Δv applied—
Miss distance—
Time to encounter—
⚠ IMPACT TRAJECTORY
Impactor spacecraft
Orbital elements
Semi-major axis a—
Eccentricity e—
Period—
Momentum transfer: Δv = β·mimpactor·vimpactor / masteroid,
β ≈ 3.6 (DART's measured ejecta-momentum enhancement, 2022). The impulse is applied
retrograde (against the asteroid's motion) at the chosen lead time, then both bodies are
propagated forward with RK4 under solar gravity (GM☉ = 4π² AU³/yr²). Earlier impacts have
more years to accumulate into a large position shift — the same "keyhole" leverage the real
DART/Hera missions exploit.