Impact-Detection Experiment

A meteoroid-particle impact-detection experiment was included as one of the secondary experiments of the Explorer XIII satellite. Its main purpose was to extend micrometeoroid measurements to a low population range where few data exist. An additional purpose was to correlate with and to augment the data amassed by previous satellites employing similar experimental technique. Impact detectors having three threshold levels of momentum sensitivity, nominally 0.01, 0.1, and 1.0 gram-centimeter per second, were provided to meet these objectives.

An impact detector consists of an impact-sensitive detecting surface with an attached transducer, and signal-conditioning, impact-event counting, and count-storage circuitry. Two physical configurations of detecting surface were used. One configuration was a pair of stainless-steel plates having total geometric area of 0.142 square meter mounted on the conical portion of the satellite forward shell and used for the high and the low sensitivity impact detection. The twenty 0.005-inch-thick pressurized-cell penetration detectors were also sensitized for impact detection and formed the second type of detecting surface. This configuration had a detecting surface area taken as 0.186 square meter and was used for intermediate sensitivity impact detection.