Author Topic: STS-126: SSME Ignition in Super Slow Mo Video  (Read 57401 times)

Online Chris Bergin

Fair few requests relating to this, following the use of a screenshot in a recent article:
http://www.nasaspaceflight.com/2008/12/sts-126-ifa-review-clean-launch-of-endeavour/

Rather than posting a better res image, as per request, Steven (Ford) has kindly created a three minute edit of the 2 hour long (330mb) video on L2 (numberous engineering angles on the pad, such as SSMEs, SRBs, Holddown Posts, even the camera inside the TSMs!) that covers that particular angle.

You'll get an idea of how slow mo this is as it covers 8 seconds in real time.

Those SSMEs are very, very cool and this is a very good shot of them building up thrust ahead of T-0.

The watermark is because youtubers love leeching without accreditation.

Enjoy!

Offline mdrapp

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #1 on: 12/17/2008 02:23 AM »
You know...everytime my L2 sub lapses....something like this comes along.  Rejoining now... :D
--Michael

Offline Shuttle Scapegoat

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #2 on: 12/17/2008 02:28 AM »
Fair few requests relating to this,

I was one of them, thank you for this freebie, really awesome!

Offline History Buff

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #3 on: 12/17/2008 03:38 AM »
Absolutely beautiful. The sequence of ignition appears to be a hyrogen rich bleed of fuel before it's mixed with liquid oxygen? Or the other way around? The orange flame before the blue glow.

Creates a beautiful shape at full thrust too.

Thanks for uploading that here.

Offline Jim

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #4 on: 12/17/2008 11:04 AM »
Hydrogen rich, hence the need for the sparklers

Offline shuttlefan

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #5 on: 12/17/2008 12:45 PM »
Hydrogen rich, hence the need for the sparklers

I think alot of folks still think the sparklers ignite the engines, but they actually ignite any free, unburned hydrogen under the engine nozzles so there's not an explosion down there at engine start. Just wanted to clarify that for anyone 'new' to shuttle launches.

Offline rdale

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #6 on: 12/17/2008 01:58 PM »
The timer.

Offline ETEE

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #7 on: 12/17/2008 02:22 PM »
Hydrogen rich, hence the need for the sparklers

I think alot of folks still think the sparklers ignite the engines, but they actually ignite any free, unburned hydrogen under the engine nozzles so there's not an explosion down there at engine start. Just wanted to clarify that for anyone 'new' to shuttle launches.

So what does ignite the engines?
Echo Tango Echo Echo

Online Chris Bergin

Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #8 on: 12/17/2008 02:33 PM »
Hydrogen rich, hence the need for the sparklers

I think alot of folks still think the sparklers ignite the engines, but they actually ignite any free, unburned hydrogen under the engine nozzles so there's not an explosion down there at engine start. Just wanted to clarify that for anyone 'new' to shuttle launches.

So what does ignite the engines?

Big spark plugs/torch ignitors that fire in the pre-burner inside the SSME.

From the Space Shuttle Main Engine Orientation Presentation (105 pages) on L2:

"ASI SPARK IGNITER
The spark igniter generates sparks at a rate and energy level sufficient to ignite the propellants in the
ASI chamber.
Six igniters are used on the SSME, two each (for redundancy) in the MCC and both preburners.  The
spark igniter is completely self-contained in that a 26-VDC input as provided by the controller, results in
a 10-kilovolt, 50 sparks per second output.  The igniter is hermetically sealed and welded."

Offline ETEE

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #9 on: 12/17/2008 02:49 PM »
Thank you very much for that glimpse into L2 Chris.  I had always assumed that the sparklers ignited the main engines.
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Offline ugordan

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #10 on: 12/17/2008 03:49 PM »
Without going into that L2 presentation now, how stable would combustion be if the igniters (in the combustion chamber) were shut down?
« Last Edit: 12/17/2008 03:49 PM by ugordan »

Offline Captain Scarlet

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #11 on: 12/18/2008 01:22 PM »
Oh lordy, that's something special. I also found it beautiful, as much as I know it's a truckload of power coming out of the aft.

Offline Ford Mustang

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #12 on: 12/18/2008 05:11 PM »
Oh lordy, that's something special. I also found it beautiful, as much as I know it's a truckload of power coming out of the aft.

More than just a truck.  ;)

Offline Paul Howard

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #13 on: 12/21/2008 12:42 AM »
Really nice clip, even if it's 3 minutes out of a two hour video. Still very impressive.

Offline Stowbridge

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #14 on: 12/30/2008 12:53 AM »
Very good clip. Interesting how less pronouced the bending of the stack is on this video, and also good to see the clear separation of the start up sequence of each individual engine.
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Offline DaveJSC

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #15 on: 01/23/2009 08:34 PM »
The timer.

Down to a 1000th of a second I think.

Offline John B

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #16 on: 03/19/2009 10:36 PM »
Oh lordy, that's something special. I also found it beautiful, as much as I know it's a truckload of power coming out of the aft.

All engines are impressive.

Offline mongo

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #17 on: 03/20/2009 06:25 PM »
In regards to the timer on the right side of the screen, can anybody help with interpretation of it or is it REALLY technical?

Offline Jim

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #18 on: 03/20/2009 06:32 PM »
It is just a timer so that events can be time stamped

Offline psloss

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #19 on: 03/20/2009 06:35 PM »
In regards to the timer on the right side of the screen, can anybody help with interpretation of it or is it REALLY technical?
Some of the confusion is perhaps that the numbers are inverted...from the bottom going up: hours, minutes, seconds, and so on for the time of day in GMT.  Recall that liftoff for STS-126 was in the general vicinity of 00:55:39 GMT.

Offline rtphokie

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #20 on: 06/09/2009 02:39 PM »
is the original, longer video available somewhere.

Offline stockman

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #21 on: 06/09/2009 02:44 PM »
is the original, longer video available somewhere.

L2
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Offline rtphokie

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #22 on: 06/09/2009 02:45 PM »
is the original, longer video available somewhere.

L2

I figured as much, where on L2?

Offline stockman

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #23 on: 06/09/2009 02:47 PM »
is the original, longer video available somewhere.

L2

I figured as much, where on L2?

If you have a subscription to L2 simply do a SEARCH on "QUvis" - I think the STS126 one is the first hit..
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Offline rtphokie

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #24 on: 06/09/2009 02:51 PM »
is the original, longer video available somewhere.

L2

I figured as much, where on L2?

If you have a subscription to L2 simply do a SEARCH on "QUvis" - I think the STS126 one is the first hit..

Got it now, thanks!

Offline Longhorn John

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #25 on: 06/12/2009 03:37 PM »
Super impressive. Good idea to link in the latest article on the super slo mo vids.

Offline TonyJ73

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #26 on: 02/08/2010 04:26 AM »
Never seen that before, how it goes from orange to blue as the LOX is mixed in.

Offline LarryL8

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #27 on: 07/17/2010 06:04 PM »
Big fan of the SSMEs, that is a beautiful sight seeing it come to life.

Offline Tommy E

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #28 on: 02/17/2011 08:29 PM »
Hello everybody. Read the news storys all the time but first time on the forum. Sorry for the stupid question but why do the SSMEs take a few seconds to ignite and power up and the SRBs fire up almost immediately?

Awesome video.
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Offline ChrisGebhardt

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #29 on: 02/17/2011 08:33 PM »
Hello everybody. Read the news storys all the time but first time on the forum. Sorry for the stupid question but why do the SSMEs take a few seconds to ignite and power up and the SRBs fire up almost immediately?

Awesome video.

Because of the way liquid v. solid engines work.

Offline Tommy E

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #30 on: 02/17/2011 08:39 PM »
Hello everybody. Read the news storys all the time but first time on the forum. Sorry for the stupid question but why do the SSMEs take a few seconds to ignite and power up and the SRBs fire up almost immediately?

Awesome video.

Because of the way liquid v. solid engines work.

So that is why Ares I-X ignited and went up straight away. But Delta 4's are liquid and that seemed to go up straight away too?
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Offline ugordan

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #31 on: 02/17/2011 08:40 PM »
Because of the way liquid v. solid engines work.

That's really cutting it short. A pressure-fed liquid engine could have just as fast a startup.

A less short answer would be because the SSME is an incredibly complex piece of hardware with complex propellant flow paths, etc. It takes time to spin the turbopumps up to speed and reach full thrust. Big engines tend to need several seconds to really get going.

Offline ugordan

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #32 on: 02/17/2011 08:41 PM »
But Delta 4's are liquid and that seemed to go up straight away too?

Delta IV engine starts ignition at about 6 seconds before liftoff as well.

Offline Tommy E

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #33 on: 02/17/2011 08:42 PM »
Big engines tend to need several seconds to really get going.

And that explains Saturn V. That took time to build up and the announcer says "all engines running" when still on the pad and then it went up :)

Cool, thank you.
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Offline ChrisGebhardt

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #34 on: 02/17/2011 08:43 PM »
Hello everybody. Read the news storys all the time but first time on the forum. Sorry for the stupid question but why do the SSMEs take a few seconds to ignite and power up and the SRBs fire up almost immediately?

Awesome video.

Because of the way liquid v. solid engines work.

So that is why Ares I-X ignited and went up straight away. But Delta 4's are liquid and that seemed to go up straight away too?

Delta-4 does not do what you claim. Engine ignition occurs at T-7secs for the Delta-4. Liftoff is at T0.
« Last Edit: 02/17/2011 08:46 PM by ChrisGebhardt »

Online Chris Bergin

Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #35 on: 12/01/2011 08:17 PM »
Bump due to conversation about RS-25s on the Con Ops thread in the SLS section.

Offline Liryc

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #36 on: 03/14/2012 12:19 PM »
Hey guys !

Just found this thread, and had to say, the video is just great !

One question though : what about the water deluge system on the SSME ?
On the we can see the rainbirds flooding the SRB side of the MLP with water, but what about the SSME ?
I guess there must be some water deluge there too ?
I've seen it already, but couldn't find the source anymore..

Cheers !
Cyril

Offline Jim

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #37 on: 03/14/2012 12:48 PM »
Hey guys !

Just found this thread, and had to say, the video is just great !

One question though : what about the water deluge system on the SSME ?
 we can see the rainbirds flooding the SRB side of the MLP with water, but what about the SSME ?
I guess there must be some water deluge there too ?
I've seen it already, but couldn't find the source anymore..


There is a deluge in the SSME duct but there is not one needed on the top side.  The rainbirds are not there for the SRB exhaust, notice that they do not "come on" until after liftoff.  The rainbirds cover the deck of the MLP with water so that the acoustic noise from the vehicle does not reflect of the deck and damage the vehicle.

Offline Liryc

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #38 on: 03/14/2012 03:05 PM »
Ok, thanks !

Offline Liryc

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #39 on: 03/15/2012 02:08 PM »
There is a deluge in the SSME duct but there is not one needed on the top side.  The rainbirds are not there for the SRB exhaust, notice that they do not "come on" until after liftoff.  The rainbirds cover the deck of the MLP with water so that the acoustic noise from the vehicle does not reflect of the deck and damage the vehicle.

Allright. Is it the same for the deluge in the SRB holes ? Is it also set up ater lift off or before the SRB ignition ?

this is the system i'm talking about :



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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #40 on: 03/15/2012 07:14 PM »
Cyril_13

Perhaps you may want to review this thread.  Unfortunately, some of the video links are broken, but if you go to the KSC video library, and search on "Sound suppression water test", you will get two video clips and stills.

http://forum.nasaspaceflight.com/index.php?topic=653.0
« Last Edit: 03/15/2012 07:27 PM by catdlr »
Tony De La Rosa

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #41 on: 03/15/2012 08:05 PM »
Cyril_13

Perhaps you may want to review this thread.  Unfortunately, some of the video links are broken, but if you go to the KSC video library, and search on "Sound suppression water test", you will get two video clips and stills.

http://forum.nasaspaceflight.com/index.php?topic=653.0

The video of the test and the interview afterwards can be viewed in L2 at this link: http://forum.nasaspaceflight.com/index.php?topic=9594.0

Tony D.
Tony De La Rosa

Offline Liryc

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #42 on: 03/15/2012 08:34 PM »
Cyril_13

Perhaps you may want to review this thread.  Unfortunately, some of the video links are broken, but if you go to the KSC video library, and search on "Sound suppression water test", you will get two video clips and stills.

http://forum.nasaspaceflight.com/index.php?topic=653.0

The video of the test and the interview afterwards can be viewed in L2 at this link: http://forum.nasaspaceflight.com/index.php?topic=9594.0

Tony D.
Cheers!
One problem though... I get the message "The topic or board you are looking for appears to be either missing or off limits to you." when clicking on your link.

I've read the 3 pages, very interresting stills, but no information on when the deluge inside the SRBs holes is started.

That's amazing to see how many deluges they have : 2 in SRBs holes, one for the SSMEs, one on the MLP with the rainbirds, one on the deflector edge and one in teh SRB trench, after the SRB deflector !!
... and I might even heve forgotten one.... :)

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #43 on: 03/15/2012 08:42 PM »
One problem though... I get the message "The topic or board you are looking for appears to be either missing or off limits to you." when clicking on your link.
L2 is subscription access only. To gain access to all the L2 boards you need to sign up for it: http://www.nasaspaceflight.com/l2/
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Offline Liryc

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #44 on: 03/15/2012 10:21 PM »
L2 is subscription access only. To gain access to all the L2 boards you need to sign up for it: http://www.nasaspaceflight.com/l2/
Oh.... I see...
I'll give it some thoughts :)

Thanks for the info!

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #45 on: 03/16/2012 04:17 PM »
Cyril_13

Perhaps you may want to review this thread.  Unfortunately, some of the video links are broken, but if you go to the KSC video library, and search on "Sound suppression water test", you will get two video clips and stills.

http://forum.nasaspaceflight.com/index.php?topic=653.0

The video of the test and the interview afterwards can be viewed in L2 at this link: http://forum.nasaspaceflight.com/index.php?topic=9594.0

Tony D.
Cheers!
One problem though... I get the message "The topic or board you are looking for appears to be either missing or off limits to you." when clicking on your link.

I've read the 3 pages, very interresting stills, but no information on when the deluge inside the SRBs holes is started.

That's amazing to see how many deluges they have : 2 in SRBs holes, one for the SSMEs, one on the MLP with the rainbirds, one on the deflector edge and one in teh SRB trench, after the SRB deflector !!
... and I might even heve forgotten one.... :)

I believe the flame trenches (both SSME and SRB) start to flood at the same time, around T-10 seconds (don't quote me on that). The "rainbirds", which deluge the MLP deck, start after liftoff.

These questions are probably better off in the Shuttle Q&A or LC39 Q&A threads.

Offline Liryc

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #46 on: 03/19/2012 08:05 AM »
Yep, thanks you're right, I'll go and ask there.

Cyril

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #47 on: 12/20/2012 03:16 PM »
Another cool thread. What will be the main difference between the RS-25D and RS-25E? Will actual hardware be removed?

Offline wolfpack

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Re: STS-126: SSME Ignition in Super Slow Mo Video
« Reply #48 on: 01/03/2013 01:20 PM »
Another cool thread. What will be the main difference between the RS-25D and RS-25E? Will actual hardware be removed?

Engineering answer? Basically cheaper turbopump design, since no need for re-use.

Cynical answer? One exists, the other won't.  ;D

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