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Difference between Hohmann transfer and "normal" transfer?


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We all know how to get to another celestial body- get the right angle and burn prograde. You get an intercept with your target body. When at your periapsis, burn retrograde. You're now orbiting your target body.

    Apparently, the Hohmann transfer is often the most efficient way to get to another body. This is accomplished with 2 prograde burns, which does not seem to be what the "normal" transfer does, even if you use the parent body as a reference frame. How do you do a Hohmann transfer in KSP, and what are the differences between such a transfer and the "normal" one?

Thanks.

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4 hours ago, LHACK4142 said:

    Apparently, the Hohmann transfer is often the most efficient way to get to another body. This is accomplished with 2 prograde burns

In practical terms, both of these are Hohmann transfers. The difference is that in your scenario, you're capturing at a planet, and in the Wikipedia definition of "Hohmann transfer", they're just circularizing at the new orbit without a planet.

Hohmann_transfer_orbit.svg

Edited by HebaruSan
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If you do a pure Hohmann - using two prograde burns as given by the formulas - you would end up in the sphere of influence of the destination body, with no orbital velocity(lithobraking ensues!). A transfer to a body with its own gravity needs to also solve achieving orbit around it. More complicated, but still called Hohmann.

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3 hours ago, LHACK4142 said:

We all know how to get to another celestial body- get the right angle and burn prograde. You get an intercept with your target body. When at your periapsis, burn retrograde. You're now orbiting your target body.

    Apparently, the Hohmann transfer is often the most efficient way to get to another body. This is accomplished with 2 prograde burns, which does not seem to be what the "normal" transfer does, even if you use the parent body as a reference frame. How do you do a Hohmann transfer in KSP, and what are the differences between such a transfer and the "normal" one?

Thanks.

they are the same thing. the description of the hohmann transfer says two prograde burns, because both are prograde from the perspective of the sun. in the capture burn, you're still burning prograde compared to the sun, because the planet is going faster than you and you must match velocity, at least enough to get captured.

in ksp, when doing a hohmann transfer to an external planet, you'll see the planet "sneaking up" behind you. at this point the perspective changes to that of the planet.

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