Halo

I know ever since my James Webb Space Telescope article you’ve been wondering what a Lagrange point orbit really looks like.

 

Here are a couple of pictures to clear things up.

 

The first shows the five Lagrange points with respect to the Sun and Earth. Lagrange points are locations in space where gravitational forces and the orbital motion of a body balance each other. This allows the body to remain in one place with respect to the Earth and Sun. In the diagram, the Webb telescope will be inserted into the L2 point which is about a million miles from Earth. As you can see, this location keeps the Sun and Earth always on one side of the telescope, allowing the use of just one heat shield and dramatically simplifying orbital positioning, control over the sun’s light,  and data transfer back to Earth.

 

The telescope will be in a very large orbit AROUND the L2 point, but with a very particular kind of orientation called a “halo orbit”. Basically that means the orbit will be such that it is perpendicular to the Earth-Sun orbital plane and will look like a halo over the Earth.