Polar Radiant Energy in the Far InfraRed Experiment

Revealing new aspects of the Arctic climate by measuring the full spectrum of polar radiant energy.

Image courtesy of the Earth Science and Remote Sensing Unit, NASA Johnson Space Center


PREFIRE makes the first full spectral measurements of Far InfraRed (FIR) radiation, revealing the full spectrum of Arctic radiant energy. It fills a major gap in our knowledge of the Arctic energy budget and the role of FIR radiation in Arctic warming, sea ice loss, ice sheet melt, and sea level rise.


The Arctic is Earth’s thermostat. It regulates the climate by venting excess energy received in the tropics.


Nearly 60% of Arctic emission occurs at wavelengths longer than 15 μm (FIR) that have never been systematically measured.


PREFIRE quantifies spatial and temporal variability in spectral FIR emission and the atmospheric greenhouse effect.

Image courtesy of NASA Visible Earth


How are we measuring and what will we do with the data?

PREFIRE measures variations in FIR emissivity and greenhouse effect via thermal radiometric sampling at the top of the polar atmosphere. These measurements are integrated with models to understand the role of FIR radiation in Arctic climate.

Baseline Mission

Two 6U CubeSat spacecraft in two different 470-650 km altitude, near-polar (82°-98° inclination) orbits, each with a Heritage miniaturized IR spectrometer, covering the 0-54 μm region at 0.84 μm spectral resolution, operating for one seasonal cycle (a year) with diurnal subsampling.

Threshold Mission

One 6U CubeSat spacecraft (470-650 km altitude) in near-polar orbit (82° - 98° inclination), operating for a half seasonal cycle (6 months).


CubeSat Orbit

Two spacecraft in polar orbits sample Arctic and Antarctic surfaces and clouds, providing sub-diurnal coverage

Image courtesy of NASA Visible Earth


TIRS Opto-mechanical design

Thermal IR Spectrometer (TIRS)

  • Flight-proven hardware and design—TIRS uncooled detector and filter block design maturity are from Mars Climate Sounder and Diviner
  • Instrument has adequate margins (mass, power, volume, and data rate)
  • Orbit and mission design flexibility for accommodating different launch opportunities

Technical Specifications

Thermopile array
64 x 8 pixels
Spectral sampling
0.84 μm from 0-54 μm
Spatial coverage
8 cross-track pixels with 1.3° footprints
< 3 kg
Data rate
12 kbps
< 6 W
Image courtesy of NASA Visible Earth

Science Team

For more information, contact Erin Hokanson Wagner
Image courtesy of NASA Visible Earth

Latest News

Website Launch

16th June 2020

Welcome to the PREFIRE Website, hosted at the Space Science and Engineering Center.

Read more
Image courtesy of NASA Visible Earth



  • Peterson, C., X.H. Chen, Q. Yue, X.L. Huang, The Spectral Dimension of Arctic Outgoing Longwave Radiation and Greenhouse Efficiency Trends from 2003-2016, JGR-Atmospheres, 124,, 2019.
  • Brian H. Kahn, Brian J. Drouin, T.S. L’Ecuyer, Assessment of sampling sufficiency for low-cost satellite missions: Application to PREFIRE, submitted to J. Atmos. Ocean. Tech. on February 10, 2020
Image courtesy of NASA Visible Earth



The PREFIRE project will start science operations no earlier than 2022, after which mission data will be publicly accessible through the NASA Langley Atmospheric Science Data Center
Image courtesy of NASA Visible Earth