Topics

A method was developed for performing relatively high-speed wavefront sensing and control to overcome thermal instabilities in a segmented primary mirror telescope [e.g., James Webb Space Telescope (JWST) at L2], by using the onboard fine guidance sensor (FGS) to minimize expense and...

The Ps-aerogel system [Ps is positronium (an electron-positron-hydrogen-like atom)] has been evaluated and optimized as a potential tool for planetary exploration missions. Different configurations of use were assessed, and the results provide a...

Optical hardware has been developed to measure the depth of defects in the Space Shuttle Orbiter’s windows. In this hardware, a mirror is translated such that its position corresponds to the defect’s depth, so the depth measurement problem is transferred to a mirror-position measurement problem. This is...

Aircraft-engine rotating equipment usually operates at high temperature and stress. Non-invasive inspection of microcracks in those components poses a challenge for the non-destructive evaluation community. A low-profile ultrasonic guided wave sensor can detect cracks in situ. The key feature of the...

A proposed method of automated, precise alignment of a ground-based astronomical telescope would eliminate the need for initial manual alignment. The method, based on automated identification of known stars and other celestial objects in the telescope field of view, would also eliminate...

Optical combs generated by a monolithic resonator with Kerr-medium can be used in a number of applications, including orbital clocks and frequency standards of extremely high accuracy, such as astronomy, molecular spectroscopy, and the like. The main difficulty of this approach...

A large-format hybridized AlGaN photodiode array with an adjustable bandwidth features stray-light control, ultra-low dark-current noise to reduce cooling requirements, and much higher radiation tolerance than previous technologies. This technology reduces the size, mass, power, and cost of...