On 25 Aug 2017 11:52, "Jeff Rowse" <xxxxxx@hotmail.com> wrote:

Unless you have some sort of magic material like the Carvorite in HG Wells' "The First Men In The Moon

Which is exactly what contra-grav is, except that, instead of being a material, the CG generates a field which negates gravity. Of course, you still need power to energise that field, but in the handwavium physics of the TU that power is far less - by several orders of magnitude - than that required to hold the ship up using thrusters alone.