kerbal-space-program
In the career mode, we have to take care about cash now. It means we need to reclaim as much as feasible.
I fly high, it's easy. But it also means that when I jettison unneeded parts, they soon get far away that they gets put "on rails". Too deep in atmosphere, and they are gone. Do I still get refund for them, if they have proper parachute mounted? Or are the money lost for good and I shouldn't bother putting parachutes and deorbit engines at all when I'm too high for it to matter?
The tech tree only affects the parts list in the Vehicle Assembly Building and the Space Plane Hangar. Vessels that contain not-yet-unlocked parts will not be broken.
That said, if you already have unlocked the part in the tech tree (by having manually added it to the tech tree and then unlocking it), it will not be locked when the tech tree changes. Part unlocks and tech node unlocks are independent of one another in this regard. This is to preserve backwards-compatibility if the tech tree is rearranged, and in preparation for currency to be added. (Currency, as currently planned, will be required to unlock the individual parts, while research points are used for the nodes.)
You're best bet is to err on the side of safety and use too many. The potential financial loss for chutes ($700 each for radial) is much less than the potential financial loss of your entire ship.
I'd love to be able to give you some simple formula like "Use 1 chute for ever x tons". But there is no simple formula. The complex formula can be calculated using the tool you've linked to.
That said, these are some excellent tips:
or i-beams
instead of lander legs
. Modular girders and i-beams have 6x higher impact tolerance (80m/s) than the strongest lander legs (12m/s). You can land a 1000 ton ship on Kerbin with a single chute if it can survive a 80m/s landing.Good luck.
Best Answer
No, you don't. "On rail" parts which go too deep into the atmosphere just disappear. This even happens when they would have survived the landing (for example because they have parachutes attached). To recover a part you must supervise its landing. This means that it is currently hard to recover the first stage of a rocket, because you can not supervise both the upper stage on its way into orbit and the lower stage on its way back to ground. So no Grasshopper launch system yet.
However, I did construct a launch system which has a first stage of solid rocket boosters (which are dirt cheap) and a reusable second stage which can bring a payload of up to 15 tons onto a sub-orbital trajectory. After leaving the atmosphere I can detach the payload, use the payloads engine to get it into a parking orbit, and still have enough time to switch back to the second stage before it despawns so I can land and recover it.
Here is a screenshot of the system with a 15 ton payload on top.
Also, you can only recover a part which has a command pod attached to it. So if you want to recover a stage, you need to add at least a probe core to it.