At this point
in your journey, you are still close to the Earth. The TransferX MFD is
calculating how much Earth will slow you up in your climb away from it,
and using that information to plot your orbit around the Sun once you've
escaped from Earth. The plot you are seeing takes both bodies into
account.
As you get further and further away from Earth, this complicated adjustment of your anticipated course becomes less and less necessary. The TransferX MFD will automatically compute when to stop taking Earth into account, and this will happen at around 900,000 kilometres from Earth. Each planet has a different sphere of influence (SOI) depending on its mass and distance from the Sun.
Inside 900,00 km yout craft is in the sphere of influence of the minor body, Earth. Outside it, the Transfer MFD automatically switches to a different mode - the major sphere of influence (SOI) mode.
If you've never done an interplanetary flight before - they're long. Mars will take around half an hour at 10,000 times acceleration. This is quite short - flying to Saturn takes three hours, and Neptune takes all night.
The
major SOI mode has
(at present) no variables. However, you can still track your closest
approach to the target. You can use this to fine-tune your path towards Mars.
But you shouldn't do this straight after the mode switches. Earth is still very close, and is affecting your path even though the TransferX MFD is no longer taking it into account. In fact, when the switchover occurs, the MFD's projected orbital path becomes less accurate for a little while. Just wait, and things will improve.
It does no harm to wait until you are well away from Earth, and it is no longer seriously affecting your track. You will see the closest approach moving around less as time goes by and Earth becomes more distant. One good rule of thumb is to use the orbit MFD, and wait for G=1.00 to come up at the bottom.
You should then adjust the closest approach at regular intervals. The closer you are to being exactly on target the better, and the closer you get to the target, the more it matters.
One way I use to adjust my trajectory is to set the autopilot to prograde, and then use the various linear thrusters in short bursts to find out which directions of thrust help to reduce the error. Then you can either continue to use the linear thrusters for small adjustments, or use the hover engine for larger ones.
The influence of other planets will continue to affect your targeting, so you should adjust your trajectory at regularly. By the time you get towards the end of your journey, you should have the closest approach down to small numbers of millions of metres, as I have below.
TransferX does not take the gravity of the target into account, so your actual closest approach will be less than indicated - particularly if it means a close pass to the planet..
Finally you will approach Mars. Mars is much lighter than Earth, and at this point we are still outside Mars's sphere of influence. The final part of the approach is not something the TransferX MFD helps with, because you don't really need it.
There is a bug in Orbiter which causes a crash if you use the orbit MFD too far from a planet. For safety's sake, use it with REF=Sun until G drops to 0.99. At this point it is safe to switch over to REF=Mars
At large distances, the PeD given by the orbit window wanders around quite badly because of the Sun's gravity. However, you can trust the closest approach from the TransferX MFD. Once you start to get close to the planet, PeD wanders around much less, and you can start to rely on it.
A good point to aim for is a PeD of 3.5M . Keep adjusting your track regularly to ensure that you'll hit it accurately. A PeD of 3.3M will have you adding an extra crater to the surface, so make sure that you stay on target. You will rapidly draw very close to Mars.
We get this
close because doing so is efficient. When you reach just before Periapsis,
engage reverse Autopilot, and, ensuring you're lined up properly, hit full
reverse thrust. It's quite a long burn, but eventually your orbit will
change from a hyperbola to an ellipse. You have been captured by Mars.
You have arrived !!
