Astro-H will carry two hard X-ray telescopes. Each of these telescopes will require 1278 reflectors that reflect hard X-rays, and the manufacture of this large number of mirrors is now proceeding at a brisk pace. The manufacture of the reflectors for the first of these two telescopes (HXT1) has already been completed, and the accuracy and strength of its mirror housing are now undergoing verification.
The housing is a cylindrical-shaped container inside of which a number of bars radiate from the center. The bars have all had grooves notched into them, and the ends of the reflectors will be inserted into these grooves and fastened firmly to the bar. In order for these reflectors to provide as clear an image as possible, tests are underway to “fine-tune” the placement of both the reflectors and the bars. The “tuning” of the bars must be carried out with a precision of 10 microns or better. If the bars move from their proper settings, the mirrors will also shift, which can result in a large distortion of the X-ray images. For this reason it is of critical importance that these bars do not move during the strong vibrations that will occur during the launch of the satellite. Even though the bars are firmly fastened to the housing, there is still the possibility of them shifting from their positions. This is a very difficult problem. Even though the system to fasten the bars has undergone many improvements, a housing was specially prepared at the end of March for use in vibration tests where at last the requirements were successfully met. The picture demonstrates a vibration test, where both the housing and the test preparations have been completed. Finally, the first telescope system will be assembled and properly set.