Task 541: propagation.rs + WASM Compound-Analysis Tests

Status: DONE

Summary

Rust propagation.rs (3 new tests, 43→46)

1. circular_orbit_state properties: position at (r,0,0), velocity at (0,v_circ,0), time=0
2. elliptical_orbit_state_at_periapsis: r_p = a(1-e), v_p from vis-viva, specific energy = -μ/(2a)
3. Angular momentum conservation for elliptical orbits (e=0.7) — was only tested for circular

WASM wasm.test.ts (1 new test)

1. orbital_elements: eccentric orbit (e=0.5) at periapsis has correct radius and speed

Impact

propagation.rs now directly tests state constructor helpers and angular momentum for elliptical orbits. WASM orbital elements group expanded from 2 to 3 tests covering circular, inclined, and eccentric cases.