Model & Assumptions
CONIC FROM ORBITAL ELEMENTSEQ. 1
r(ν) = a(1 − e²) / (1 + e cos ν)
T = 2π √(a³ / μ)
a is the semi-major axis, e the eccentricity, ω the argument of periapsis (rotating the conic in plane), and ν the true anomaly locating the spacecraft on it. μ = 398 600.4418 km³/s².
- Two-body gravity only — no J2, drag, or third-body perturbations.
- Planar motion: inclination and RAAN are not drawn, so the conic is shown in its own plane.
- Geometry is exact for the elements shown; the marker is placed by true anomaly, not propagated in time.
- Periapsis below the surface is flagged rather than clipped — the conic is still drawn.