An extensive solid state nuclear track detector array for the study of ultra heavy cosmic ray nuclei aboard the NASA Long Duration Exposure Facility (LDEF)

The Long Duration Exposure Facility (LDEF), which is scheduled to be placed in Earth orbit during 1984 by the NASA Space Transportation System (flight STS-13), will carry a large array (approx. 20 m2sr) of solid state nuclear track detector stacks. This array has been designed to study the charge spectrum of ultra heavy (Z > 30) cosmic ray nuclei, in particular those with Z > 70, by collecting a larger sample of events than that obtained in any previous exposure. Pre-flight calibration with high energy ultra heavy ions has been employed for the first time. An update on the implementation and astrophysical significance of the experiment is presented together with related detector development results. (author)