Solar array thermal snap and the characteristics of its effect on UARS

The single solar array on the Upper Atmosphere Research Satellite (UARS) is subjected to a thermal distortion when the spacecraft enters and exits the Earth's shadow. The distortion results in a torque that alters the spacecraft attitude. Due to the sudden nature of the attitude discontinuity, the effect has been termed 'thermal snap'. Thermal snap has also been experienced by Landsats 4 and 5. Analyses by the spacecraft builder addressed the impact of the resultant torque on the onboard control system. This paper discusses the results of comparisons between the predicted effects of thermal snap on UARS and actual attitude solutions from UARS telemetry data. In addition, this paper describes the characteristics of the thermal snap on UARS in terms of maximum displacement, solar beta angle, and solar array drive angle. Comparisons are made between the actual times of thermal snaps and the predicted spacecraft sunrise and sunset times. The effects of the UARS thermal snap are summarized and a general comment is made relating possible effects of thermal snap on other satellites. Also, an analysis of UARS attitude solutions that span periods of thermal snap was performed to determine whether the gyro sampling time of 1/8 second is sufficient to properly model the resulting spacecraft attitude without compromising the accuracy requirements. The results of this analysis are discussed

A Handbook for the Intervention Specialist at Meadows Elementary School: Four Program Components

The purpose of this study was to develop a handbook detailing four important components of the intervention specialist\u27s program at Meadows Elementary School in the North Thurston School District, Lacey, Washington. The development of a handbook was useful due to the fact that since 1988, three different individuals had served as the intervention specialist. Such rapid turnover caused disruptions m services to Meadows students, especially those who were at-risk. The four components were Meadows\u27 Hosts and Hostesses, Intramurals, Conflict Managers and Meadows\u27 Helpers. Each program utilized students interacting positively with other students as a means to improve the whole school climate. The process followed in each program\u27s development was first to assess the needs of the students. Then, relevant literature was reviewed to discover successful programs in operation or promising directions in which to proceed. Next, each program had to be coordinated with all parts of the school community. Training student volunteers was part of this coordination and each program\u27s goals required that specific skills be mastered. Finally, paperwork supporting the implementation of each program was assembled. Several evaluation forms were created to measure each program\u27s success. The result of the study was a handbook titled, A Handbook for the Intervention Specialist at Meadows Elementary School: Four Program Components

A simple expedient for obtaining large quantities of Neurospora

Large scale growth in carboy

Recent free-flight boundary-surface aerody- namic noise measurements

Free-flight boundary-layer aerodynamic noise measurement

Designing Assessments and Tools for your Program

Presenters and participants will discuss strategies and best practices available to chairs to involve faculty and external constituents in defining student learning outcomes (SLO), direct assessments and a process/department culture of continuous improvement

ASPECTS OF SELECTION FOR PERFORMANCE IN SEVERAL ENVIRONMENTS WITH HETEROGENEOUS VARIANCES

Dairy cattle evaluation schemes routinely assume homogeneous variance with respect to environment. Increasing evidence suggests the presence of systematic changes in variance components associated with mean level of performance. Best linear unbiased prediction procedures that account for heterogeneity are reviewed. The consequences of incorrectly assuming homogeneity for evaluation are demonstrated for a progeny test and an artificial breeding program that screens dams of sires from heterogeneous populations. Selection assuming homogeneity can be very efficient when heritability, and therefore accuracy of selection, is greatest in the more variable environment. Conversely, appreciable reduction in response results when heritability is greater in the less variable environment

Assessment Of An Engineering Technology Outreach Program For 4th-7th Grade Girls

This paper describes a workshop led by female Engineering Technology students, with support from female faculty, to provide an introduction to Engineering Technology to 4th – 7th grade girls through a series of interactive laboratory experiments. This outreach program was developed to improve attitudes towards science and engineering in middle school-aged girls by making science tangible and fun. The workshop takes place on a college campus and makes use of four different Engineering Technology laboratories. Each lab activity includes a hands-on experiment, beginning with an overview of the engineering technology discipline and a brief description of the theories related to the experiment. The day culminates with a panel session between the participants and the college students. An ancillary outcome of the program is that it serves as a community building event for female Engineering Technology college students. Connections are developed between the students and between students and faculty in the college. The college students gain the satisfaction of influencing the attitudes of participants and develop critical communication skills. An attitude survey given to participants before and after the workshop shows that participation in these workshops results in a more positive attitude towards science and technology. College student volunteers were also surveyed after the workshop to determine the impact of their participation. A full workshop description is given in this paper as well as analysis of the assessment results for the participants and the college students.

Attitude Accuracy Study for the Earth Observing System (EOS) AM-1 Spacecraft

Earth Observing System (EOS) spacecraft will take measurements of the Earth's clouds, oceans, atmosphere, land, and radiation balance. These EOS spacecraft are part of the National Aeronautics and Space Administration's Mission to Planet Earth, and consist of several series of satellites, with each series specializing in a particular class of observations. This paper focuses on the EOS AM-1 spacecraft, which is the first of three satellites constituting the EOS AM series (morning equatorial crossing) and the initial spacecraft of the EOS program. EOS AM-1 has a stringent onboard attitude knowledge requirement, of 36/41/44 arc seconds (3 sigma) in yaw/roll/pitch, respectively. During normal mission operations, attitude is determined onboard using an extended Kalman sequential filter via measurements from two charge coupled device (CCD) star trackers, one Fine Sun Sensor, and an Inertial Rate Unit. The attitude determination error analysis system (ADEAS) was used to model the spacecraft and mission profile, and in a worst case scenario with only one star tracker in operation, the attitude uncertainty was 9.7/ll.5/12.2 arc seconds (3 sigma) in yaw/roll/pitch. The quoted result assumed the spacecraft was in nominal attitude, using only the 1-rotation per orbit motion of the spacecraft about the pitch axis for calibration of the gyro biases. Deviations from the nominal attitude would show greater attitude uncertainties, unless calibration maneuvers which roll and/or yaw the spacecraft have been performed. This permits computation of the gyro misalignments, and the attitude knowledge requirement would remain satisfied