TransX - The orbit eject function

This mode exists to solve a problem familiar to anyone who's ever tried to get an Apollo command module back from the moon. How do I go from an existing lunar orbit into an efficient Earth transit? This mode helps to plan a solution to that problem.

Most of the rest of the time, it is better to use Eject mode and start from the surface. Even when in orbit, you may be able to find an efficient way of working with the Eject mode, and that is usually better. But, if all else fails, the Orbit Eject mode may be what you need if you're in orbit around a planet or moon.

How do I access the Orbit eject function?
You need to use the FN (Shift-F) key to switch TransX to the orbit eject function.You also need to set MAJ and MIN correctly. MIN will be the object you're orbiting, and MAJ will be the body that MIN orbits. Set MAJ first, as setting MAJ resets MIN.

You may set a target if you want to. If you want to fly to the central body (eg Moon to Earth) do not set a target at all, and the MFD will give you information relevant to flying to the central body instead.

Orbit Eject function views

There is another set of variables which apply specifically to this mode.

Minor view variables

Variables shared between minor and major views

Major view variables

How do I use these variables?

Usually the best method is to set some prograde velocity until you reach escape velocity of the minor body, and a bit more. Then adjust both the Prograde velocity and the eject date to refine a good course for your flight, switching back and forth between the views until you're happy. Below are two screenshots I took using AMSO in Orbiter version 190402, showing an orbit created by adjusting both these variables. This particular AMSO scenario has a lunar orbir almost coplanar with the Earth/Moon system, so it produces a nice result.

Some orbits just don't produce a nice result whatever you do. In such circumstances, it's often best to just do the best you can without using too much fuel, and aim to sort it out once you get out of that body's SOI.

When you cross the border of the SOI, you will be switched into the Cruise function, which also contains information helping you to target the central body if you wish.

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Orbiter Mars - (C) Duncan Sharpe 2003