A CubeSat is a type of miniaturized satellite for space research that usually has a volume of exactly one liter (10 cm cube), weighs no more than 1 kilogram, and typically uses commercial off-the-shelf (COTS) electronics components.
Beginning in 1999, California Polytechnic State University (Cal Poly) and Stanford University developed the CubeSat specifications to help universities worldwide to perform space science and exploration.
The term "CubeSat" was coined to denote nano-satellites that adhere to the standards described in the CubeSat design specification. Cal Poly published the standard in an effort led by aerospace engineering professor Jordi Puig-Suari.
Professor Bob Twiggs, from the Department of Aeronautics & Astronautics at Stanford University, has contributed to the CubeSat community. His efforts have focused on CubeSats from educational institutions.
Since CubeSats are all 10x10 cm (regardless of length) they can all be launched and deployed using a common deployment system. CubeSats are typically launched and deployed from a mechanism called a Poly-PicoSatellite Orbital Deployer (P-POD).
P-PODs are mounted to a launch vehicle and carry CubeSats into orbit and deploy them once the proper signal is received from the launch vehicle. The P-POD can deploy 1U, 2U, or 3U CubeSats in any combination up to a maximum volume of 3U.
CubeSat forms a cost-effective independent means of getting a payload into orbit. Most CubeSats carry one or two scientific instruments as their primary mission payload. Several companies and research institutes offer regular launch opportunities in clusters of several cubes.