Other issues were that the LESS had to be as light as possible so as not to significantly reduce the cargo capacity of the LEM, and easy to pack into the LM in such a way that it would not interfere with the other cargo. One consequence was that most designs used detachable legs: the legs would be set up on the lunar surface, the LESS assembled on top of them, and the legs then left behind as the LESS launched. This did not directly reduce the mass required, but it did reduce the empty mass of the LESS, which reduced the fuel required to lift it to orbit, which also reduced the thrust required from the engines and the total mass of the design.