Question

Few years ago, on February 22, 2017, NASA announced that seven newly identified planets (Trappist-1) orbiting a nearby dwarf star offer a realistic chance to seek signs of life beyond the solar system.

These stars are around 39 light years away.

A low-cost way of sending spacecraft to these planets would be to use the radiation pressure on a square solar sail. The intensity of the sun’s electromagnetic radiation at such distances is about 3000 W/m2. Assume that the solar sail is totally reflective.

What side length of sail would be needed to accelerate a 100 Kg spacecraft toward Trappist-1 at

a=10-5 m/s2

(Hint: The force that will create such acceleration is

F=ma=100×10-5 =10-3 N

Answer 1