0018933 on the first two ebots, ’ 2.3.5 Rocket Developmert, The project cloud sampling rocket (see Section 2.2.1) was a new one of complex design, The main motor had been used previously on the ASP (etmospheric sounding projectile) znd the sustainer motor on the RTV (reentry test vehicle), but the nese cone and zasociited equipment had not been used 2s a component of a rocket before, Development work ¢na similiar sampling device kad been done during Operation Plumbbob, and at the end cf the cperation a satisfactory unit for land recovery kad evolved. After Plymbbob, Project 21.3, Task Unit 2, was set up for the purpose of developing a sea recovery version of the rocket fer Operation Hardtack, When Project 2.2 was established, the existing rocket contracts were exterded to provide additional units for use on this program, Because of the experimental nature cf the rocket, the sponsors cf this work, UCRL, assessed the probzbility of ebtaining any rocket data as being of the order of 50%, The development problems were the reepensibility ef Preject 21.3, but a review of their work at the Exiwetok Proving Grounds is of interest since a large portion cf Project 2.8 was directly depandent cn the evailebility of 2 suiteble rocket-borre clcud sempler. This review will also serve to previde an explanztion cf the circumstzncez which led to the cancellation of the rocket experiment pricr to Shot Ozk, .