28 research outputs found
Emittance measurements of Space Shuttle orbiter reinforced carbon-carbon
The spectral and total normal emittance of the Reinforced Carbon-Carbon (RCC) used on Space Shuttle nose cap and wing leading edges has been measured at room temperature and at surface temperatures of 1200 to 2100 K. These measurements were made on virgin and two flown RCC samples. Room temperature directional emittance data were also obtained and were used to determine the total hemispherical emittance of RCC as a function of temperature. Results of the total normal emittance for the virgin samples showed good agreement with the current RCC emittance design curve; however, the data from the flown samples showed an increase in the emittance at high temperature possibly due to exposure from flight environments
A transient search using combined human and machine classifications
Large modern surveys require efficient review of data in order to find transient sources such as supernovae, and to distinguish such sources from artefacts and noise. Much effort has been put into the development of automatic algorithms, but surveys still rely on human review of targets. This paper presents an integrated system for the identification of supernovae in data from Pan-STARRS1, combining classifications from volunteers participating in a citizen science project with those from a convolutional neural network. The unique aspect of this work is the deployment, in combination, of both human and machine classifications for near real-time discovery in an astronomical project. We show that the combination of the two methods outperforms either one used individually. This result has important implications for the future development of transient searches, especially in the era of Large Synoptic Survey Telescope and other large-throughput surveys
Isolated Roughness Induced Boundary-Layer Transition: Shuttle Orbiter Ground Tests and Flight Experience
Recent Orbiter wind tunnel data and flight data have been used to evaluate boundary-layer transition induced by discrete-roughness elements on the Orbiter windward surface. Orbiter flow field calculations have been used to compute transition parameters and disturbance parameters for correlating the results and comparing the trends. Existing transition correlations have been modified and applied to the Orbiter. These correlations provide a means to predict transition on the Orbiter given a known isolated roughness element. Furthermore, these data and data reduction methods provide information and guidance for the prediction of transition due to &screte-roughness elements on future winged reentry vehicles