Solid state detector package for the Mars laser transponder

We are presenting the concept, design and construction of an all solid state photon counting detector package for the laser transponder operating on the surface of the planet Mars. The Earth-Mars laser transponder experiment is proposed by NASA to provide range measurements to the Mars planet with decimeter accuracy. To detect the optical pulses at the Mars side of the transponder link, the photon counting detector with nanosecond timing resolution is required. The solid state photon counter based on silicon avalanche photodiode has been selected for its unique properties just suitable for the Mars surface environment: low operating voltage, low power consumption, low sensitivity to radiation. The concept of the detector enables to avoid any analog signal processing - amplification and discrimination, which are usually both temperature dependent and power consuming. The detector is based on the space qualified components.