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Mach 10 X43A Flight Successful
Sector Bug writes "NASA's X43A research aircraft made its third and final flight today, firing its scramjet engine at Mach 10 (7,000 MPH) or close to it, setting a new record. "
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Meanwhile, CNN is still reporting the flight as being delayed on the front of their Science and Space page.
Not even close.
Hubbles orbital speed is approximately 16,900 miles per hour.
Sorry, teleporters just kill you and then make a copy. A perfect, soul-less copy.
...had to hunt for it, but here it is:
/ x43.jpg
http://spaceflightnow.com/news/n0106/02x43failure
The rocket gets it up to the minimum speed at which the scramjet can operate: Mach 5-6.
Then the prototype separates and fires the scramjet to reach Mach 10. It is thought that a scramjet can operate at least until Mach 15.
(sorry I know this debate is a classic but miles say nothing to me and I guess that many international slashdoters feel the same)
Yahh, hiii haaaaa! -Major Kong, from Dr. Strangelove
24000 miles at 7000 miles per hour means you'd be home in 3.4285714285714285714285714285714 hours.
SJW: a person who perceives an injustice, and while correcting it, commits a greater injustice.
A related question, how does this (and the speed of orbital rockets) compare to the fastest man-made object (whatever that may be)?
Particle accelerators accelerate anything from electrons and protons to ions close enough to C that the difference is academic.
For macroscopic objects, I believe compressed-gas guns used for simulating micrometeorite strikes and for producing shockwaves to study things like the metallic hydrogen phase transition accelerate projectiles to tens of km/sec, or larger than but of the same magnitude as orbital velocities.
Various other types of cannon (the so-called "ram accelerator", used to simulate scramjets, and various flavours of electromagnetic cannon) can also reach projectile speeds in the "greater than but still comparable to orbital" range.
Not even close.
Hubbles orbital speed is approximately 16,900 miles per hour.
You are not even close. He was asking about orbital ROCKETS! Not objects in orbit. Orbital rockets are the things that lift the satellites into orbit.
The space shuttle does not get anywhere near 16,900 mph on lift off. That is the speed it gradually gets to once in orbit, NOT ON LIFT OFF.
After 60 seconds, the Shuttle has accelerated to Mach 1 (the speed of sound). About one minute later (two minutes into the flight), the solid rockets burn the last of their fuel. By this time the shuttle is over 25 miles high. The now-empty solid rockets are released in order to reduce the weight carried the rest of the way to orbit. [They parachute into the ocean off the Florida coast, and are recovered to be refilled with fuel and used again.]
After the solid rockets are released, the shuttle is still attached to the external tank and its launch engines are still being fed propellants from the tank. When the shuttle reaches an altitude of about 57 miles, it changes trajectory to fly more horizontally, and pick up speed. In order to achieve orbit, it needs to accelerate to approximately 17,500 mph (~5 miles/sec). Once it reaches this critical speed (about 8-1/2 minutes after lift-off), the shuttle launch engines are shut off, and the shuttle separates from the external tank. The tank re-enters the atmosphere and burns up on re-entry. It is the only part of the Shuttle system that cannot be used again.
Please, if you are pretending to supply information, make it at least vaguely close to correct. :-(
The rocket boosted it all the way up to max speed. The scramjet wasn't even lit at quite the max speed, though close (the research vehicle decelerates slightly in the few seconds after separation from the rocket before the scramjet lights).
The scramjet *MAYBE* did as well as stopping the deceleration for a few seconds. One of the researchers, who I was talking to as we watched the B52 flyby and landing, said that he thought perhaps they got just a little positive acceleration (i.e. it sped up slightly), but small enough that he couldn't tell for sure from the quick look he took so far.
But then, that is what was being aimed for.
According to Google, mach 10 = 3.4029 kilometers / second Warp 1 = speed of light = 299,792.458 km/s Therefore Mach 10 is roughly equal to warp .000001
Physicists use the metric system, but 16900 mi/h is indeed correct. To clarify this:
Acceleration of Gravity = Acceleration Centripetal
((Gm)/r^2) = (v^2)/r
G=6.67*10^-11
m = mass of earth = 5.98*10^24 kg
r = radius of Hubble from Earth core = 6980000 m
((6.67*10^-11)(5.98*10^24))/(6980000^2) = (v^2)/6980000)
v = 7559.373392 m/s or 16909.83 mi/h
To apply Spaceballs retroactivly;
At the breaking of the 60MPH:
We shall call it ludicrous speed.
At the breaking of the sound barrier;
We shall call it ludicrous speed.
At the breaking of the speed needed for stable orbitals;
We shall call it ludicrous speed.
The point is that we will always be breaking the limits we set now, so to call it ludicrous speed is ok, but the speed will likely be pedestrian in a few years. There's always a speed barrier we'll be breaking.
"For years, I struggled with reality... but I'm happy to say I finally won out over it." -- Elwood P. Dowd
Highly Off-Topic, but yes..
The McWhirter twins, IIRC. One (or maybe both) of them were obsessed with quirky facts. Then in 1950 they set up a business together to sell facts to newspapers. Roughly at the same time, the managing director of Guinness had an argument about the fastest bird in Europe but couldn't find any facts on it. Somehow, they ended up in contact with eachother and made the book we know as the Guinness Book of Records. Although they did have certain rules about what would and what wouldn't get put into the book.. no supernatural records (obvious reasons, I guess), no sex records (was to be a family book), no criminal feats (didn't want people doing illegal things to get into the book), and no records like eating the most marshmellows at once (didn't want people to die in the proccess). One died playing tennis, and one was killed by the IRA whilst offering £50,000 for information on terrorists..
The article link doesn't have much in the way of interesting details, so, here are some slightly better links to hopefully raise the signal ratio:
The first one is an article with some details, the second is some artwork that explains the scramjet and the flight path.
From the looks of it, the scramjet engine doesn't appear to be a very sophisticated device. It's just a funnel that doesn't ignite the fuel until it has already reached supersonic speed.
The tricky part, if I'm guessing correctly, is building a vehicle that can withstand the 3600 degree heat of flying at Mach 10 in the upper atmosphere. It succeeded, but there was no human pilot inside of this one. I think that will be the next step: to build a craft, as small and light as possible, just to ferry crew into space, leaving cargo payloads to be sent up using a much cheaper but less safety constrained kind of lift capability.
It's the last flight of the B-52B mothership, but it is being replaced with an H
L /E C03-0258-04.html
http://www.dfrc.nasa.gov/Gallery/Photo/B-52/HTM
Parts for the engine were becoming rare and costly for the B
A related question, how does this (and the speed of orbital rockets) compare to the fastest man-made object (whatever that may be)?
I thought the fastest man-made object was Pioneer or Viking at around 45k mph. However, a quick Google indicates that Helios supposedly traveled at 150,000 mph.
I'm positing that the particles in particle accelerators are not "man-made" in this context.
>Circumference of Earth at equator = 24,900 miles = 3 hours 33min 26 seconds
Please, if you get a scramjet of your own, take the extra time to go around the earth and fly above sea level!
"it flew at an altitude of approximately 110,000 feet"
Circumference = 24,900 miles
diameter = 7925.9 miles
Radius = 3963.0 miles
110,000 ft = 20.8miles
So ((3963.0 miles + 20.8 miles)2)pi = 25031.0 miles
25031.0 miles / (7000 miles/hr) = 3 hr 34min 33 seconds
Diffrence: 1 min 7 seconds
Um not quite. Warp numbers are exponents so... it would be log 3.4029 in base 299,792.458.
See each warp re warps the previous one so...
Now where's my autographed shot of Kirk telling Picard he was out saving the galaxy while his grandfather was in diapers?
The message on the other side of this sig is false.
ummm.... the difference is 30 years of rocket since, very low oxidizer levels, and the use of some very familiar jet technology.
I am the Alpha and the Omega-3
The speed of sound is approx. sqrt((gamma)RT)
Assuming Ideal Gas
Gamma (roughly constant for air (1.4))
R = Ideal Gas Constant
T = Absolute Temperature (relates to density, etc)
(somehow I knew those thermodynamics and aerodynamics courses would pay off someday)
At 100,000 ft, the temperature is only somewhat lower. This only marginally lowers the speed of sound, but also lowers problems with skin heating at high speed, parasite drag, etc.
So, no, noone is pulling a fast one. This is an impressive achievement for an air-breathing vehicle. Now if anyone can find an article detailing if they got any positive thrust out of it or if it was all the pegasus booster.
--Kei
Note that the inlet is built out of the forward body of the vehicle, so the shockwave is still external.
Its only the portion of the stream that enters the combustion zone that is being propelled, the rest can be reguarded as bypass air.
Also note the tail of the aircraft is formed to handle post/hyper-sonic exhaust.
--Kei
It's called Kilometres per hour :)
End Communication.
The guy who designed the SR-71's engines ended up winning one of the most prestigious aviation prizes (no, I can't remember which) for the way that the movable engine inlets ended up being responsible for something like 80% of the thrust produced at high speeds. He later became director of the Lockheed Skunkworks in the era where they produced the F117A.
Less is more.
The SR71 uses one of the more complex methods of maintaining high mach travel, but it isn't the only one. The B70 Valkyrie experimental strategic bomber solved the problem using wings that folded down vertically to encompass the shockwave beneath the fusalage and literally ride it. It's supremely ironic that this aircraft can outrun today's B1-b Lancer by a full two times the speed of sound using 1950s technology.
Some history on this forgotten, stunning piece of aviation engineering.
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"I couldn't see this doing much for manned flight, but most of what we send up isn't manned anyway. It could also have some pretty kick ass millitary application, say for dramatically increasing the payload of current rocket propelled artillery rounds."
Funnily enough, studies about that go back a long way, circa 1930. dr.Sanger eventually studied a Ramjet powered design, a model of which is in the Deutsches Museum in Munich, Germany. It would have been a cheaper alternative to the Space Shuttle, with a mother vehicle starting from a plain aerodrome and an orbital vehicle piggybacking on it. Basically the mother vehicle is the same concept inferred for the mysterious project Aurore Recce aircraft.
The military have always been attracted to these concepts, witness the Dynasoar in the late fifties, but the rationale is the same for civilian uses; higher efficiency and flexibility in bringing payloads in low earth orbit or suborbital flight.
"If a boss demands loyalty, give him integrity. But if he demands integrity, give him loyalty." (John Boyd, 1927-1997)
one sixth. Typical H2/O2 rockets use a five to one ration of oxidizer to fuel. It's still a huge advantage, though.
All things being equal (they aren't, but it gets you in the timezone), an H2/O2 rocket massing 1000T at launch would mass only about 340T by the time it reached Mach 15. A 1000T scramjet would mass about 830T at the same point. From Mach 15, the flight profiles of both would be about the same (both using rockets from that point on, of course), and they'd both burn up ~55% of their remaining mass to get to orbit. So the pure rocket puts ~150T into orbit, the scramjet-rocket hybrid puts ~370T into orbit.
Note: Ignoring friction. Ignoring the atmosphere when convenient, and including it when helpful to do so. Ignoring the details of staging and such, and the extra mass of the airframe built around the scramjet stage. Ignoring the need of the scramjet to reach some high speed before it begins combusting. Ignoring [physical reality as much as possible]....
"I do not agree with what you say, but I will defend to the death your right to say it"
"What I don't understand is why you spend so much money in fuel and oxidiser to get the external tank nearly into orbit, then for the additional cost of presumably not very much (in the scheme of things), let the thing fall back to earth and burn up?
Would it not make more sense to take the tank into orbit and use it for something? It's got to be (at least nearly!) air-tight, why not add it to the Space Station as another module for something? Use it for spare parts - got a leak, hack a suitable sized bit off the old tank and stick it over the hole. Just stack them up in orbit somewhere for raw material to build a interplanetary space ship?"
You're absolutely correct. Unfortunately, a lot of factors and events have stopped any of these things from happening.
The ET itself is completely space-worthy. It was designed to operate in space long after reaching orbit. Early plans for space stations and platforms included the ETs since they remain completely useable. What's more, the tanks still have a lot of H2 and O2 left after a launch. So in reality, the shuttle could reach much higher orbits if it _kept_ the ET attached on orbit. This was purposely designed-in, since the original plans for what's now the ISS called for a higher orbit than usual. So any visit to the space station would require one to keep the ET. Even if it was just hanging around LEO, the H2 and O2 in the tank are extremely valuable and are worth leaving in orbit.
So why don't they do this? Well, they just don't have a reason to anymore...
First, the shuttle no longer needs access to the higher orbit, since the ISS we have is in a much lower orbit. This was done to accomodate the Russian launch sites. This has crippled a lot of the usefulness of the ISS compared to it's original goals, but that's a whole other post.
Second, managing the ETs and their contents are more trouble than they're worth. What I mean is that the only immediate usefulness of the H2 and O2 would be for the ISS, but it's just less of a planning headache to have the supplies sent up by Progres than mapping out astronaut time to transfer stuff from the ET through the shuttle to the station (and having to manoeuver with the ET attached). We can say that making orbital warehouses of the tanks and their contents for future missions and projects is a great idea, but it brings up the question of where and how. Do you store them at the ISS, or at some designated point out of the way? If the ISS, you've just added another headache to the crew. If at some other point in space, you have to have station-keeping thrusters to maintain orbit and attitude. NASA has no need for any of these headaches currently.
Thirdly, the whole idea is moot since the shuttle's death warrant has already been signed. Well, it was signed a long time ago, but suffice it to say that the shuttle isn't going to be around much longer. There's no incentive to change their operations now, so they'll just keep chucking everything away until the program is over.
It's really quite sad to look back at the past thirty years* of the shuttle and ISS programs and realize how poorly they've been executed and how many opportunities and resources have been squandered needlessly. I have the utmost respect for the engineering teams and all the people who put the shuttles together and made them fly, but the shuttle program really has ruined NASA for decades.
Blah.
* - the shuttle fleet has only been flying since '81, but the design work began in the early 70's
You run H2 rich fuel mixtures to lower the average molecular weight of your exhaust stream, which increases the exhaust speed for a given combustion temperature. Exhaust speed is proportional to Isp, and high Isp is good.
I get that figure from the Space Shuttle and Saturn systems. Though I believe that there are some 1:6 ratios out there these days.
Keep in mind it's a matter of tradeoffs. 1:9 gives you smaller tankage, but lower Isp. Higher fuel:oxidizer ratios increase the size of the fuel/oxidizer tanks, but increase Isp. SO you aim for the "ideal" balance, and we seem to have settled around 1:5 as our ideal point.
"I do not agree with what you say, but I will defend to the death your right to say it"