OSIRIS-REx Visible and Infrared Spectrometer (OVIRS)

OSIRIS-REx Visible and Infrared Spectrometer (OVIRS)
Name	OSIRIS-REx Visible and Infrared Spectrometer (OVIRS)
Mission	OSIRIS-REx
Operator	NASA / University of Arizona
Manufacturer	Malin Space Science Systems / NASA Goddard Space Flight Center
Launch date	October 8, 2016
Launch vehicle	United Launch Alliance Atlas V
Spacecraft	OSIRIS-REx (spacecraft)
Target	101955 Bennu
Spectral range	0.4–4.3 μm
Detectors	HgCdTe array
Mass	20.8 kg
Power	29 W

OSIRIS-REx Visible and Infrared Spectrometer (OVIRS) The OSIRIS-REx Visible and Infrared Spectrometer (OVIRS) is a point spectrometer flown on the OSIRIS-REx mission to investigate the near‑Earth asteroid 101955 Bennu. OVIRS measured reflected sunlight across the visible and infrared to map mineralogy, organics, and surface alteration, supporting sample site selection and contextual analysis for the sample return to Earth under NASA stewardship.

Instrument Overview

OVIRS is one of the principal remote sensing instruments on OSIRIS-REx (spacecraft), operating alongside the OSIRIS-REx Thermal Emission Spectrometer (OTES), the OSIRIS-REx Camera Suite (OCAMS), and the OSIRIS-REx Laser Altimeter (OLA). Developed through a collaboration involving NASA Goddard Space Flight Center, the University of Arizona’s Lunar and Planetary Laboratory, and Lockheed Martin, OVIRS provided high signal-to-noise spectroscopic measurements used by teams at institutions including Malin Space Science Systems and Arizona State University. The instrument’s design leveraged heritage from instruments like the New Horizons Ralph and spectrometers on Mars Reconnaissance Orbiter and Mars Odyssey.

Design and Specifications

OVIRS is a compact, cryo-cooled point spectrometer using a transmissive grating and a HgCdTe focal plane array supplied by industry partners such as Teledyne Technologies. The optical path includes a telescope assembly, order-sorting filters, and a slit assembly feeding the detector with a spectral resolving power optimized for absorption band identification similar to instruments on Galileo (spacecraft) and Cassini–Huygens. Key specifications include a spectral range of 0.4–4.3 μm, spectral sampling designed to detect features known from studies by Vernazza et al. and Rivkin et al., and a field of view tailored to the spatial scales needed for mapping candidate collection sites characterized by teams at Jet Propulsion Laboratory. OVIRS mass and power budgets were constrained during integration at Lockheed Martin Space Systems facilities in Colorado, and thermal control was coordinated with NASA Goddard Space Flight Center engineers to mitigate detector dark current.

Science Objectives and Capabilities

OVIRS was designed to address science goals defined by NASA’s New Frontiers program and the OSIRIS-REx science team, including detection of hydrated minerals noted in surveys by NEOWISE and identification of organic compounds referenced in studies by Brown University and Caltech. Capabilities emphasized detection of the 0.7 μm hydration band, the 3.4 μm organics band, and diagnostic silicate and carbonate features, linking spectral signatures to laboratory spectra from institutions like Smithsonian Institution and Carnegie Institution for Science. OVIRS contributed to investigations into space weathering processes explored by researchers from University of Colorado Boulder and Brown University and provided context for isotopic and petrographic analyses conducted by teams at Johnson Space Center and Field Museum of Natural History after sample return.

Calibration and Operations

Preflight calibration of OVIRS used facilities at NASA Goddard Space Flight Center and testbeds with standards traceable to National Institute of Standards and Technology to characterize radiometric response, spectral line shape, and stray light comparable to methods used for instruments on Hubble Space Telescope and Spitzer Space Telescope. Inflight calibration relied on solar analog stars including standards used by European Space Agency missions and periodic observations of Moon and deep space for dark current assessment. Operations planning for OVIRS integrated with mission timelines coordinated at Lockheed Martin and NASA Goddard, with commanding uplinks from Deep Space Network stations in Goldstone, California, Madrid, and Canberra. The instrument’s duty cycle balanced signal accumulation with thermal constraints to preserve detector performance across proximity operations near Bennu.

Data Processing and Products

OVIRS raw telemetry were processed through pipelines developed by teams at NASA Goddard Space Flight Center, University of Arizona, and Planetary Data System archives, producing calibrated spectra, reflectance (I/F) cubes, and observation geometry tables analogous to data products from Mars Science Laboratory and Dawn (spacecraft). Level 1 products included radiometrically calibrated spectra; Level 2 products provided photometrically corrected reflectance; Level 3 mosaics combined multiple pointings into spectral maps tied to shape models produced by University of Arizona and OLA teams. Data releases adhered to policies of NASA and were ingested into archives used by investigators at Brown University, MIT, University of Washington, Southwest Research Institute, and international partners such as CNES and JAXA.

Key Findings from Bennu and Mission Contributions

OVIRS identified widespread hydrated minerals on 101955 Bennu, confirming predictions from telescopic observations by Arecibo Observatory and spectroscopic campaigns led by Smithsonian Astrophysical Observatory; these detections aided sample site selection at sites like Nightingale and Osprey characterized in mission reports. OVIRS spectra revealed organic-rich materials, with 3.4 μm features consistent with aliphatic organics discussed in analyses by NASA Johnson Space Center and Carnegie Institution for Science, contributing to interpretations of carbonaceous chondrite analogs such as CI chondrite and CM chondrite meteorites studied at Natural History Museum, London. The instrument documented spectral heterogeneity related to space weathering processes similar to findings from Hayabusa2 at Ryugu, informing comparative planetology work at University of Tokyo and Tohoku University. OVIRS data supported high-level mission outcomes, including contextualizing returned samples analyzed at Johnson Space Center and cited in publications by teams at Nature (journal), Science (journal), Proceedings of the National Academy of Sciences, and numerous academic institutions worldwide.

Category:Spacecraft instruments