Make propagation faster

[astrojuanlu]

Hi! I'm the creator and lead developer of poliastro, one of spacetech-ssa dependencies. I am thrilled to see it being used in this project 😍

I noticed that predict_orbit is using .apply on a function that repeatedly calls the cowell method for a given value of elapsed_seconds:

spacetech-ssa/orbit_prediction/orbit_prediction/physics_model.py

Lines 88 to 105 in 66ac04e

	def _propagate_orbit(elapsed_seconds):
	"""Propagates the closed over orbit into the future by
	`elapsed_seconds` and returns the resulting state vector
	of the new orbit with the position measured in meters and the
	velocity measured in meters per second.
	:param elapsed_seconds: The number of seconds into the future to
	propagate the orbit to
	:type elapsed_seconds: float
	:return: The 6 element state vector of the propagated orbit
	:rtype: pd.Series
	"""
	prop_orbit = orbit.propagate(elapsed_seconds*u.s,
	method=cowell,
	ad=J2_perturbation,
	J2=Earth.J2.value,
	R=Earth.R.to(u.km).value)

spacetech-ssa/orbit_prediction/orbit_prediction/physics_model.py

Line 154 in 66ac04e

future_rows[physics_cols] = future_rows.elapsed_seconds.apply(orbit_propagator)

Instead of using Orbit.propagate, poliastro.twobody.propagation.propagate offers a lower level interface that accepts an array of times, and calls the propagator in a tight loop:

https://docs.poliastro.space/en/stable/api/safe/twobody/propagation.html#poliastro.twobody.propagation.propagate

This is just some low hanging fruit I noticed while skimming at the code, but there are probably other things that could be optimized, some of which are already in our roadmap. Would be happy to collaborate with the project :)

[calstad]

@astrojuanlu Thanks for the tip and thank you for creating poliastro. Sorry I let this issue fall through the cracks! I will take a look soon at your suggestion.