Chopter 2 PROCEDURE 2.1 PARTICIPATION The project participated in Shots Cherokee, Zuni, and Navajo (air, land and water detonations, respectively) and to a limited extent in Shot Tewa (a surface detonation over shallow water). The original intent of the project was to participate in Shots Cherokee, Zuni, and Navajo only. However, since there were four rockets (spare units) remaining at the conclusion of the Navajo event, the decision was made in the field to fire them during Shot Tewa. Forty rockets and radiation transducers with accompanying telemetering gear were used. Thirty-six rockets were fired for Shots Cherokee, Zuni, and Navajo. Twelve rockets were fired in two salvos of six during these events. The first salvo was fired at 7 minutes and the second at 15 minutes after detonation with 2-second intervals between rockets of each salvo. The four additional rockets were fired during Shot Tewa at 7 minutes after detonation with 10second intervals between them. For Shots Cherokee, Zuni, Navajo (second salvo), and Tewa, the rockets of a single salvo had different trajectories in a single vertical plane. For Shot Navajo, the six rockets of the first salvo were fired at the Same quadrant elevations but at different azimuthal angles. Trajectories were determined before the detonations on the basis of predicted winds. Some rockets were fired so as to pass through the cloud or stem into a radiation-free area while their signals were still being received, so that the contamination of the rocket could be estimated. 2.2 INSTRUMENTATION Fifty units of an especially developed rocket were produced for this operation. The radiation transducers, likewise, were especially developed. Commercial equipment served as the transmitting and receiving units. 2.2.1 Rockets. Prior to the acceptance of the proposal for this project, there was no singlestage, solid-fuel rocket that could attain an altitude of 100,000 feet when launched from sea level. Design, fabrication, and testing of the rocket was accomplished by Cooper Development Corporation, who also had the responsibility for lauaching the rockets and recording their data in the field. The result was a 6,-inch diameter by approximately 12-foot-long rocket capable of attaining a maximum altitude of about 200,000 feet or a maximum range of about 230,000 feet. The radiation detector and telemetering transmitter were located in the ogive (head assembly). Figure 2,1 is a schematic drawing of the rocket. This rocket, the atmospheric-sounding projectile (ASP), was a ground-launched ballistic missile using a Solid fuel. The single-grain propellant consisted of a stabilized ammonium perchlorate oxidizer with a Thiokol base. The single-stage motor had q total impulse of 31,000 lb-sec and a burning time of 5.8 secunds. The burnout velocity of the rocket was approximately 5,400 ft/sec. The prelaunch weight was 245 pounds with a burnout weight of 93 pounds. Rockets were launched from a simple rail-type launcher employing a zero-tipoff system. Figure 2.2 shows one set of rockets on their launchers at Site How. In this zero-tipoff launching System, as a rocket moves forward, it is supported on the rail by two launching shoes. As the forward shoe leaves the front of the rail, it drops free of the rocket, and the after shoe is sheared off by a block on the launcher rail, permitting the rocket to continue to move parallel to the rail without tipoff error. 13