News Changes to the SpaceX BFR rocket.

kuddel · Mar 14, 2024

In Orbiter, "landing" at these ridiculous speeds sometimes makes a vessel to bounce very very far and fast into outer space....
maybe they were checking if that's a real phenomenon

Thunder Chicken · Mar 14, 2024

Urwumpe said:
Likely the engine compartment was simply trying to leave Planet Earth.

Maybe the engines woke up, realized they had to decelerate from 270 m/s to 0 in less than one second, and they gave it their all?

Thunder Chicken · Mar 14, 2024

kuddel said:
In Orbiter, "landing" at these ridiculous speeds sometimes makes a vessel to bounce very very far and fast into outer space....
maybe they were checking if that's a real phenomenon

Well, it's orbital ellipse probably did have next apogee far in outer space...~~over China~~ over Australia. The programmers probably forgot to tell it that there was a rock in the way.

Urwumpe · Mar 14, 2024

Thunder Chicken said:
Maybe the engines woke up, realized they had to decelerate from 270 m/s to 0 in less than one second, and they gave it their all?

Generally, I don't want to be the guy who told the engine and propellant delivery system designers that they should assume g >> 270 m/s² for the hydrostatic calculations of the head pressure. There are not many easier ways to destroy a pipe.

Thunder Chicken · Mar 14, 2024

Urwumpe said:
Generally, I don't want to be the guy who told the engine and propellant delivery system designers that they should assume g >> 270 m/s² for the hydrostatic calculations of the head pressure. There are not many easier ways to destroy a pipe.

On the bright side, they don't have to worry about the pumps cavitating.

Urwumpe · Mar 15, 2024

Thunder Chicken said:
On the bright side, they don't have to worry about the pumps cavitating.

Sure? They begin starting the engines at a fraction of a g and they try to ramp up thrust fast on a very large rocket. I can imagine the size of the rocket making this even harder, while everything experiences the same accelerations the flow could react with quite some delay. That they can start the engines at all is quite a miracle.