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One of the more interesting consequences of orbital mechanics is it takes far more delta-v to get close to the sun, than it does to leave the solar system entir
by throwaway2048 7y ago
One of the more interesting consequences of orbital mechanics is it takes far more delta-v to get close to the sun, than it does to leave the solar system entirely.
Think about this in terms of how fast the earth is moving to avoid "falling into" the sun, anything that leaves the earth has that velocity too.
- DavidSJ 7y agoIf you do a Hohmann transfer — the most basic sort, used by most Δv calculations — from Earth to the Sun, yes. But if you give yourself solar escape velocity (a savings of about 59% in your hyperbolic Earth escape velocity, which works out to a huge savings of about 18.9 km/s Δv if you do your burn in Low Earth Orbit), then once you get very far from the Sun you can stop yourself virtually for free, and fall straight down. The whole trip would take decades though. The same basic idea works for reaching any inner object orbiting any body. In practice you can probably do better by aiming for a planet and slingshotting, but that gets more complicated.