modified some default values in Pointing.py

from astropy.time import Time

class Pointing(object):

    def __init__(self, id=0, ra=0., dec=0., img_pa=0., timestamp=1621915200, sat_x=0., sat_y=0, sat_z=0, sat_vx=0, sat_vy=0, sat_vz=0, exp_time=150., pointing_type='MS'):

    def __init__(self, id=0, ra=0., dec=0., img_pa=0., timestamp=1621915200, sat_x=0., sat_y=0., sat_z=0., sat_vx=0., sat_vy=0., sat_vz=0., exp_time=150., pointing_type='MS'):

        self.id = id

        self.ra = ra

        self.dec = dec