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

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

#151

Post by mturmon » Thu, Sep 01, 2016, 3:57 PM UTC

artursapek wrote: post #50

My mind goes to the debugging stage after the dust has settled... how would a rocket scientist determine the cause of a RUD like this?

If you're interested in this, you would enjoy reading the analysis of the breakup of the shuttle Columbia (not the earlier Challenger analysis, which is in itself interesting). Give yourself an hour.

The basic link is: http://www.nasa.gov/columbia/home/CAIB_Vol1.html

Start at chapter 2, on page 27. Highlights: "lock the doors" (page 44), the hunt for debris (page 45), reconstruction (page 47, 72, 74ff). It's really an amazing engineering detective story.

The fault tree analysis methodology is on page 85ff.

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

#152

Post by gist » Thu, Sep 01, 2016, 3:57 PM UTC

mtkd wrote: post #78

tomjen3 wrote: post #61

Earlier quoted context omitted.

There were no personal injuries, so I can't really be sad about a piece of electronics.

On any project like that many engineers involved will have invested more than regular hours and pushed their work life balance - losing it all a couple of days from launch into space - that's harsh dude

It's the life that they've chosen. It comes with ups and downs.

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

#153

Post by dogma1138 » Thu, Sep 01, 2016, 3:57 PM UTC

TFortunato wrote: post #119

dogma1138 wrote: post #101

Earlier quoted context omitted.

LN2 isn't combustible. LN2 isn't stored at the high pressures that cryogenic LOX and RP-1 are. RP-1 has a flashpoint of 110f, liquid oxygen would turn pretty much every spark into a party including turning a lot of materials which are not normally combustible under atmospheric levels of oxygen highly combustible. Basically once the cryogenic fuel starts to warm up you have to launch or to empty the tanks, the tanks a…

Thanks for the info! My experience in the past was mainly with large LN2 dewars, with liquid helium refrigerators added to re-condense the N2 gas back to a liquid, limiting the pressure (and limiting how often you needed and LN2 refill!). We had blow-off valves as a fail safe if pressures got too high if the cooling head ever failed. I'm sure working with cryogenic fuels is a whole different world. As I commented, it…

>As I commented, it's not that there aren't cryogenic temperature pressure relief valves, just that they may not be what you want!

Yeah for sure, if you think about it even if the rocket was filled with inert gas venting it might be very tricky. You have an erect rocket on a launch pad, you have to vent evenly as a pressure relief valve is effectively a "rocket engine" at high enough pressures. If one of them freezes and you don't have even distribution it can topple over.

You also have to vent the tanks in order and at a certain rate I would assume for example you want to vent to top tanks first to prevent the rocket from becoming too top heavy, and you also want to vent it at a certain rate to prevent quick shifts in the balance and weight distribution of the rocket.

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

#154

Post by Patrick_Devine » Thu, Sep 01, 2016, 3:58 PM UTC

artursapek wrote: post #51

Looks like they had a payload go with it. Sad. > "SpaceX confirm Amos-6 was aboard the Falcon 9 and was lost in the explosion." https://twitter.com/NASASpaceflight/status/77135388623807283...

This disaster may have bigger implications for Spacecom. They were in the middle of being acquired by Beijing Xinwei and the successful launch of Amos 6 was supposed to be a factor in closing the deal[1]. I have no idea what blowing up on the pad means for the merger.

1. http://www.satellitetoday.com/technology/2016/08/24/spacecom...

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

#155

Post by dTal » Thu, Sep 01, 2016, 3:58 PM UTC

mabbo wrote: post #109

nateberkopec wrote: post #65

Earlier quoted context omitted.

I know nothing about space - why are they doing tests, where the rocket could possibly explode or fail, with the payload on board?

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…

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.

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

#156

Post by kuschku » Thu, Sep 01, 2016, 4:00 PM UTC

sangnoir wrote: post #95

Symmetry wrote: post #62

The payload was apparently on the rocket at the time[1]. A $200 million loss there, which sucks for the insurance company but better than losing a $2b custom government bird. [1] https://twitter.com/SpaceflightNow/status/771352977315684352...

> A $200 million loss there, which sucks for the insurance company but better than losing a $2b custom government bird. In fairness, when did the government last lose a bird? Doesn't the ULA have a '100%' success rate (where success is getting payload to space, though some payloads fail to make it to the planned orbit)

ESA’s Ariane also has a far better successrate than SpaceX’s Falcon, and if I’d send a satellite to space, unless it would be a really cheap one, I’d likely not use the Falcon as delivery vehicle.

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

#157

Post by kuschku » Thu, Sep 01, 2016, 4:02 PM UTC

api wrote: post #131

Shanea93 wrote: post #99

Earlier quoted context omitted.

Aon International Space Brokers ( http://www.aon.com/singapore/risk-services/products-services... ) covers liability for the payloads to be delivered, however, SpaceX shoulders the financial burden of losing the rocket itself, as only the contents are insured.

It will also likely increase the cost of insuring SpaceX launches. I'm sure it's like car insurance. Of course SpaceX is so much cheaper than their competition that it may not matter, and reuse is about to make them cheaper still. Short term setback, but probably not so awful long term. Also glad nobody got hurt. It's just money.

> Of course SpaceX is so much cheaper than their competition that it may not matter, and reuse is about to make them cheaper still.

They’re 2 million USD more expensive per launch for a mid-size satellite than the Ariane 5 is, so I’m not sure I understand what you mean.

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

#158

Post by gist » Thu, Sep 01, 2016, 4:02 PM UTC

ars wrote: post #121

gist wrote: post #76

Earlier quoted context omitted.

Agree. "Sad" is the PC thing to say when something like that happens. In most people's lives it's a big "who cares". [1] The fact that you were downvoted (at least when I saw your comment) indicates people don't agree with what you are saying and is an example of trying to enforce a particular type of thinking on someone else as far as what they should think or feel. [1] Of course I wouldn't say "who cares" directly…

He was downvoted for only looking at first-order effects: People harmed during the fire. And ignoring second-order effects: People harmed because of the results of the fire. The second group of people is not less important than the first.

Why is it necessary to feel sad and to even consider all of that? That is my point. What bothers you bothers you and what doesn't is fine, less to think about. You can't go around being bothered by everything 'bad' that happens in the world to someone else. I don't think that is healthy in any way. By "bothered" I don't mean indicating in words that something is sad. I mean actual concern as if it impacts you or someone you know personally.

Sorry but I can't relate to this type of tragedy at all. I can relate to someone getting hacked and losing their business or customer information though. That pain I can imagine. And to hear someone say to me "that's sad" about the latter when knowing they don't have any idea what it is really like to me is just lip service and almost patronizing.

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

#159

Post by brianwawok » Thu, Sep 01, 2016, 4:04 PM UTC

kuschku wrote: post #156

sangnoir wrote: post #95

Earlier quoted context omitted.

> A $200 million loss there, which sucks for the insurance company but better than losing a $2b custom government bird. In fairness, when did the government last lose a bird? Doesn't the ULA have a '100%' success rate (where success is getting payload to space, though some payloads fail to make it to the planned orbit)

ESA’s Ariane also has a far better successrate than SpaceX’s Falcon, and if I’d send a satellite to space, unless it would be a really cheap one, I’d likely not use the Falcon as delivery vehicle.

So you would rather pay $600 million per launch with 95% chance of success vs $200 million per launch with 93% chance of success?

There is no such thing a 100% chance of success, everyone has a chance of failure. I would not put ESA more than a few % more reliable. Math says your satellite would need to be really expensive for the price difference to be worth it.

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

#160

Post by mikeash » Thu, Sep 01, 2016, 4:05 PM UTC

gist wrote: post #76

tomjen3 wrote: post #61

Earlier quoted context omitted.

There were no personal injuries, so I can't really be sad about a piece of electronics.

Agree. "Sad" is the PC thing to say when something like that happens. In most people's lives it's a big "who cares". [1] The fact that you were downvoted (at least when I saw your comment) indicates people don't agree with what you are saying and is an example of trying to enforce a particular type of thinking on someone else as far as what they should think or feel. [1] Of course I wouldn't say "who cares" directly…

You wouldn't say it directly to someone involved in the project, but you'll say it in a public forum where there's a decent chance some of those people will see it?