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Inflated Delta Vs

6 Oct 2012, 23:41 UTC
Inflated Delta Vs
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Parking Orbit delta Vs Inflated Delta Vs"What's delta V from Earth orbit to Mars orbit?" -- a common question in science fiction or space exploration forums. The usual answer given is around 6 km/s, the delta V needed to go from a low, circular Earth orbit to a low, circular Mars orbit. A misleading answer, in my opinion.There are a multitude of possible orbits and low circular orbits take more delta V to enter and exit. A science fiction writer using 6 km/s for Earth orbit to Mars orbit has a needlessly high delta V budget.There are capture orbits that take much less delta V to enter and exit. By capture orbit I mean a periapsis as low as possible and apoapsis as high as possible. A capture orbit's apoapsis should be within a planet's Sphere Of Influence (SOI).On page 124 of Prussing and Conway's Orbital Mechanics, radius of Sphere Of Influence is given by:rsoi = ( mp / ms ) 2/5 rspwherersoi is radius of Sphere Of Influencemp is mass of planetms is mass of sunrsp is distance between sun and planet. The table below is modeled after a mission table at Atomic Rockets, a popular resource for science ...

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