New Small Satellite Capabilities for Microwave Atmospheric Remote Sensing

Several advanced technology missions flying microwave radiometers for high-resolution atmospheric sensing are in varying stages of development. Microwave instrumentation is particularly well suited for implementation on a very small satellite, as the sensor requirements for power, pointing, and spatial resolution (aperture size) can be accommodated by a nanosatellite platform. The MicroMAS-2 mission is in development with an advanced four-band radiometer observing near 90, 118, 183, and 206 GHz to provide precipitation, temperature, and humidity measurements from a 3U CubeSat.  The first of two MicroMAS-2 flight units will launch in March 2017. The Microwave Radiometer Technology Acceleration (MiRaTA) CubeSat will demonstrate multi-band atmospheric sounding and co-located GPS radio occultation on a 3U CubeSat. MiRaTA will launch in 2017 as a secondary payload on the JPSS-1 satellite. MiRaTA is designed for a one-year mission life and will fly a tri-band sounder (60, 183, and 206 GHz) and a GPS radio occultation (GPS-RO) sensor comprising a modified COTS receiver and antenna patch array.  Finally, The Time-Resolved Observations of Precipitation structure and storm Intensity with a Constellation of Smallsats (TROPICS) mission was recently selected by NASA as part of the Earth Venture–Instrument (EVI-3) program. The TROPICS constellation comprises 12 CubeSats in three low-Earth orbital planes. Each CubeSat will host a high performance radiometer to provide temperature profiles using seven channels near the 118.75 GHz oxygen absorption line, water vapor profiles using 3 channels near the 183 GHz water vapor absorption line, imagery in a single channel near 90 GHz for precipitation measurements (when combined with higher resolution water vapor channels), and a single channel at 206 GHz that is more sensitive to precipitation-sized ice particles.

Building upon this work, the Earth Observing Nanosatellite-Microwave mission is being formulated by MIT Lincoln Laboratory for the NOAA National Environmental Satellite, Data, and Information Service as part of the Polar Follow-On (PFO) budget request to extend JPSS for two more missions, and provides a means to mitigate the risk of a gap in continuity of weather observations. The PFO request aims to achieve robustness in the polar satellite system to ensure continuity of NOAA’s polar weather observations. The baseline EON-MW design accommodates a scanning 22-channel high-resolution microwave spectrometer on a 12U CubeSat platform to provide data continuity with the existing AMSU and ATMS microwave sounding systems. EON-MW will nominally be launched into a sun-synchronous orbit for a two to three year mitigation mission in 2019 that will also extend technology demonstration beyond what MicroMAS and MiRaTA will achieve. Key EON-MW features include a compact dual-reflector radiometer design that permits the entire microwave sounding payload to be developed with a total mass of approximately 4 kg while maximizing antenna aperture for optimal spatial resolution. The spacecraft bus is approximately 16 kg, and the entire satellite (prior to solar array deployment) measures approximately 22x22x34 cm. Communications to ground are accomplished with a space-qualified X-band transceiver and a ground station to be nominally located at a high latitude. Average power consumption of the satellite is approximately 50 W. This presentation will provide an overview of the EON-MW mission, discuss key satellite and payload subsystems, describe risk reduction and mission planning, and present key attributes of the ground and data segments.