Re: Laser launched rockets
My impression from the video (s -- I watched a couple of the related ones in English as well) is that the laser is focused by the shape of the underside of the craft to superheat the air flowing through the vents in the body, causing a rapid expansion of that air that pushes against the body of the craft and produces the thrust. This presents the practical use of the craft with two major problems:
1) The craft is limited to use where the density of air is great enough to provide the necessary thrust. So, no orbital lifting.
2) the laser must be directly underneath the craft, and lined up properly, or it will at best produce unbalanced thrust, which would drive it further, or completely, out of alignment with the laser, and back into gravity's persistent embrace. So, no flying on windy days. Or near the jet stream, if you can even fly that high.
It is an interesting technology, but it doesn't seem very useful.