Telescope assembly alignment simulator for SOFIA

Access to the cavity containing the SOFIA telescope will be severely limited to maintain mirror cleanliness. This will minimize mirror emissivity and extend the time between mirror cleaning/coating cycles, but precludes full access to the telescope for alignment of science instruments. Since there will be over 20 instrument change-outs per year, they must be efficient and trouble-free if SOFIA is to achieve its anticipated flight rate. A telescope assembly alignment simulator (TAAS) is being designed and built to enable verification of most mechanical, electrical, and optical interfaces between a science instrument and the telescope system. It is anticipated that an instrument will typically spend about a week on this simulator to complete its functional check-out and prepare for integration with the SOFIA telescope. This advance work on the simulator will enable the installation of science instruments onto the observatory in less than four hours. The current TAAS design and prototyping activities are described.