An Attached Solar Sail Using Radiation Pressure to Deflect a 60-Metre Asteroid

This paper computes a solar sail of 9,000 m2, a square 94.9 m on a side at an areal density of 7.5 g per square metre, attached to a 60 m asteroid of mass 282,743,339 kg. Solar radiation pressure of 9.08e-06 N per square metre gives a force of 0.0817 N and an acceleration of 2.89e-10 m per second squared. Over 4 years the sail delivers 36.5 mm per second against a requirement of 19.8 mm per second for a 7,000 km displacement with eight years of warning, a margin ratio of 1.84 and a computed separation of 12,895 km. This is a computed study of a deflection system for planetary defence, with no targeting or weapon application. It is simulated, not measured.