The PolSIR instrument – short for Polarized Submillimeter Ice-cloud Radiometer – will help humanity better understand Earth’s dynamic atmosphere and its impact on climate by studying ice clouds that form at high altitudes throughout tropical and sub-tropical regions. The PolSIR mission consists of two 12U CubeSats, each equipped with a cross-track scanning polarized submillimeter radiometer in two spectral bands with center frequencies at 325 and 684 GHz.

The mission is led by Dr. Ralf Bennartz, principal investigator at Vanderbilt University in Nashville, Tennessee. Dr. Dong Wu, an atmospheric scientist in the Climate and Radiation Laboratory (Code 613), is the deputy PI.

NASA Goddard will also provide the project management team that builds the two instruments.

Science operations will be conducted by the Space Science and Engineering Center at the University of Wisconsin - Madison. The two spacecraft will be built by Blue Canyon Technologies in Lafayette, Colorado.

The CubeSats will fly in orbits separated by three to nine hours. Over time, these two instruments will observe the full diurnal cycle of cloud ice content.

The award is for lifecycle costs no more than $37 million, which does not include launch costs. As an Earth Venture instrument, PolSIR is a lower-cost instrument with a targeted research goal. The Earth Venture class also focuses on providing frequent flight opportunities, so innovative science investigations can be flown relatively quickly, generally within five years.