What is the maximum weight for 6U and 12U cubesat in kg.? Please, give links/references.
In this link it's stated that, 6U is 12kg, 12U is 24kg. But 1U is 1.33 kg, how is it possible?
There are different standards. The original standard is 1 kg/ unit, but there are other options today. CalPoly, which launches the highest number of cubesats today, sets the standard at 1.33 kg/ unit. If you have a cubesat launched by someone else, they might allow even more mass. NASA states that simply it depends on the dispenser, which is true.