An astronaut is marooned in a powerless spaceship in circular orbit around the asteroid Vesta. The astronaut reasons that puncturing a small hole through the spaceship's outer surface into an internal water tank will lead to a jet action of escaping water vapor expanding into space. Which way should the jet be aimed so the spacecraft will most likely reach the surface of Vesta? Assume that the initial orbital radius is much larger than the radius of Vesta. (In Isaac Asimov's first published story Marooned off Vesta, the jet was oriented differently, but the ship reached the surface anyway.)