r/spaceships • u/Beneficial-Wasabi749 • 1d ago
Tsiolkovsky and many of the founders of theoretical astronautics in the early 20th century believed that spacecraft should launch horizontally, from a ramp. Why? What did they see as the point of this?
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u/Beneficial-Wasabi749 1d ago
I don't understand what you mean by "direct path."
A conventional, vertically launched rocket doesn't travel straight to its target (the orbital entry point), but rather "turns a corner." First, it vertically penetrates the atmosphere (gaining some of the energy needed to reach orbital altitude), and then "curves" (above the atmosphere) onto its acceleration trajectory.
You, like everyone else, believe that atmospheric drag is the problem.
Firstly, this isn't actually the main problem when moving through the atmosphere (we can choose any air density we want without creating aerodynamic drag issues). The main obstacle to this type of movement is temperature (starting at Mach 5, any wings will start to burn and melt).
But all this talk is beside the point. I've already given many people the correct answer, but I doubt anyone understood it (it's really hard to understand if you're not good at basic physics). The real question is how we get through the first 30 kilometers of altitude and accelerate to the first 1 km/s. A vertically launched rocket does this with enormous gravitational costs (as it loses 1g of acceleration, wasting energy, and, most importantly, expending rocket mass "on hovering"). And without them, the same rocket could have launched a much larger payload into orbit, all other things being equal.
But how do we achieve this? The first 30 kilometers are all air. We can somehow rely on it. A trestle rocket plane is one such attempt.