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SpaceX Falcon 9 Launch Live Thread (05/19/2012) 04:55 EDT) First Commercial Rocket into Space!
05/18/12 | Kevin Davis

Posted on 05/18/2012 6:50:06 PM PDT by KevinDavis

Best of luck to SpaceX.



TOPICS: Business/Economy; Miscellaneous; News/Current Events
KEYWORDS: dragon; falcon; iss; nasa; space; spacex
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To: Kakaze

Engine #5 seems to have had a high pressure reading. That’s the trouble with so many engines...


61 posted on 05/19/2012 2:00:42 AM PDT by Errant
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To: markman46

Engine 5 abort...chamber pressure high.

Next launch window Tuesday, May 22 at 12:44am Pacific.

*sigh*


62 posted on 05/19/2012 2:01:10 AM PDT by hoagy62 ("Tyranny, like hell, is not easily conquered..."-Thomas Paine. 1776)
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To: markman46

If I heard right an over pressure in engine 5......if they go tomorrow I’ll be here.


63 posted on 05/19/2012 2:01:23 AM PDT by Kakaze (I want the Republic back !)
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To: Errant

or engine 5 pressure chamber was high


64 posted on 05/19/2012 2:02:06 AM PDT by markman46 (engage brain before using keyboard!!!)
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To: hoagy62

ya it sucks.. I’ll be here on the 22 too


65 posted on 05/19/2012 2:03:45 AM PDT by markman46 (engage brain before using keyboard!!!)
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To: markman46

Yea, I suppose they can run a test on the sensor. If it checks out, then what? Engine change?


66 posted on 05/19/2012 2:05:11 AM PDT by Errant
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To: Errant

i don’t know


67 posted on 05/19/2012 2:07:30 AM PDT by markman46 (engage brain before using keyboard!!!)
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To: markman46

I *might* be here on the 22nd. IF I can manage to wake up then. Got an early start for work on that day as well. As it stands, gotta be up and about in 2 hours anyway.


68 posted on 05/19/2012 2:07:35 AM PDT by hoagy62 ("Tyranny, like hell, is not easily conquered..."-Thomas Paine. 1776)
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To: Errant

Sounds like a reboot and they try to go tuesday, god speed guys.


69 posted on 05/19/2012 2:08:58 AM PDT by Kakaze (I want the Republic back !)
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To: hoagy62

oh man!! good luck for today


70 posted on 05/19/2012 2:09:56 AM PDT by markman46 (engage brain before using keyboard!!!)
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To: markman46

Too bad they couldn’t shut the one down and launch on the remaining 8. Maybe in future designs...


71 posted on 05/19/2012 2:10:56 AM PDT by Errant
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To: Errant

I always get nervous with engine counts of more than 5. The Soviets (as you might recall) never developed the large-capacity engines (like the Saturn V’s F-1) and relied on multiple smaller engines. Their moon rocket (the N-1) might actually have succeeded IF the first stage didn’t have to rely on the perfect sychronization of something like 22 engines.

To me, more engines = more that can go wrong.Today could be mild proof of that.


72 posted on 05/19/2012 2:17:32 AM PDT by hoagy62 ("Tyranny, like hell, is not easily conquered..."-Thomas Paine. 1776)
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To: hoagy62
I'm with you. I know it is expensive to build large engines but too many small engines working at 100 percent, increases the odds of failure.

Another thing, the one area where you could have extra capacity without too much of a weight penalty would be engine size.

No doubt they'll get it figured out in a timely manner. That's the great thing about private enterprize!

73 posted on 05/19/2012 2:27:08 AM PDT by Errant
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To: Errant
I'm with you. I know it is expensive to build large engines but too many small engines working at 100 percent, increases the odds of failure.

A friend who was working in the design and engine testing phase said that it was a very deliberate choice to go with more engines/smaller engines exactly for the reason of what happened today. The ability to abort the launch AFTER engine start. This is the largest engine they can make that can reliably be shut down after ignition and initial rev up of the engines.

An uncontrolled engine is a constant fear among the designers; the launch vehicle depends upon exact control of all engines throughout the initial launch. If I recall correctly, it's less than a few thousand feet after clearing the tower that the launch vehicle can compensate for engine failures of up to seven of the nine engines and remain in controlled flight.

74 posted on 05/19/2012 7:41:32 AM PDT by kingu (Everything starts with slashing the size and scope of the federal government.)
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To: hoagy62

I didn’t stay up for it because I had a feeling it wasn’t going to happen. To see that the countdown had made it all the way to T-1 second is just frustrating. Oh well. They’ll get another crack at it on the 22nd.

My opinion in regards to engine #5 is that it is a faulty sensor that caused the problem. Hopefully it’ll be easy to change it, test it, and see the Falcon 9 off to LEO.


75 posted on 05/19/2012 7:58:46 AM PDT by Jack Hydrazine (It's the end of the world as we know it and I feel fine!)
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To: kingu
Thanks for sharing the above. For sure, they are committed to the 9 engine configuration for now. I was reading were this isn't the first time that they've had problems with the #5 engine over-pressurizing. I assume it is the engine in the middle of the pack. It could be some kind of fuel flow/starvation issue at maximum throttle or maybe some kind of exhaust back pressure problem from the surrounding eight. Throttling it back for the time being might be the quickest fix. Just changing out the engine might not help, since they've had problems with this engine in the past.

Some questions come to mind. If it's the center engine, it shouldn't be as critical for control as any of the others. Also, since they only had 1,000 lbs of cargo on-board, and the craft is rated for putting up to 5 tons into orbit, seems they should have had plenty of thrust available to continue with the remaining eight engines; especially if #5 is the center engine.

Do you know if all of these engines are gimbaled? Is #5 an engine critical for flight control?

My hat is off to them! They've certainly accomplished a lot!!

Thanks,

76 posted on 05/19/2012 8:17:58 AM PDT by Errant
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To: KevinDavis

SPACEX/NASA DISCUSS LAUNCH ABORT OF FALCON 9 ROCKET
http://www.youtube.com/watch?feature=player_embedded&v=nV_JqBOeXMk#!


77 posted on 05/19/2012 8:33:30 AM PDT by Jack Hydrazine (It's the end of the world as we know it and I feel fine!)
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To: Errant
The Falcon 9 has full gimbal control over all engines, including the center engine. And full control over each engine's thrust, including the center one, is deemed critical for mission success.

The actual (fear) thought that my friend has on the over-pressure issue is that a fuel feeder that was designed for test fires has been used in configuring the vehicle for flight, and that the variation in pressure is coming from increased pressure from gravity feed. It would give a slight anomaly readings during ignition sequence which would seem to immediately go away as soon as flight got underway.

It wouldn't affect flight - just those moments from ignition and hold until flight. And the 'fix' is simply adjusting the tolerance parameters for ignition and hold release.

His comment about the design / construction / testing phases has been: Detailed engineering meets real world conditions, and a whole lot of 'rocket science' has been applied to the construction and testing phases - that of changing things on the fly to make the engines work in the real world.

78 posted on 05/19/2012 9:11:40 AM PDT by kingu (Everything starts with slashing the size and scope of the federal government.)
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To: Errant
Some questions come to mind. If it's the center engine, it shouldn't be as critical for control as any of the others. Also, since they only had 1,000 lbs of cargo on-board, and the craft is rated for putting up to 5 tons into orbit, seems they should have had plenty of thrust available to continue with the remaining eight engines; especially if #5 is the center engine.

Treating this separately as it is a separate issue. Yes, they could have completed the mission of delivery today by shutting down engine 5 and continuing the mission with the other 8 engines. Yes, that ability would work in full payload conditions, but is outside of the parameters of this test - It is a test flight first, a resupply mission second. The test flight regime required all systems to be nominal throughout the entire mission, including launch.

It is probable that what will happen is that the parameters for the sensor on engine 5 will be expanded as to what is nominal under launch conditions with extensive review of the data from the flight before making it a permanent adjustment.

The least likely exercise is simply changing the engine from the other Falcon 9 rocket on site - or rather was the least likely at the time of the flight meeting - the amount of press out there stating that it was a bad engine might force them to do the engine change.

The plan at this point is to scope out the engine, examine the data, and reset for the Tuesday launch window with no changes to the flight package.

79 posted on 05/19/2012 9:24:34 AM PDT by kingu (Everything starts with slashing the size and scope of the federal government.)
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To: kingu
Muchas gracias! Releasing it and the resulting G-force ought to certainly help with the fuel flow.

Thanks for the information on the gimbal control. I was looking everywhere to no avail.

It'll be interesting to learn what they determine the issue to be and the final fix. Certainly real world meets the best engineering has always been a problem. lol

Please keep us posted,

80 posted on 05/19/2012 9:30:44 AM PDT by Errant
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