The KAO Telescope

The defining feature of the KAO is, of course, that it has a hole carved out in the side of it and has a telescope mounted in the cavity (the bottom of the picture is facing towards the front of the plane).

To get a better view of the telescope, we could climb into the telescope cavity with Terry, or we could lift the telescope out of the plane with a very powerful crane.

This is the telescope without the KAO. The KAO's telescope is a conventional Cassegrain reflector with a 36-inch (91.5 cm) aperture, designed primarily for observations in the 1- to 500-micron spectral range. The telescope looks out the left side of the a ircraft at an elevation of between 35 and 75 degrees. The KAO performs astronomical observations analogous to those made in ground-based or space-based telescopes. The KAO's observing capabilities fill a unique niche in astronomical science, however. Its flight capability allows it to rise above much of the water vapor in the Earth's atmosphere (allowing observations of infrared radiation which is blocked before reaching ground-based facilities), as well as travel to almost any point on the Earth's surfac e for an observation. Between flights, the facility is ground-based, allowing systems development, maintenance, and repair.

Here is a simplified diagram of the telescope mounted inside the KAO. Light enters the top of the telescope and is reflected and focussed by the curved Primary Mirror. The light is then reflected off of the Secondary Mirror to the Tertiary Flat mirror. The Tertiary Flat mirror is just a flat mirror of polished aluminum that reflects the light of the telescope through the window of the mounting flange. The entire telescope rests on an air bearing powered by the compressors in the back of the plane. The telescope cavity and the telescope itself are kept chilled by the extreme altitude and the liquid nitrogen, also in the back of the plane.