6, 7 series
First Sensor AG
The x-ray satellite NuSTAR, launched in June 2012, is equipped with three DL400 PSDs from First Sensor. The DL400s area duolateral, two-dimensional PSDs with 400mm² active area. They are used for continuous alignment of the telescope optics with respect to the sensor unit. Optics and sensors in x-ray telescopes are separated by are large distance due to the long focal length of x-ray lenses. The 10m deployable mast in the NuSTAR satellite is characterized by low weight and low costs, yet it lacks the required buckling resistance for an optical system. Tilt and torsion of the optics with respect to the sensor are therefore monitored four times each second by three lasers. They are mounted to the optics unit and aligned to the PSDs which are placed on the sensor base. Every single DL400 detector has been measured and tested extensively by engineers of the Jet Propulsion Lab. Six out of seven components have been qualified for the highest demands of space application.