Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

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

twitter.com

Post reply on HN
Print view View original

131–140 of 588 posts

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

#131

Post by gorgoiler »

l1tany11 wrote: post #121
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 r…

One might make the same observations about software “bugginess” and complexity. The pace of improvement is such that everyone is riding the bleeding edge and, as such, the carpet inevitably gets a few spots of blood on it.

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

#132

Post by freetime2 »

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

I'm more surprised that they work at all.

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

#133

Post by GMoromisato »

This is a crushing setback for Blue Origin.

I feel for the engineers. They have been the underdogs for so long, but with the recent successful recovery of the New Glenn booster, it finally seemed like they had some bragging rights. Now they're looking at a year minimum before they get back to a regular launch rhythm.

The question now is: What went wrong? If they're lucky, it's just a stupid mistake. Maybe an incorrect procedure while loading fuel, or maybe a manufacturing error got past QC.

If they are unlucky, the cause will be a mystery, and it will take them months to nail down the root cause.

Early in Falcon 9's history, the Amos 6 satellite was stacked on the rocket during a routine static fire and the whole thing blew up. It happened so fast that there were only a few bits of telemetry between "everything normal" and "no signal". For a brief moment SpaceX suspected sabotage by rival ULA. They even requested access to a ULA building to see if a sniper could have taken a shot at the rocket.

It turned out to be an exotic failure: liquid oxygen had gotten caught inside a buckled liner in the carbon composite pressure vessels. Friction ignited it, and the entire second stage blew up, destroying the rocket.

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

#134

Post by Polizeiposaune »

angled wrote: post #127
oconnor663 wrote: post #120

Earlier quoted context omitted.

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?

Where would you put the other ballast?

You've got two large tanks making up the bulk of the stage's structure - one for oxidizer, one for fuel. They have large diameter pipes that feed propellant to the engines. You can't mix the ballast with either the oxidizer or fuel, and you can't feed the engines from anywhere but the propellant tanks...

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

#135

Post by oconnor663 »

angled wrote: post #127
oconnor663 wrote: post #120

Earlier quoted context omitted.

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?

The vehicle is designed to hold all that fuel, plus whatever payload it carries on top, but it's not designed to have heavy loads attached to it in any other way. Rockets are so intensely optimized for weight that sometimes they're barely strong enough to stand upright if you fuel them the wrong way: https://www.youtube.com/watch?v=imkdz63agHY.

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

#136

Post by gorgoiler »

angled wrote: post #127
oconnor663 wrote: post #120

Earlier quoted context omitted.

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?

If you are writing an integration test for some new and potentially bug-ridden code then you might opt to mock, say, the database connection.

Doing so risks having to write so much database logic — with all the potential for getting that code buggy as well — that it’s often better to avoid the mock and test the entire system, end-to-end.

This was an end-to-end rocket test.

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

#137

Post by generuso »

JumpCrisscross wrote: post #75
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…

> not clear what "full duration static fire" means You fire the rocket as if it’s going to space, but you keep it on the pad. (From the engine’s perspective, it did a full launch.)

The problem is that there is no standard meaning for the "full duration" in this context.

Some reports say that this means "running all seven BE-4 engines at full thrust for up to 38 seconds".

In flight the engines fire for 190 seconds.

So what the full duration means, and whether they fill the tanks with just enough fuel for the firing, or with a larger amount to help the clamps to hold the stage down, all this we will probably only find out from the investigation, if the results are ever published.

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

#138

Post by areoform »

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

I've talked about this a few times before but – https://news.ycombinator.com/item?id=47726133 / https://news.ycombinator.com/item?id=47726078 - to repeat myself;

It's because we're a very primitive species, and the forces involved here are genuinely new. It's physically not possible at our current level of technology to make this "safer" due to the distances and energies involved.

I will let John Young explain it his way;

    > ‘You put some people on top of four million pounds of high explosives, you light the fuse, and in eight and a half minutes they are going eight times faster than a rifle bullet. What part of that sounds safe to you?’
As an aside, if you've never heard of John Young, I recommend learning a bit about him. He was an incredible person. And that statement is very funny in his voice; https://www.youtube.com/watch?v=KezwDfFcFhU

He test flew the shuttle. They put an ejection seat in the shuttle – which was obviously insane. And a reporter asks him about ejecting while the solid rocket motors were burning, https://www.youtube.com/watch?v=JLU4CK7UHd4

(I'm deeply saddened that I will never get to meet the man and ask him the secret to his magical heart rate.)

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

#139

Post by testing22321 »

verzali wrote: post #109
testing22321 wrote: post #68

Earlier quoted context omitted.

The entire point of SpaceX’s recent launch was an explosion. They were aiming for that outcome. They wanted that outcome. The fact they did it with pinpoint accuracy even with engine issues and an in tact heat shield is a monumental success for a test flight.

SpaceX also had a massive explosion on the ground not that long ago.

Absolutely, they were running a test on a test stand.

For BO it’s much better to have this now when there is no payload or people on board so they can correct whatever the issue is.

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

#140

Post by rdtsc »

7e wrote: post #19
senectus1 wrote: post #15

Earlier quoted context omitted.

it'll probably be a favorable event for SpaceX's IPO.

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

If anything their one engine out unexpected but successful test boosts their position a bit.
Post reply on HN