X-43A flight this Saturday. (27th)

NASA's Experimental X-43A Scramjet powered craft is scheduled to fly again off the coast of Southern California this saturday.

www.nasa.gov...

Incidentally, in the article it says this:

This is the first time a non-rocket, air-breathing scramjet engine has powered a vehicle in flight at hypersonic speeds. No vehicle has ever flown at hypersonic speeds powered by an air-breathing scramjet engine.

But I thought in 2002 the HyShot scramjet test in Woomera was a success? Mach 7.6?
news.bbc.co.uk...

Incidentally you can watch this live on NASA TV over the web.
www.nasa.gov...

Having read that, I will defintley be watching Saturday.

Reading the part about the B-52 launch made me think about another thing I've always wanted to know the answer to-and maybe some of the bright folks around here know.

According to Janes, the service ceiling of a B-52 is 50K feet. When I have worked in the right seat on a few of these there is a box with a rheostat on it labeled "Pressure Suit Faceplate Defog." Why do you suppose someone might be wearing a pressure suit at FL500?

Kano,

Do you know how fast they will attempt to go on this flight?

Approximately 5000 mph is the objective.

More impressive to think of it as 2.22 km/second though.

Near Mach 7 I think.

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www.air-attack.com...
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Check out this graphic, it's a very simple diagram of what the flight will be like:

www.dfrc.nasa.gov...

[Edited on 25-3-2004 by Zion Mainframe]

So the plane will be lost to the ocean? Why don�t they try to recover it, or land on terra firma?

Cool.I b watchin' to see how she flies.

Originally posted by Sargon of Agade
According to Janes, the service ceiling of a B-52 is 50K feet. When I have worked in the right seat on a few of these there is a box with a rheostat on it labeled "Pressure Suit Faceplate Defog." Why do you suppose someone might be wearing a pressure suit at FL500?

The only time I can think of a pressure suit being anywhere near a B-52 was when they were air-dropping X-15s and other such manned craft. However, these were obviously controlled from the cockpits of those craft. Maybe it's a design feature left over from some early B-52s, when there was a requirement for them to go higher. Or maybe some were modified for special high altitude missions? (without significant modification? Yeah, I know...) Still, pressure suits are required above 60 000 feet Maybe it was felt they might be needed at 50? Still, I would like to know the story behind this.

I will also be watching this saturday, ill be watching it live all day i hope because my leg is messed up and i cant walk around so ill be watching all day and night i dont know the time it will air for me because im in EST time but i better get the pop corn going

[Edited on 25-3-2004 by ShadowMan]

So the plane will be lost to the ocean? Why don�t they try to recover it, or land on terra firma?

They're gonna trash the X-43 into the Ocean?!

Yea right... they'll retrieve it, if it goes to the ocean.

Then again the X-43 is just a flying mini-wing... I could see them allowing it to crash into the Ocean.

[Edited on 26-3-2004 by Shugo]

I think we should be thinking about what planes already in service this is based on. The Aurora perhaps? Maybe a B-3 bomber?

AMM you've caught my curiosity with bringing up a B-3 bomber. Why do you think a B-3 bomber exists... although... thinking back I think it does. I'll look through my records and if I find anything I'll U2U you.

Well here's a peice that says some about the b-3 platform.

www.globalsecurity.org...

The pressure suit requirement is a function of cabin altitude vs. time. If you are cruising at 50K with a cabin altitude of 8k there is no problem. But if the cabin loses pressure and goes to the same altitude as the aircraft you only have a useful consciouness of about 8 seconds. Thats why you need a pressure suit...just in case. Current biz jets which are certificated to 51k are allowed this altitude because the manufacturer of the aircraft has proven that there is no reasonable possiblility of a loss in cabin altitude before the pilot can descend to a safe altitude.

"The pressure suit requirement is a function of cabin altitude vs. time. If you are cruising at 50K with a cabin altitude of 8k there is no problem. But if the cabin loses pressure and goes to the same altitude as the aircraft you only have a useful consciouness of about 8 seconds. Thats why you need a pressure suit...just in case. Current biz jets which are certificated to 51k are allowed this altitude because the manufacturer of the aircraft has proven that there is no reasonable possiblility of a loss in cabin altitude before the pilot can descend to a safe altitude."

True, but it's due to O2 levels-not pressure. I have been well above 40, but only with a mask- not a suit. In my experience the only guys wearing pressure suits are the U-2's and the SR-71 who routinely go above 65K. Up there if you were to lose cabin pressure your blood would do the same thing as what happens to a well shaken bottle of Coke when you open it.
As to the useful conciousness you are exactly right and I've never really understood the physiology of that either. I was the clown that volunteered to take of his mask in the altitude chamber at 35K. They video'ed me and in about 20 seconds or so after taking off the O2 mask I was toast. Couldn't figure out how to put a round peg in the square hole and all. The instructor says, "Sargon... put your mask on or you will die and I just laugh at him! Why is that the case when I can easily hold my breath 3X that long?

Originally posted by kinglizard
So the plane will be lost to the ocean? Why don�t they try to recover it, or land on terra firma?

they'll recover it. and if this thing, say, blew up over land i think it would reak a bit of havoc on what's below. also, on land there's a greater chance of it landing somewhere making it harder to obtain... like in mountains or some farmer's fields.

i'm not sure how it's landing though. perhaps slow itself down somehow and pop some parachutes? that would make for a very easy recovery in water. they could even catch it in the air in that case.

The B-3 does not exist.

Right now we have mass of B-52s, B-2s, and B-1s it wil be way too expensive to maintain all of those aircraft and the B-3, virtually impossible.

You might want it to happen but can you pay the extra taxes?

I hope this time everything goes as it has been planned. hope it survives the 8000 kmph as the stress on the surface is extreem.

did you know its partialy made with wood?

Originally posted by Sargon of Agade
True, but it's due to O2 levels-not pressure. I have been well above 40, but only with a mask- not a suit. In my experience the only guys wearing pressure suits are the U-2's and the SR-71 who routinely go above 65K. Up there if you were to lose cabin pressure your blood would do the same thing as what happens to a well shaken bottle of Coke when you open it.
As to the useful conciousness you are exactly right and I've never really understood the physiology of that erhaeither. I was the clown that volunteered to take of his mask in the altitude chamber at 35K. They video'ed me and in about 20 seconds or so after taking off the O2 mask I was toast. Couldn't figure out how to put a round peg in the square hole and all. The instructor says, "Sargon... put your mask on or you will die and I just laugh at him! Why is that the case when I can easily hold my breath 3X that long?

Perhaps it's due to the fact that you're exhaling all the unused air in your lungs... at 35k altitude... erm, (converts to metric in head)... you're looking at about 1/8 atmosphere. That means you're only using 1/8 of the volume in your lungs, only 20% of which is O2. Holding your breath at sea level, you still have loads of unused O2 in your lungs - although it runs out quite quickly depending on what you're doing. Breathing in pure oxygen at altitude makes up for deficit that quite nicely.