Book reviews

Teaching/Communication/Extension/Profession,

Extreme Ultraviolet Reflective Grating Characterization and Simulationsfor the Aspera SmallSat Mission

The Aspera SmallSat mission is designed to detect and map the warm-hot gaseous component of the halos of nearby galaxies through long-slit spectroscopy of the ionized O VI emission line (103.2 nm) for the first time. The Aspera Rowland circle type spectrograph uses a toroidal grating coated with a multilayer film consisting of aluminum, lithium fluoride, and magnesium fluoride capping to optimize reflectivity in the extreme ultraviolet (EUV) waveband from 103 to 104nm. We discuss the grating characterization test setup at the University of Arizona (UA), which will validate the multilayer coating and grating efficiency in a UV vacuum chamber. We also simulate the reflectivity of the multilayer thin film coating using IMD IDL software to compare simulated results with measured reflectivity. Additionally, non-sequential ray trace simulations and 3D CAD modeling are used for verification of the test setup. Finally, the implications of the differences between the measured and simulated reflectivity and grating efficiencies are considered, including impact to the mission

Models of classroom assessment for course-based research experiences

Course-based research pedagogy involves positioning students as contributors to authentic research projects as part of an engaging educational experience that promotes their learning and persistence in science. To develop a model for assessing and grading students engaged in this type of learning experience, the assessment aims and practices of a community of experienced course-based research instructors were collected and analyzed. This approach defines four aims of course-based research assessment—(1) Assessing Laboratory Work and Scientific Thinking; (2) Evaluating Mastery of Concepts, Quantitative Thinking and Skills; (3) Appraising Forms of Scientific Communication; and (4) Metacognition of Learning—along with a set of practices for each aim. These aims and practices of assessment were then integrated with previously developed models of course-based research instruction to reveal an assessment program in which instructors provide extensive feedback to support productive student engagement in research while grading those aspects of research that are necessary for the student to succeed. Assessment conducted in this way delicately balances the need to facilitate students’ ongoing research with the requirement of a final grade without undercutting the important aims of a CRE education

We're trading hearts

Gift of Dr. Mary Jane Esplen.Piano vocal [instrumentation]I love you come what may [first line]We're trading hearts today [first line of chorus]A [key]Moderato [tempo]Wedding ceremony of Tom C. Connors and wife (photograph) [illustration

Stretched Membrane with Electrostatic Curvature (SMEC) Mirrors for Extremely Large Space Telescopes

ABSTRACT Very lightweight mirrors can be constructed by stretching a membrane to form a flat surface. Adding tension to the membrane, making it flat, can be done by discrete attachment points, or by using a continuous boundary. Such lightweight mirrors are very attractive for space telescopes where a 100m aperture can be made up of smaller mirror segments. 1 Adding a slight curvature to each segments simplifies the optical train. 2 This article looks at the making of a curved membrane mirror, and demonstrates its use. Measurements of the flat membrane, and the curved figure will be shown

Testing and alignment of the LBTI

The Large Binocular Telescope Interferometer (LBTI) has been developed and tested and is almost ready to be installed to LBT mount. In preparation for installation, testing of the beam combination and phasing of the system have been developed. The testing is currently in progress. The development of a telescope simulator for LBTI has allowed verification of phasing and alignment with a broad band source at 10 microns2. Vibration tests with the LBTI mounted to the LBT were carried out in July 2008, with both seismic accelerometers and an internal optical interferometric measurement. The results have allowed identification of potential vibration sources on the telescope. Plans for a Star Simulator that illuminates each LBT aperture at the prime focus with two artificial point sources derived from a single point source via fiber optics are presented. The Star Simulator will allow testing of LBTI with the telescope and the adaptive secondaries in particular. Testing with the Star Simulator will allow system level testing of LBTI on the telescope, without need to use on-sky time. Testing of the Star Simulator components are presented to verify readiness for use with the LBTI.12 page(s