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Posts Tagged ‘ballistic’

Spacetransportnews has a link to another in the long list of nontechnical space dreams.

Earth’s radius is about 7000 km. The Van Allen belts start somewhat above 500 km from Earth’s surface. Hence, ballistic arcs have to be either very short or then very shallow. And shallow arcs mean high speed. Close to orbital. New York to Paris is about 6000 km. That’s roughly one seventh of the great circle. It is very clear that to travel such a distance ballistically and at low altitude, you need most of orbital velocity. ICBM:s have very high apogees because of this.

The corridor between the atmosphere’s top and the Van Allen belts is so narrow, just a couple hundred kilometers, compared to the horizontal distances, a couple thousand kilometers, that ballistic point to point travel for humans does not make sense.

Nobody seems to recognize this fact. We get vague dreamy projections by even the normally technically hard nosed engineer people in the alt space circles. Wake up. Orbital mechanics wins. Transatlantic point to point is harder than orbital.  Never mind transpacific.

Grumpy mode off…

Word coin: Narrow suborbital ballistic corridor.

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