3I/ATLAS is on a hyperbolic trajectory, meaning it is not bound to the Sun and is moving through our Solar System only once. Because it's an interstellar object, its orbit is open and extremely steep, giving it far more kinetic energy than a normal comet. Spacecraft launched from Earth are designed for elliptical orbits, not for chasing an object that is literally escaping the Solar System. This fundamental orbital mismatch is the first, and biggest, barrier.