2018.B.3.4. Testing the Compact Infrared Imager and Radiometer (CIIR) CubeSat Instrument

Author(s)

Rory Evans (1)
Simon Calcutt (1)
Neil Bowles (1)

University of Oxford, United Kingdom

Session

B.3

Keywords

CubeSat, Thermal Infrared, Asteroid, Mineralogy, Temperature

Abstract

The thermal infrared is a powerful tool for exploration of planets and small solar system bodies, allowing remote measurements of surface temperature and the identification of atmospheric species or surface mineralogy by analysis of spectral features. The Compact Infrared Imager and Radiometer (CIIR) is a 4U instrument for a 6U CubeSat, capable of both broadband imaging from 5 to 20 µm at medium resolution (150 m at 800 km altitude), and spectral characterisation from many narrow filters (>10) in that range.

CIIR has been developed using experience of previous infrared instrumentation at the University of Oxford by miniaturising the optics, detector, and blackbody required into a suitable volume and mass, with commercial-off-the-shelf subsystems transforming the instrument to a CubeSat. The CubeSat will use a combination of broadband images and spectral mapping to characterise a variety of planetary bodies and is currently being studied at Oxford for application to the Earth or small bodies such as asteroids.

The current development of CIIR is using a test breadboard that is representative of the final CubeSat instrumentation. This breadboard features a full optical system, internal CubeSat structure, and scanning mechanism, and is undergoing a series of environmental tests including vibration testing and thermal cycling to validate the performance of the instrument in space. This testing is crucial to raise the TRL of several features of the instrument.

CIIR includes a novel optical system to achieve data comparable to typical instruments. The system uses an uncooled microbolometer to reduce the complexity and power requirements of conventional infrared detectors; in addition the filter array is not placed on the detector but at an intermediate focal plane, allowing many more filters to be used, and reducing noise to the detector. To calibrate the system CIIR includes a cavity blackbody placed at the end of the optical path, this is a traceable radiometric target, ensuring < 0.5 K accuracy.

This talk will cover the design of the CIIR instrument, the current status of the test breadbroad, and the future steps required to achieve the goal of building and testing a calibrated flight ready system.