The Multiband Imaging Photometer for Spitzer (MIPS) provides long wavelength capability for the mission, in imaging bands at 24, 70, and 160µm and measurements of spectral energy distributions between 52 and 100µm at a spectral resolution of about 7%. By using true detector arrays in each band, it provides both critical sampling of the Spitzer point spread function and relatively large imaging fields of view, allowing for substantial advances in sensitivity, angular resolution, and efficiency of areal coverage compared with previous space far-infrared capabilities. The Si:As BIB 24µm array has excellent photometric properties, and measurements with rms relative errors of 1% or better can be obtained. The two longer wavelength arrays use Ge:Ga detectors with poor photometric stability. However, the use of 1.) a scan mirror to modulate the signals rapidly on these arrays, 2.) a system of on-board stimulators used for a relative calibration approximately every two minutes, and 3.) specialized reduction software result in good photometry with these arrays also, with rms relative errors of less than 10%.
The Multiband Imaging Photometer for SIRTF (MIPS) provides the Space Infrared Telescope Facility (SIRTF) with imaging, photometry, and total power measurement capability in broad spectral bands centered at 24, 70, and 160tm, and with low resolution spectroscopy between 50 and 95p.m. The optical train directs the light from three zones in the telescope focal plane to three detector arrays: l28x128 Si:As BIB, 32x32 Ge:Ga, and 2x20 stressed Ge:Ga. A single axis scan mirror is placed at a pupil to allow rapid motion of the field of view as required to modulate above the 1/f noise in the germanium detectors. The scan mirror also directs the light into the different optical paths of the instrument and makes possible an efficient mapping mode in which the telescope line of sight is scanned continuously while the scan mirror freezes the image motion on the detector arrays. The instrument is designed with pixel sizes that oversample the telescope Airy pattern to operate at the diffraction limit and, through image processing, to allow superresolution beyond the traditional Rayleigh criterion.The instrument performance and interface requirements, the design concept, and the mechanical, optical, thermal, electrical, software, and radiometric aspects of MIPS are discussed in this paper. Solutions are shown to the challenge of operating the instrument below 3K, with focal plane cooling requirements down to 1.5K. The optical concept allows the versatile operations described above with only a single mechanism and includes extensive self-test and on-board calibration capabilities. In addition, we discuss the approach to cryogenic end-to-end testing and calibration prior to delivery of the instrument for integration into SIRTF.
On July 4th, 2005, in celebration of our nation's birthday, NASA's Deep Impact Impactor spacecraft collided with comet Tempel1 at 10km/sec -marking the first hypervelocity impact of a celestial body by a human-made spacecraft. With closing speeds of 23,000 mph, the Impactor's active guidance system steered it to impact on a sunlit portion of the comet's surface. As it closed in on Tempel 1, the Impactor's camera relayed close-up images of the comet's surface to the Flyby spacecraft for downlink to Earth. Meanwhile, the Flyby spacecraft used its two instruments to image the impact and then continued to photograph the comet as it followed its orbital path around the Sun. The primary science data was returned to Earth in near real-time, and all data was returned to Earth within 24 hours of the encounter.For the NASA Discovery-class Deep Impact mission, a two-part Deep Impact spacecraft was constructed: the Impactor spacecraft and the impact characterization (flyby) spacecraft, and an associated suite of surveillance instruments. These instruments included one high resolution visible imager, two identical medium-resolution visible imagers (one on the flyby and one on the Impactor) and one infrared spectrometer. The two-part spacecraft launched together in January 12, 2005 and separated on July 3 rd , 24 hours before reaching its Tempel 1 target. The Impactor separated from the flyby spacecraft and autonomously positioned itself directly in front of the encroaching Tempel 1 comet for a spectacular hypervelocity impact.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.