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Orbital Sciences Antares rocket explodes after liftoff

nasa.gov

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Re: Orbital Sciences Antares rocket explodes after liftoff

#131

Post by _kst_ »

_kst_ wrote: post #80
callesgg wrote: post #61

Earlier quoted context omitted.

I expected it to self desturct. Why would it not do that? Was it to close to the ground?

There wouldn't have been much point in a self destruct. The rocket launched, then it looked like there was an explosion in or near the boosters (which apparently caused a loss of thrust), then it fell back onto the pad and exploded. Blowing it up at a higher altitude just would have spread the debris a little farther.

According to the press conference just now, the range safety officer apparently did send a destruct signal. The signal probably would have been sent very close to the time the rocket hit the ground. In my relatively ignorant opinion, it was going to blow up one way or another. We'll probably get more details later.

Re: Orbital Sciences Antares rocket explodes after liftoff

#132

Post by InclinedPlane »

TerraHertz wrote: post #110

In the videos you can see the quality of the rocket flame changes suddenly about half a second before the obvious explosion in the engine area. The jet becomes more orange and less convergent. At 1:03 in https://www.youtube.com/watch?v=aL5eddt-iAo So, as a general comment, something bad happened with the gear that pumps fuel into the engines in the right proportion. Maybe involving a major leak of fuel into the struc…

The NK-33/AJ-26 is no longer manufactured, and most of the stockpile is owned by Aerojet-Rocketdyne or Orbital (something like 50 engines). Considering that those engines have already been bought and paid for, there's no real benefit either way to them failing just a downside to Aerojet-Rocketdyne and OSC.

Re: Orbital Sciences Antares rocket explodes after liftoff

#133

Post by InclinedPlane »

MichaelAO wrote: post #50
ars wrote: post #25

Anyone know what the cargo was? Anything unique or expensive? Or just regular supplies?

According to Motherboard: - A pea growing experiment from students in Houston - A human health study investigating blood flow to and from the brain in space - 19 student projects from New Jersey - A reentry breakup recorder - A meteor dust analyser - 1,360 pounds of food - Spacewalk equipment - Flight crew equipment - Fight procedures books - Computers - Classified "Crypto equipment" Source: https://twitter.com/mothe…

> - A reentry breakup recorder

Right, there was to be a video recording of the Cygnus spacecraft as it reentered and broke up (it's designed to disintegrate). Kind of ironic now.

Re: Orbital Sciences Antares rocket explodes after liftoff

#134

Post by joelrunyon »

UnoriginalGuy wrote: post #125
uptown wrote: post #106

Truly unfortunate that it failed. Here's Elon Musk's comment about the Antares rock two years ago: Musk: The results are pretty crazy. One of our competitors, Orbital Sciences, has a contract to resupply the International Space Station, and their rocket honestly sounds like the punch line to a joke. It uses Russian rocket engines that were made in the ’60s. I don’t mean their design is from the ’60s—I mean they start…

And he was wrong. They had 4 successful launches since then. Plus it seems unprofessional to be bad mouthing a competitor like that in public.

Here's his statement on twitter from today: "Sorry to hear about the @OrbitalSciences launch. Hope they recover soon"

https://twitter.com/elonmusk/status/527247155954610176

Was he speaking facts? Because if they were using rockets made in the 60s - he's not really badmouthing them as much as he is making public facts.

Re: Orbital Sciences Antares rocket explodes after liftoff

#135

Post by calinet6 »

readerrrr wrote: post #128
UnoriginalGuy wrote: post #125

Earlier quoted context omitted.

And he was wrong. They had 4 successful launches since then. Plus it seems unprofessional to be bad mouthing a competitor like that in public.

What exactly was he wrong about?

Well, if you can take 80% as a success rate at a quarter the cost per launch due to re-using old parts, and build that into your business model somehow (insurance, assurance, whatever and however it might be done), then maybe it can be viable as opposed to using new materials and expensive innovation to get a more reliable result at a higher cost.

I'm not arguing for that business strategy; I think it would not be successful. I also don't think that re-using old rocket parts actually reduces cost to orbit significantly (I haven't looked at the numbers). I also don't think that what I think matters a whole lot.

However, it's worth a discussion beyond simply rejecting the model at face value.

Re: Orbital Sciences Antares rocket explodes after liftoff

#136

Post by Lambdanaut »

joelrunyon wrote: post #134
UnoriginalGuy wrote: post #125

Earlier quoted context omitted.

And he was wrong. They had 4 successful launches since then. Plus it seems unprofessional to be bad mouthing a competitor like that in public.

Here's his statement on twitter from today: "Sorry to hear about the @OrbitalSciences launch. Hope they recover soon" https://twitter.com/elonmusk/status/527247155954610176 Was he speaking facts? Because if they were using rockets made in the 60s - he's not really badmouthing them as much as he is making public facts.

Comparing their rockets to "the punchline of a joke" is definitely bad mouthing, just factual badmouthing.

Despite that, I don't blame him. Being factual is what's important.

Re: Orbital Sciences Antares rocket explodes after liftoff

#137

Post by gedmark »

Using 50 year old Russian engines was a risky move on Orbital's part, but in fairness the NK-33's are a pretty amazing piece of technology. The US has still yet to build anything matching its performance:

http://en.wikipedia.org/wiki/NK-33

297 seconds of Isp is huge. The Saturn V's F1 engine only had 263 seconds. And the closest we've come since to that level of performance in a Lox/RP-1 engine is the Merlin 1D which will have 282.

They did it by using an oxygen-rich, fully staged combustion cycle. Which means that most of the fluid flowing around the engine and through the turbines of the pumps is super hot pure oxygen at 2000 psi. That's crazy. The US has brought over NK-33's and taken them apart and we still don't quite know how the Russians got it to work.

Of course, performance is only one consideration. All the other things you'd expect like integration costs, reliability of your suppliers, etc. made the Antares a pretty risky bet. But given Orbital's choices of developing their own engine from scratch, buying a hyper-expensive engine from Rocketdyne, or buying a wonder of engineering for cheap from the Russians, buying a bunch of surplus NK-33's wasn't totally crazy.

Re: Orbital Sciences Antares rocket explodes after liftoff

#138

Post by hudibras »

xb95 wrote: post #93
mixmax wrote: post #90

Earlier quoted context omitted.

actually the correct technical term to use here would be CATO - Catastrophe At Take Off

Only slightly less euphemistic than flying's CFIT - Controlled Flight Into Terrain. AKA "whoops, the ground".

And going the other direction, euphemistically-wise, the U.S. military's official designation for things* that fall off aircraft is TFOA: Things Falling Off Aircraft.

*Anything from loose nuts or fasteners up to improperly-attached fuel tanks or bombs.

Re: Orbital Sciences Antares rocket explodes after liftoff

#139

Post by keehun »

It seemed like from the press conference that Orbital will be footing most of the bill. The best Frank from OS could say was that "some of the rocket" was insured. Someone below cited $110 million minimum insurance, but that's not even close to the number OS gave out in the conference at $200m for just the rocket (which I think included neither the manifest nor the damage to the pad/environment and any necessary repair/cleanup)
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