Trans-Lunar Injection Simulator

You are in a highly elliptical orbit around the Earth, the blue dot in the middle. The moon and sun are placed as they were on April 2, 2026, when Orion performed its trans-lunar injection burn during the Artemis II mission, in order to fly-by the moon and do a free return trajectory to the earth.

Your goal: decide how much fuel to burn (Delta-v slider), at which point in the orbit (burn position slider), and in which direction (burn direction slider) in order to do your trans-lunar injection.

This simulation aims to be "realistic" by factoring:

• the Earth's gravity
• the Moon's gravity
• the Sun's gravity
• the Earth's slightly oblate shape due to its rotation (modeled with the J2 harmonic, see the spherical harmonic model wiki article ->)
• the Sun's Radiation Pressure (if you're unaware, the photons of the Sun impact a small force on the spacecraft, see radiation pressure wikipedia article ->)

(of course, i made assumptions about various parameters of the spacecraft, and this simulation is 2D. it's not going to reflect the real world too well)

If you're interested in learning more about this simulation, I did a little write up here ->