Have you ever been watching a sci-fi show, and heard the captain of the ship yell “All Stop!” at the helmsman? Have you ever wondered what that actually means?
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Orion CEV |
I once had a long debate with a fellow astrophysics student over the question of what ‘all stop’ really means for a spaceship.
See, for a real life spacecraft (lets say the Shuttle or Apollo missions) the vessel itself never stops, from the moment it leaves the planet to the moment it lands again. It is constantly moving: either orbiting earth, or the moon, or moving between the two. But it is always moving at speeds of at least 17,000 mph (all the way up to 24,000 for a lunar mission). You can only imagine that for interstellar missions, the same principle must be true, probably to an even greater extent.
Well I decided to try and imagine the physics and do some simple calculations.