LEO Launch Window & COLA Screening Tool

daily Low Earth Orbit (LEO) launch opportunities from a geographic launch site into a target orbital plane

test_launch_window.m is a standalone MATLAB application that estimates daily Low Earth Orbit (LEO) launch opportunities from a geographic launch site into a target orbital plane. Optionally screens each opportunity against a CelesTrak/Space-Track-style active satellite catalog (active.txt) using Collision on Launch Avoidance (COLA) methods aligned with common operational-tool conventions (a NASA CARA-style Pc2D_Foster probability-of-collision combination, CCSDS 508.0-B-1 Conjunction Data Message field names for secondary covariance, and approximate USSTRATCOM/18 SDS screening volumes).

Coordinate transforms use the classical IAU-76/FK5 equinox chain with the full 106-term IAU-1980 nutation series (nut80.dat), CelesTrak Earth Orientation Parameters (EOP-All.txt) for UT1-UTC, and polar motion (including the TIO locator s') and nutation corrections. Frame and SGP4 helpers are the Vallado/Mahooti m-files in this folder, plus a local ITRF->GCRF reimplementation inside test_launch_window.m. Default site/orbit inputs model a real case (the Jiuquan Satellite Launch Center launching toward the Tiangong Space Station orbital plane), but every input is editable. The tool is intended for engineering analysis, mission concept studies, and educational use. It is not a certified range-safety or USSPACECOM/18 SDS flight-operations COLA product -- see Section 12.

References:

• Foster, J. L. and Estes, H. S., “A Parametric Analysis of Orbital Debris Collision Probability and Maneuver Rate for Space Vehicles,” NASA/JSC, 1992.
• Akella, M. R. and Alfriend, K. T., “Probability of Collision Between Space Objects,” Journal of Guidance, Control, and Dynamics, 2000.
• Alfano, S., “A Numerical Implementation of Spherical Object Collision Probability,” Journal of the Astronautical Sciences, 2005a.
• Alfano, S., “Relating Position Uncertainty to Maximum Conjunction Probability,” Journal of the Astronautical Sciences, 2005b.
• CCSDS 508.0-B-1, “Conjunction Data Message,” Recommended Standard, 2013.
• USSTRATCOM / 18th Space Defense Squadron, Spaceflight Safety Handbook for Operators (screening-volume conventions).
• Vallado, D. A. and McClain, W. D., Fundamentals of Astrodynamics and Applications (IAU-76/FK5 reduction, polar motion, TIO locator s′).
• http://celestrak.org/SpaceData/EOP-All.txt
• http://www.celestrak.org/NORAD/elements/gp.php?GROUP=active&FORMAT=tle