CubeSats to demonstrate next generation of Earth-observing technology

Three cubesats were on board Orbital ATK’s Cygnus cargo spacecraft when it launched on 21 May from NASA’s Wallops Flight Facility in Virginia, USA. The launch was Orbital ATK’s ninth commercial resupply mission to the International Space Station. Each cubesat is the size of a cereal box and will be used to test and demonstrate the next generation of Earth-observing technology. One of the satellites is RainCube, a miniaturised precipitation-studying radar instrument that weighs 11.8kg. It is smaller, has fewer components and uses less power than traditional radar instruments. NASA’s Earth Science Technology Office (ESTO) In-Space Validation of Earth Science Technologies (InVEST) programme selected the RainCube to demonstrate that such a diminutive radar can be operated successfully on a cubesat platform. This mission marks the first time an active radar instrument has been flown on a cubesat. If successful, RainCube could open the door for lower-cost, quick-turnaround constellation missions, in which multiple cubesats work together to provide more frequent observations than a single satellite. “A constellation of RainCube radars would be able to observe the internal structure of weather systems as they evolve according to processes that need to be better characterised in weather and climate forecasting models,” said RainCube principal investigator Eva Peral of NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California. The second cubesat on board the spacecraft is CubeRRT, which has been developed by Joel Johnson of The Ohio State University and funded by the InVEST programme. CubeRRT, which stands for the CubeSat Radiometer Radio Frequency Interference Technology Validation mission, has been developed to test a new way to improve data collection from space and overcome radio frequency interference issues. The third cubesat is the TEMPEST-D (Temporal Experiment for Storms and Tropical Systems Demonstration) mission, which will improve monitoring of cloud processes, specifically storm development and the identification of the time when rain begins to fall. NASA’s Earth System Science Pathfinder programme selected Steven Reising of Colorado State University to develop, build and demonstrate a five-frequency radiometer based on newly available low-noise amplifier technologies developed with support from ESTO. The TEMPEST-D mission will validate the miniaturised radiometer technology and demonstrate the spacecraft’s ability to perform drag manoeuvres to control TEMPEST-D’s low-Earth altitude and its position in orbit.