| ▲ | advisedwang 4 hours ago | |
> A full-flow staged combustion engine is very complex, and prior to the Raptor only two had been built, neither of which successfully flew on a rocket. Isn't the Space shuttle main engine / SLS engine a full-flow staged combustion engine? | ||
| ▲ | Tuna-Fish an hour ago | parent | next [-] | |
In SSME, most of the LOX never goes through a preburner. The SSME uses the same kind of fuel-rich combustion chambers for both preburners. This presents a problem for the oxidizer side because any leaking along the shaft between ox pump and turbine in either direction would be catastrophic. This is resolved by an extremely expensive and complex multi-stage helium-purged rotating seal. One of the cool parts about most FFSC designs, and the raptor in particular, is that they can afford slight leaking from high pressure to low pressure through any seal in the system and it's broadly safe, and only marginally reduces performance. This allows them to be made much more cheaply. | ||
| ▲ | nbadg 3 hours ago | parent | prev | next [-] | |
No, it's a fuel rich staged combustion cycle: https://en.wikipedia.org/wiki/RS-25 | ||
| ▲ | pixl97 2 hours ago | parent | prev [-] | |
As it said raptor was the first and the SLS engines are way older. I think China has made a full flow engine too. | ||