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Second Test of X-43A Scramjet Tomorrow
pinkUZI writes "NASA says its new Hyper-X, a jet capable of flying some 5,000mph - seven times the speed of sound - will be ready to take a test cruise across the Pacific this Saturday. This is actually NASA's second attempt; the first, in 2001, failed when stabilizing fins flew off the plane's booster rocket and controllers ordered the craft destroyed. CNN has the story." NASA's mission web page has more information, photos, etc.
the b-52 to launch the plane. Will they be able to develop on of there that can take off on its own? or will we always be launching them from the underbellies of a big plane.
30% Troll, 50% Underrated, 10% Interesting
Score:5, Troll
The article starts off with this:
The space agency's dogged pursuit of extreme speed, officials hope, will ultimately make space flight easier to accomplish.
OK, so exactly how is this supposed to aid space flight efforts? There is no mention made of that in the article at all.
I would have thought that the ability to reach incredible speeds in horizontal flight inside the atmosphere is unrelated to both:
1) Entering orbit (horizontal flight).
2) Flying in vaccum (different conditions than in atmosphere).
I'm confused ... any thoughts?
I hear there's rumors on the Slashdots
The danger here is that the darn thing will carry all of these systems and have no capacity left over for payload. I recall the Boeing SST back in the late 60's early 70's was based on a swing wing concept. The scale of the mechanical systems to swing the large wing faced them with a difficult choice of a swing wing or passengers...but not both.
In the physics world one has a sense that they are on to something when the math becomes elegant and simple...I think in the "no moving parts" nature of the scram jet are appealing...a turbofan/scram/rocket combination is not
When the people fear their government, there is tyranny; when the government fears the people, there is liberty.
But if the earth's circumference is around 25,000 miles, and this jet can go 5,000 miles an hour, that would mean it would take only 2.5 hours to get from any location to any other.
Okay, if it only takes 2.5 hours at top speed to go anywhere on the planet, how much time is spent accelerating and decelerating versus actually flying at Mach 10? And how much fuel are you burning in the process? I remember working at LaRC when they were just starting to test scramjets and I still think the science is good for orbit, but bad for commercial applications.
Almost as interesting as the X programs is the B-52 mothership that launches them. There was an Air & Space article years ago (no online version at airspacemag.com) about it.
It's an aging early-model B-52B, evidenced by the non-pointy nose and is 49 years old. There are virtually no spare parts remaining for it, and most of the current inventory (Gs, Hs) don't have any parts commonality.
Plus, we never sold any of them to other countries, so it's not like there's a stockpile somplace else on the globe. The cost to replace it is prohibitive, given the structural reinforcements needed to carry the craft aloft. Also, the airframe is very young from an hours perspective. In fact, it's the lowest hour B-52 in the inventory.
The USAF has loaned an H-model to NASA to become the next generation launch platform, but I haven't heard much about it since the 2001 announcement.
It's a supremely important beast in the research arsenal. And, given our penchant for resurrecting C-64s as web servers and using mame to emulate decades-old cabinet games, it seems like the sort of thing that would interest the average computer geek.
Like so many things, it's the logistical details of maintaining an archaic aircraft against all odds (and lack of funding) that really become the story rather than the whizz-bang doodad that always gets the front page pictures.
Amateurs discuss tactics. Professionals discuss logistics.
We USED TO be able to go from New York to London in two hours. What the hell went wrong?
1) US refusing Concorde at supersonic speed over US territory.
2) Price of petrol
3) 2 hours of transatlantic flight, 2 hours to go to the initial airport, 2 hours to go from the final airport...
4) Looking back at this, it was somewhat an ecological catastrophe
How will all those factors be taken into account by the sdcramjet developers?
Indeed, all you would need to do to lift a 5-pound object above the Earth's atmosphere would be to supply an engine which can provide 5.1-pounds of thrust for a VERY long time. Trouble is, when you shut the engine off (or ran out of fuel) you would just fall back to Earth unless you somehow managed to achieve orbital trajectory and velocity. You do the math on how much fuel that would take (a lot - more than you could ever possibly carry). Without escape velocity, the Earth has you - forever! It doesn't matter if you travel as far as the Sun - unless you have escape velocity with respect to the Earth, you're going home. Gaining escape velocity with respect to the Sun is another problem. . .
For the more technically-mided folks out there, the idea is to achieve higher kinetic energy than you currently posess in gravitational potential energy with respect to the Earth. The farther away you go from Earth, the higher your potential energy is (the longer you "fall" to get back to our planet) - so you have to integrate from the surface of the Earth to infinity altitude to determine the total energy you would need to escape the Earth's gravity. The masses cancel each other out - and you're left with approximately 25,000 mph for your escape velocity.
Be nice to me - I haven't had my coffee yet today.
This sig is a test. If this had been an actual sig, you would be reading something quite a bit wittier than this now.
My sister Caity died of cancer at 11 years old a couple years ago..
Caity was out in California for proton radiation treatment, Joel (uncle in law / NASA engineer) held a party for his Engineering Section at his house and Caity drew a picture of the X43 plane's logo on the sidewalk in chalk.
After Caity passed Joel took the picture of her sidewalk drawing and went to Nasa to have the plane named in Caity's honor and have her picture on the side of the plane.
I hope this one does a lot better than the last time, it has a lot of sentimental value!
Mountain Dew and doughnuts, because breakfast is the most important meal of the day!
Your post was mostly right except for this part. IF (yes that's a big if;) you had sufficient fuel, as you pointed out above, you could fly at 1 MPH to the Moon. And, once you reach the crossover point (where the Moon's gravitational field is stronger than the Earth's), you have escaped in the sense of escape velocity. You won't be going back home.
Escape velocity is only relevant for ballistic (unpowered) objects.
Given our current propulsion systems, all of our spacecraft are essentially ballistic except for the new ion powered ones - and those are very low thrust. Practical antimatter propulsion would make things a lot more interesting! :-)
Galileo: "The Earth revolves around the Sun!"
Score: -1 100% Flamebait
http://www.jpl.nasa.gov/about_JPL/jpl101.pdf
The way this reads is there was a race after sputnik to launch the first U.S. satellite. The JPL/Army Orbiter lost out to the Navy's Vangaurd. Vangaurd exploded on the pad and JPL revived Orbiter but they focused on the satellite more than the rocket. They turned their focus to payloads from them on, and NASA came in to being in 1958 and assumed hegemony over rocket R&D elsewhere. As for not changing the name I assume it was:
A. Sentimental, since the early JPL had a rich history
B. To cheap to print new stationary and change signs
C. Geeks busy doing geek stuff and didn't get around to it
The original founders are a colorful group. Theodore Von Karman was the leader and guding force.
Jack Parsons, leading chemist, who was part of an "esoteric order" rumored to be fond of drugs and orgies.
Tsien Hsue-shen is considered to be the father of the Chinese missile and space program. He was held hostage in the U.S. for a number of years during the red scare when he wanted to return home to China. He was released by Eisenhower as part of prisoner exchanges in Korea.
@de_machina