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A SpaceX Falcon 9 rocket has exploded at Cape Canaveral

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

#481

Post by tominous »

tmptmp wrote: post #438
rbanffy wrote: post #410

Earlier quoted context omitted.

On brain surgery, the worst case scenario is one dead person. Rockets tend to inflate the body count prodigiously.

On a slightly light-but-not-so-light note: A brain surgery can result in worse still: like, surgeon performs a surgery, makes some mistake, the patient is alive and gets up and goes home, but due to the surgical damage caused becomes a serial killer. So, strictly speaking a brain surgery can also result in a body count that is greater than 1. Respectfully submitted.

On a similar note, there's also the case of the leg amputation that killed 3 people: the patient (gangrene), the assistant (gangrene from fingers accidentally being amputated) and a spectator (from "fright").

See: https://en.wikipedia.org/wiki/Robert_Liston

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

#483

Post by WalterBright »

reddog wrote: post #461
WalterBright wrote: post #448

Earlier quoted context omitted.

> Unfortunately, the "move fast and break things" attitude doesn't work with rockets. Rocket technology has never advanced without catastrophic failures. "Breaking things" is the only way forward with it. Rockets, of necessity, have to push designs to their limits, or they'll never lift off the pad.

I don't know if I agree. Aside from Challenger (I know -- a pretty big aside), what catastrophic launch failures were there with the Mercury, Gemini and Apollo program rockets? Or the Delta 2. And doesn't the old-fashion-can't-even-land-on-a barge Atlas 5 have a perfect launch and mission success record of 62 of 62? It seems like building and launching a rocket that doesn't explode every 14th time is possible but its…

The Mercury rockets had a lot of catastrophic failures before the first manned launch.

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

#484

Post by dang »

monocasa wrote: post #198

That was my immediate thought too. Israel is known for playing rough when it comes to sovereignty concerns, particularly of a technological nature.

Since this subthread went off the rails in several directions at once, we've detached it from https://news.ycombinator.com/item?id=12406651 and marked it off-topic.

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

#485

Post by perseusprime11 »

manarth wrote: post #250
BinaryIdiot wrote: post #227

Earlier quoted context omitted.

This was my first thought but then again I don't know how expensive the one was and if they built one and it launched successfully, what would they do with the second one? Seems like a damned-if-you-do-and-damned-if-you-don't scenarios.

The payload was reported at $200 million. Although whether it would cost an additional $200 million to build a second is another question, but I doubt there would be that significant an economy of scale for just one extra unit.

Why does a satellite cost so much? I always thought it was a computer with solar panels orbiting in space using gravitational force?

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

#486

Post by TrevorJ »

dogma1138 wrote: post #390
TrevorJ wrote: post #374

Earlier quoted context omitted.

They definitely do vent LOX boiloff.

Yes through the bleeder valves but a bleeder valve isn't an emergency pressure release valve. Bleeder valves are designed to bleed gas from a system which contains a liquid. They aren't designed to be used to relieve pressure in an emergency situation, infact under high enough pressure they stop working all together. In a more common setting you see these types of valves on breaks and on heating systems that use hot…

Agreed, I wasn't contending that they are used in an emergency context.

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

#487

Post by dredmorbius »

reddog wrote: post #461
WalterBright wrote: post #448

Earlier quoted context omitted.

> Unfortunately, the "move fast and break things" attitude doesn't work with rockets. Rocket technology has never advanced without catastrophic failures. "Breaking things" is the only way forward with it. Rockets, of necessity, have to push designs to their limits, or they'll never lift off the pad.

I don't know if I agree. Aside from Challenger (I know -- a pretty big aside), what catastrophic launch failures were there with the Mercury, Gemini and Apollo program rockets? Or the Delta 2. And doesn't the old-fashion-can't-even-land-on-a barge Atlas 5 have a perfect launch and mission success record of 62 of 62? It seems like building and launching a rocket that doesn't explode every 14th time is possible but its…

Apollo had 17 missions and at least four failures or near failures that come to mind:

* The Apollo 1 launch-pad fire, during a training session, using a 100% pressurised oxygen atomosphere. Three dead. Grissom, White, and Chaffee. I can list them from memory.

* Apollo 11 suffered a lunar lander computer crash in the final seconds before landing, was programmed to land on what would have been unsurvivable terrain, and had fewer than 30 seconds of fuel left when it finally touched down.

* Apollo 12 was struck by lightning as it left the launch pad, knocking out much of the electrical system, which had to be reset. Fortunately they built things robustly.

* Apollo 13 had an oxygen tank explode as it was en route to the moon. The mission was aborted, though orbital mechanics meant that the astronauts still had to orbit the Moon, then return to Earth.

Any of 11, 12, or 13 could have ended with fatalities. One scenario for the command module pilot (Michael Collins in Apollo 11) was, if needs be, to leave his two crew members on the lunar surface and to return to Earth alone.

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

#488

Post by dredmorbius »

vel0city wrote: post #443
nixos wrote: post #423

Earlier quoted context omitted.

Unfortunately, it's 2 for 29. But if you look at the FT version, it's 1 for 8. 1. What kind of insurance will be needed on a billion dollar NSA satellite? $100 million? $125 million? It's not so cheep anymore, and considering delays etc. It's not such a great deal anymore. 2. They probably should have a "stable" platform and a "beta" platform, with a discount offered for beta. Unfortunately, the "move fast and break…

Well, the moving fast part is pretty important in rockets. Breaking things on the other hand...

Thats's what the explosive bolts are for.

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

#489

Post by dingo_bat »

Animats wrote: post #314
Phlarp wrote: post #211

Earlier quoted context omitted.

I also have to suspect things like isolated, dedicated and redundant comm links with the flight termination system are part of these guidelines. Perhaps even a "dead man's switch" that terminates the flight if this separate communication system loses signal at some point. (Even if this means a costly false positive or two~)

For the Space Shuttle, the flight termination system had two huge 10KW transmitters to send the signal. That would get through despite damaged receiving antennas, noise, or jamming.

10kW? That sounds like a lot of energy to dump into air. Certainly unhealthy for operators or people near the tx site.

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

#490

Post by dredmorbius »

objclxt wrote: post #347
TheGuyWhoCodes wrote: post #283

Earlier quoted context omitted.

There is something flying just above when the explosion starts, probably a bird, but how hard will it be to just fly a drone there with some kind of projectile? [Edit] Pre and Post explosion: http://imgur.com/a/IIzg2

> but how hard will it be to just fly a drone there with some kind of projectile? It's a massive long metal tube full of extremely flammable things...what seems more likely: drone with projectile entering a highly restricted piece of airspace, or as rockets are want to do, it blew up by itself.

NB: wont to do.

Though you've given me a reason to look up the etymology. Now I now: http://www.etymonline.com/index.php?term=wont&allowed_in_fra...

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