NASA Lunar Reconnaissance Orbiter (LRO)

2006 - 2007

Project overview

The Diviner experiment is a nine channel infrared filter radiometer designed for payload inclusion on the JPL Lunar Reconnaissance Orbiter (LRO) mission due to be launched in 2008. Its mission is to investigate the thermal radiation, mineralogical composition and structure of the lunar environment with a view to enabling future human exploration. The Diviner instrument will measure lunar surface temperatures, solar reflectance, and spectral emission by limb and nadir mapping to identify possible locations of ice formation. It will map mineralogical rock compositions and lunar soil (regolith) using spectral locations of infrared emission maxima in three narrow-band filter channels (7.8, 8.25 and 8.5µm). Following earlier success of the NASA Mars Climate Sounder (MCS) design deployed on the 2005 Mars Reconnaissance Orbiter mission, Diviner utilizes a similar linear, 21-element, uncooled thermopile detector array at the focal detector plane. As thermopiles are sensitive to a broad range of radiant energy, from ultraviolet through to the thermal infrared regions, interference rejection and materials absorption are of paramount importance to the spectral design. The instrument is constructed with two identical co-boresighted telescopes, one for mid-infrared mineralogy and thermal observations, designated 'A' (8-25µm), the other for thermal sensing at far infrared wavelengths, 'B' (25-200µm) using mesh filters supported by dielectric layers.

The Diviner experiment is a joint US-UK development project between the JPL, California Institute of Technology and Oxford University Department of Atmospheric, Oceanic and Planetary Physics. The University of Reading are responsible for the spectral design and fabrication of the mid-infrared focal plane interference filters.

Delivered hardware

Description	Filter Type	Quantity	Wavelength Region	Substrate Material	Dimensions
Mid-IR Filters	Narrow bandpass filters	4 channels	7.5 - 25.0 µm	Germanium (Ge), Zinc Sulphide (ZnS)	9.00 mm L x 0.94 mm W x 0.40 mm T
LWP Filters	Longwave-pass edge filters	1 channel	8.0 - 50.0 µm	Silicon (Si)	10.5 mm L x 3.85 mm W x 0.30 mm T