TROPICS

TROPICS [MIT]

TROPICS (Time-Resolved Observations of Precipitation structure and storm Intensity with a Constellation of Smallsats) is a constellation of seven identical 3U CubeSats provide sounding with 30-minute median revisit rate.

Each TROPICS CubeSat, based on the MicroMAS and MicroMAS 2a, 2b satellites, is a dual-spinning 3U CubeSat equipped with a 12-channel passive microwave spectrometer providing imagery near 90 and 206 GHz, temperature sounding near 118 GHz, and moisture sounding near 183 GHz. Each CubeSat comprises a 2U spacecraft bus with ADCS, avionics, power, and communications, and a 1U spinning radiometer payload with highly integrated, compact microwave receiver electronics. Initially, a constellation of twelve satellites was planned, but it has been reduced to seven.

The science objectives of the mission are:

• Relate precipitation structure evolution, including diurnal cycle, to the evolution of the upper-level warm core and associated intensity changes
• Relate the occurrence of intense precipitation cores (convective bursts) to storm intensity evolution
• Relate retrieved environmental moisture measurements to coincident measures of storm structure (including size) and intensity
• Assimilate microwave radiances and/or retrievals in mesoscale and global numerical weather prediction models to assess impacts on storm track and intensity

This observing system offers an unprecedented combination of horizontal and temporal resolution to measure environmental and inner-core conditions for tropical cyclones (TCs) on a nearly global scale and is a profound leap forward in the temporal resolution of several key parameters needed for detailed study of high-impact meteorological events (TCs being the primary emphasis in this proposal). TROPICS will demonstrate that a constellation approach to earth Science can provide improved resolution, configurable coverage (tropics, near global, or global), flexibility, reliability, and launch access at extremely low cost, thereby serving as a model for future missions.

The TROPICS constellation will be formulated with four CubeSats in each of three orbital planes with the following launch parameters: equally spaced RAAN (±30° tolerance), 600 km altitude (550±50 km tolerance), 30° inclination (±3° tolerance). These mission parameters will meet science requirements should the threshold number of CubeSats (eight) be implemented. Analyses have shown orbit lifetime of 9 years, well over the expected mission lifetime of one year and well in advance of the 25-year de-orbit requirement. This configuration yields 30-minute median revisit rates with average spatial resolution better than precipitation and all-weather temperature and humidity (PATH) requirements, all from a low-cost, low-risk CubeSat constellation platform.

Blue Canyon Technologies received a contract to build seven identical XACT-based 3U-class CubeSats. One will be launched as a pathfinder for checkout and optimization of all mission elements prior to the primary six satellite constellation.