> I really think this is overrated in how much of a technology risk this is. Specially if you have enough weight that you can invest in the solution.
Refueling is a schedule risk, maybe the first design will fail to account for something and it will take a couple iterations to get it right. There is zero risk that the problem is unsolvable.
I would agree mostly. If you need to many iterations you might run out of money however.
In general I think refueling is a far smaller problem then the heat shield.
The heat shield is such a massive component that it's conceivable that the first design is flawed, and resolving the flaw requires a dry mass increase that cuts into the payload and makes a Mars return unachievable.
If the first stage is reusable, having a cargo launcher second stage that is none, reusable can be done for 30M.
First stage reuse is wall proven already.
> Starship will be unable to leave Earth's gravity well.
If its not reusable you can use it like any upper stage and it could launch anything anywhere you want.
> And if they can't refuel in orbit (which as of now, has only been performed a handful of times with small satellites)
The physics is well understood. We do it constantly with non cryogenics.
I really think this is overrated in how much of a technology risk this is. Specially if you have enough weight that you can invest in the solution.