NASA Goddard Space Flight Center has developed SpOC Cube, a complete coronagraph that fits into a 6U CubeSat. SpoC Cube is designed to minimize noise from the coronagraph that can interfere with data collection and analysis. One way to avoid this light contamination is to place the occulter as far away from the instrument as possible. SpoC Cube’s occulter is a full seven feet away, nearly twice as far as in the STEREO spacecraft that collects similar data. Additional noise reduction is achieved by using a spherical-shaped occulter rather than a flat disk (think nature’s most effective occulter, the Moon).
A tennis-ball-sized occulter made from titanium is the current design but in the future, it may be a larger inflatable design that can be positioned even further away from the instrument. It will fly in formation with a CubeSat equipped with an imaging spectrograph and study the Sun’s corona and more particularly, coronal mass ejections. These are bubbles of charged particles that speed across the solar system and can disrupt electronics on low-Earth-orbiting satellites and damage terrestrial power grids when they slam into Earth’s protective magnetosphere.