Merge pull request #1567 from DhruvJ22/src_constants_mean_elements

Added GM of various moons and mean distances of multiple systems

src/poliastro/constants/general.py

@@ -49,6 +49,15 @@
     "GM_neptune",
     "GM_pluto",
     "GM_moon",
+    "GM_phobos",
+    "GM_deimos",
+    "GM_europa",
+    "GM_ganymede",
+    "GM_enceladus",
+    "GM_titan",
+    "GM_titania",
+    "GM_triton",
+    "GM_charon",
     "M_earth",
     "M_jupiter",
     "M_sun",
@@ -239,6 +248,114 @@
     system="si",
 )
 
+# NASA. (n.d.). Planetary satellite physical parameters. NASA.
+# from https://ssd.jpl.nasa.gov/sats/phys_par/sep.html
+GM_phobos = Constant(
+    "GM_phobos",
+    "Phobos gravitational constant",
+    0.0007087,
+    "km3 / (s2)",
+    0.0000006,
+    "NASA Planetary Satellite Physical Parameters",
+    system="si",
+)
+
+# NASA. (n.d.). Planetary satellite physical parameters. NASA.
+# from https://ssd.jpl.nasa.gov/sats/phys_par/sep.html
+GM_deimos = Constant(
+    "GM_deimos",
+    "Deimos gravitational constant",
+    0.0000962,
+    "km3 / (s2)",
+    0.0000028,
+    "NASA Planetary Satellite Physical Parameters",
+    system="si",
+)
+
+# NASA. (n.d.). Planetary satellite physical parameters. NASA.
+# from https://ssd.jpl.nasa.gov/sats/phys_par/sep.html
+GM_europa = Constant(
+    "GM_europa",
+    "Europa gravitational constant",
+    3202.71210,
+    "km3 / (s2)",
+    0.00050,
+    "NASA Planetary Satellite Physical Parameters",
+    system="si",
+)
+
+# NASA. (n.d.). Planetary satellite physical parameters. NASA.
+# from https://ssd.jpl.nasa.gov/sats/phys_par/sep.html
+GM_ganymede = Constant(
+    "GM_ganymede",
+    "Ganymede gravitational constant",
+    9887.83275,
+    "km3 / (s2)",
+    0.00017,
+    "NASA Planetary Satellite Physical Parameters",
+    system="si",
+)
+
+# NASA. (n.d.). Planetary satellite physical parameters. NASA.
+# from https://ssd.jpl.nasa.gov/sats/phys_par/sep.html
+GM_enceladus = Constant(
+    "GM_enceladus",
+    "Enceladus gravitational constant",
+    7.21037,
+    "km3 / (s2)",
+    0.00009,
+    "NASA Planetary Satellite Physical Parameters",
+    system="si",
+)
+
+# NASA. (n.d.). Planetary satellite physical parameters. NASA.
+# from https://ssd.jpl.nasa.gov/sats/phys_par/sep.html
+GM_titan = Constant(
+    "GM_titan",
+    "Titan gravitational constant",
+    8978.13710,
+    "km3 / (s2)",
+    0.00025,
+    "NASA Planetary Satellite Physical Parameters",
+    system="si",
+)
+
+# NASA. (n.d.). Planetary satellite physical parameters. NASA.
+# from https://ssd.jpl.nasa.gov/sats/phys_par/sep.html
+GM_titania = Constant(
+    "GM_titania",
+    "Titania gravitational constant",
+    226.9,
+    "km3 / (s2)",
+    4.61,
+    "NASA Planetary Satellite Physical Parameters",
+    system="si",
+)
+
+# NASA. (n.d.). Planetary satellite physical parameters. NASA.
+# from https://ssd.jpl.nasa.gov/sats/phys_par/sep.html
+GM_triton = Constant(
+    "GM_triton",
+    "Triton gravitational constant",
+    1428.49546,
+    "km3 / (s2)",
+    0.61603,
+    "NASA Planetary Satellite Physical Parameters",
+    system="si",
+)
+
+# NASA. (n.d.). Planetary satellite physical parameters. NASA.
+# from https://ssd.jpl.nasa.gov/sats/phys_par/sep.html
+GM_charon = Constant(
+    "GM_charon",
+    "Charon gravitational constant",
+    105.88,
+    "km3 / (s2)",
+    0.28,
+    "NASA Planetary Satellite Physical Parameters",
+    system="si",
+)
+
 # Archinal, B. A., Acton, C. H., A’Hearn, M. F., Conrad, A., Consolmagno,
 # G. J., Duxbury, T., … Williams, I. P. (2018). Report of the IAU Working
 # Group on Cartographic Coordinates and Rotational Elements: 2015. Celestial

src/poliastro/constants/mean_elements.py

@@ -0,0 +1,227 @@
+"""
+@author: Dhruv Jain, Multi-Body Dynamics Research Group, Purdue University
+
+This module complements constants defined in `astropy.constants` with
+mean distances between sun-planet and planet-moon systems
+
+Mean distances between the two bodies are required for CR3BP model
+CR3BP model's goal is to approximate the behavior of a satellite in an
+ephemeris model. Thus, it is reasonable to us low precision mean distances values as
+for more comprehensive mission designs, the CR3BP trajectories are differentially
+corrected in an ephemeris model with high precision mean distances.
+
+Low precision mean distance between sun-planet were obtained from:
+* NASA. (n.d.). Approximate positions of the planets. NASA.,
+  from https://ssd.jpl.nasa.gov/planets/approx_pos.html
+
+Low precision mean distance between planet-moon were obtained from:
+* NASA. (n.d.). Planetary satellite mean elements. NASA.
+  from https://ssd.jpl.nasa.gov/sats/elem/sep.html
+
+All computed at J2000, except "Pluto - Charon" -> Epoch: 2020-01-01.5 TDB
+
+"""
+
+from astropy import units as u
+from astropy.constants import Constant
+
+__all__ = [
+    "mean_a_mercury",
+    "mean_a_venus",
+    "mean_a_earth",
+    "mean_a_mars",
+    "mean_a_jupiter",
+    "mean_a_saturn",
+    "mean_a_uranus",
+    "mean_a_neptune",
+    "mean_a_moon",
+    "mean_a_phobos",
+    "mean_a_deimos",
+    "mean_a_europa",
+    "mean_a_ganymede",
+    "mean_a_enceladus",
+    "mean_a_titan",
+    "mean_a_titania",
+    "mean_a_triton",
+    "mean_a_charon",
+]
+
+mean_a_mercury = Constant(
+    "mean_a_mercury",
+    "Mercury's orbit mean semimajor axis around Sun",
+    (0.38709927 * u.au.to(u.km)),
+    "km",
+    0,
+    "NASA Planetary Satellite Mean Elements",
+    system="si",
+)
+
+mean_a_venus = Constant(
+    "mean_a_venus",
+    "Venus's orbit mean semimajor axis around Sun",
+    (0.72333566 * u.au.to(u.km)),
+    "km",
+    0,
+    "NASA Planetary Satellite Mean Elements",
+    system="si",
+)
+
+mean_a_earth = Constant(
+    "mean_a_earth",
+    "Earth's orbit mean semimajor axis around Sun",
+    (1 * u.au.to(u.km)),
+    "km",
+    0,
+    "NASA Planetary Satellite Mean Elements",
+    system="si",
+)
+
+mean_a_mars = Constant(
+    "mean_a_moon",
+    "Mars's orbit mean semimajor axis around Sun",
+    1.52371034 * u.au.to(u.km),
+    "km",
+    0,
+    "NASA Approximate Position of Planets",
+    system="si",
+)
+
+mean_a_jupiter = Constant(
+    "mean_a_jupiter",
+    "Jupiter's orbit mean semimajor axis around Sun",
+    (5.20288700 * u.au.to(u.km)),
+    "km",
+    0,
+    "NASA Planetary Satellite Mean Elements",
+    system="si",
+)
+
+mean_a_saturn = Constant(
+    "mean_a_saturn",
+    "Saturn's orbit mean semimajor axis around Sun",
+    (9.53667594 * u.au.to(u.km)),
+    "km",
+    0,
+    "NASA Planetary Satellite Mean Elements",
+    system="si",
+)
+
+mean_a_uranus = Constant(
+    "mean_a_uranus",
+    "Saturn's orbit mean semimajor axis around Sun",
+    (19.18916464 * u.au.to(u.km)),
+    "km",
+    0,
+    "NASA Planetary Satellite Mean Elements",
+    system="si",
+)
+
+mean_a_neptune = Constant(
+    "mean_a_neptune",
+    "Neptune's orbit mean semimajor axis around Sun",
+    (30.06992276 * u.au.to(u.km)),
+    "km",
+    0,
+    "NASA Planetary Satellite Mean Elements",
+    system="si",
+)
+
+mean_a_moon = Constant(
+    "mean_a_moon",
+    "Moon's orbit mean semimajor axis around Earth",
+    384400,
+    "km",
+    0,
+    "NASA Planetary Satellite Mean Elements",
+    system="si",
+)
+
+mean_a_phobos = Constant(
+    "mean_a_phobos",
+    "Phobos's orbit mean semimajor axis around Mars",
+    9400,
+    "km",
+    0,
+    "NASA Planetary Satellite Mean Elements",
+    system="si",
+)
+
+mean_a_deimos = Constant(
+    "mean_a_deimos",
+    "Deimos's orbit mean semimajor axis around Mars",
+    23500,
+    "km",
+    0,
+    "NASA Planetary Satellite Mean Elements",
+    system="si",
+)
+
+mean_a_europa = Constant(
+    "mean_a_europa",
+    "Europa's orbit mean semimajor axis around Jupiter",
+    671100,
+    "km",
+    0,
+    "NASA Planetary Satellite Mean Elements",
+    system="si",
+)
+
+mean_a_ganymede = Constant(
+    "mean_a_ganymede",
+    "Ganymede's orbit mean semimajor axis around Juputer",
+    1070400,
+    "km",
+    0,
+    "NASA Planetary Satellite Mean Elements",
+    system="si",
+)
+
+mean_a_enceladus = Constant(
+    "mean_a_enceladus",
+    "Enceladus's orbit mean semimajor axis around Saturn",
+    238400,
+    "km",
+    0,
+    "NASA Planetary Satellite Mean Elements",
+    system="si",
+)
+
+mean_a_titan = Constant(
+    "mean_a_titan",
+    "Titan's orbit mean semimajor axis around Saturn",
+    1221900,
+    "km",
+    0,
+    "NASA Planetary Satellite Mean Elements",
+    system="si",
+)
+
+mean_a_titania = Constant(
+    "mean_a_titania",
+    "Titania's orbit mean semimajor axis around Uranus",
+    436300,
+    "km",
+    0,
+    "NASA Planetary Satellite Mean Elements",
+    system="si",
+)
+
+mean_a_triton = Constant(
+    "mean_a_triton",
+    "Triton's orbit mean semimajor axis around Neptune",
+    354800,
+    "km",
+    0,
+    "NASA Planetary Satellite Mean Elements",
+    system="si",
+)
+
+mean_a_charon = Constant(
+    "mean_a_charon",
+    "Charon's orbit mean semimajor axis around Pluto",
+    19600,
+    "km",
+    0,
+    "NASA Planetary Satellite Mean Elements",
+    system="si",
+)