Gravity Tractor: Slow-Push Asteroid Deflection

Instead of slamming into a near-Earth asteroid, a gravity tractor simply parks a spacecraft nearby and lets its own gravitational pull tug the rock off course over years of continuous, gentle station-keeping. This simulator models the real physics — a = G·m_sc/d² acceleration imparted for the length of the mission, the resulting Δv, and how much of a miss distance that buys once the asteroid's remaining warning time runs out. Tune spacecraft mass, hover distance, mission duration and total warning time and watch the deflected trajectory pull away from Earth in real time, with the mission graded safe, marginal, or insufficient against a two-Earth-radius safety margin.