Allow Boilers to be used in space with Rocket fuel

[BlueTemplar]

Nice that we actually agree then, how then about a similar requirement for fuel to be burned in space boilers than what I suggested in the other thread ?

[...] having a minimum value to be accepted [in boiler] :
- Area (on belt) : energy content of a single item
- Volume (in inventory) : energy content of a single stack of items
- Mass (in rocket) : energy content of the cargo that a single rocket can carry
- Vehicle acceleration
- Vehicle top speed
(or maybe it could even be a combination of several minimum requirements above ?)
(- If some fuels are still too problematic to balance for this, even if restricted to their higher quality versions : Item type)

(These requirements could be the same as my suggestion for rocket part for simplicity, or different — for balance.)

[Panzerknacker]

I think only one requirement would be enough, wether the fuel can burn in a 0 hPa environment. And I think it would also be fine if only rocket fuel meets that requirement, to start with atleast.