Re:Starship goes up. Starship goes down. But is the program ...
by ChuckMcM on Thursday March 04, 2021 @02:49PM
(#26347258)
I liked this article because it echoes some of the questions my non-technical friends ask me when I'm bullish on SpaceX and Starship.
There are huge unknowns here still. Perhaps the largest one is whether or not they will be able to solve the reentry heat shield problem. They don't really have enough fuel reserve to to decelerate, and their ceramic tiles (like most tiles) are brittle so you can't put them edge to edge without having the expansion/contraction of the underlying rocket damage them. That means a design that is both effective at shielding the rocket from the plasma of re-entry, while adjusting to different expansion coefficients.
There was a LOT of engineering work on the shuttle with this issue which lead to the very complex and difficult to refurbish system that the shuttle ended up with.
If you can refuel in orbit, not a problem as you could use propulsive descent all the way and keep your velocity low enough to avoid the heating issues. Not the case here.
There are huge unknowns here still. Perhaps the largest one is whether or not they will be able to solve the reentry heat shield problem. They don't really have enough fuel reserve to to decelerate, and their ceramic tiles (like most tiles) are brittle so you can't put them edge to edge without having the expansion/contraction of the underlying rocket damage them. That means a design that is both effective at shielding the rocket from the plasma of re-entry, while adjusting to different expansion coefficients.
There was a LOT of engineering work on the shuttle with this issue which lead to the very complex and difficult to refurbish system that the shuttle ended up with.
If you can refuel in orbit, not a problem as you could use propulsive descent all the way and keep your velocity low enough to avoid the heating issues. Not the case here.