Space Shuttle main engine startup in slow-mo!

[Deadweasel]

Thought you folks might enjoy this!

Space Shuttle main engines firing in slow motion (LiveLeak)

One of the little curiosity points I used to wonder about -and which I've actually been asked more than a few times- is "what's with the shower of sparks under the nozzles?"

When I was a kid, I used to think that's how they fired the engines, like lighting an acetylene torch. Heh, silly kid!

The Space Shuttle main engines operate with liquid hydrogen and liquid oxygen. They are stored in those big white rounded tanks on opposite sides of the launch pad area and loaded on the Shuttle only at the (virtual) last minute before launch. The reason they are kept so far apart is that when mixed, hydrogen and oxygen are extremely explosive. (I mean, duh, they're powering a ROCKET ENGINE with the mix, right?)

Because of its high volatility, it's extremely dangerous to allow any leaks or seepage to accumulate around the pad.

Liquid hydrogen is used to cool the engine nozzles and then re-circulated to intermix with the rest of it being injected into the combustion chamber. This pre-heats the fuel slightly, increasing engine efficiency as it warms up, so it's actually in motion within the engines a bit before ignition. The sparklers shower the area underneath the main engines to burn off any escaping hydrogen gas so it can't accumulate and cause an "unplanned thermal concussive event" (understatement of the decade) the second the Shuttle's engines light off.

Another fun fact:

Most of the "smoke" you see billowing around the pad is not smoke, but water vapor. Immediately before lighting the engines, the engine apertures in the pad are doused with a water curtain, which pulls the particulate byproducts of the booster engines' operation out of the air. A great deal of the water is vaporized in the process, resulting in massive clouds forming around the pad at the time of launch.

The shuttle's main engines themselves also produce water vapor as an emission.

The result is that the Space Shuttle quite literally made it rain behind it as it fired for orbit.

Enjoy!

[WillHop]

Have a feeling this is in the wrong section. Still, thats pretty cool!

[Deadweasel]

Have a feeling this is in the wrong section. Still, thats pretty cool!

Uh oh, I think I did that previously too.

Which section should it be in? I'm getting a bit of a track record for (unintentionally) doing that.... >_>

[Awaras]

Awesome video.

Something I never noticed on any other shuttle launch video I saw:

Above the right engine, there are three circles arranged one on top of the other, kind of like a traffic light. The top one bursts open at around 1:02 into the video, followed by the other two a few seconds later. Does anyone know what is their purpose? Some kind of pressure indicator?

[WillHop]

Uh oh, I think I did that previously too.

Which section should it be in? I'm getting a bit of a track record for (unintentionally) doing that.... >_>

The Space Lounge I think?

[Deadweasel]

Awesome video.

Something I never noticed on any other shuttle launch video I saw:

Above the right engine, there are three circles arranged one on top of the other, kind of like a traffic light. The top one bursts open at around 1:02 into the video, followed by the other two a few seconds later. Does anyone know what is their purpose? Some kind of pressure indicator?

Those are maneuvering thruster apertures, basically RCS ports. You're seeing the protective coverings being blown open as the systems are pressurized and vented for operation. You can see more of those here

[Deadweasel]

The Space Lounge I think?

"Oooohhh..."

"MOOOOOOOODSSS!!!"

[lajoswinkler]

The water which is released below the shuttle is not for catching the particles, or at least that's not its main use. It's to dampen the sound waves of the supersonic exhaust which could otherwise damage the shuttle.

[Deadweasel]

The water which is released below the shuttle is not for catching the particles, or at least that's not its main use. It's to dampen the sound waves of the supersonic exhaust which could otherwise damage the shuttle.

Yes, that most of all, I had forgotten about that!

It's amazing, all the little things that go into these designs and procedures to address problems that most folks weren't even aware were present!

[Hodo]

When I explained to a friend of mine who is an actual rocket scientist who works for NASA in Florida, on how I think the space shuttle worked or any NASA rocket for that matter.

In simplest terms, NASA takes one highly volatile fuel, and mixes it with another volatile mixture, starts a small leak out of the bottom of the rocket then strikes a match. It either goes up, or goes boom. Good news is, they have LOADS of experience in making things go up.

[rasheed]

Woow. I thought the fuel was ignited by that sparks too until now.

Nice vid

[FITorion]

shuttle picture thread?

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[Deadweasel]

shuttle picture thread?

Wait, I thought [naughty filtered word relating to smut] wasn't allowed on these forums... XD

Awesome pics! Wish I'd been able to see a launch or landing before it all came to an end.

[Behemot]

You may see. Private company (besides Russia) is now the cosmic leader and private companies are mostly the best way to organise things. You already heard how much cheaper they can get stuff into space than all these bloody (multi)national agencies?

[Deadweasel]

I'm rooting for Virgin Galactic. SpaceShipOne/Two have a special place in my heart.

[FITorion]

Wait, I thought [naughty filtered word relating to smut] wasn't allowed on these forums... XD

Awesome pics! Wish I'd been able to see a launch or landing before it all came to an end.

Living in Florida has its advantages.

[Murph]

When I explained to a friend of mine who is an actual rocket scientist who works for NASA in Florida, on how I think the space shuttle worked or any NASA rocket for that matter.

In simplest terms, NASA takes one highly volatile fuel, and mixes it with another volatile mixture, starts a small leak out of the bottom of the rocket then strikes a match. It either goes up, or goes boom. Good news is, they have LOADS of experience in making things go up.

Yeah, that's pretty close to the truth. Rocket engines more or less use a prolonged controlled explosion. If it all goes wrong, the component parts are all present in pretty much perfect proportions for an extremely large, short, uncontrolled explosion. The LC39 pads have emergency personnel bunkers about 30–40' underneath them, with supplies for people to survive for a week, or something like that, in case it all goes wrong with sufficient warning for them to slide down a chute into the bunkers. There's also a couple of armoured personnel carriers available for blast-protected evacuation. A worst-case catastrophic failure on the pad with a heavy-lift rocket would likely be measured in at least kilotons.

If memory serves, the sound suppression water system also helps to protect the concrete exhaust channels from shock damage, but the main concern is to prevent the shock waves damaging the rocket and its crew.

[jwenting]

always assumed the "sparks" are ice crystals blasted off the engines. After all, the engines are cooled by the fuel so a thin layer of ice may accumulate on them in between the fuel pumps being started and the engines igniting.

Not sure if that's all of it though.

[Nibb31]

You may see. Private company (besides Russia) is now the cosmic leader and private companies are mostly the best way to organise things. You already heard how much cheaper they can get stuff into space than all these bloody (multi)national agencies?

And who do you think pays the private companies?

I'm rooting for Virgin Galactic. SpaceShipOne/Two have a special place in my heart.

SpaceShipTwo isn't a spaceship. It's a suborbital stunt plane.

[Deadweasel]

SpaceShipTwo isn't a spaceship. It's a suborbital stunt plane.

Currently, yes you're right.

However, Burt Rutan had designs that went far beyond sub-orbital hops. It's just that since Branson sponsored and subsequently bought the whole thing up, he's focusing on the aspect that's capable of being commercialized the quickest.

Rutan has always been the pioneer and biggest champion of composite airframe designs, but the X-Prize competition was the best and most public way for him to demonstrate just how much those materials can do (and how cheaply). It was especially needed to help soften the impact of John Denver's crash, which happened in a Long EZ, one of Rutan's designs. (The media focused hard on the plane, not so much on the fact that Denver was doing touch-and-go's with one tank running dry like a newb.)

He gives a brief glimpse of some of those designs during a two part Discovery special about SpaceShipOne called "Black Sky: The Race for Space", and "Black Sky: Winning the X-Prize".

Thing is, Rutan is the kind of guy who doesn't just doodle. When he gets an idea in his head, he'll run it right up to the build stage if left unchecked.

I think the only limiting factors to his orbiter ideas are money and effective affordable propulsion. Nobody's going to replicate the Shuttle's lifting system these days. While its engines were among the most efficient in the world, the rest of the launch system required ridiculous amounts of money, complexity and manpower to produce, operate and recycle. Sadly, the White Knight approach would not be feasible for an orbiter capable of carrying any appreciable load -be it equipment or passengers- up to orbital altitude and velocity, so unless Branson comes back for seconds (which I kind of expect he will if Virgin Galactic takes off, so to speak), he's kind of stuck in a Howard Stark situation.

"I'm limited by the technology of my time..."

[jwenting]

yes, he has grand plans. But for now SS2 is already years late and still no sign of it nearing service entry, and the future orbital craft were to be funded in large part by the income from the SS2 fleet.

[Nibb31]

Currently, yes you're right.

However, Burt Rutan had designs that went far beyond sub-orbital hops. It's just that since Branson sponsored and subsequently bought the whole thing up, he's focusing on the aspect that's capable of being commercialized the quickest.

Rutan is a great aircraft designer. However, he isn't an expert in spacecraft.

The SS1 and SS2 are not spacecraft. They aren't even hypersonic, let alone orbital. They are atmospheric vehicles with passive attitude control and no thermal protection for re-entry.

The SS1/SS2 concept simply doesn't scale to an orbital vehicle at all. To go orbital would need at least a second rocket stage, some sort of RCS, and a TPS. The actual vehicles would end up being twice as heavy, the mothership would have to be 10 times larger than it is making air-launch impractical, the feathered wing concept would be useless.

It would have to be a totally different vehicle.

[Floule]

shuttle picture thread?

MOAR PICS!

No, really, we need a space shuttle pictures thread! The space shuttle looks so awesome, and i still can't believe that humans can manage to bring such a monster safely back to earth!

This one is my favorite:

wow, much space, such resolution

(My desktop background )

[rdfox]

For the record, a fully fueled Saturn V exploding on the launch pad would have had a yield of almost exactly two kilotons.

This is why pads 39A and 39B are three and a half miles apart, and also three and a half miles from the VAB--it's to make sure that if a Saturn V blew up on the pad, they'd still have at least one pad and the VAB operational. There were also provisions made for 39C, and plans for 39D and 39E, since Complex 39 was planned out in an era when they thought they'd literally be launching a Saturn V every month(!) by the early 70s. (Technically, 39A *is* 39C; the decision was made that they'd only build the two pads closest to the VAB, and redesignate the closest one, originally marked 39C, as 39A; the third pad, originally to be 39A, would be surveyed and plans made to build it, but it wouldn't be built unless a pad accident, pad damage from launch, or sheer rate of flights required it. 39D and 39E were longer-range plans, intended for either Nova boosters or for Saturn Vs that used nuclear third stages, and would have been served by a completely separate crawlerway that would go through the Nuclear Assembly Building to install the reactor cores into those nuclear upper stages. The "elbow" in the crawlerway to 39B shows where original 39A/"backup" 39C would have been; that pad would have been at the end of an extension of the "straight" portion past the turn to 39B. As it turned out, 39B was only used for one launch during the Saturn V era, Apollo 10, and was essentially an unnecessary backup. However, at the time, nobody knew how much damage the Saturn V would do to the pad when launched, so having two pads was seen to be essential. Given it was also used for the Skylab and Apollo-Soyuz Saturn IB launches, allowed for quicker turnaround between launches in the Shuttle era, and was the *only* reason the final Hubble service mission could be flown, I don't consider 39B wasteful. As a side note, NASA doesn't plan to upgrade 39A from the Shuttle configuration until/unless they find a need for more than one operational pad at Complex 39 in the post-Shuttle era...)

[SargeRho]

Nibb, SS1 and 2 go above 100km. They are, by very definition, Spacecraft. Not orbital, I give you that, but they are deffinitely Spacecraft. And SS3 is planned to be Orbital, if SS2 is successful.