It is known that the radius of the Earth is 6400km. The weight (W kg) of a body varies inversely as the square of its distance (d km) from the centre of the Earth. A space shuttle is orbiting the Earth, for which its greatest and smallest distances from the Earth surface are 4200km and 1500km respectively. When the space shuttle is the farthest from the centre of Earth, a spaceman inside weighs 22kg. How heavy is the spaceman when the space shuttle is the nearest to the centre of the Earth.