- Thread starter
- #1

By the way, this just worked 10mins ago. I restarted Mathematica and my computer but it now insist z isn't an equation.

Code:

```
ClearAll["Global`*"];
me = 5.974*10^(24);
mm = 7.348*10^(22);
G = 6.67259*10^(-20);
\[Mu] = G*(me + mm);
re = 6378;
rm = 1737;
\[Pi]1 = me/(me + mm);
\[Pi]2 = mm/(me + mm);
x = -4671;
y = -6578;
r12 = r1 = r2 = 384400;
(*r1=Sqrt[(x+\[Pi]2*r12)^2+y^2];
r2=Sqrt[(x-\[Pi]1*r12)^2+y^2];*)
M = me + mm; vi = 8;
\[Nu] = -\[Pi]/2;
e = 1;
vi = 10.8662;
\[Gamma] = ArcTan[e*Sin[\[Nu]]/(1 + e*Cos[\[Nu]])];
vx = vi*(Sin[\[Gamma]]*Cos[\[Nu]] - Cos[\[Gamma]]*Sin[\[Nu]]);
vy = vi*(Sin[\[Gamma]]*Sin[\[Nu]] + Cos[\[Gamma]]*Cos[\[Nu]]);
rx = -4671;
ry = -6578;
rz = 0;
\[CapitalOmega] = Sqrt[\[Mu]/r12^3];
\[Mu]1 = G*me;
\[Mu]2 = G*mm;
r0 = {rx, ry, rz};
v0 = {vx, vy, rz};
s = NDSolve[{x''[t] -
2*\[CapitalOmega]*y'[t] - \[CapitalOmega]^2*
x[t] == -\[Mu]1/r1^3*(x[t] + \[Pi]2*r12) - \[Mu]2/
r2^3*(x[t] - \[Pi]1*r12),
y''[t] -
2*\[CapitalOmega]*x'[t] - \[CapitalOmega]^2*
y[t] == -\[Mu]1/r1^3*y[t] - \[Mu]2/r2^3*y[t],
z''[t] == -\[Mu]1/r1^3*z[t] - \[Mu]2/r2^3*z[t],
x[0] == r0[[1]],
y[0] == r0[[2]],
z[0] == r0[[3]],
x'[0] == v0[[1]],
y'[0] == v0[[2]],
z'[0] == v0[[3]]},
{x, y, z}, {t, 0, 1000000}];
NDSolve::deqn: Equation or list of equations expected instead of False in the first argument {0. -7.10426\[CenterDot]10^-12 (-4671)[t]==-8.63204\[CenterDot]10^-14 (-379729.+(-4671)[t])-7.01794\[CenterDot]10^-12 (4670.66 +(-4671)[t]),0. -7.10426\[CenterDot]10^-12 (-6578)[t]==-7.10426\[CenterDot]10^-12 (-6578)[t],<<5>>,False,(z^\[Prime])[0]==0}. >>
```