Marshall Amateur Radio Club experiment (MARCE) post flight data analysis

The Marshall Amateur Radio Club Experiment (MARCE) data system, the data recorded during the flight of STS-61C, the manner in which the data was reduced to engineering units, and the performance of the student experiments determined from the data are briefly described

Tetherline system for orbiting satellites

A system for tethering one orbiting space vehicle to another was designed so that a tetherline between the vehicles is controlled by a motorized reel which in turn is controlled to deploy, retrieve, or maintain a constant line length while effecting a stabilizing influence on the line. This is accomplished by applying a tension to the line which takes into account the instantaneous length of the line, rate of change of the length of the line, and certain constants which vary depending upon the mode of operation, deployment, retrieval, or station keeping

Attitude control system

An attitude control system is described in which angular rate signals are generated by rate gyros mounted closely adjacent to gimbaled engines at the rear of a vehicle. Error signals representative of a commanded change in vehicle angle or attitude are obtained from a precision inertial platform located in the nose region of the vehicle. The rate gyro derived signals dominate at high frequencies where dynamic effects become significant, and platform signals dominate at low frequencies where precision signals are required for a steady vehicle attitude. The blended signals are applied in a conventional manner to control the gimbaling of vehicle engines about control axes

Gratitude in Adolescents: Examining the Role of Attachment, Parental Gratitude, and Discounting

From early childhood, parents often teach their children to use their manners by saying “Thank you”; however, are there any benefits from experiencing gratitude during youth? Understanding the relationship between gratitude and other areas, such as happiness and decision-making, can potentially help researchers in planning interventions for youth. The purpose of this study was to determine the relationship between gratitude and decision-making in youth, as well as the role of maternal gratitude and the mother-child attachment in determining gratitude in youth. Two hundred four participants (102 mothers, 102 adolescents) completed an online survey. Mothers and adolescents completed two gratitude questionnaires and indicated their preference for a hypothetical smaller reward now or a larger reward later. Adolescents completed two additional questionnaires about their behavior and their relationship with their mothers. Results indicated that there was not a relationship between gratitude in youth and their preferences in the decision-making task; however, there a relationship between their gratitude and their mother\u27s. Youth gratitude was also related to prosocial behavior. Finally, the mother-child relationship played a role in explaining youth gratitude. The results of the study give researchers greater insight into the importance of mothers fostering gratitude in their children. By understanding this, researchers and professionals can be in a better position to help foster positive outcomes in children

A tether tension control law for tethered subsatellites deployed along local vertical

A tethered subsatellite deployed along the local vertical is in stable equilibrium. This applies equally to subsatellites deployed in the direction towards the earth from the main spacecraft or away from the earth. Momentary perturbations from this stable equilibrium will result in a swinging motion, which decays very slowly if passive means are relied upon to provide damping. A control law is described which actively damps the swinging motion by employing a reel, or other mechanism, to apply appropriate tension as a function of tetherline length, rate of change of length, and desired length. The same control law is shown to be useful for deployment and retrieval of tethered subsatellites in addition to damping to steady state

Growth in Disability Benefits: Explanations and Policy Implications

This collection of original papers reveals why caseloads of the nation\u27s two largest income entitlement programs for disability - Social Security Disability Income (SSDI) and Supplemental Security Income (SSI) - have soared.https://research.upjohn.org/up_press/1191/thumbnail.jp