A CubeSat is a small satellite in the shape of a 10 centimeter cube and weighs just 1 kilogram. That's about 4 inches and 2 pounds. The design has been simplified so almost anyone can build them and the instructions are available for free online. CubeSats can be combined to make larger satellites in case you need bigger payloads. Deployable solar panels and antennas make Cubesats even more versatile. The cost to build one? Typically less than $50,000.