The radiation pressure from the Sun has a negligible effect on the orbit of a satellite, but it does pose a problem in terms of keeping a spacecraft pointing in the appropriate orientation. Consider the GOES-N geosynchronous weather satellite shown in Figure P23.60. The satellite body is roughly a cube 2.0 m on a side with a 2.0-m by 4.0-m solar panel attached to the center of one face of the satellite’s body. Assume the center of mass of the spacecraft is at the center of the cube.
(a) Find the maximum force on the solar panel from the radiation pressure when the panel is perpendicular to the Sun’s rays.
(b) Calculate the torque on the spacecraft about its center of mass when the Sun’s rays are perpendicular to the solar panel.
(c) Estimate the moment of inertia about the center of mass of the satellite, assuming uniform density and assuming the solar panel and other projections are negligible compared with its overall mass of 900 kg.
(d) What maximum rotational velocity, in degrees per hour, will the torque produced from a 5-min exposure to full sunlight? Assume the initial angular speed is zero.