def test_4_target_velocities():
"""
Calculate the velocities at the starting and ending positions
"""
results = find_target_velocities(earth, mars)
assert number_fudger(results['V1'], 29.78)
assert number_fudger(results['V2'], 24.007)
def test_3_transfer_period():
"""
Find the period in seconds of the transfer orbit using Kepler's Third Law
"""
results = find_transfer_period(earth, mars)
assert number_fudger(results, 44734138.6)
assert number_fudger(results, (4.493 * 10**7))
def test_2_transfer_orbit():
"""
Find the semimajor axis of the transfer orbit
"""
a_transfer = find_transfer_orbit(earth, mars)
assert number_fudger(a_transfer, 188768611.5)
assert number_fudger(a_transfer, 188000000)
def test_7_arrival_velocity():
"""
Calculate the velocity at arrival
"""
results = find_velocity_at_destination(earth, mars)
assert number_fudger(results, 21.476)
def test_6_insertion_velocity():
"""
Calculate the change in velocity required to eject from p_start
"""
results = find_insertion_velocity(earth, mars)
assert number_fudger(results, 2.946)
def test_8_final_injection_velocity():
"""
Calculate the velocity required to inject into final orbit
"""
results = find_arrival_injection_velocity(earth, mars) * 1000
assert number_fudger(results, 2650)
def test_1_semi_major_axis():
"""
Get the semi major axis of start and finish positions
"""
results = find_semimajor_axis(earth, mars)
assert number_fudger(results['SMA Start'], 149598023)
assert number_fudger(results['SMA Finish'], 227939200)
# STEP 2
"""
Note - Step 2 isn't being tested because it is a constant
"""
# STEP 3
"""
def test_5_transfer_velocity():
"""
Calculate the velocity of the transfer orbit at periapsis
"""
results = find_transfer_velocity(earth, mars)
assert number_fudger(results, 32.731)