0018933 the propulsion unit, ejection of the parachute, closure of the sampling section and activation of the radio beacon. The parachute system consisted of a pilot chute, a pilot chute shroud cutter and the main canopy. The pilot chute was withdrawn from its compartment when the propulsion section was jettisoned, but remained attached by shrouds to the nose section until the latter had slowed down to a speed which would not cause damage to the main canopy. At this time the shrouds were cut and the main canopy was withdrawn from the nose section by the pilot chute shrouds, which were attached toa bag containing the large pzrachute, The front closure of the sampling unit, made by a ball joint, and the aft closure, consisting of a cone and "O-ring" seal, were closed after sampling, The radio beacon was activated at launch time so that search craft equipped with radio direction finders could locate the nose sections, Figure 2.1 shows 2 complete rocket on a launcher. Part Ais the primary motor, Part B the sustainer mector, Part C the parzchute compartment, Part D the electronics compartment and Part E the zir sampling nose section. Figure 2.2 gives the important dimensions of the diffaser-and filter in the air sampling nose section, Figure 2.3 is a view of a battery of six rockets assembled for firing. 2.2.2 Aircraft-Borne Samplers. Three different types of equipment were