Appendix 6.1

Devin Cummings

6.1.1

MATLAB File – gravity.m

%Devin Cummings

%AAE 450 Design Project -- Manned Mission to Mars

%Human Gravity Differences

R = 10:.5:2000;

%R is length of tether in meters

a = 0.38*9.8;

%a is centripetal acceleration needed to match Mars gravitational acceleration

w=sqrt(a./R);

%w is angular spin rate needed to attain desired Mars acceleration in hab in rad/sec

wrev=w./(2.*pi).*60;

%wrev is angular spin rate in rpm

figure(1)

plot(R,wrev)

xlabel('Radius of Tether (meters)')

ylabel('Angular Velocity needed to attain Mars gravity (rpm)')

title('Tether Length for Hab Module vs. Angular Velocity needed for Mars Gravity')

gtext({'To produce 0.38g:','2 rpm requires 85m tether radius','1 rpm requires 340m tether radius'})

%Gravity Gradient Calculations

gg=0.01.*9.8.*0.38./13048;

%gg=gravity gradient in 1/s^2

wggmax=sqrt(gg);

h=2;

%h is height of astronaut in meters

af=a;

%accel at feet in m/s^2

ah=w.^2.*(R-h);

%accel at head in m/s^2

percdiff=(af-ah)./af.*100;

%percdiff is percent difference between head and feet

figure(2)

plot(R,percdiff)

xlabel('Radius of Tether (meters)')

ylabel('Percent Difference in Gravity between Head and Feet (%)')

title('Tether Length for Hab Module vs. Percent Difference of Gravity between Head and Feet')

%Coriolis Acceleration (ac) - should not exceed 0.25*centripetal acceleration (a)

v=1;

%v is velocity of astronaut walking inside hab module

alpha=pi/2;

%alpha is angle between angular velocity vector w and astronaut walking velocity v

ac=2.*w.*v.*sin(alpha);

figure(3)

plot(R,ac)

xlabel('Radius of Tether (meters)')

ylabel('Coriolis Acceleration for astronaut walking at a rate of 1 m/s')

title('Tether Length for Hab Module vs. Coriolis Acceleration felt by Astronauts')

6.1.2

MATLAB File – ssvolume.m

%Devin Cummings

%AAE 450 Design Project -- Manned Mission to Mars

%Storm Shelter Volume

r=.8;

%r is interior radius of storm shelter in meters

h=2;

%h is interior height of storm shelter

t=0.25;

%t is desired thickness of water for shielding

Vtot=pi*(r+t)^2*(h+2*t)-pi*r^2*h;

disp('Volume of Water needed to protect crew is');

disp(Vtot);

Vwat=5.5

%Vwat is volume of water being taken

Vextra=Vwat-Vtot

%Vextra is extra wash water

hextra=Vextra/(pi*(r+t)^2);

%hextra is extra height on top of storm shelter to contain left over water

htotal=h+2*t+hextra;

disp('Total height of storm shelter is');

disp(htotal);

diamtot=2*(r+t);

disp('Outer diameter of storm shelter is');

disp(diamtot);

Vcheck=pi*(diamtot/2)^2*htotal-pi*r^2*h

6.1.3

MATLAB File – thermalcontrol.m

%Devin Cummings

%AAE 450 Design Project -- Manned Mission to Mars

%Thermal Control Calculations

%Spacecraft Parameters

P=3.8e26;%total power output of sun, W

Aref=396;%Reference area, m^2

Atot=831.863;%Total area, m^2

Q=500;%Dissipated power of s/c, W

E=0.6;%emittance, unitless

alpha=0.95;%apsorptance, unitless

%Other Parameters

o=5.67e-8;%Stefan-Boltzmann Constant,W/(m^2K^4)

a=0.61;%Venus planetary albedo

Rv=6051800;%Equatorial Radius of Venus, m

%Location Parameters - Closest to Sun

rv1=17.7e9;%distance from Venus, km

D1=99.7e9;%distance from Sun, km

alt1=rv1-Rv;

%Location Parameters - Closest to Venus

rv2=8000000;%distance from Venus, km

D2=108e9;%distance from Sun, km

alt2=rv2-Rv;

%%%%%%%Case 1 = closest to Sun,%%%%%%%%%%%%%%%%%%%%%

%Solar Radiation Intensity

Js1=P/(4*pi*D1^2)

%Visibility Factor

H1=alt1/Rv;

F121=1/((1+H1)^2);%V. Factor at worst case, full visibility

%Planetary Reflection Radiation

Ja1=Js1*a*F121

T1=(((alpha/E)*((Aref/Atot)*Js1)+(Aref/Atot)*Ja1+Q/(E*Atot))/o)^(1/4)

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%%%%%%%Case 2 = closest to Venus,%%%%%%%%%%%%%%%%%%%%%

%Solar Radiation Intensity

Js2=P/(4*pi*D2^2)

%Visibility Factor

H2=alt2/Rv;

F122=1/((1+H2)^2);%V. Factor at worst case, full visibility

%Planetary Reflection Radiation

Ja2=Js2*a*F122

T2=(((alpha/E)*((Aref/Atot)*Js2)+(Aref/Atot)*Ja2+Q/(E*Atot))/o)^(1/4)

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