Space Shuttle Program Launch Pad Aborts

[chillaxer1993]

at 3:00 what is being sprayed on the orbiter

[lars330]

@chillaxer1993 I believe it's an fire extinguisher.

[Mrjasonorum]

@chillaxer1993  water to cool down

[greenseaships]

6 aborts in 135 missions (not counting 51F which reached orbit)? Not bad!

[MrJimboygwapo]

only atlantis had no abort. yay!



[greenseaships]

@MrJimboygwapo Technically, Challenger did not have a pad abort. Her only launch abort was after liftoff and allowed her to reach orbit (51F)

[hoghogwild]

@greenseaships Challenger had an RSLS(Redundant Set Launch Sequencer) abort after a 3 SSME(Soace Shuttle Main Engines) were lit. An issue with engine #2 caused the pad abort at T -3 seconds July 2nd 1985 Challenger did Abort to Orbit The center engines 1st high pressure fuel turbopump turbine(HPFTP) failed, which was fine,then it's redundant #2 sensor failed which triggered the ATO,the orbiter made it to a lower orbitand mission was a success.Only in flight abort in 30 years of Shuttle flight

[slapnpopbass]

Fascinating video, I had no idea that this had happened so often. Thanks for posting.

[scooby1971]

Cool to note that even minutes after engine shutdown, the shuttle stack is still swaying from the force of lighting the 3 main engines!

[broadhurst04]

STS 68 aborted at ZERO? what kept the SRBs from igniting? If they had, would the shuttle have gotten off the pad?

[brch2]

@broadhurst04- ON STS-68, there was a high temp indicator on a part of engine 3, and the command to abort was actually given by the computer around T-1.9 seconds. However, the command to shut down the other engines was not given till a little over a second later for one, and a little over 2 seconds for another, which is why it appeared to be at T-0. But, an abort can be initiated until a microsecond before SRB ignition theoretically, due to how fast the computer processes inputs and commands.

[znttnt11]

3 people think space is stupid

[Pokefan186]

endeavors was the worst

[afortaleza]

STS-68, man, that was so close to SRB ignition.

[mstegman123]

damned youtube.....why is it that every time i go to full screen mode, what has already been loaded for a video is erased and it has to re-buffer the entire thing. this is very frustrating.

[silicon212]

@mstegman123 It's because in full-screen mode, it's loading in a higher resolution than the default windowed mode. If you start the video in at least 480p (or the highest available if less) resolution, you will not have this problem.

[Tyrannobeast]

The SSMEs sound really creepy after a cut off, almost like whale song.

[olympicnut]

Should this even count as an abort? It does not look like the main engines even started. There was also not the usual chatter about an "RSLS abort, GLS safeing is in progress, etc." It appears the engine start command was not sent. The hydrogen burn ignitors also shut down very quickly, which they probably would not do if the engines has actually started. The fire suppression water spray directed at the main engines also did not happen.

[Cellmate412162]

@olympicnut What happened was that the ground controllers never practiced an RSLS situation before the STS 41-D pad abort. Also the video footage was had some brightness issues, which explains why the engines didn't seem to ignite. And the fire suppression system wasn't automated at the time, but at the same time they should have paid attention to the fire dectectors since there actually was a small spot fire on the pad. I hope someone got fired for that.

[olympicnut]

I was referring to STS-93. That was not an RSLS abort. The main engine engine ignition command was not issued. STS-93 should be removed from the video and the 51F on the pad orbit put in to make it technically accurate.

[Cellmate412162]

@olympicnut Sorry about that. I thought you were talking about STS 41-D.

[olympicnut]

They never practiced it? That seems hard to believe. When they conduct FRFs of new orbiters on the pad, they have to deal with a main engine shutdown. They should count as practice.

[Cellmate412162]

@olympicnut @olympicnut I know. I too was stunned by that. On YouTube, check out the FRFs for STS-1, STS-6, & of course STS-41D. They didn't activate the fire suppression system at all during those tests! From what I heard, the launch controllers got more serious at practicing RSLS situations after STS 51-L.

[don312000]

@Cellmate412162 The water was released on the STS49 test (youtube wont let me post the link but search "STS 49 FRF" and you'll find it), and they actually gave an RSLS Abort command. The video for thet STS26 test didnt last long enough to know for sure if they released the water or not on that one.

[Cellmate412162]

@don312000 Actually, I found another STS-26 FRF video, which is longer. And they did activate the fire suppression system. (just like you I can't post links on YouTube)

[GreatExterminator]

I'm amazed how long the twang lasts after the engines have cutoff.

[TheSiodmy]

STS-51F was not pad abort, it was an "Abort To Orbit"

pad abort is when the launch is aborted before booster ignition

[olympicnut]

Actually, Challenger had a pad abort and then an ATO several weeks later for 51F.

[kennerfreak7]

at 350 if the flight director had said booster ignition it could have been another shuttle loss because once the srbs turn on they cant be turned off

[GreatExterminator]

@kennerfreak7

I think the computers control SRB ignition, so it wouldn't matter what the flight director said. :)

[olympicnut]

The computers on the orbiter take direct control of the launch sequence at T-31 seconds. The flight director is also in Houston and does not take over until after lift-off. The launch director is responsible until lift-off.

[virustwin]

4:08 they all look so disappointed :(

[edweibe]

I remember this well. The moan sound the orbiter made was errie.

[deimos2k6]

wow very interesting, I was ever wandering how abort sequences were.... what is most of all the main problem that causes shuttle to abort? tnx

[mach25man]

@deimos2k6 Sensors that fail and give false readings....

[Cellmate412162]

One question gets to me. During the Apollo Program, did the launch pad had any fire suppression system in case the Saturn 5's F-1 engines shut down before liftoff?

[TheGregEgg]

I remember watching STS-51 live.

[puncheex]

Notice at about 3:06 the chugging sound of the APUs stop right after the director (NTD) tells the pilot (PLT) to shut them off.

[Zoomer30]

And my mind the OAA being whipped back into place after the abort is just to make the public feel better, since if something really bad was going to happen I don't see a large crew spread over 2 decks being able to get out fast, even before they had to wear spacesuits.

[puncheex]

@Zoomer30: No, it's not window dressing. There are hundreds of things that can go wrong during a launch; most are survivable, some are not. Some are close enough to the wire that exiting from the shuttle manually and evacuating from the tower down free-fall lines to Armoured Personnel Carriers are a possibility. Like shuttle abort/return to Kennedy, they have never had to be invoked, and could fail with a high probability, but that escape is practiced.

[puncheex]

@puncheex: One possibility that springs to mind is a fire in the SSME area not fed by fuel directly that can't be put out; in that case there may well be time to get out, and we'd be really pissed if NASA didn't get the arm in position when it could have, wouldn't we?

[don312000]

@puncheex That STS 93 scrub almost led to a crew evacuation. I remember hearing an interview Cady Coleman gave once...when they called the abort and she heard the call about the hydrogen leak, she was already out of her seat and had started the procedure for getting the hatch open just in case they needed to abandon ship.

[Zoomer30]

In my mind the last one with Columbia dies not really "count" since it was before SSME start and it was triggered by a member of the launch team who so a spike in the gasous hydrogen in the aft compartment, not by the computer. Really is a GLS Hold not a RSLS abort.

[Justinh789]

Haha, can you imagine being one of those astronauts? the adrenaline of knowing you're going to be rocketing up and then...poof cutoff

[Pete4000uk]

at 2:40 is that the shuttle rocking? :s

[Postie218]

@Pete4000uk yes, it can do that

[puncheex]

@Pete4000uk: After the main engines start at t-6.3, their thrust bends the stack towards the main tank (because the shuttle engines are on the other side - it's called "twang". The tip of the tank at the top moves about 2 meters. At t-3 the computer checks to make sure all three are up to at least 90% full power before it arms the boosters. That last three seconds is also calculated to allow the twang to damp out and come back to full upright before the boosters open up.

[ExcelSub]

STS -68 Endeavour is the only shuttle to abort at T- 0

[ExcelSub]

STS -68 Endeavour is the only shuttle to abort at T- 0

[penfat1]

brakebrake brakebrake

[puncheex]

@penfat1: No - that's break-break-break-break. He's demanding attention on the channel because he thinks one of the engines may not have completely shut down. "Cutoff" is the magic word on the launch director's channel; it causes an abort if the computers haven't already triggered one. The engines have to be carefully shutdown; excess H2 can cause an explosion, so it's cut off a second before O2 is cut off. "Safed" is a condition under which no adverse reaction can be commanded to happen.

[penfat1]

poor sts 68 crew they got up to 1 second and then.......WE HAVE A CUTOFF

[predatortheme]

scared and annoyed :D

[Atlantis135]

Great video, nice job! :-)

[penfat1]

2:52-look at that swinging motion

[frezzoni]

Wow, you're right! At first I thought it was just the crew access arm, but if you look carefully it's actually the whole orbiter which is rocking... =:-O

[bubblinbrownsugar616]

Oh My GOD Endeavor! 1 SECOND?!?! That is scary as hell.

On a side note, hydrogen is one bitch of an element I tell ya.

[RJY4356]

@bubblinbrownsugar616 A scarier instance- for the astronauts- was STS-75 in Feb. 1996. The pilot later said expected there would BE an abort because the left engine only read 40% thrust, yet the SRBs lit and surprised the hell out of the crew. Within a minute, Houston confirmed to them that all 3 engines were running fine, they just had a faulty cockpit gauge. But they thought they were going to abort and were damn surprised to find themselves lifting off!

[bubblinbrownsugar616]

Good God!!!! I think I found a bigger respect for the Astronauts than I had before!!!

That's crazy!!!!!

[predatortheme]

dude, oxygen can be a bitch aswell.. 1 spark on 100 percent oxygen and you got a nice fire

[bubblinbrownsugar616]

LOLOL!! True True!!!

[puncheex]

@predatortheme: No unless you have fuel; oxygen all by itself can't do anything.  Hydrogen, on the other hand, can explode in the air because air is 21% oxygen anyway. Liquid oxygen is dangerous because it can explosively vaporize, like steam out of water, and 100% oxygen is nearly hypergolic; it needs the barest excuse in the presence of almost any fuel to ignite.

[puncheex]

@bubblinbrownsugar616: The closest the shuttle has ever gotten to launch before an abort, at t-1.9 seconds. The computers have verified that all 3 SSMEs are at 90% thrust, and it's waiting for the twang to damp out before the boosters are finally armed and fired. After cutoff it takes about four seconds to successfully stop the main engines and disengage the turbopumps. Meanwhile pyrotechnics all over the shuttle and the pad are being disarmed and safed so no electrical failure can fire them.

[englishguy2005]

Judy Resnik was aboard the first one on here. God bless you Judy! You, Dick, Mike, Christa, Greg, Ron and Ellison are forever in my heart.

[MusicStudyMan]

@englishguy2005 Check out "Ron's Piece" by Jean-Michele Jarre if you haven't already. Due to be the first piece of music played live in Space by Ron on his Saxophone..

[spavatch]

2:32 - look at that swinging motion, the inertia of the whole aggregate is simply collosal.

[bschott]

@spavatch

there is a national geographic show called "Seconds from Disaster" that has an episode covering the Challenger disaster. They show that swinging motion is called "The Twang", when the main engines push the shuttle stack forward by over a meter, prior to the SRBs igniting and being released from the launch pad. In fact the shuttle stack vibrates once every three seconds (natural frequency of the twang) for the first seconds of launch. Couple videos round here about it

[antimatterXXXIII]

These engines depend on burning the fuel to cool themselves, paradoxically, so when the suddenly have to shut down it's a big deal and the fuel pumps have to be shut down immediately to prevent a catastrophe - this makes a fantastic groaning sound you can hear at about 2:10 and after. It's hard to stop those pumps!

[Cellmate412162]

Thanks for posting. I don't know in anyone knows this, but NASA's first RSLS abort was on December 12, 1965 within the Gemini program. Right after countdown, Gemini 6's engines had shut down. I would like to see a video of that event.

[mach25man]

What is RSLS ?

[Cellmate412162]

RSLS stands for Redundant Set Launch Sequencer. Starting at 0:15 into the video, you can hear one of the ground controllers say "We have an RSLS abort."

[mach25man]

OK I got it. The back up launch sequencer failed. Thanks...

[RJY4356]

@Cellmate412162 No, the RSLS means Redundant Set Launch Sequencer, and refers specifically to the computers onboard the space shuttle only, commanding a shutdown. The Gemini shutdown was because of a piece of plastic stuck in the fuel lines. The engines ran for 2 seconds then shut off.

[don312000]

@Cellmate412162 It's on Youtube!!! It wont let me post links, but search "Aborted Launch Gemini 6 (CBS)" and you'll find it, complete with Uncle Walter giving commentary!!!!!

[Cellmate412162]

@don312000 Thanks for the info!!!

[doolok]

Another interesting fact...the main engines on the shuttle can be turned off in case of emergency. The solid rocket boosters cannot be turned off once they are fired.

[afortaleza]

Holy crap, endeavor was so close, imagine sitting there and feeling all that horsepower and all of a sudden cut off...man, frustrating.

[John19182004]

it's spelled Endeavour.

[afortaleza]

@John19182004 Sorry mate, bad french over here.

[DeathstormX]

why do those sparks always shot out across each other underneath the shuttle when its about to launch

[tomboi1978]

those sparks are to light any hydrogen hanging around before it can accumulate and become a danger.

[englishguy2005]

Those sparks are to burn of any residual hydrogen which may be present near the main engines at ignition. A lot of people think those sparks actually ignite the engines, like you would light a gas hob with a spark, but thats not true :-)

[nzoomed]

that would be scary if you were the astronauts

[RJY4356]

You've got them all except the STS-51 F abort- July 12, 1985.

[juancarlosbascu]

Exactly, because the STS-51 F abort video doesn't on internet I think :/

[nickhawkman]

@juancarlosbascu lol and he called it "launch pad" aborts, sts 51 f was an ATO abort.

[ArbiterNL]

@juancarlosbascu STS-51 F abort is on the intertnet, BUT thats an ATO (Abort To Orbit) abort and not a pad abort.

[kooldog98]

pass

[sockcutter]

I can't believe nobody said FAIL yet.

I am disappoint.

[BroadwayDivo]

The guy announcing STS 68 sounded scarred

[IamTheEditor]

RSLS Abort. Computer shuts the mains down when it detects a problem with one of them before SRB ignition. It's the last abort option before SRB cutoff 128 seconds later.

[RJY4356]

That was Bruce Buckingham, an idiot. He was startled because the clocks actually got to zero and he was about to say lift-off. The actual abort was at T-1.8 seconds.

[John19182004]

takes one to know one.

[UdallIn72]

It must suck to go all the way through the terminal countdown, only to abort, like, three seconds from SRB ignition.

[Ronaldo7PortugalFan7]

Would you rather die? or see others die?

[UdallIn72]

Heh. I'm not saying I don't recognize the NEED for these aborts, or that I would prefer loosening the safety strictures on a machine that's already way too dangerous.

I'm just saying that it would be irritating, psychologically, to get yourself all amped up psychologically, wait around in the crew cabin for several hours, run all your checklists, do all your procedures, and then have the launch aborted AFTER the engines started.

Preferable to dying, no doubt, but still irritating.

[darkguardian1314]

Just to add: STS-51F Challenger took off and had an engine shut off in flight. Abort to orbit (ATO) It's always scary with all that fuel and no fast way to get out of the shuttle in case of explosion. Thanks.

[Neptuneaus]

I remember STS 68 almost gave me a heart attack.

[gnfti]

I'm afraid I can't do that, Dave.

[yankeevictor]

It's called the "twang"

[sgabriel]

Check out the sway from 2:55 to 3:19!

[Postie218]

@sgabriel the shuttle can sway up to 4 degrees from vertical

[oreoweb6]

@sgabriel The sway of the shuttle at main engine start is called the twang

[amadeus5889]

@sgabriel Looks like the shuttle is gasping for breath.

[im99mining]

nice!!!!!!!1 :) 5 stars :D