alt Hacker NewsIs it normal to load ALL the propellant when doing a static fire? (I presume that's the case, anyway, given the sheer magnitude of the kaboom.)
I know a WDR typically would, but I don't think they perform an ignition for those.
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In September 2016 almost exactly the same thing happened to a Falcon 9 at the Cape, also on a static fire. New Glenn is bigger, so bigger bang, but pretty much exactly the same thing.
Off the top of my head, I recall in SpaceX's case it was a helium tank failure- a helium tank weld failed and the helium tank itself shot through the cryogenic oxygen, hit the far wall, and gave off a spark. But that sort of failure is only apparent when everything is pressurized correctly, which means tanks have to be full. The goal of the test is that you detect that sort of failure before it goes boom and then can fix it.
https://www.youtube.com/watch?v=_BgJEXQkjNQ is a video of SpaceX's failure.
I don't know anything about this particular launch, but one reason static fires sometimes load more fuel than you'd think is that the hold-down clamps aren't rated for the total thrust of the vehicle. Launch thrust is usually 1.2-1.6x the launch weight (if it's <1x you will not go to space today), so after subtracting gravity you've got 0.2-0.6x the weight acting upwards on the clamps. But rockets are mostly fuel by weight, so if you static fire it nearly empty, then that gravity term goes to ~zero, and the clamps have to hold the full 1.2-1.6x. You could overbuild them to handle that -- which isn't the end of the world, because they don't need to fly -- but it can be easier to just add extra fuel and detank it afterwards.
Isn’t that the point of the test fire? To find out if there’s a problem that will make it go boom
The weight of the propellant helps hold the rocket on the pad during the test fire, reducing how much force the hold-downs need to exert to keep the rocket on the pad, and stressing the rocket's structure in the same way it will be stressed at launch.
Test fires with a near-empty rocket would put considerably more force on the pad's hold-downs and the corresponding parts of the rocket's structure.
Blue also had a fuelled 2nd stage on top of the booster for the static fire, which is not out of the ordinary.
SpaceX has a "cap" that is held down with cables that it uses when it needs to test-fire a first stage by itself at its McGregor test site; static fires at launch sites are usually done with the 2nd stage on top.