Showing papers by "Kenneth P. Klaasen published in 2003"

Exploring Asteroid Interiors: The Deep Interior Mission Concept

Abstract: Deep Interior is a mission to determine the geophysical properties of near-Earth objects, including the first volumetric image of the interior of an asteroid. Radio reflection tomography will image the 3D distribution of complex dielectric properties within the ~1 km rendezvous target and hence map structural, density or compositional variations. Laser altimetry and visible imaging will provide high-resolution surface topography. Smart surface pods culminating in blast experiments, imaged by the high frame rate camera and scanned by lidar, will characterize active mechanical behavior and structure of surface materials, expose unweathered surface for NIR analysis, and may enable some characterization of bulk seismic response. Multiple flybys en route to this target will characterize a diversity of asteroids, probing their interiors with non-tomographic radar reflectance experiments. Deep Interior is a natural follow-up to the NEARShoemaker mission and will provide essential guidance for future in situ asteroid and comet exploration. While our goal is to learn the interior geology of small bodies and how their surfaces behave, the resulting science will enable pragmatic technologies required of hazard mitigation and resource utilization.

Operations and calibration of the solid-state imaging system during the Galileo extended mission at Jupiter

Abstract: The solid state imaging (SSI) subsystem on the National Aeronautics and Space Administration's (NASA's) Galileo spacecraft has successfully completed a 4-yr extended mission exploring the Jovian system. The SSI remained in stable calibration throughout its total 12-yr flight time and returned valuable scientific data until the end of the mis- sion. A slight loss in spatial resolution occurred between the last primary- mission calibration and that done during the extended mission. The ab- solute spectral radiometric calibration has been determined to 5 to 7% accuracy across the camera's eight spectral filters. A possible shift in the central wavelength of one of the methane-absorption-band filters of ;3 nm shortward may have occurred late in the extended mission. The charge-coupled device (CCD) detector endured the harsh radiation en- vironment at Jupiter to a total dose of ;4 krad without any serious per- manent damage. Some radiation-induced problems in the detector clock- ing and signal-chain electronics rendered the 2-32-pixel summation modes unusable and required that the CCD light flood and erasure prior to each exposure be disabled. However, good-quality imaging continued to be possible even in the most extreme radiation fluxes encountered. The successful return of 1453 images during the extended mission nearly matched the number of frames returned during the primary mission. © 2003 Society of Photo-Optical Instrumentation Engineers.