Disgracefully negative headlines and coverage of this historic event from AP, BBC, and NPR this morning.
Watching so-called adults throw tantrums over people they hate being allowed a voice is such a disappointment.
SpaceX Starship rocket explodes minutes after launch from Texas
601–610 of 1001 posts
Re: SpaceX Starship rocket explodes minutes after launch from Texas
#602Anyone know how the controlled demolition works? I imagine something more sophisticated than a "radio controlled bomb" but maybe KISS.
Re: SpaceX Starship rocket explodes minutes after launch from Texas
#603Earlier quoted context omitted.
> "Fail fast" applies to more than just software. Yes, but let's not take the analogy too far. For people who work in safety-critical design (including software), it takes a different mindset than what is often prevalent in silicon valley. When the stakes are high, you don't really want to "move fast and break things". You can actually see this in SpaceX. In development when stakes are relatively low (e.g., no payloa…
> You can actually see this in SpaceX. In development when stakes are relatively low (e.g., no payload or passengers), the risk threshold is high. But they start taking a more measured approach when that risk starts to ratchet up. The danger being, advocates of one approach don't always know when/how to transition to the other. This corroborates "fail fast". They achieve reliability and safety by launching far more t…
>This corroborates "fail fast".
But it also shows "fail slow" later. My point is that "fail fast" is not some hard rule to abide by, but contextually dependent on the risk at stake.
Re: SpaceX Starship rocket explodes minutes after launch from Texas
#604Earlier quoted context omitted.
I'm seeing a lot of people salty about "Starship explodes". Isn't that also an accurate description of what happened?
"Failure at Stage Separation" would be far more specific and informative. But also get far few clicks.
Okay. Failed at stage separation, then spiraled out of control and exploded.
Re: SpaceX Starship rocket explodes minutes after launch from Texas
#605Earlier quoted context omitted.
I suspect SpaceX will have to add something resembling an escape system before the thing gets "man-rated". That system could also be used to protect the passengers in case of a failed landing. It will add weight and thus lower the carrying capacity but they seem to have enough margin to allow for such an addition. They already have the header tanks in the top of Starship, adding a number of escape engines and some ex…
Something like the B-58's armored escape capsule, perhaps. Each seat had an armored capsule that could close up, including oxygen and steering. https://en.wikipedia.org/wiki/Escape_crew_capsule
The B-58 article has an interesting note:
> Unusually, the ejection system was tested with live bears and chimpanzees; it was qualified for use during 1963 and a bear became the first living being to survive a supersonic ejection.
Re: SpaceX Starship rocket explodes minutes after launch from Texas
#606Initially posted this as a reply, but going top-level, cause the hot takes are too spicy for my liking. So the plan was to test x, y, and z. Launch sequence and takeoff, stage separation and Starship engine light, and the post-launch stuff like booster wet landing, reentry, and heat tiles. The booster by itself is not aerodynamic, so the only way to test x is with a starship on top. And if you have starship, you migh…
The thing that bothers me about this rapid unplanned disassembly development methodology is all the environmental damage that this thing is doing. It was bad enough blowing up next to a wildlife preserve, but now they are (with some degree of certainty) blowing it higher up and scattering fragments across a huge area. The rockets are not getting any smaller. > so the only way to test x is with a starship on top. Why…
What are your thoughts on volcanoes?
Re: SpaceX Starship rocket explodes minutes after launch from Texas
#607Earlier quoted context omitted.
How could this be a success? It was a catastrophic failure. Sorry but bullshitting releases only works in software.
The goal of this flight was always to prove they could get off the launch pad. They got past max-q, ergo it’s a success. The launch pad is intact, so the next starship rolling off the assembly line should launch in a couple months.
> The launch pad is intact
For a very loose definition of intact. It had a crater gouged out underneath it including under some of the supports. They'll have to rebuild that, and "couple months" sounds optimistic.
Re: SpaceX Starship rocket explodes minutes after launch from Texas
#608People want to see 100% success in all things. But that isn't very economical. Compare the SLS to Starship. SLS has had a 100% success rate. One launch, one success. But it costs $2B per launch (and climbing) and has taken 12 years to get here. Plus, it's stealing pieces of the Space Shuttle, which was developed in the 70s over a long period of time. Starship will launch a half a dozen "failures" before they achieve…
>> People want to see 100% success in all things. But that isn't very economical. That sounds logical, but isn't really a thing in aerospace/space. Complicated high-energy systems have thousands of failure points. So to have any chance of success each failure point needs to be engineered below, by way of example, a 0.0001% chance of failure. That costs lots of money. But say one decides to accept more risk for less c…
Only if the failure points are arranged in series - A AND B AND C must happen to have a successful outcome.
If the failure points are arranged in parallel - X OR Y OR Z must happen to have a successful outcome, with multiple redundant paths to success, your total failure rate is the chance that ALL of X, Y, and Z fail. This is a much lower number than when they are in series.
To use concrete math - say that Starship has 33 raptor engines with a failure rate of 0.01%, 3 grid fins with a failure rate of 0.05%, and a fuel tank with a failure rate of 0.001%. If it's engineered so that all 33 raptor engines, all 3 grid fins, and the fuel tank all need to work for a successful launch, the success rate of the whole system = 0.9999^33 * 0.9995^3 * 0.99999 = 0.9952 = ~0.5% chance of failure. If it's engineered so that it can get to orbit on 28 out of the 33 raptor engines, 2 out of the 3 grid fins, and there is a double-hull to the fuel tank with a failure rate of 0.005%, then the chance of failure for each subsystem is 0.0001^5 = 10^-20, 0.0005^2 = 2.5 * 10^-7, and 0.00001 * 0.00005 = 5 * 10^-10, and when you multiply out those subsystem failure rates you get 1 - (1 - 10^-20) * (1 - 2.510^-7) * (1 - 510^-10) = 0.9999997495 = ~0.000025% chance of failure.
Moreover, lets look what happens if you take the multiply-redundant design above and then increase the chance of failure of each component 100x. Raptor engines are now 99% reliable, grid fins are now 95% reliable, and fuel tanks are now 99.9% reliable. The overall failure rate for each subsystem becomes 0.01^5 = 10^-10, 0.05^2 = 2.5 * 10^-3 and 0.001 * 0.005 = 0.000005. When you multiply out those subsystem failure rates you get 1 - (1 - 10^-10) * (1 - 2.510^-3) * (1 - 510^-6) = 0.00250498759 = ~0.2% chance of failure. The multiply-redundant system, even with component failure rates 100x higher, still has better reliability than the perfectly-engineered system where every component must perform exactly to spec.
This principle is used all the time in practical engineering. It's why Google builds server farms out of thousands of commodity PCs, hooked up in primary/replica clusters with replication and transparent failover. It's why ships have watertight compartments and double-hulls. It's why passenger jets have multiple engines, multiple hydraulic control systems, and multiple flight computers. Any engineer worth their salt is going to avoid SPOFs and assume that components will fail, then build redundancies into the design so that a partial failure does not endanger overall mission success.
Re: SpaceX Starship rocket explodes minutes after launch from Texas
#609Earlier quoted context omitted.
How could this be a success? It was a catastrophic failure. Sorry but bullshitting releases only works in software.
When SpaceX says their goals were to clear the launch tower, collect data and nothing more this seems like a huge success.
That's the benefit of setting expectations at zero. "We only guaranteed excitement!"
I sure hope the engineering team is more honest about the results.
Re: SpaceX Starship rocket explodes minutes after launch from Texas
#610Earlier quoted context omitted.
Sorry but engineering doesn't give a shit about your feelings. The primary objective was to leave the pad and not destroy the billion dollars of gear on it. Everything else after that was a win.
How was the gear not destroyed in that explosion? I genuinely don't know.
Keeping the Starship intact wasn't a primary goal it seems.
They also seems to have been up front about it to both internal and external audiences.