JF Mezei wrote:

On 2017-06-21 09:58, Robert Clark wrote:
The new start-up Arca Space Corporation will test this year for the very
first time, more than 50 years after the aerospike was developed, the
high


Would an aerospike engine be inherently more complex/costly to build?
or it is more or less a conventional engine with different engine bell?


You've confused. An aerospike engine essentially doesn't have an
engine bell. That's the point of the 'spike'.


In the case of linear aerospike, is there a single combustion chamber
with manifolds that direct thrust left/right (to provide steering), or
is there a single turbopump but multiple combustion chambers with
manifolds to direct fuel/oxidizer to the combustion chambers?


No.


And in terms of steering in the other axis, does the whole thing rotate?


What 'other axis' are you referring to?


Couldn't they make an engine bell in X shape at which point thrust could
be vectors in both axis?


I don't know what you're talking about now, but it's not an aerospike.


In the case of a round aerospike, is it just the inner portion which
moves to steer or does the whole kit move?


If by 'round' you mean 'annular aerospike', you steer them by using
one or more of the same techniques used to steer any other rocket.


--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn