Why Orbit the Fixed Points?

To address this question, it is important to first give an idea of why one would wish to send a spacecraft mission to the vicinity of a fixed point of the rotating earth-sun system. Here are a couple of reasons:

• Since the position of the spacecraft at a fixed point remains stationary with respect to both the earth and the sun, a data collection device such as a solar collection panel could be positioned to point in a single direction without having to make large angle corrections
• A data-transmission antenna could be pointed in the direction of the earth, also without the necessity of directional corrections

Then why orbit a fixed point instead of maintaining the spacecraft position at the point itself? There are several reasons with varying degrees of subtlety. Here is one example:

Intense radiation from the sun interferes with data transmission if the spacecraft sits directly between the earth and sun.

Orbiting fixed point L1 (shown below) at a convenient radius solves the data transmission interference problem.