Design review is becoming a basic requirement during the design and development of military systems. The main purpose of the design review is to increase the system's inherent and operational reliability. The major portion of this paper is the result of reliability's effort to comply with Paragraph 3.6 of NPC 250-1 Reliability Program Provisions for Space Contractors. The design review to be discussed is a reliability circuit design review with emphasis placed on what should be reviewed and the review techniques employed. The basic circuit design review prerequisites, component parts and their ratings, are discussed at the beginning of this paper. The remainder deals with the organization and reviewing of circuits. The review items include worst-case circuit performance, component applications, failure mode analysis, noise rejection, electrical stress, and the determination of component temperatures. Many examples are included to illustrate how each item was accomplished. This paper is intended not only to give the reliability analyst cognizance of basic design problems and troublesome circuits, but also, to aid him in formulating a design review program.
Because of the increased reliability required of rocket systems in their more recently assigned missions, previously acceptable design features must be reappraised ad refined. In the region of rocket engine system stability, the probles is centered in two areas, the combustor and the propellant feed system The principal interest of this paper lies in the coupling that occurs between the feed system and combustion dynamics, often termed a "buzzing" instability then the dymics are characterized by periodic pressure oscillations in the range of 200 to 1000 cps appearing in the combustion chamber and' the feed system.
This paper deals with several selected aspects of the signal distribution in automatic checkout systems. These are: 1) The use of relay matrices as control elements; 2) The inclusion of self-checking capabilities; 3) Problems of systems integration. These aspects are not unique to automatic checkout systems. However, due to the nature of automatic checkout systems as presently being designed around digital circuitry, they find either fuller or different applications than in other types of systems. Also, while they are on the surface somewhat disconnected in nature, they tend to interrelate during the implementation of an automatic checkout system.
The Saturn S-IVB stage has a requirement for orbiting around the earth for up to 4.5 hours with approximately 60 percent of its initial propellant remaining at the end of the coast (prior to restart) . Extensive analyses must be performed to insure that this requirement is met. Both the maximum and minimum heat transfer rates are important because the maximum rates affect the hydrogen boiloff losses and thus the initial propellant loading requirements. The minimum rates are important because the boil off gases are used to maintain a minimum axial thrust level by venting the gases continuously through aft facing nozzles. This provides for a settling of the propellant throughout the orbital coast and alleviates the need for periodically venting the tank under zero gravity.
This paper reviews the milestones achieved with cryogenic liquid propellant rocket engines, discusses current technology improvement programs, and projects future engine designs. During the last two decades, these cryogenic rocket engines have played a major role in rocketry and achieved numerous important milestones. These engines power the Vanguard, Redstone, Thor, Atlas, and Titan I vehicles , the Saturn I and Uprated Saturn I vehicles, and will soon be employed in the Saturn V for the Apollo missions. The requirements dictated by these vehicles have necessitated growth from the 27,000-pound-thrust Vanguard engine to the 7,600,000-pound-thrust booster cluster for the Saturn V. Gains in specific impulse have also been significant. The successful application of liquid hydrogen in the Centaur and Saturn upper-stage rocket engines was a major achievement.