With antimatter, material, which is repelled rather than attracted by Earth is invented human race will solve the problem of completely free air movement

Alexander Alexandrovich Bogdanov : politician, physician,  philosopher
...I mean, to receive that type of the material that repels rather than attracts to the Earth, Sun and other bodies familiar for us, you used to compare with a diamagnetic repulsion of bodies and the repulsion of parallel currents of different direction. All this was just mentioned there, but I think that you yourself give it more importance than you wanted to show.
- You are right - I said - and I think exectly in this way the human race will solve the problem of completely free air movement, and then the task of communication between the planets. But this idea wright or not, it is completely useless as long as there is no exact theory of matter and gravity. If another type of matter exists, it is obviously impossible to find it: the power of repulsion eliminated it from the entire solar system, and even more true - it does not come of it, when it began to organize in the form of the nebula. Hence, this type of matter should still theoretically be constructed and then invented. Now, there is no data for this and, in fact, we can only anticipate the problem.
- And yet, this problem has already been solved - Manny said.

"Red Star"