Ship disappears

[Cdsxbox]

My first stage booster it made to land like the falcon 9 with mechjeb without me flying it it has a probe core and when i get far away from it it gets deleted why ? 

[bewing]

There are two things you need to know to understand this.

The first is called the "physics bubble". Calculating the movement of objects and their interaction with the air and ground takes an immense number of calculations. The game cannot do all those calculations for multiple ships and still do the simulation in near real time. So in the stock game, the first solution chosen for this problem is that only a region about 25km in radius is fully modeled (depending on your location, it could be smaller). Craft outside this range are either stored "on rails", or are autodeleted.

So the second concept is autodeletion. Calculating objects crashing into terrain also takes an immense number of calculations. So to simplify that calculation, each celestial body has an "autodeletion altitude". Any craft that is outside the physics bubble and is below the autodeletion altitude is assumed to have crashed into the terrain, and will be marked "destroyed". On Kerbin, the autodeletion altitude is 25km.

In stock, the only way around this is to watch the craft land.

There are other mods to the game that will allow you to stop time for one craft while you pilot another craft, and then switch back. Or mods that will just assume that any parts that are reentering the atmosphere with enough parachutes will land themselves -- and give you refunds for those parts.

 

[Kryxal]

Just one thing, the last time I looked it was 23 km, not 25 km.

[Snark]

31 minutes ago, Kryxal said:

Just one thing, the last time I looked it was 23 km, not 25 km.

I believe the actual criterion for auto-deletion (on any planet with an atmosphere) is the altitude at which the atmosphere reaches 1% of Kerbin sea-level pressure.  On Kerbin, that happens to be at approximately 23 km IIRC.  On other planets, it would be at other altitudes (a lot lower on Duna, a lot higher on Eve, for example).

[bewing]

Airless bodies also have autodeletion, though.

[Greenfire32]

Yeah unfortunately crafts that are sub-orbital will get deleted once you get far enough away from them (unless it's traveling away from the planet, in which case it will remain loaded. Only crafts moving towards the planet will get deleted). The best way to get your boosters landed is to take your craft into a high suborbital trajectory and then switch to your booster. While your craft continues to apoapsis, you can land your booster. Once booster is on the ground, switch back to your craft and burn for orbit. Once you're parked in orbit, switch back to the booster and "recover."

Job done.

It's a bit of a hassle, but as others have mentioned above, there are mods to help with this.

Edited February 12, 2018 by Greenfire32