Example - 61 - Compute v_inf and arrival declination from flyby dates (2)

In this example, we compute the arrival v_inf and declination from a trajectory whose last flyby and arrival dates are known.

Note: This examples requires astropy and poliastro to be installed. These are not installed by default when AMAT is installed and must be installed separately using pip install astropy and pip install poliastro.

[1]:

import numpy as np
from astropy.time import Time
from AMAT.arrival import Arrival

In this example, we use the flyby dates from Option 5: Uranus Orbiter Concept with Probe presented in the NASA Ice-Giants Pre-Decadal Study Report.

[2]:

arrival = Arrival()
arrival.set_vinf_vec_from_lambert_arc(lastFlybyPlanet='JUPITER',
                                      arrivalPlanet='URANUS',
                                      lastFlybyDate=Time("2036-03-28 00:00:00", scale='tdb'),
                                      arrivalDate=Time("2043-05-17 00:00:00", scale='tdb'))

[3]:

print("Arrival v_inf vector, ICRF: "+str(arrival.v_inf_vec)+" km/s")

Arrival v_inf vector, ICRF: [-4.0742798   6.69346343  3.04912046] km/s

[4]:

print("Arrival v_inf magnitude: "+str(round(arrival.v_inf_mag, 2))+" km/s.")

Arrival v_inf magnitude: 8.41 km/s.

[5]:

print("Arrival Declination: "+str(round(arrival.declination, 2))+" deg.")

Arrival Declination: -47.88 deg.

Compare with values in page 406 of the NASA Ice-Giants Pre-Decadal Study Report.