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6

In addition to Russell Borogove's good answer there is another factor here to keep in mind: When you are dealing with planets you can't just add together separate burns. If you add up the energy needed to escape Earth, the energy needed to go from Earth's orbit to Mars' orbit and the energy needed to enter Mars' orbit you will get more than 16 km/sec. In ...


6

16 km/s is about right for Earth surface to low Mars orbit, summing up a few entries in this table. I am not sure as how he did it though, and was unsure if he used the escape velocity of Earth, the Hohmann Transfer, and also if that was only that velocity computed needed to be obtained once At a minimum, this would be split into ascent to LEO (~9.4 km/...


1

Welcome to the site! I am afraid the answer you are looking for is not the one you want. Long story short, the optimal gravity turn must be calculated numerically, because the atmospheric density profile and velocity field is inherently numerically defined based on local conditions at the time of launch. (There's the standard atmosphere, and then accounting ...


3

In addition to the answers above, one should add that assuming you can get to Mars very, very fast, you will therefore arrive there with a very high velocity relative to Mars. This makes the problem of landing on Mars much harder. Also, if something goes wrong at Mars insertion, the Martian explorers are hurtling off into deep space with no way back. The ...


3

Liftoff at T-0 is common, but not universal. For Ariane 5, T-0 is the moment of ignition of the Vulcain engine. In a nominal countdown, checkout takes 6 seconds, and the solids are ignited when checkout finishes, leading to liftoff at T+7. I suspect there is some flexibility built into this: if the checkout takes longer, this is easily accommodated and ...


3

If you look at this delta-v map of the solar system, you can see that to get from the surface of the Moon to Neptune transfer requires about 7.67 km/s of delta-v. To get to Neptune from the surface of Mars requires 10.56 km/s of delta-v. So even if you were magically transported to Mars first, it would still take more energy to get to Neptune than it would ...


0

As such, I was wondering if there is a way to accurately track both position and velocity for the launch vehicle's ascent to orbit. How would tracking multiple reference targets be achieved during a real launch event? You cannot. Position and velocity are dependent variables (velocity is by definition the time derivative of the position), so controlling one ...


1

As such, I was wondering if there is a way to accurately track both position and velocity for the launch vehicle's ascent to orbit. If possible, have more accurate actuators and reference models. Improves the tracking of states easier. But since there is a relationship between position and velocity you cannot properly control both. The reason is simple: If ...


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