Rendezvous radar for the orbital maneuvering vehicle

This paper describes the development of the Rendezvous Radar Set (RRS) for the Orbital Maneuvering Vehicle (OMV) for the National Aeronautics and Space Administration (NASA). The RRS was to be used to locate, and then provide vectoring information to, target satellites (or Shuttle or Space Station) to aid the OMV in making a minimum-fuel-consumption approach and rendezvous. The RRS design is that of an X-Band, all solid-state, monopulse tracking, frequency hopping, pulse-Doppler radar system. The development of the radar was terminated when the OMV prime contract to TRW was terminated by NASA. At the time of the termination, the development was in the circuit design stage. The system design was virtually completed, the PDR had been held. The RRS design was based on Motorola's experiences, both in the design and production of radar systems for the US Army and in the design and production of hi-rel communications systems for NASA space programs. Experience in these fields was combined with the latest digital signal processor and micro-processor technology to design a light-weight, low-power, spaceborne radar. The antenna and antenna positioner (gimbals) technology developed for the RRS is now being used in the satellite-to-satellite communication link design for Motorola's Iridium telecommunications system

Rendezvous radar for the orbital maneuvering vehicle

The Rendezvous Radar Set (RRS) was designed at Motorola's Strategic Electronics Division in Chandler, Arizona, to be a key subsystem aboard NASA's Orbital Maneuvering Vehicle (OMV). The unmanned OMV, which was under development at TRW's Federal Systems Division in Redondo Beach, California, was designed to supplement the Shuttle's satellite delivery, retrieval, and maneuvering activities. The RRS was to be used to locate and then provide the OMV with vectoring information to the target satellite (or Shuttle or Space Station) to aid the OMV in making a minimum fuel consumption approach and rendezvous. The OMV development program was halted by NASA in 1990 just as parts were being ordered for the RRS engineering model. The paper presented describes the RRS design and then discusses new technologies, either under development or planned for development at Motorola, that can be applied to radar or alternative sensor solutions for the Automated Rendezvous and Capture problem

The Effect of Frequency of Home Visits on Parent Behavior and Child Achievement

Statement of the Problem. The problem of this study was to determine if the frequency of home visits made to families enrolled in a home-based early childhood education program was related to changes in parental behavior and student achievement. Design of the Study. The procedural analysis for the study was the randomized three group pretest-posttest design. One hundred twenty low income families who had one or more children between three and five years of age, and who volunteered to participate in the home-based early childhood education program, were selected for the study. The early childhood program consisted of three basic components: (1) a half-hour television program ( Captain Kangaroo ) broadcast five days per week, (2) a once per-week group experience for the children, and (3) paraprofessional home visitors who made weekly visits to homes in order to deliver to and instruct parents how they should teach their own children. Four measurement instruments were used to secure data on parent behavior and child achievement. Each instrument was administered at the beginning and end of the project year. The High/Scope Home Environment Scale and the Schaefer Behavior Inventory were administered to parents in an attempt to determine the degree of parental behavior change. Children who participated in the program were administered the Peabody Picture Vocabulary Test and the Cooperative Preschool Inventory in an effort to determine their degree of cognitive growth. Records of parent participation in group meetings and child attendance at group sessions were also recorded in order to determine the amount of parent and child participation in the program. Summary and Conclusions. (1) A visit to parents once per week was no more effective in influencing parent behavior than a visit once every two weeks. However, a parent who received a visit once per week or once every two weeks was more likely to develop a positive change in parent behavior toward his/her children than a parent who received no visits; (2) a visit once per week was no more effective in influencing child achievement than a visit once every two weeks. The child who received a visit once per week or once every two weeks, however, was more likely to have a higher level of achievement than a child who received no visits; (3) parent behavior was not significantly related to parent and child participation in the program as measured by the number of group sessions attended by the children and the number of parent meetings attended by the parents during the program year; (4) the greater the degree of positive change in parent behavior, the greater the degree of child achievement; (5) the number of parent meetings attended by parents and the number of group sessions attended by the children were not significantly related to the level of achievement attained by the children

Using Appreciative Inquiry as a Tool for Congregational Change

Successful navigation of congregational change is difficult. Churches face numerous technical and adaptive challenges. While leaders can often guide their churches through technical change with logic, negotiation and even force, adaptive change requires a deeper form of reprogramming and congregational discernment. The College Church of Christ, having been in decline for nearly two decades, went through an intensive process of appreciative inquiry to elicit data that might fund a new, life-giving narrative. This article discusses that process and challenges that arose in moving on to next steps

A Dynamic Model Investigation of the Effect of a Sharp-Edge Vertical Gust on Blade Periodic Flapping Angles and Bending Moments of a Two-Blade Rotor

A two-blade rotor having a diameter of 4 feet and a solidity of 0.037 was subjected to sharp-edge vertical gusts while being operated at various forward speeds to study the effect of the gusts on the blade periodic bending moments and flapping angles. Variables studied included gust velocity, collective pitch angle, flapping hinge offset, and tip-speed ratio. Dimensionless coefficients are derived for the periodic components of the incremental changes in blade flapping angles and bending moments which arise when a rotor blade penetrates a sharp-edge gust. Mental changes in both the flapping angles and bending moments are essentially proportional to gust velocity, and the coefficients express the ratio of these increments to gust velccity. The results show that the flapping coefficient usually increases with an increase in collective pitch angle, is generally dependent on tip-speed ratio, and is essentially independent of the amount of flapping hinge offset. The bending-moment coefficient is also dependent on collective pitch angle and tip-speed ratio. Expected reductions in bending moments are realized by the use of flapping hinges, and further reductions in bending moments are achieved as the amount of flapping hinge offset is increased. Comparison of the experimental results of this investigation with limited available theoretical results shows substantial agreement but indicates that the assumption that the response of the rotor to a sharp-edge gust is independent of the collective pitch angle prior to gust entry is probably inadequate