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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

#471

Post by grkvlt »

_puk wrote: post #239
mabbo wrote: post #109

Earlier quoted context omitted.

They do the tests to validate that this rocket won't turn into a cruise missile, headed for the nearest residential area. Not an impossible scenario. Lots of energy stored up in one of those rockets. Just like when we test software, they want to have everything as close to what they would expect on launch day as possible (2 days from now). All the stresses, the structure, etc. That means putting stage 2 and the paylo…

Could they not have mocked the payload?

The payload is mated early to save time by speeding up the launch schedule [1] so a mock payload would have the opposite effect - it would need mated and then removed after the test fire.

[1] https://twitter.com/pbdes/status/771411924907094016

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

#472

Post by superman_ »

stock_toaster wrote: post #463
claar wrote: post #421

Earlier quoted context omitted.

Frame-by-frame: http://rowvid.com/?v=_BgJEXQkjNQ&t=71.75&s=0.25

Was that a bird flying in the background right as the explosion occurred? If so, it must have really scared the crap out of it!

That was me. Sorry I couldn't save it in time, I was held up trying to find a phone booth.

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

#473

Post by mikeash »

nraynaud wrote: post #453
raverbashing wrote: post #422

Earlier quoted context omitted.

Yes that's my guess as well. 200 million dollar firecracker

stupid question: is that the actual manufacturing price, or is there some one time R&D and tooling in it?

Seems like a really good question to me! I'd guess there's some one-time stuff involved, so the replacement won't cost $200 million, but it won't be a whole lot cheaper. My totally uninformed random guess would be something like $100-150 million for the second one. Maybe more, it could be that the one-time stuff is already amortized across multiple satellites.

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

#474

Post by throwanem »

hyperbovine wrote: post #470
throwanem wrote: post #412

Earlier quoted context omitted.

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

The thing about thoughtful people is that they dislike being told what to think.

One might expect they also recognize the difference between being told what to think, and not being told what to think.

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

#475

Post by OrwellianChild »

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 whole of rocketry has been fraught: https://en.wikipedia.org/wiki/List_of_spaceflight-related_ac...

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

#476

Post by caf »

izacus wrote: post #440
dTal wrote: post #155

Earlier quoted context omitted.

Nitpick: you're thinking of a ballistic missile. Cruise missiles are more like exploding fixed-wing drones. The V-1 flying bomb was a cruise missile, and the V-2 rocket was a ballistic missile.

Not sure what exactly are you nitpicking here - ballistic missiles have propulsion for a short time after lunch and afterwards continuing on a ballistic (hence the name) trajectory towards the targets. Cruise missiles have propulsion usually during most of the flight. A rocket straying off course could either smash into city under full power (thus being a cruise missile) or have its propulsion cut off remotely before…

Cruise missiles are designed to rely on aerodynamic lift (and typically use air-breathing engines, although there have been some "boost-glide" weapons that used rocket engines).

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

#477

Post by icanhackit »

Tloewald wrote: post #341
wfunction wrote: post #317

Earlier quoted context omitted.

How good is the photo quality? Is it close to entry-level DSLRs'?

It's shockingly good for what it is, which is why the camera was sold out for six months and still commands pretty much its original retail price nearly a year after release. Its big weakness is autofocus speed (making it useless for birders, etc.)

> Its big weakness is autofocus speed

In my experience the autofocus speed in daylight is fine and it's especially good at focusing on what you want it to focus on, so it's great for birders. The problem is noise-reduction i.e. image quality. Do a bit of pixel peeping and it begins to look like a watercolor painting.

I was lucky enough to get one the day it was released early last year. Fun toy, and great for travel/sightseeing where you often can't use your feet as a zoom, but not even close to 1" type sensor quality let alone SLR.

Saving my pennies for a Sony RX10 III 24-600mm equiv superzoom, thought it's roughly 3 times the price of the P900. Good review here: https://youtu.be/Ad1JDfmyNxI

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

#478

Post by diggernet »

trothamel wrote: post #228

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

Nice to see that the payload didn't start to topple until around 6s after the blast. Gives hope of the launch abort system having time to do its job had this been a manned launch.

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

#479

Post by MertsA »

akiselev wrote: post #202
jsprogrammer wrote: post #188

Earlier quoted context omitted.

How often is the self-destruct mechanism tested?

Very often. Air Force range safety guidelines require a million dollar flight termination system and most of that cost is testing and quality control. I don't have an authoritative list of all flight terminations but it happens at least once every few years whenever a rocket fails to follow the set flight path.

As an example, the strut failure in the falcon 9 a while back didn't explode from the failure, that was the flight termination system that actually caused the fireball when things started going south.

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

#480

Post by angryspacesheep »

ygra wrote: post #396
angryspacesheep wrote: post #343

Earlier quoted context omitted.

How many Falcon 9s have been launched using this fueling method?

As far as I know that was one of the defining changes of the Falcon 9 Full-Thrust, which flew first in December 2015 with Orbcomm OG2 M2. So, every Falcon 9 this year, plus one.

Thank you
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