# Search results

1. ### How calculate semi-latus rectum of parabola or hyperbola?

The semi-latus rectum is necessary for the formula However, if we refer to Wikipedia, we need to know the semi-major axis to calculate the semi-latus rectum. But the semi-major axis is only defined for circles and ellipses, if I am not getting it wrong. So assume I am in a parabolic or...
2. ### How calculate the minimum Delta v necessary to change one given orbit into another given orbit?

The question is to be understood in the idealized model where I have only one point mass and a vessel with neglectable mass in orbit, Newton mechanics. Thanks for your help!
3. ### API Question Get name/mass of a CELBODY (and what if it is NULL?)

I want to get ephemeris data of all bodies. So I do the following: unsigned int nGBodies = oapiGetGbodyCount(); for (unsigned int iGBody = 0; iGBody < nGBodies; iGBody++) { OBJHANDLE hGBody = oapiGetGbodyByIndex (iGBody); CELBODY *pGBody = oapiGetCelbodyInterface (hGBody); ... }...
4. ### Flight Question What is changing Phobos' orbit?

Hey, do you know why the orbit of Phobos seems to change so fast? When it approaches its apoapsis (on 2021-12-01), in Orbit MFD, the "ApT" value of Phobos decreases at 1.14 seconds per second, meaning that the apoapsis location is moving about 0.14 seconds (295 meters) backwards every second. If...
5. ### TransX How to restart TransX when buggy?

Sometimes, my TransX has a bug, so I want to restart it. Simply cancelling all plans, going back to stage 0 or restarting Orbiter does not seem to work. A frequent bug is (I don't know how to trigger it) that changing the velocities in manoeuvre mode stops influencing the orbit in the next stage...
6. ### TransX Creating escape plan from Earth to Moon while on ground

The opportunity to create an escape plan in TransX while standing on the ground, instead of going to orbit first and then creating the plan, may be important in order to minimize the time in earth orbit. This is no problem when going from Earth to any other planet: I set the "select target"...
7. ### TransX How to effectively plan multi-planet hopping backwards?

Good evening! On TransX, it is no problem to choose the "sling direct" plan to go from planet A to planet B. Therefore, one can adjust the "departure" date, the "departure" angle and the "departure" velocity and then try to find a good combination of those, such that the vessel would just arrive...