Vessel flies through Luna's sphere of influence with no encounter and no SOI transition

[Maxi]

Game Version​

2026.7.9.5018

Operating System​

Windows 10

What Happened​

If i use the Transfer planner to plan an Hohmann Transfer from the default LEO starting position -> Luna the trajectory does not interact with the Luna SOI (both visuals and physics are (not) affected).

A vessel on a near-coplanar, highly eccentric Earth orbit passes straight through Luna's sphere of influence. The flight plan never predicts an encounter, no closest approach marker appears even with Luna targeted, and no SOI transition ever happens. the vessel stays parented to Earth and keeps following its unperturbed Earth ellipse while it is deep inside Luna's SOI.

In the attached save the vessel "Rocket" (the default rocket) is 12,826 km from Luna's centre. Luna's sphere of influence is about 61,800 km, so the vessel is at roughly 21 percent of the SOI radius. Luna is set as the target, so the game draws Luna's SOI sphere in map view, and the vessel marker is clearly inside it (see screenshot).

Vessel state in the save, at game time 4d 14:17:37:

• Parent body: Earth
• Semi-major axis 188,940 km, eccentricity 0.965, periapsis 6,620 km, apoapsis 371,257 km
• Distance to Luna: 12,826 km
• Relative inclination to Luna: 0.01 degrees

The flight plan consists of a single Earth-centric patch.

There is no encounter marker, no closest approach marker, and warping forward carries the vessel through the SOI without any visible trajectory effect on the vessel from Lunas gravity.

What Was Expected​

The trajectory intersects Luna's sphere of influence, so the flight plan should show a Luna encounter patch, and the trajectory, encounters etc. should be affected.

Reproduction Steps​

1. Load the attached save "No Encounter in Luna SOI bug" (system Sol, vessel "Rocket", Luna already set as target).
2. Switch to Map View and follow "Rocket".
3. Observe that the vessel marker sits inside Luna's drawn sphere of influence..
4. Observe the flight plan: one Earth-centric patch, no Luna encounter marker, no closest approach marker.
5. Unpause and let time run: the vessel continues along the Earth ellipse through Luna's SOI as if Luna just was not there.

Reproduction Rate​

Encountered independently in several earlier sessions on comparable near-coplanar transfers.

Additional Info​

• Save File: "No Encounter in Luna SOI bug" (attached).
• Mods: Reproduced with only Core enabled. No mods.