Ed wrote:

NASA upgraded its nondestructive test methods after
the 51-L and 34D-9 failures, but no test can
absolutely preclude the possibility of an
instantaneous case failure, even on shuttle SRBs.

[thanks for the thorough and informative post]

Do you know offhand how many of the Titan 34D solid boosters have
flown? I can appreciate the concern about SRBs in general. However, I
still feel that the STS SRB history _specifically_, with 225 out of 226
mission firings that performed satisfactorily (a 99.56% success rate) -
with the lone failure having been addressed and even then potentially
survivable in a CEV launcher application - I feel that that at least
warrants consideration as suggested in Jeff Foust's article in The
Space Review.

There are probably other considerations, too. For one, is the SRB too
rough a ride for anything placed atop it?

Jon