{ "cells": [ { "cell_type": "markdown", "id": "30424983-2b30-44b5-b3b1-b97999fe49de", "metadata": {}, "source": [ "### Lookup Tables\n", "Until now we have performed what we call \"live\" calculations.\n", "This means that at each epoch of interest we have requested the spacecraft position, attitude, the position of the sun, the spacecraft distance from the Sun, etc. \n", "\n", "For some calculations, e.g., involving tight time sampling, or when computing planetary radiation (see below) this approach might just be too computationally expensive to be acceptable. \n", "This is why we introduce the concept of the _Lookup Table of Normalized Geometry Vectors_ (**LUT**)\n", "\n", "The fundamental concept behind it is that since we can write radiative accelerations as:\n", "\n", "