The particular system now being fabricated is designed for use with an Aerobee 100 rcecket and for sampling from 40 to 85 kilometers. Although the rocket was designed specifically to capture rhodium 102 particles in a particular altitude range, the system of sampling is not limited to these conditions, situation where matter of interest is contained in atmospheric air. This sampling system is applicable to any At this time it is the only system for capturing near molecular particles above balloon altitudes. Reference 1. 134 Karig, H.E., Gagnon, R.J., Bass, W.A., Analysis and Design Specifications for Cryogenically Cooled Rhodium 102 Collector, National Engineering Science Co. Report, Contract AF 19(604)-7341,