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| {{Orphan|date=February 2009}}
| | Hi there, I am Alyson Boon even though it is not the name on my birth certification. Credit authorising is how he tends to make money. Mississippi is where her home is but her husband desires them to move. To climb is some thing she would by no means give up.<br><br>Take a look at my web-site :: online psychic reading ([http://myfusionprofits.com/groups/find-out-about-self-improvement-tips-here/ myfusionprofits.com]) |
| '''Gate orbits''' are optimal circular departure orbits for transfer from one planet to another. At certain specific orbits around a cosmic body, the additional [[delta-v|delta-''v'']] required to go from orbital velocity to [[hyperbolic trajectory]] for an interplanetary transfer, is minimal. Gate orbits can therefore be very useful for minimising the [[delta-v budget|delta-''v'' budget]] for an interplanetary trip.
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| For example, the required delta-''v'' for a [[Hohmann transfer orbit]] from the Earth to Mars (considering Earth at 1 AU and Mars at 1.52 AU) is 2.94 km/s. To reach 2.94 km/s at infinity from a [[low Earth orbit]] at, say 200 km altitude, requires a 3.61 km/s burn. If the vehicle were to leave the Earth's attraction from the 92,000 km high Mars gate orbit instead, required delta-''v'' would be only 2.08 km/s. At higher still orbits the required delta-''v'' rises again. For example, at 150,000 km, required delta-v is now 2.17 km/s.
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| Reducing the delta-''v'' from 3.61 to 2.08 km/s can reduce the total mass of the vehicle by as much as 38%, or increase the payload by 62%!
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| The radius of a given gate orbit can be calculated using the following equation:
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| :<math>r = {2\mu \over v_\infty^2}</math>
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| where:
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| *<math>r\,</math> is the distance between the [[orbiting body]] and the [[central body]], in km
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| *<math>\mu\,</math> is the [[standard gravitational parameter]], in km<sup>3</sup>s<sup>−2</sup>
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| *<math>v_\infty\,</math> is the required velocity at infinity, in km·s<sup>−1</sup>. Remember <math>v_\infty^2</math> is also known as <math>C3</math>
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| == External links ==
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| * [http://www.christov.com/space/IGO-5.pdf Interplanetary Gate Orbits by Marco Christov]
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| [[Category:Spaceflight]]
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| [[Category:Orbital maneuvers]]
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Latest revision as of 13:27, 5 May 2014
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