Here's an update...
December 04, 2003: XCOR Aerospace passed a significant milestone recently when it logged its 2,000th rocket engine firing. This is the total of the
five types of engines the company has designed and built in-house. Cumulative run time is 224.7 minutes, or 13,482 seconds as rocket scientists like
to measure run time. Igniter-only operations are not counted in this tally; just engine runs with both igniter and main stage components. About 2600
additional igniter tests have been performed in development, life testing, and preflight checkouts.
In all these 2,000 runs, XCOR has yet to experience an engine explosion or hard start. While we are optimistic that we have designed out the causes of
engine explosions, we never run without a blast shield surrounding the engine.
www.xcor.com...
These guys are getting good.
Nah... 
