• OSIRIS-REx Thermal Emission Spectrometer
  • Launch: September 2016
  • Arrival: December 2018
  • Currently: Orbiting Bennu

What is it?

The OSIRIS-REx Thermal Emission Spectrometer, OTES for short, is an instrument on board NASA’s OSIRIS-REx spacecraft. With a design heritage from two previous infrared spectrometers, OTES is a robust and proven instrument for operations at asteroid Bennu.

What does it do?

The OSIRIS-REx Thermal Emission Spectrometer (OTES) provides mineralogical and thermal emission spectral maps and local spectral information of candidate sample sites by collecting thermal infrared data from 4 to 50 micrometers.

Why is it significant?

Bennu is believed to be a primitive asteroid, thus offering scientists a chance to examine a carbon-rich object that may be little changed from the early solar system.

Science Objectives

  • Return and analyze a sample of Bennu’s surface
  • Map the asteroid
  • Document the sample site
  • Measure the orbit deviation caused by non-gravitational forces (the Yarkovsky effect)
  • Compare observations at the asteroid to ground-based observations
The OSIRIS-REx spacecraft is orbiting Bennu, a carbonaceous asteroid whose regolith may record the earliest history of our solar system. Bennu may contain the molecular precursors to the origin of life and the Earth’s oceans. OSIRIS-REx will determine Bennu’s physical and chemical properties and collect a carefully chosen sample of its surface for return to Earth. Bennu is also one of the most potentially hazardous asteroids, with a relatively high probability of impacting Earth late in the 22nd century. Mission data will be critical to have in the event of an impact mitigation mission. Finally, asteroids such as Bennu contain natural resources such as water, organics, and precious metals. In the future, these asteroids may one day fuel the exploration of the solar system by robotic and manned spacecraft.

Meet the Group


  • Phil Christensen, OTES Instrument Scientist
  • Arizona State University
  • Vicky Hamilton, Deputy Instrument Scientist
  • Southwest Research Institute


  • Saadat Anwar, Software Engineer
  • Arizona State University
  • Heather Bowles, Configuration Management
  • Arizona State University
  • Stillman Chase, System Engineer
  • Arizona State University
  • John Fahlgren, Mission Assurance Engineer
  • Arizona State University
  • Zoltan Farkas, Mechanical Engineer
  • Arizona State University
  • Tara Fisher, Administrator
  • Arizona State University
  • Greg Mehall, Project Engineer
  • Arizona State University
  • Mark Miner, Thermal Engineering
  • Arizona State University
  • William O'Donnell, Opto/Mechanical Engineer
  • Arizona State University
  • Dan Pelham, Opto/Mechanical Engineer
  • Arizona State University
  • Sam Pellicori, Optical Engineer
  • Arizona State University
  • Nick Piacentine, IT Manager
  • Arizona State University
  • John Robinson, Mission Assurance Advisor
  • Arizona State University
  • Steve Ruff, Instrument Calibration
  • Arizona State University
  • Lisa Schulze, Procurements
  • Arizona State University
  • Ken Shamordola, Electrical Engineer
  • Arizona State University
  • Tom Torville, Mechanical Design Engineer
  • Arizona State University
  • Tom Wolverton, Structural Engineer
  • Arizona State University
  • Robert Woodward, Manufacturing Engineer
  • Arizona State University
  • Gates West, Lead Electrical Engineer
  • Moog Broad Reach Co.
  • Orson John, Reliability Engineer
  • NASA Goddard Space Flight Center


  • Chris Haberle
  • Arizona State University
  • Andy Ryan
  • University of Arizona



    Frequently Asked Questions

    • What is OTES?

      OTES is a thermal emission spectrometer. It detects thermal (heat) emission from the surface materials of asteroid Bennu at a variety of infrared wavelengths. The data from OTES lets scientists determine what minerals are present and measure the temperature of the surface.