import numpy as np from core_functions import *
masses = [5.972e24, 419725] u_0 = np.array([[0,0,0,0,0,0], [400000, 0, 0, 0, 7823.6, 0]])
T = 5400
delta_t = 10
u, times = ivp_RK4(u_0, T, delta_t, masses)
rx = [] ry = [] rz = []