The S-IVB explosion was due to a design flaw of major proportions. The helium
pressure tanks were mounted inside the LH2 tank, to allow more helium to be
stored. The helium tanks were made of titanium, and the explosion was due to
failure of the girth welds from hydrogen embrittlement.
Sent from my iPhone
On Sep 1, 2016, at 11:56 PM, Jonathan Goff <jongoff@xxxxxxxxx> wrote:
Henry,
Apparently there was at least one Thor failure in 1957 (digging through
Wikipedia here) that happened during fueling. But any way you slice it, it
looks like pre-ignition launch failures like this haven't really happened in
~50yrs in the US. So personally, I hope for SpaceX's sake that it was due to
some quirk of the F9 vehicle, whether it was subcooling, or having COPVs
inside the LOX tank, rather than a ground handling accident. Because to me at
least, having an umbilical fail and take out a launch vehicle when nobody
else in the US has had a failure like that in over half a century, over 1000
liquid fueled rocket launches and dozens of vehicle iterations, looks far
worse than running into some subtlety of a cutting-edge launch vehicle...
Sorry if that's a wee bit rambly,
~Jon
On Thu, Sep 1, 2016 at 9:33 PM, Henry Spencer <hspencer@xxxxxxxxxxxxx> wrote:
On Thu, 1 Sep 2016, Jonathan Goff wrote:
I think someone was saying an Atlas event in 1959 was the last US pad
explosion during fueling. Though there was also the SIVB-503 test stand
event that also let go during fueling in ~1962, but that wasn't with an
operational vehicle with a payload on top.
The S-IVB-503 explosion was in January 1967. However, it was not actually a
fueling accident -- the stage was fully fueled and ready to go. The failure
happened while the test crew was working through the startup sequence for an
acceptance-test firing.
I don't have details on the Atlas failures, alas.
Henry
