Lucky Sailor

[Goodman]

Last night I somehow discovered there would be a rocket launch in Virginia that could be seen from from our back window in PA. At the same time the International Space Station would be visible passing over us at 50° off the horizon. I thought it would be fun for the kids (okay, and me too) so we turned on NASA TV and waited. The ISS passed over beautifully but the resupply rocket headed there had its launch scrubbed. Seems there was a sailboat down range and in the interest of safety the launch was cancelled and rescheduled for today.
Attempt #2 wasn't successful either, and it looks like the sailor from last night was damn lucky launch was cancelled!
http://www.dailymail.co.uk/news/arti...ast-Coast.html

[alismith]

I live about 20 miles from the launch site (as the crow flies), and went to watch it tonight. I was recording it on my Ipad (with a telephoto lens attached) and was listening to the launch radio feed. At one minute before launch, I started recording. I could see the sky light up when the main booster fired, then the sky got even brighter, followed by a dark cloud rising up above the trees on the horizon. The radio said the Antares rocket exploded 6 seconds after liftoff. I kept recording the cloud for another two minutes. When I got back home, it was all over the TV, showing the actual NASA launch camera as it recorded the explosion. Pretty spectacular sight.

It's a good thing no one was hurt. That was the only plus thing tonight. Since all the computers were on immediate lockdown so all the individual feeds could be reviewed, I have an idea those people aren't going home tonight.

Hopefully, they'll find out the problem and get things straight before the next launch.

p.s. This rocket wasn't a NASA-built rocket. It was built by a private contractor.

[alismith]

http://news.yahoo.com/commercial-sup...224100998.html

[skorpion]

p.s. This rocket wasn't a NASA-built rocket. It was built by a private contractor.

Probably had "MADE IN CHINA" stamped on the side.

[Viking350]

Probably had "MADE IN CHINA" stamped on the side.

They used 60's era Russian rocket motors.

[Krupski]

They used 60's era Russian rocket motors.

Don't knock Russian rocket engine technology. They were the first to design, build and perfect an oxidizer rich staged combustion engine (which the US thought to be impossible).

Frankly, I'm amazed myself that it works... but it does.

Usually, a staged combustion engine uses a FUEL rich gas generator to run the turbopumps.

For it to work at several thousand degrees F and OXIDIZER rich is amazing. How the engine doesn't eat itself alive I have no idea.

[Viking350]

Don't knock Russian rocket engine technology. They were the first to design, build and perfect an oxidizer rich staged combustion engine (which the US thought to be impossible).

Frankly, I'm amazed myself that it works... but it does.

Usually, a staged combustion engine uses a FUEL rich gas generator to run the turbopumps.

For it to work at several thousand degrees F and OXIDIZER rich is amazing. How the engine doesn't eat itself alive I have no idea.

http://www.washingtonpost.com/news/m...oviet-engines/

[studmuffin]

OP, thread is misleading. I thought the sailor bought the red headed wart faced, shrewish chain smoking evil shrew of a call girl a drink

Buy me a drink sailor and you might get lucky LOLOLOLOLOLOL

[alismith]

The 60's era, Russian engine may be the culprit. They've had problems with them in the past.

According to the article, they should have a better idea in about a week as to whether the engine were the cause, or not.

http://news.yahoo.com/russians-deliv...191254991.html

[Schuetzenman]

Video I saw of it showed it lift off, gain some altitude then boosh, the bottom of the rocket blew out. (small explosion). Then it starts to fall slowly back to earth and when it hits KA-BAM that's when it really blows up. Sure looked to me like the engine blew up.

[Krupski]

Video I saw of it showed it lift off, gain some altitude then boosh, the bottom of the rocket blew out. (small explosion). Then it starts to fall slowly back to earth and when it hits KA-BAM that's when it really blows up. Sure looked to me like the engine blew up.

All rocket engines are acoustic chambers with a huge source of wide spectrum acoustic energy inside them (think of blowing across the neck of a soda bottle and making a tone).

It's very difficult to make any engine that doesn't "sing" at it's resonant frequency(s) (called "combustion instability").

Engines usually have an array of acoustic chambers and baffles inside them to prevent resonance and instability.

When an engine goes unstable, the heat transfer to the combustion chamber increases by several hundred percent, as well as thousands of G's of vibration which will usually tear an engine apart in a fraction of a second.

I watched the video several times and it looked like the exhaust plume got a lot brighter (but still looked right) just before it exploded, which makes me think the engine went unstable and tore itself apart.

Another thing that unstable combustion produces is a dramatic loss of thrust, which I could see by the fact that the rocket stopped climbing and was almost stationary BEFORE it exploded and fell.

A possible problem may also have been a burn-through caused by the oxidizer rich gas generator exhaust used in that particular engine. Blowing pure oxygen on stainless steel (or even Inconel 750X) at a few thousand degrees F is bound to start something bad (picture a cutting torch). The burn through would have been at the inlet to the turbopump turbine, which of course would cause the pump to slow down as the leak burned through (also causing a loss of thrust because less fuel and ox are being pumped into the engine).

All in all though, I'll bet that combustion instability was the problem (but of course they will call it a "dust cover left in a fuel line" as they always do for the unwashed masses)...

Oh well, with rockets it's not a matter of IF one will blow to hell, it's a matter of WHEN. At least this one wasn't manned.

[skorpion]

They used 60's era Russian rocket motors.

Thought you were joking until I heard this mentioned on the radio. We can thank Insane Hussein Obama for devolving NASA and forcing them to scrounge up old parts to stay operational.

[studmuffin]

All rocket engines are acoustic chambers with a huge source of wide spectrum acoustic energy inside them (think of blowing across the neck of a soda bottle and making a tone).

It's very difficult to make any engine that doesn't "sing" at it's resonant frequency(s) (called "combustion instability").

Engines usually have an array of acoustic chambers and baffles inside them to prevent resonance and instability.

When an engine goes unstable, the heat transfer to the combustion chamber increases by several hundred percent, as well as thousands of G's of vibration which will usually tear an engine apart in a fraction of a second.

I watched the video several times and it looked like the exhaust plume got a lot brighter (but still looked right) just before it exploded, which makes me think the engine went unstable and tore itself apart.

Another thing that unstable combustion produces is a dramatic loss of thrust, which I could see by the fact that the rocket stopped climbing and was almost stationary BEFORE it exploded and fell.

A possible problem may also have been a burn-through caused by the oxidizer rich gas generator exhaust used in that particular engine. Blowing pure oxygen on stainless steel (or even Inconel 750X) at a few thousand degrees F is bound to start something bad (picture a cutting torch). The burn through would have been at the inlet to the turbopump turbine, which of course would cause the pump to slow down as the leak burned through (also causing a loss of thrust because less fuel and ox are being pumped into the engine).

All in all though, I'll bet that combustion instability was the problem (but of course they will call it a "dust cover left in a fuel line" as they always do for the unwashed masses)...

Oh well, with rockets it's not a matter of IF one will blow to hell, it's a matter of WHEN. At least this one wasn't manned.

Good read, I actually learned something. Can I smoke your fingernail clippings for wisdom?

[Krupski]

Good read, I actually learned something. Can I smoke your fingernail clippings for wisdom?

I usually eat 'em, but I suppose I could save a few.....

[Krupski]

Thought you were joking until I heard this mentioned on the radio. We can thank Insane Hussein Obama for devolving NASA and forcing them to scrounge up old parts to stay operational.

Those "60's era Russian engines" you are laughing at used an advanced technology that the Americans could never perfect.

The closest the US has come to that design is the Space Shuttle main engine.

If you care to know, rocket engines use centrifugal pumps to send the fuel and oxidizer into the engine. Those pumps, of course, need to be spun by some kind of a "motor".

Rocket engines use a hot gas powered turbine to spin the pumps.

The hot gas can come from a lot of different places. The old German V2 rocket used a separate tank of hydrogen peroxide decomposed over a catalyst to generate hot, high energy steam to spin the turbine. But the weight of the hydrogen peroxide, it's tank and plumbing were all "dead weight"... none of it went into making thrust.

Next came a gas generator that tapped a tiny bit of the engine's own fuel and oxidizer to be burned to make the hot turbine gas. But since the turbine is uncooled, the gas generator must be run VERY rich to keep the flame temperature down (else the turbine would immediately melt). All this fuel and oxidizer is also wasted since it doesn't go into the engine itself to make thrust. The turbine "exhaust" is just dumped overboard.

Finally came the "staged combustion" cycle (which the Space Shuttle engine uses). ALL of the fuel and a small part of the oxidizer is used to make a high energy, relatively cool fuel rich gas to run the turbine, then the turbine "exhaust" gas is injected into the combustion chamber and burned with the rest of the oxygen. Therefore, ALL of the propellant goes into the engine and the efficiency is the highest.

The American design uses a fuel rich gas to run the turbine, never oxidizer rich. Imagine a several thousand degrees F flame with excess oxygen in it trying to spin the turbine. It would act exactly like a cutting torch (igniting the metal, then burning it in the excess oxygen). The US didn't think it was possible to make a staged combustion engine that uses an OXYGEN rich gas generator.

But, that's exactly what the Russian NK-33 (Aerojet AJ-26) uses... an oxidizer rich gas generator. Why do they do it? Without going into another whole story... it's a lot more efficient and generates a lot more turbine power (which allows less fuel and ox to be "wasted" on the pumps and therefore more available for the engine itself).

Don't knock the Russians. They got a satellite and a man into orbit before we did, and they made the oxygen rich staged combustion engine work before we did. They were fairly close behind us in the moon race as well (until their N1 monster rockets blew all to hell and ended their moon program).

[Viking350]

And apparently the Russians couldn't perfect it either.

[Krupski]

And apparently the Russians couldn't perfect it either.

One rocket blows up and suddenly the Russians are no good?

Ever see Toy Story? Woody says "Rockets? Rockets EXPLODE!".

Fortunately SOME of them don't.

[Schuetzenman]

Good read, I actually learned something. Can I smoke your fingernail clippings for wisdom?