Thermographic Imaging of the Space Shuttle During Re-Entry Using a Near Infrared Sensor

High resolution calibrated near infrared (NIR) imagery of the Space Shuttle Orbiter was obtained during hypervelocity atmospheric re-entry of the STS-119, STS-125, STS-128, STS-131, STS-132, STS-133, and STS-134 missions. This data has provided information on the distribution of surface temperature and the state of the airflow over the windward surface of the Orbiter during descent. The thermal imagery complemented data collected with onboard surface thermocouple instrumentation. The spatially resolved global thermal measurements made during the Orbiter s hypersonic re-entry will provide critical flight data for reducing the uncertainty associated with present day ground-to-flight extrapolation techniques and current state-of-the-art empirical boundary-layer transition or turbulent heating prediction methods. Laminar and turbulent flight data is critical for the validation of physics-based, semi-empirical boundary-layer transition prediction methods as well as stimulating the validation of laminar numerical chemistry models and the development of turbulence models supporting NASA s next-generation spacecraft. In this paper we provide details of the NIR imaging system used on both air and land-based imaging assets. The paper will discuss calibrations performed on the NIR imaging systems that permitted conversion of captured radiant intensity (counts) to temperature values. Image processing techniques are presented to analyze the NIR data for vignetting distortion, best resolution, and image sharpness. Keywords: HYTHIRM, Space Shuttle thermography, hypersonic imaging, near infrared imaging, histogram analysis, singular value decomposition, eigenvalue image sharpnes

Near-Infrared Spectroscopy of Hayabusa Sample Return Capsule Reentry

As part of the 2010 airborne observational campaign for the Hayabusa capsule reentry, a system of four colocatedcameras was deployed to track and measure the spacecraft fragmentation and sample return capsule descents. These instruments included an intensified video camera for narrow-field tracking, an intensified video camera for visible and near-infrared spectral measurements from 400 to 900 nm, and a near-infrared spectrograph for high-resolution measurements from 980 to 1080 nm. The latter was configured to monitor the spectral evolution of capsule emissions during descent, seeking evidence of possible carbon signatures due to ablation of the heat shield. The data complement previous Stardust capsule observations in which distinct 1069 nm emission signatures were measured, likely associated with carbon ablation from the Phenolic Impregnated Carbon Ablator heat shield. The Hayabusa capsule spectra also exhibited 1069 nm line emissions, appearing intermittently at ∼13∶52∶05, persisting from approximately 13:52:10 to 13:52:20 as the capsule approached peak heating, and weakening to undetectable levels after ∼13∶52∶20. Continuum emission and nitrogen line emissions were detected simultaneously. The evolutions of these signatures over the course of reentry are investigated, in comparison with model predictions and complementary campaign data

New Double Stars from Asteroidal Occultations, 1971 - 2008

International audienc

New Double Stars from Asteroidal Occultations, 1971 - 2008

International audienc

New Double Stars from Asteroidal Occultations, 1971 - 2008

International audienc

Initial Results from the USNO Dispersed Fourier Transform Spectrograph

We have designed and constructed a “dispersed Fourier Transform Spectrometer” (dFTS), consisting of a conventional FTS followed by a grating spectrometer.

Minor Planet Observations [244 Geocentic Occultation Observations]

International audienc