Before posting feature requests or bug reports, please read the FAQ.
Works with stock aerodynamics and FAR
Reportedly works with
real solar system
Outer Planets Mod
Compatible with Blizzy's toolbar
If you see weird spirals or other crazy lines everywhere, double-check you didn't enable "body-fixed mode" by mistake
If the predicted trajectory seems inaccurate, check that you set the correct orientation in the Descent profile (or checked Prograde or Retrograde), and that you keep that orientation all the time
It's not possible to predict a trajectory for a future stage. We know this is a highly requested feature, but unless we duplicate big parts of the KSP-internal code, we are limited to simulating the current state of the vessel.
Parachutes are not simulated (that's usually not a problem if you open it near the ground)
A build of Trajectories 1.7.0 for KSP 1.2.2 can be downloaded here.
The mod displays trajectory predictions, accounting for atmospheric drag and lift. Works with the stock aerodynamic model, and with Ferram Aerospace Research (FAR).
With this mod, you can
choose precisely the location where you'll crash. The typical precision is about 6km.
Plan Aerobraking maneuvers that can, for example, put you on intersection trajectory with another body (see point 1 about what you can do from there)
Keep in mind that this software comes without warranty of any kind, and in particular that it may or may not help you survive, reach a specific target, or anything at all. But it usually helps
See your predicted trajectory
Open the map view
This is it ; trajectory display is enabled by default, you have nothing else to do
White is the trajectory in space, red is the trajectory in atmosphere, the red cross is your impact point (that takes the body rotation into account to show the impact point on the terrain, this is useful both for bodies with and without atmosphere)
Disable the trajectory display
Click on the Trajectories icon in the stock KSP toolbar (or Blizzy's toolbar if it's installed) to display the main UI
Click "Display trajectory" to toggle it on/off
Click "complete" to toggle display of the complete trajectory (including parts where it is superimposed with the stock KSP trajectory)
Set a target point (nav ball guidance)
Adjust your velocity so that the red cross is located where you want to go
Click "Set current impact as target" to enable the green cross
Alternatively, there is a button to set the target on the KSC (works on Kerbin only obviously), or you can enter longitude/latitude
Go back in flight view, and notice the two new indicators on the nav ball
The square indicator shows where you need to point your craft at if you were exactly following the predicted trajectory
The circle indicator is a hint about the direction you should go to adjust your actual trajectory to reach the target (this is not necessarily where you need to point, what's important is the direction between the square and the circle, and the distance between them indicates how far you are from the perfect trajectory)
Use this toggle to switch between the regular mode (similar to stock KSP orbits), or body-fixed mode. In body-fixed mode, the trajectory is displayed relatively to the body frame, following the body rotation. This mode makes sense for atmospheric or low terrain fly-by, and also to adjust a geostationary orbit. However, for most high orbits, it will just look funny. This can help you keep occupied for those 2-year-long planetary transfers, but try not to burn up all the fuel to see how it can make funny curved lines.
You can plan aerobraking or re-entry after manoeuvers, just place your nodes as usual and see the predicted trajectory. Keep in mind that you always place nodes on the stock trajectory, that might be very different from the predicted one, so you may have to place nodes at a point that have an effect somewhere else on the predicted trajectory (especially when planning landing on a body without atmosphere with body-fixed mode). Also, atmospheric prediction can happen only for the body you are currently orbiting, so you can't plan a Kerbin re-entry while you're still arround the Mun.
Support and Bugs
If you have questions and feedback regarding a current release, feel free to post in this thread.
Please post bug reports on the GitHub bug tracker. If you don't know how, don't want to learn or are unsure it's a bug, you can ask in this thread.
This mod is a community project! It was originally written by @Youen and is currently maintained by @Kobymaru.
The following people have already contributed to this project (in approximative order of commits):
Youen (Github neuoy)
Kobymaru (Github fat-lobyte)
atomicfury (Github sawyerap)
And many others.
You want to be part of this list? Contributions are very welcome! Read our Introduction for Contributors, fork the Repository on Github and have a go at the code!
When you feel that your changes are mature enough to be included, send me a pull request! Also, please let us know what you are working on in the development thread.
It's always best if you work on your "pet problem" - a bug that needs to be fixed or that you personally want to see implemented. Or you could just grab an issue from our Issue Tracker!
For discussions about Mod internals and Development, please head over to the development thread.
The changelog started with release v1.6.7. For the changes in versions older than that, please visit the GitHub releases page.
This mod is under MIT license, feel free to look at the source code: https://github.com/neuoy/KSPTrajectories