  The development of CubeSat and more frequent launch chances of sounding
rockets are a total game changer to the space program, and it allows us to
build space instruments to be more achievable and affordable. Therefore, it
gives us a good opportunity to build a small cosmic ray detector which has
capabilities to measure the flux, direction, and even energy of cosmic rays at
the height above the limitation of balloon experiments, and it may open a new
door for building a constellation of detectors to study cosmic ray physics.
Compact Scintillator Array Detector (ComSAD) is dedicated for the sounding
rocket mission of Taiwan's National Space Organization. In paper, we present
the idea, design, and performance of ComSAD which is also suitable for CubeSat
missions in the future.
