A SpaceX Falcon 9 rocket has exploded at Cape Canaveral • Hacker News Board

Re: A SpaceX Falcon 9 rocket has exploded at Cape Canaveral

#411

Post by clock_tower » Thu, Sep 01, 2016, 8:59 PM UTC

JohnStrange wrote: post #170

300bps wrote: post #105

Earlier quoted context omitted.

You're advocating the Broken Window Fallacy. http://www.investopedia.com/ask/answers/08/broken-window-fal...

I'm kind of skeptical about this alleged fallacy, where I have to admit that I'm not an economist. The usual formulations of it seem to be something crucial missing. I've heard that many producers of goods deliberately introduce failure points, e.g. in electronics by using cheap solder or capacitors with a limited lifetime. Buttons also fail way too easily. Or think of batteries that cannot be replaced. Do they all c…

My reading of it: there's a continuum in production philosophy from throw-away culture to built-to-last products, and the broken-window fallacy (which Krugman, IIRC, doesn't think is a fallacy at all) is the extreme end of throw-away culture.

Building to last means high up-front costs, little flexibility (think of the Empire State Building and how much it must have cost to install air conditioning in it), but beautiful products with low total cost of ownership; throw-away goods are low on up-front costs, and they make it easy to respond to new technology, but they have a high total cost of ownership and they tend to be pretty ugly as well. A society which focuses on quality will be wealthier and more beautiful (look at Europe's low GDP and high standard of living), but one that's constantly rebuilding junk will be more equal; every 1970s Volvo still owned by an old-money family in 2016 is a Ford assembly-line worker without a job, or thereabouts...

Re: A SpaceX Falcon 9 rocket has exploded at Cape Canaveral

#412

Post by throwanem » Thu, Sep 01, 2016, 9:02 PM UTC

npiazza83 wrote: post #373

stcredzero wrote: post #216

Earlier quoted context omitted.

However, the adjective is an accurate measure of the theory's merit.

Don't like it? Send an email to hn@ycombinator.com "Tone" policing on HN is getting a bit ridiculous.

God forfend anyone should try to maintain a quality of discourse that encourages thoughtful people to stick around.

Re: A SpaceX Falcon 9 rocket has exploded at Cape Canaveral

#413

Post by CydeWeys » Thu, Sep 01, 2016, 9:03 PM UTC

dmix wrote: post #123

ygra wrote: post #80

Earlier quoted context omitted.

Same reason anyone else does tests: Find potential and actual issues earlier than in production. The static fire they were doing is sort of a short integration / smoke (pun not intended) test whether the rocket as a whole (whether the payload is attached already depends on the customer; it reduces time between test and launch, though) works properly. Other tests are part of sort of a pre-flight checklist directly bef…

Is launch pad designed to take a hit like this? Or do you think it would have caused a lot of damage to Cape Canaveral.

The pictures of the aftermath speak for themselves. The strongback is a mangled wreck, and all of the fuel tanks blew up. The vast majority of the launch complex, expressed in economic terms, is going to need to be rebuilt.

Re: A SpaceX Falcon 9 rocket has exploded at Cape Canaveral

#414

Post by anchpop » Thu, Sep 01, 2016, 9:05 PM UTC

npiazza83 wrote: post #373

stcredzero wrote: post #216

Earlier quoted context omitted.

However, the adjective is an accurate measure of the theory's merit.

Don't like it? Send an email to hn@ycombinator.com "Tone" policing on HN is getting a bit ridiculous.

I think you may have replied to the wrong comment

Re: A SpaceX Falcon 9 rocket has exploded at Cape Canaveral

#415

Post by npiazza83 » Thu, Sep 01, 2016, 9:06 PM UTC

throwanem wrote: post #412

npiazza83 wrote: post #373

Earlier quoted context omitted.

Don't like it? Send an email to hn@ycombinator.com "Tone" policing on HN is getting a bit ridiculous.

God forfend anyone should try to maintain a quality of discourse that encourages thoughtful people to stick around.

Its a difficult distinction to make. I don't think it unreasonable to expect some nuance on the part of moderators. My personal suggestion would be to remove subjective comments more readily in threads related to highly technical topics where there is MUCH to discuss related to the science or engineering of the piece but show some discretion in threads regarding topics which are inherently political or more subjective. So, here, I would actually say moderation is warranted. But if this were a piece on Edward Snowden, perhaps less demand for utter tact.

"Only in an irrational and unknown direction can we come to wisdom again."

Re: A SpaceX Falcon 9 rocket has exploded at Cape Canaveral

#416

Post by CydeWeys » Thu, Sep 01, 2016, 9:07 PM UTC

mitchty wrote: post #134

dmix wrote: post #123

Earlier quoted context omitted.

Is launch pad designed to take a hit like this? Or do you think it would have caused a lot of damage to Cape Canaveral.

Unlikely, it wouldn't be much of a launch pad if it couldn't handle failure modes for rockets (aka bombs with a hole in one end). Compare to this Saturn V launch. https://www.youtube.com/watch?v=DKtVpvzUF1Y

It would be incredibly difficult to armor a launch pad to survive an explosion on-pad, so they aren't. The real solution is to have multiple launch pads (the space shuttle had three), so that if one blows up on the pad you have backups you can use until the blown up one is rebuilt.

The energy released in the first few seconds of a controlled launch is not remotely comparable to the energy released by an entire rocket blowing up simultaneously. Also, with an explosion, the entire rocket, along with parts of the strongback and other structures it's attached to, become shrapnel. Superheated water exhaust is a lot easier to protect against.

Re: A SpaceX Falcon 9 rocket has exploded at Cape Canaveral

#417

Post by peeters » Thu, Sep 01, 2016, 9:10 PM UTC

vkou wrote: post #173

ocdtrekkie wrote: post #147

Earlier quoted context omitted.

I suspect the $2b custom government bird refers to the space shuttle. Of which we have, in fact, lost more than one.

The shuttle was a vehicle with vastly different capabilities, and technical challenges to overcome, compared to a Falcon rocket. There have been 133 successful shuttle launches, and 2 failed ones. There have been 27 successful Falcon launches, and 2 failed ones.

I know this will seem like nitpicking, but this was not a failed launch. It was during the inspection phase, which is performed to uncover flaws in the vehicle before launch. Small consolation I know because in this case the payload was lost anyway. But it's still important to note that the expectation of failure is going to be higher for inspection/static fire, and that in the case of commercial crew launches, the crew would not be near the pad at the time of static fire.

Re: A SpaceX Falcon 9 rocket has exploded at Cape Canaveral

#418

Post by filereaper » Thu, Sep 01, 2016, 9:11 PM UTC

GarrisonPrime wrote: post #409

rbanffy wrote: post #328

Earlier quoted context omitted.

Upper stage, so, unrelated to the reused first stage. Rocketry is hard... And very unforgiving.

As unforgiving as brain surgery. :)

https://www.youtube.com/watch?v=THNPmhBl-8I

Re: A SpaceX Falcon 9 rocket has exploded at Cape Canaveral

#419

Post by dansze » Thu, Sep 01, 2016, 9:13 PM UTC

GarrisonPrime wrote: post #409

rbanffy wrote: post #328

Earlier quoted context omitted.

Upper stage, so, unrelated to the reused first stage. Rocketry is hard... And very unforgiving.

As unforgiving as brain surgery. :)

Except in brain surgery the surgeon generally still gets paid.

Re: A SpaceX Falcon 9 rocket has exploded at Cape Canaveral

#420

Post by rsp1984 » Thu, Sep 01, 2016, 9:17 PM UTC

trothamel wrote: post #228

Here's good video of the test/failure: https://www.youtube.com/watch?v=_BgJEXQkjNQ#t=1m10s

Can somebody properly explain the different stages of the explosion? Obviously there's the first explosion but then after about 3.5 seconds there's a second, bigger one.

What's exploding in the first boom and what in the second?

Then, about 12 seconds in, the "nose" is falling down and causing a 3rd explosion. Why hasn't the nose "co-exploded" already with the 1st or 2nd explosion?