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Blue Origin's New Glenn blows up during static fire test

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Re: Blue Origin's New Glenn blows up during static fire test

#121

Post by l1tany11 »

userbinator wrote: post #113

Does anyone else find it surprising that rockets are a century old[1] and yet still seem to fail spectacularly with amazing regularity, often due to some small flaw? Is it just that they're still relatively niche machines and thus haven't benefited from mass manufacturing improvements? [1] https://en.wikipedia.org/wiki/File:Goddard_and_Rocket.jpg

Simplest explanation comes from Tory Bruno: they design with a factor of safety just above 1. 1.1 to 1.25. This is one of the reasons they wait for good weather to launch… they are trying to maximize payload. Also until recently, it’s been sort of a vicious cycle: rocket is very exquisite and expensive, so spacecraft needs to last longer and thus gets more exquisite and expensive, etc.

Have you seen how many issues race cars have? Same shit. It goes on and on.

Re: Blue Origin's New Glenn blows up during static fire test

#122

Post by hvb2 »

userbinator wrote: post #113

Does anyone else find it surprising that rockets are a century old[1] and yet still seem to fail spectacularly with amazing regularity, often due to some small flaw? Is it just that they're still relatively niche machines and thus haven't benefited from mass manufacturing improvements? [1] https://en.wikipedia.org/wiki/File:Goddard_and_Rocket.jpg

The engines are seeing significant development. These engines are the most complex of their kind, they inject the fuel and oxidizer as hot gases. Google full flow staged combustion cycle

What you refer to as the rocket, meaning the tube itself isn't failing. It's just that a big explosion will treat it apart

Re: Blue Origin's New Glenn blows up during static fire test

#123

Post by Polizeiposaune »

mholt wrote: post #89

Is 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.

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.

Re: Blue Origin's New Glenn blows up during static fire test

#124

Post by senectus1 »

kortilla wrote: post #20
7e wrote: post #19

Earlier quoted context omitted.

Surely not as favorable for the IPO as SpaceX’s own recent explosion and multiple engine failures?

Blowing up on the pad is incredibly worse from a design data collection perspective, a risk to life perspective, and a downstream impact to future launches perspective (nobody can use that site for a couple of months).

not to mention 7 days before it was meant to deliver a payload to space... a proper commercial payload. not just a POC payload.

Re: Blue Origin's New Glenn blows up during static fire test

#125

Post by sobellian »

userbinator wrote: post #113

Does anyone else find it surprising that rockets are a century old[1] and yet still seem to fail spectacularly with amazing regularity, often due to some small flaw? Is it just that they're still relatively niche machines and thus haven't benefited from mass manufacturing improvements? [1] https://en.wikipedia.org/wiki/File:Goddard_and_Rocket.jpg

You know what they say, nature abhors colossal tanks of high-explosive.

Re: Blue Origin's New Glenn blows up during static fire test

#126

Post by SilverElfin »

pylotlight wrote: post #12
SilverElfin wrote: post #3

Shame. I would love to see a competitor rein in SpaceX.

> rein in? You don't like going to space? What do you have against progress?

I have a lot against its owner, who has been enabling a corrupt administration and boosting outright supremacists on social media. Not to the corrupt action of the fast track listing and the voting structure of SpaceX. And the fraudulent acquisition of xai and x that is basically taking from SpaceX to pay off other investors

Re: Blue Origin's New Glenn blows up during static fire test

#127

Post by angled »

oconnor663 wrote: post #120
mholt wrote: post #89

Is 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.

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…

Why use fuel, though? Is there something about its specific density and weight distribution that rules out using other types of ballast?

Re: Blue Origin's New Glenn blows up during static fire test

#128

Post by generuso »

_moof wrote: post #45
generuso wrote: post #21

It is not clear what "full duration static fire" means, but if the stage was fully fueled, the fuel tank would have contained 1000 tons of methane. The heat of combustion of methane is 55 MJ/kg. TNT equivalent is defined as 4.2 MJ/kg. In terms of heat output (not blast or other effects) this would have been equivalent to 13 kilotons of TNT. The first atomic bomb had yield of 20 kt TNT, of which about half was in heat…

> TNT equivalent is defined as 4.2 MJ/kg. It isn't this simple for liquid oxygen and methane mixtures, and there's a great deal of disagreement between industry and regulators over what the right percentage of TNT equivalence is. Naturally, industry thinks the percentage is low, and regulators are skeptical, so there's a government-run test campaign going on as we speak to collect data for proper modeling.

The TNT is relevant, because the atomic bomb energy output was defined in terms of TNT equivalent. Not the energy of the blast, but the total output. For Trinity this was 20 kt, or 20*4.2 TJ.

This serves as a basis of comparison for this deflagration. If we are considering specifically the appearance of the late fireball, the heat output is the relevant figure of merit.

Assuming about 10-15% of the total bomb energy remained in the heat of the late fireball (with the rest spent on the blast wave, peak thermal radiation and neutron/gamma radiation), the fireball of this rocket deflagration could have exceeded the late fireball from the bomb. But this assumes the tanks were fully filled, which we do not know yet.

Re: Blue Origin's New Glenn blows up during static fire test

#129

Post by Polizeiposaune »

mandevil wrote: post #93
mholt wrote: post #89

Is 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.

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…

Wasn't a bad weld; it was a bad interaction between liquid or solid oxygen and what were previously thought to be inconsequential defects in the composite-overwrapped pressure vessel the helium was loaded into.

Quoting from one of the press releases:

"The recovered COPVs showed buckles in their liners. Although buckles were not shown to burst a COPV on their own, investigators concluded that super chilled LOX can pool in these buckles under the overwrap. When pressurized, oxygen pooled in this buckle can become trapped; in turn, breaking fibers or friction can ignite the oxygen in the overwrap, causing the COPV to fail. In addition, investigators determined that the loading temperature of the helium was cold enough to create solid oxygen (SOX), which exacerbates the possibility of oxygen becoming trapped as well as the likelihood of friction ignition.

"The investigation team identified several credible causes for the COPV failure, all of which involve accumulation of super chilled LOX or SOX in buckles under the overwrap."

https://web.archive.org/web/20170216160231/http://www.spacex...

Re: Blue Origin's New Glenn blows up during static fire test

#130

Post by oconnor663 »

userbinator wrote: post #113

Does anyone else find it surprising that rockets are a century old[1] and yet still seem to fail spectacularly with amazing regularity, often due to some small flaw? Is it just that they're still relatively niche machines and thus haven't benefited from mass manufacturing improvements? [1] https://en.wikipedia.org/wiki/File:Goddard_and_Rocket.jpg

https://web.archive.org/web/20120503175355/https://www.nasa....

> The percent propellant has huge implications on the ease of fabrication and robustness in achieving the engineering design (and cost). If a vehicle is less than 10% propellant, it is typically made from billets of steel. Changes to its structure are readily done without engineering analysis; you simple weld on another hunk of steel to reinforce the frame according to what your intuition might say. I can easily overload my ¾ ton pickup by a factor of two. It might be moving slowly but it is hauling the load.

> Once the vehicles become airborne, the engineering becomes more serious. Light weight structures made of aluminum, magnesium, titanium, epoxy-graphite composites are the norm. To alter the structure takes significant engineering; one does not simply weld on another chunk to your airframe if you want to live (or drill a hole through some convenient section). These vehicles cannot operate far from their designed limits; overloading an airplane by a factor of two results in disaster. Even though these vehicles are 30 to 40% propellant (60 to 70% structure and payload), there is room for engineering to comfortably operate thus there is a robust, safe, and cost effective aviation industry.

> Rockets at 85% propellant and 15% structure and payload are on the extreme edge of our engineering ability to even fabricate (and to pay for!). They require constant engineering to keep flying. The seemingly smallest modifications require monumental analysis and testing of prototypes in vacuum chambers, shaker tables, and sometimes test launches in desert regions. Typical margins in structural design are 40%. Often, testing and analysis are only taken to 10% above the designed limit. For a Space Shuttle launch, 3 g’s are the designed limit of acceleration. The stack has been certified (meaning tested to the point that we know it will keep working) to 3.3 g’s. This operation has a 10% envelope for error. Imagine driving your car at 60 mph and then drifting to 66 mph, only to have your car self-destruct. This is life riding rockets, compliments of the rocket equation.

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