WHAT NEEDS TO BE DONE TO THIS CODE SO IT WILL RUN??
# Calculate the velocity required to escape a circular orbit of Earth,
# depending on a user-entered orbital distance.

import math

escape_velocity_meters_per_sec = 0 # Required velocity to escape orbit
grav_constant = 6.67384e-11 # Earth's gravitational constant
earth_mass_kilograms = 5.972e24 # Mass of the Earth

radius_meters = float(input('Enter distance from center of Earth: '))
print()

if radius_meters < 6317000: # 6317 km is the average radius of the Earth
escape_velocity_meters_per_sec = 0 # No escape possible!
print('Houston, we have a problem')


else:
standard_grav_param = grav_constant * earth_mass_kilograms
escape_velocity_meters_per_sec = math.sqrt(2*standard_grav_param / radius_meters)
print('Thrust to {:.0f} m/s to escape these Earthly shackles.'.format(escape_velocity_meters_per_sec))