Hi everyone... I have written a simple program on matlab that will draw an orbit using ode45 to integrate the two body problem which is rddot = -mue.*rv/R^3
where:
rddot: second derivative of position vector (acceleration)
mue: Earth constant (which is known to be = 398600 km^3/s^2)
rv: position vector
R: position scalar
and my problem is the orbit will complete one circle without a problem but it will decay as it complete more than one period around the earth which I'm sure it's not the realistic case..
for example, completing one period it will look normal:
if I wanted to complete more than one period, the orbit will decay:
this picture is taken after completing 20 rotations.
someone please help if found any problem in my code or my mathematical expression,
this is my code:
r0=[-7072.7292 3150.61 123.8]';
v0=[0.4600 -4.2446 -7.312]';
y0=[r0;v0];
T=14332.25;
tspan=[0 T];
odefun=@dfdf;
[t,y]= ode45(odefun,tspan,y0);
xv = y(:,1);
yv = y(:,2);
zv = y(:,3);
plot3(xv,yv,zv)
axis equal
function [dydt]=dfdf(t,y)
rv=y(1:3);
R=norm(rv);
mue=398600.44189;
rdot=y(4:6);
rddot = -mue*rv/R^3;
dydt = [rdot;rddot];
end
