Orthogonal Mirror Telescopes for X-ray Astronomy.

Crossed mirror telescopes are presented as an alternative to the present telescope systems used in x-ray astronomy. These instruments generally have a higher x-ray collecting efficiency but a poorer angular resolution than the more conventional paraboloid-hyperboloid telescopes. They also can be made more easily and quickly as was demonstrated by a recent rocket flight that used a simplified mirror design with only one-dimensional focusing.