# Time Step Stability Test Configuration
# Contains bodies with different orbital periods for testing RK4 stability

[[bodies]]
name = "Mercury"
mass = 3.285e23
radius = 2.439e6
parent_index = -1
color = { r = 0.7, g = 0.7, b = 0.7 }
orbit = {
    semi_major_axis = 0.0,
    eccentricity = 0.0,
    true_anomaly = 0.0
}

# Low Mercury orbiter at 200 km altitude (MESSENGER-like)
# Period ~12 hours - most restrictive case
[[bodies]]
name = "Mercury_Orbiter"
mass = 1000.0
radius = 1.0
parent_index = 0
color = { r = 1.0, g = 0.0, b = 1.0 }
orbit = {
    semi_major_axis = 2.639e6,
    eccentricity = 0.0,
    true_anomaly = 0.0
}

[[bodies]]
name = "Jupiter"
mass = 1.898e27
radius = 6.9911e7
parent_index = -1
color = { r = 0.9, g = 0.7, b = 0.5 }
orbit = {
    semi_major_axis = 0.0,
    eccentricity = 0.0,
    true_anomaly = 0.0
}

# Io - Jupiter's moon
# Period ~1.77 days
[[bodies]]
name = "Io"
mass = 8.93e22
radius = 1.822e6
parent_index = 2
color = { r = 0.9, g = 0.9, b = 0.3 }
orbit = {
    semi_major_axis = 4.217e8,
    eccentricity = 0.0,
    true_anomaly = 0.0
}

[[bodies]]
name = "Earth"
mass = 5.972e24
radius = 6.371e6
parent_index = -1
color = { r = 0.0, g = 0.5, b = 1.0 }
orbit = {
    semi_major_axis = 0.0,
    eccentricity = 0.0,
    true_anomaly = 0.0
}

# Moon - Earth's moon
# Period ~27.3 days
[[bodies]]
name = "Moon"
mass = 7.342e22
radius = 1.737e6
parent_index = 4
color = { r = 0.7, g = 0.7, b = 0.7 }
orbit = {
    semi_major_axis = 3.844e8,
    eccentricity = 0.0,
    true_anomaly = 0.0
}