Subject : Satellite Communication and Networks

Topic : Overview of Satellite Systems, Orbits and Launching

Marks : 5M

A Solar Sail converts sunlight as a propulsion by means of a large membrane while a Solar "Power" Sail gets electricity from thin film solar cells on the membrane in addition to acceleration by solar radiation. What's more, if the ion-propulsion engines with high specific impulse are driven by such solar cells, it can become a "hybrid" engine that is combined with photon acceleration to realize fuel-effective and flexible missions

A solar sail can move forward without consuming propellant as long as it can generate enough energy from sunlight. This idea was born some 100 years ago, but it had lots of technical hurdles such as the appropriate material and deployment method for the sail. Recently, we have finally seen some prospect of using this technology practically.

The sail of the IKAROS is a huge square some 20 meters in a diagonal line, as thin as 0.0075 mm, and made of polyimide resin. On the membrane of the sail, thin film solar cells are attached as well as an attitude control device and scientific observation sensors.