A question it seems a good time to ask: what's the space travel equivalent of the waterway lock?
It would be more than a simple drive of course, or a faster-than-light portal say, in that it's not about speed, though it might be linked with warping space. It seems more than maneouvring thrusters given we're looking at movement onto another level rather than laterally. It doesn't look related to escape velocity either - that would be pushing off into the stream.
Maybe we just don't have it yet?_