Strained-layer-superlattice-based compact thermal imager for the International Space Station

Autor: Paul Finneran, Compton J. Tucker, Frank Cepollina, Justin Cassidy, Thomas Flatley, Sachidananda Babu, David Parker, Murzy D. Jhabvala, Allen Lunsford, Donald E. Jennings, Markus Loose, Jason Bundas, A. La, Beth Keer, Chris Fetter, Mani Sundaram, R. G. Stone, Elizabeth Jean Timmons, William Squicciarini, Ireneusz Orlowski
Rok vydání: 2019
Předmět:
Zdroj: Applied optics. 58(20)
ISSN: 1539-4522
Popis: The compact thermal imager (CTI) is a dual-band, strained-layer-superlattice (SLS) detector–based instrument that was installed on the exterior of the International Space Station (ISS) in conjunction with the third Robotic Refueling Mission 3 (RRM3) in 2018. The CTI serves as a pathfinder for future thermal infrared capability on Landsat. The CTI incorporates an SLS hybrid, a dual-band 3–5 and 8–10 μm, electrically switchable, 320×256 array with 30 μm2 pixels, bonded to an Indigo ISC0903 Readout Integrated Circuit (ROIC). The telescope was built around an integrated detector cryocooler assembly developed under a NASA Small Business Innovative Research award with QmagiQ, LLC. The cooler is a Ricor K508 and the front-end optics is a custom-designed, doublet lens telescope with a 150 mm focal length. The ground resolution is 80 meters/pixel from the ISS altitude of 400 km. A filter creates two spectral channels from the dual bands, 3.3–5.4 and 7.8–10.2 μm. The detector hybrid control electronics is a custom-developed system based on the Teledyne Imaging Systems SIDECAR Application-Specific Integrated Circuit. This module provides the electronic interface from the RRM3 SpaceCube on-board processor to the detector/ROIC assembly. The primary goal of this mission was to perform a technology demonstration of the SLS technology and the commercial cooler technology elevating the Technology Readiness Level (TRL) to TRL 9 on a bare-bones budget and relatively fast development cycle. Some science objectives include locating fires, approximating land surface temperatures, and monitoring evapotranspiration, sea ice, and glacier dynamics. In this paper, we will present the design of the focal plane, optics, electronics, and mechanical structure of the CTI. We will also describe the operation and qualification tests that were performed to bring the CTI to the NASA TRL 6 in preparation for the launch on a SpaceX Dragon from the Kennedy Space Center.
Databáze: OpenAIRE