Module constants 

Modules

mu

Gravitational parameter μ = GM

orbit_radius

Mean orbital radii (semi-major axes) for planets around the Sun. Source: NASA fact sheets Units: km

reference_orbits

Standard reference orbits.

Constants

AU_KM

1 Astronomical Unit in km (IAU 2012 exact definition)

C_KM_S

Speed of light in km/s (exact, SI definition)

G0_M_S2

Standard gravitational acceleration at Earth’s surface (m/s²). Used to convert specific impulse (Isp in seconds) to exhaust velocity. Source: NIST/CODATA