spiceypy

import spiceypy as spice import os # A simple kernel file for demonstration # In a real application, you would download these from NAIF # For local testing, ensure naif0012.tls is in the script's directory # or specify its full path. kernel_path = os.path.join(os.path.dirname(__file__), 'naif0012.tls') if not os.path.exists(kernel_path): # This is a dummy for demonstration. You would fetch a real kernel. print(f"Warning: '{kernel_path}' not found. Please download from NAIF if this isn't a test.") # Example: You'd typically download like this (replace with actual URL and process) # import urllib.request # url = 'https://naif.jpl.nasa.gov/pub/naif/generic_kernels/lsk/naif0012.tls' # urllib.request.urlretrieve(url, kernel_path) # Load a leap second kernel (LSK) to define Ephemeris Time (ET) try: spice.furnsh(kernel_path) except spice.exceptions.SpiceyPyError as e: print(f"Failed to load kernel: {e}. Skipping calculations.") exit() # Convert a UTC string to Ephemeris Time (ET) utc_time = '2023-01-01 T00:00:00' et = spice.str2et(utc_time) print(f"UTC: {utc_time} -> ET: {et}") # Get position of Earth relative to the Sun # Observer: SUN, Target: EARTH, Reference Frame: J2000, Aberration Correction: NONE pos, lt = spice.spkpos('EARTH', et, 'J2000', 'NONE', 'SUN') print(f"Position of Earth relative to Sun (km): {pos}") # Unload all kernels spice.unload(kernel_path) # Alternatively, spice.kclear() clears all loaded kernels