I understand atmospheric pressure has an impact on the exhaust shape, but why aren't the nozzles that feed onto the aerospike affected just like a traditional engine?
I.e. in their illustration on the page, the two nozzles next to the spike itself?
I.e. in their illustration on the page, the two nozzles next to the spike itself?
At least that's my understanding - I just like to learn about rockets.
The TLDR as I remember it, is physical nozzles on the aerospike don't work the same way as they do on a traditional rocket. It's more like like just an exit from the combustion chamber.
The appeal of an aerospike is by having lots of exhaust port aligned around a spike, is it creates a sort of virtual nozzle that is the right size for the atmospheric pressure. And as such acts sort of like a nozzle that changes shape and size as the rocket goes through the thinner and thinner atmosphere.
This in theory gains efficiency over a rocket that has a set shape for it's nozzle, and isn't always operating at optimal efficiency due to the size of the nozzle.
* Not an expert on these things, just going off of memory