NASA is giving serious consideration to the concept of solar sailing. A solar sail craft uses a large, low-mass sail and the energy and momentum of sunlight for propulsion.
(a) Should the sail be absorbing or reflective? Why?
(b) The tota1 power output of the sun is 3.9 x 1026 W. How large a sail is necessary to propel a 10,000-kg spacecraft against the gravitational force of the sun? Express your result in square kilometers.
(c) Explain why your answer to part
(b) Is independent of the distance from the sun.