.8613931 meters, with a beam width of 16.309072 Size for a gain of 30 is 9.0485194 meters, with a beam width of 5.1573815 Size for a gain of 40 is 28.613931 meters, with a beam width of 1.6309072 Size for a gain of 50 is 90.485194 meters, with a beam width of 0.51573815 Size for a gain of 75 is 1609.0796 meters, with a beam width of 0.029002087