My second order ODE explodes

Specific Domains Modelling & Simulations
2

Ahh I forgot the ‘*’:

function fn2!(ddR,dR,R,p,t) 
    ddR[1] = R[1] *-μ/r^3 # r̈x = rx * -μ/(|r|^3)
    ddR[2] = R[2] *-μ/r^3 # r̈y = ry *  -μ/(|r|^3)
end

image