Module orbits 

Structs

OrbitalElements

Classical Keplerian orbital elements.

StateVector

Cartesian state vector in an inertial frame.

Functions

brachistochrone_accel

Required constant acceleration for a brachistochrone (flip-at-midpoint) transfer.

brachistochrone_dv

ΔV for a brachistochrone transfer (constant thrust, flip at midpoint).

brachistochrone_max_distance

Maximum reachable distance for a brachistochrone transfer at given acceleration and time.

brachistochrone_time

Transfer time for a brachistochrone transfer given distance and constant acceleration.

elements_to_state_vector

Convert classical Keplerian orbital elements to a Cartesian state vector.

exhaust_velocity

Convert specific impulse (seconds) to exhaust velocity (km/s).

hohmann_transfer_dv

Calculate ΔV for a Hohmann transfer between two circular orbits.

initial_mass

Initial (pre-burn) mass (kg) given dry mass and ΔV.

jet_power

Jet power (W) for a given thrust (N) and exhaust velocity (km/s).

mass_flow_rate

Mass flow rate (kg/s) for a given thrust (N) and exhaust velocity (km/s).

mass_ratio

Tsiolkovsky mass ratio: m₀/m_f = exp(ΔV / vₑ).

oberth_dv_gain

Effective velocity change from a burn performed at periapsis of a hyperbolic flyby.

oberth_efficiency

Fractional Oberth efficiency: (Δv_inf / burn_dv) - 1.

orbital_period

Orbital period for an elliptical orbit: T = 2π * sqrt(a³/μ)

plane_change_dv

Compute the out-of-plane ΔV required for a simple plane change maneuver.

propellant_fraction

Propellant mass fraction: 1 - 1/mass_ratio = 1 - exp(-ΔV/vₑ).

required_propellant_mass

Required propellant mass (kg) given dry (post-burn) mass and ΔV.

specific_angular_momentum

Specific angular momentum magnitude for an elliptical orbit: h = sqrt(μ * a * (1 - e²))

specific_energy

Specific orbital energy: ε = -μ/(2a)

vis_viva

Vis-viva equation: v = sqrt(μ * (2/r - 1/a))