On 12/26/2015 9:48 PM, Henry Spencer wrote:
On Tue, 22 Dec 2015, David McMillan wrote:
Are the DC-X data for engine life and MTBF public?
As far as I know, not the details. A few facts did get released,
notably at Space Access presentations by the team. P&W had the engines
apart only once, during the rebuild that turned DC-X into DC-XA, which
was after about 20 cycles (assorted ground tests plus 8 flights); they
said things looked "pristine", and that they'd replaced bearings and
seals only on general principles. (Well, general principles plus the
fact that some of the seals are one-assembly-cycle items that must be
replaced after disassembly.)
However, the RL10 is an unusual engine in several ways, and how well
this reads over to (say) Merlins is unclear.
However however, there is clearly no great problem in building big
liquid engines for tens of flights, if you try. The F-1 was specified
(and thoroughly tested to verify that it met the spec) for 20 cycles and
2250s of operation, just to support development adequately.