I am curious, why T:W of booster LPRE is important? Or more important
than specific impulse? The only reason I see now could be the cost:
theoretically, the lightweight unit should be a bit chipper compared to
its more heavy equivalent. But does it matter on that scale (e.g. 450 kg
vs. 550 kg)?
Just FYI: vac T:W of latest RD-275 seems to be comparable (T:W~175). The
chamber pressure of RD-275 is comparable to that of NK-33.
Note that T:W of version of NK-33 which includes gimbaling unit and
thrust frame should be even lower. Does T:W of Merlin 1D includes
gimbaling unit and frame?
On 12/30/2015 12:17 AM, Henry Vanderbilt wrote:
NK-33 vac T:W, 138. Merlin 1D, vac T:W 180.
Mind, NK-33 in fact does have a higher chamber pressure, 2150 psi to
1410 psi for Merlin 1D.
Chamber pressure does seem to be a significant factor in engine
weight, yeah.
On 12/29/2015 1:48 PM, David Gregory wrote:
It was stated that GG engines are lighter than alternatives. At a
given chamber pressure, that's not the case.