X-43A Hits Mach 7

quiggy writes "As previously reported, NASA tested the X-43A yesterday. The results are in, and the scramjet hit Mach 7, setting a new speed record. CNN is also reporting the story, with a note that a similar jet could be tested by the end of the year, hopefully reaching Mach 10."

Comments

But at that speed...

[Alt_Cognito]

They will need to go back and save the whales etc...

Re:But at that speed...

[xs650]

The artilce that you linked to said

"Paul said although signs so far are positive, it still is too early to say the scramjet experiment succeeded. The scramjet experiment took place during the final few seconds of the flight, which lasted almost 10 minutes."

A quick search with google also did not turn up any reports of confirmed success. Do you have any?

Re:But at that speed...

[shthd]

I don't know if there is an independant peer review of their data but from their web site University of Queensland Hyshot Program Nasa's own press release doesn't say that they broke any records.... Either way Kudos to NASA....maybe now we'll get cheaper access to space

sublight speed ;)

[Janek Kozicki]

1 mach = 334 m/s ,
10 mach = 3340 m/s = 3.3 km/s ,
speed of light c = 300 000 km/s ,
(3 km/s)/(300 000 km/s) = 1/100 000 of c

this engine travelled at aprox 0.00001c !

good work scientists :)

Re:sublight speed ;)

[ewithrow]

Of course, rockets launched into space have to travel at least 11.18 km/s to reach escape velocity, which is a lot faster than mach 7. This isnt a speed record, really more of a design change in that the engine doesn't need to carry its own oxygen.

Congrats to NASA though.

Re:sublight speed ;)

[Fisher99]

So officially they can now call them sublight engines.

Re:sublight speed ;)

[Anonymous Coward]

I've always been under the impression that escape velocity is if a projectile was fired at ground level, and has no boosting at any later point. Space rockets are continiously accelerated upwards, and thus dont need to reach such speeds.

Re:sublight speed ;)

[the_2nd_coming]

it is a speed record for air breathing engines.

Re:sublight speed ;)

[fredrikj]

Indeed. You need to account for friction, though. Wikipedia article on escape velocity.

Re:sublight speed ;)

[Kiryat Malachi]

Uhm.... no. You are correct in your definition of escape velocity, but orbiting spacecraft reach speeds just about as fast.

Orbital mechanics tells us that the velocity of an orbiting object is dependent on the mass of the object you're orbiting, and the distance you are from the surface. Thus, when Shuttle is orbiting at 300km altitude, it is traveling at 7.73 km/sec. In order to achieve that orbit, it has to achieve that speed, tangential to the direction of gravity. It can do this (neglecting friction) in one burst at ground level, or over time, but it has to hit that speed to hit orbit.

Re:sublight speed ;)

[Uber Banker]

Speed is a number and velocity is a vector. So an escape velocity can vary in speed as the angle of escape changes.

If space rockets are perpendicular (well, they're not really) to the tangent of the atmosphere on exit, their speed still has to be enough to let them escape, but this speed can be really low - I take it implicitly you mean the firing of the rocket is necessary to overcome gravity rather than to reach a certain speed. Conversly, planes in the outer atmosphere can go really fast (speed) but as their velocity does not have a vector pointing upwards they won't exit.

Acceleration has little to do with it other than making the escape more efficient (of course the rocket changing vector is also acceleration).

Re:sublight speed ;)

[SillyNickName4me]

It is a speed record for a vehicle driven by an air breathing engine (ie, it gets its oxygen from the atmosphere)

Rockets have gone faster, but they carry their own oxygen.

Re:sublight speed ;)

[AndroidCat]

Rockets still have to reach escape velocity, regardless of how long they boost. However you're right about ground level--the further away, the lower the escape velocity required.

If I jumped in a '57 Space Coupe (2457) and gunned it for the stars at a constant 120 MPH, after a very long time, I'd be far enough away that escape velocity would have come down to 120 MPH and it would be safe to switch off the ignition.

Re:sublight speed ;)

[Maimun]

So an escape velocity can vary in speed as the angle of escape changes.

Wrong! It absolutely does not matter which direction the velocity vector points to. All that matters is the kinetik energy of the body. The kinetic energy is 1/2 * m * (v^2), where v is scalar, the speed in your terminology.

See this page , it is really neat, you can compute escape velocities for different planets.

Re:sublight speed ;)

[Maimun]

Escape velocity is necessary only when you want to, well, escape the Earth :)). If you want to go into Earth's orbit, the velocity is 7.8km/s. In fact, this is the minimum velocity you need, given that the direction of the movement is perpendicular to the line that connects you with the center of the Earth, never to fall down. AFAIR, 7.8km/s is that velocity at the Earth's surface. Since there is air friction at the surface, it makes sense to consider that velocity at, say, 250km or more above the surface -- it is surely smaller there, of course, and grows smaller as you go up, because the Earth's gravitational pull grows weaker.

When I studied these things in secondary school, we called 7.8km/s, "first space velocity", and 11.2km/s, "second space velocity". I think the terms are Russian (pervaya kosmicheskaya skorosty, vtoraya kosmicheskaya skorosty).

Re:sublight speed ;)

[slim-t]

Orbital mechanics tells us that the velocity of an orbiting object is dependent on the mass of the object you're orbiting, and the distance you are from the surface.

I don't have a physics book handy, but I'm pretty sure mass has nothing to do with the velocity.

Re:sublight speed ;)

[slim-t]

Then how did that original post get modded informative? I thought physics was pre-requisite for reading slashdot.

Seriously, there's a need for a "wrong" modifier, so people can mod such posts down without fear of recourse from meta-moderators who think the post is correct.

Re:sublight speed ;)

[shthd]

Doh.....I'm gonna get flamed. I read more closely. Orbital mechanics tells us that the velocity of an orbiting object is dependent on the mass of the object you're orbiting, and the distance you are from the surface. The mass of the Earth determines the Acceleration due to Gravity; and thus the orbit for a given velocity. He's correct and i am a dumbass!

Re:sublight speed ;)

[atomicdragon]

I think the poster means the velocity's direction does not matter if you are ignoring friction. If you were to travel with escape velocity towards the center of the Earth, without hitting something, you would come out of the other side of the gravity well with the same velocity at the same altitude and would be ready to go. However, in the real world the Earth is kind of the way and hitting it at escape velocity would be one heck of demonstration of friction. In that case your velocity direction determines how your kinetic energy is divided between liquefying your craft and spreading the remaining parts across the planet.

Re:sublight speed ;)

[wass]

Orbital mechanics tells us that the velocity of an orbiting object is dependent on the mass of the object you're orbiting, and the distance you are from the surface.

Not exactly true. When solving the two-body system, a number of coordinate transformations change the equations of motion into a simple one-body equation that can be solved exactly. The mass in the transformed one-body system is called the reduced mass, which is defined as mu=(A*B)/(A+B), where A and B are the masses of the two bodies in question.

Assuming A>>B (ie, Earth is much greater than the mass of a satellite), this can be rewritten exactly as mu=B/(1+B/A), or w/ a first-order taylor expansion as mu=B-B^2/A. For a standard communications satellite, the second term is approximately 10^-18 times smaller, and can realistically be dropped, and the mass of the satellite is to within measurable uncertainties B.

But you're wrong in general when you say it's independent of the mass of the object it's orbiting. In the system of the moon orbitting Earth, there's about 1% error by replacing the reduced mass by moon's mass. For a more dramatic example look at a binary star system where one star has 3x the mass of another.

Re:sublight speed ;)

[Anonymous Coward]

There is a free (beer) space shuttle simulator called Orbiter. I would recommend everyone to try it, in a few hours of experimenting you will learn so much information about space flight you will for example never post nonsense like that again *grin*.

Orbiter features more then just the shuttle, there is a slightly more powerful Delta Glider which you can in fact use to fly to Mars. And don't think it is easy, just getting to the orbit with the space shuttle will require a lot of training and reading the manual.

After two hours of so (of accelerated time of course) when I got near Mars, I was actually unable to land because of lack of fuel :(. It's a really strange feeling you get when flying on a hyperbolic curve, with no fuel, getting further and further from Mars and knowing that nothing can save you from dying in this damn spacecraft except from it being a simulation :). And yet another strange feeling is when you are descending to the Earth atmosphere with a wrong angle of attack and suddenly you just bounce of the atmosphere and Earth, there you go, hyperbolic curve again and our planet getting smaller and smaller... is that small thing Africa?

Just try it, it's a great game!

Re:sublight speed ;)

[SnowZero]

Well, it did happen a long time ago...

Re:sublight speed ;)

[wass]

You must have missed the entire point of my post. I was showing how mu exactly is B/(1+B/A). This will always be true for the 2-body system. There is only one assumption I made, which was for the satellite that A>>B. This assumption doesn't do anything until it's realized with a 1st-order Taylor expansion.

The whole point of the Taylor expansion was to give an estimate of the difference between B and mu, and in this case it's -B^2/A (to 1st order). If you don't like the expansion then keep the exact form, or take the taylor expansion to higher orders.

Anyway, since you missed the mathematics of my post, here's a recap of simple Taylor expansions.

Binomial expansion : for 1>>|x| (and n not insanely large), (1+x)^n ~= 1+(x*n)

So 1/(1+x) ~= 1-x

Recall mu=B/(1+B/A) exactly. To within some specified precision, mu~=B-(B^2/A). You can compare exact to approximate answers to see what the error terms will be.

Mach 7?

[RadRafe]

Isn't that a shaver? You know, the one with seven blades?

Mach 10? Mach 10?

[burgburgburg]

The engines canna take it, Cap'n.

4 posts...

[chimpo13]

and not a single Speed Racer joke. I'll reload in 30 seconds.

Re:4 posts...

[danratherfan]

Here he comes, here comes X-43a
He's a demon with a scramjet
He's a demon and he gets his own oxygen from the atmosphere

He's gainin' on you so you better look alive
He's busy traveling at a powerful Mach5! (or seven, or ten)

And when the odds are against him because they cuuuuuut his funding
You bet your life X-43a, will end up dead in a hanger some where.

Go X-43a, go X-43a, go X-43a, goooooooo.

Mach10?!

[DigiShaman]

And just how do you keep something going that fast from burning up in the atmosphere?

Re:Mach10?!

[Phosphor3k]

As a previous poster stated, any vehicles that we launch into orbit need to attain a speed of 11.18 km/s, which is about mach 36, for escape velocity. I imagine they've got more than a few ways to protect this vehicle traveling at a paltry mach 7.

Re:Mach10?!

[It's the tripnaut!]

And just how do you keep something going that fast from burning up in the atmosphere?


...by travelling in the exosphere.

Re:Mach10?!

[costas]

Mach 10 is a record for powered flight; it is not even close to the record of a man-maned craft; IIRC that goes to the Apollo reentry capsules that routinely hit Mach 27 on re-entry. So the heat problem has been solved for quite a while.

The real problem here is that a scramjet engine is very sensitive to its input (the air coming in) as it only spends literally milliseconds in the combustion chamber. So you have to wonder what aerodynamic tricks the X-43A designers are pulling to smooth that flow before it goes into the intake. Notice the side-view of the aircraft; the belly is smooth and curvy in order to produce many small shocks ahead of the intake and slow down the air as much as possible. A terrific aerodynamic feat, I just have to wonder if it will be reproducible (i.e. stable enought and robust to any aerodynamic event) for a manned aircraft. [Yes, I am an aerodynamicist].

Re:Mach10?!

[Phosphor3k]

Mod me down, I'm an idiot. That speed of 11.18 km/s assumes there will be no further boost during flight, and is the speed of the vehicle right when it leaves the ground. So, the vehicle can go much slower, as long as there is acceleration throughout the flight.

Stupid, Slightly OT Question

[dupper]

The news media keeps reporting NASA's previous failure to reach Mach 5. But didn't the X-15 do this in, like, the 60's?

And, to keep a little more on topic:
18 tiems the speed of light!

Re:Stupid, Slightly OT Question

[stripmarkup]

Yes, they did it in the 60s. They reached Mach 7 with a manned plane. This one is unmanned. I don't understand why it is such a big deal.

Re:Stupid, Slightly OT Question

[Boccaccio]

That was a rocket - this is an air breathing engine.

Re:Stupid, Slightly OT Question

[Anonymous Coward]

Turns out oxygen is heavy, and kind of a pain in the ass to package anyway. It's much more convienent if you can just use the oxygen that's laying about, which is significantly more difficult that it sounds when you're traveling at hypersonic speeds.

Damn gravity.

Re:Stupid, Slightly OT Question

[mindstrm]

It's not. This whole experiment is not at all about speed, and everything about a new engine design.

IIRC, Mach5 is the speed at which the scramjet is released, and ignited... up until then it's just being boosted by a conventional rocket.
During the first test, the scramjet failed.

During this test, it worked, pushing the rocket up another mach or two.

This was not meant to be any kind of speed record.. that's just how fast you need to go to get a scramjet working.

Re:Stupid, Slightly OT Question

[Anonymous Coward]

No, during the first test the rocket booster (the Pegasus) failed, mostly due to being released too low in the thick atmosphere. The entire package was destroyed by mission control before it went totally out of control.

Re:Stupid, Slightly OT Question

[the eric conspiracy]

I don't understand why it is such a big deal.

As some have noted, it's because of the engine type - air-breathing - that makes this so significant.

The economics of space travel are dominated by the cost to put something in orbit. Sitting on the launch pad, the payload to weight ratio of the Shuttle system is something like 1:50. Picking up the oxygen just lying around gives you a big increment in payload to weight ratio.

Re:Stupid, Slightly OT Question

[pfdietz]

Unfortunately, the drawbacks of airbreathing appear to outweigh the advantages, at least for vehicles intended to put objects into orbit.

The problem is that a scramjet trades a dense propellant (LOX) for more of a low density propellant (LH2). As a result, the propellant tanks on a scramjet vehicle would end up being larger (and heavier) than those on an SSTO rocket with similar payload. LH2 is also much more expensive than LOX, so your propellant costs go up (not that propellant cost is currently important, but your vehicle is also in a more aggressive thermal environment so it to will be more expensive.)

Worse, the effective Isp of a scramjet (after you take into account drag and gravity losses due to its lower acceleration) ends up being little better than the rocket. See Henry Spencer's comment on this.

About the only place scramjets may make sense is in hypersonic cruise missiles. The US military has a scheme for using hydrocarbon fuels, converting these fuels into hydrogen + CO in flight by partial combustion with a portion of the incoming air (that portion is slowed to a stop by a conventional ramjet inlet, with the fuel being used to keep the air relatively cool and the inlet from melting.) The H2 + CO + nitrogen is then injected into a scramjet for complete combustion.

Mach 10

[Boss, Pointy Haired]

is 3402 meters per second

or 12247 kilometers per hour

or 7610 miles per hour

Re:Mach 10

[Atzanteol]

People keep saying this... AFAIK "escape velocity" is the "muzzle velocity" a projectile would need to start with in order to escape the Earths gravity. But this doesn't apply to a projectile that accelerates with it's own power (ie. rocket).

Re:Mach 10

[dynoman7]

mach 10 = 20461245.5 furlongs per fortnight

Re:Mach 10

[Anonymous Coward]

Not at 95000 feet (the altitude the article claims). Assuming a standard atmosphere, the speed of sound is 315 m/s. So Mach 10 is 3150 m/s.

How soon before...

[DoctorPepper]

I can get one of these for my Toyota Corolla? Man, that sure would cut my commute time down!

Speed of sound

[CaptBubba]

For those of you wondering how to convert between Mach numbers and mph or m/s, here's a nifty java tool that lets you see how altitude affects the Mach number.

basically the higher you go, the less air there is, and the slower sound travels. So, the mach number, which is the ratio of your speed to the speed of sound, will be higher at high altitudes if the speed is constant.

Re:Speed of sound

[mindstrm]

Common misconception.

The speed of sound in a gas is affected mainly by temperature... not density or pressure.

From the page you just linked to:
"The speed of sound depends on the state of the gas; more specifically, the square root of the temperature of the gas."

Mach at 35,000 ft is 663mph

Mach at 150,000 ft is 732mph

The reason higher aircraft hit higher mach numbers is due to decreased air resistance... concorde can hit mach at 50,000 ft, but not at 20,000.. not because mach is perceptibly slower, but because there is less drag.

Re:Speed of sound

[Inspector Lopez]

To first order, the speed of sound does not depend upon the pressure at all; rather it depends primarily upon the mean mass density and the temperature.

The reduction of sound speed at altitude is due to the reduction of temperature. The temperature rises again in the upper stratosphere (ozone heating) and then drops down to its coldest temperature at the mesopause (around 120 K, at 85 km). However, the temperature increases rapidly above that, getting back to room temperature by 110 km, and heading for 1000k and beyond by the time you get to LEO.

At high altitudes the mass density is decreasing as you get more and more atomic species (e.g. O rather than O2) as well as larger fractions of light constituents (e.g. H2, H), so the speed of sound is quite high at LEO. At altitudes above the "turbopause" (somewhere around 105 km) the components of the atmosphere are no longer well-mixed, thus the different component gases stand at their own scale heights.

see scale height and speed of sound

CNN gets it wrong

[AlecC]

It also could drastically cut the time of commercial flights -- perhaps shortening the trip between New York and London to less than five hours.

Considering Concorde did that in three hours, thit wouldn't be much achievement. I make it that it could do NY-LON in just over one hour.

What I think they should have said is that it could go from any point on the earth to any other, including the antipodes, in less than five hours.

Mind you, it would take three hours to get through security on departure and an hour on arrival to collect your baggage, if it had arrived with you.

Re:CNN gets it wrong

[openmtl]

The new trans-Atlantic flight time is now 6 hours....

Midtown to JFK - 1 hour (off peak)
JFK TIA/Homeland/Patriot-enabled security -> Plane seat - 3 Hours
US -> UK flight time in new Mach 10 rocket - 2 Hours

Total time 6 hours. Your bags though would arrive 2 days later assuming that they hadn't been blown up in an anti-terrorist "controlled explosion" at LAX.

Re:CNN gets it wrong

[the_2nd_coming]

the trip to london is to short to benefit from a scramjet..

Great Things to Come

[Denix]

I think this finally points to a replacement for the space shuttle that was sorely needed. The shuttle is a decent space truck, but we need a cheaper (and safer) space "bus."

Hopefully it will be designed with a space station or dock in mind. It's my understanding that the shuttle was retrofitted for in-space docking such that the International Space Station almost had to be built around it.

"And how much more black could it be? None more black." - Spinal Tap

Re:At the present rate

[Boccaccio]

when will we see warp engines? Shortly after someone proves that its not impossible I guess.

CNN slipping,...

[epicstruggle]

CNN in a poor programming decision IMHO, did not carry any news of this while it was happening. OTOH FoxNews did!! Which supprised the hell out of me. They did ask some expert a few times how this would mean that missiles (in the future) could hit Osama in 15-30 minutes instead of the 4+hours it takes today. But at least they did have someone talking about the technolodgy/science behind this, and actually showed the takeoff, and launch of the plane. Quite nice of them.

Kudos to Fox, to CNN: do a better job, or you will fall further behind FoxNews.

later,
epic

Re:CNN slipping,...

[dealsites]

Might be slightly off-topic, but I agree with this. I have enjoyed Fox's coverage much more than CNN's. Not only in this news event but also others. I have noticed that CNN is quite a bit more PC, while FOX news seems to give your the direct information.

--
Woot, Woot! Hot Sunday deals are rolling in from all the major deal sites. Slickdeals, Ben Bargains, Techbargain and more!

Re:CNN slipping,...

[dave420]

Yet Fox still managed to blame it not hitting mach 10 on the pink-commie-leftie democrats, and "their heathen ilk"...

heh.

Re:CNN slipping,...

[bombadillo]

News is supposed to be "PC". We don't need a TV network telling us what to think. After all how many times last year did Fox news anounce that WMD were found in Iraq?

How fast ..

[the eric conspiracy]

new speed record

African or European?

10 seconds

[henryhbk]

Did anyone notice that the length of flight was 10 seconds? If it carried enough fuel for a sustained flight, it would be more impressive for a mach 7 flight. I realize this is a proof of concept flight.

Re:10 seconds

[Kiryat Malachi]

Proof of concept.

It worked for 10 seconds. That was all this design is supposed to do, and all it is likely capable of doing, but it proved their combustion chamber design works.

Now they can strap big fuel tanks on and go for a longer sustained burn, if they want to.

Re:10 seconds

[lommer]

In the scramjet reasearch buisiness, 10 seconds is an eternity. Most institutions who are researching this technology are universities and the like who don't have access to B-52s, rocket boosters, and the other equipment needed to actually flight test scramjets. Rather, they are forced to rely on less expensive wind tunnels. To simulate >mach 6 airflow (scramjet operational range), they either use an enourmous piston driven system, or a series of pressure build ups with a simultaneaous release. Regardless of the method, these techniques generally can't provide more than 5 milliseconds of flow time to test the engine. If you compare testing engines in 5 ms bursts to one sustained 10 s flight, the perspective kind of changes your opinion on how long 10 s is.

If you want a good paper on the subject, I suggest this one from the Australian National University.

Why its important

[Veteran]

SCRAM stands for Supersonic Combustion Ram (jet). What makes this different is that the combustion is taking place in air which is moving faster than the speed of sound inside the engine. Conventional Ram jets require that the air inside the engine be moving at less than sonic velocities for combustion to occur.

Conventional Ram jets are limited in top speed by the necessity to slow the incoming air down to sub sonic velocities.

Not only does the SCRAM jet have potential military applications, it can also serve as a 'midrange' stage for a lower cost to orbit booster.

X 15

[p51d007]

Yeah, Pete Knight went to Mach 6.7 in Oct 67....STILL a record to this day, for a MANNED airplane (X-15 isn't "really" a traditional airplane since it is air launched). Also Pete Knight earned astronaut wings by flying the X15 near 300,000 feet. Several of the X15 pilots received astronaut wings by flying near or over 300,000 feet. Joe Walker, went the highest to 320,000 feet! Sadly, he was killed in the 60's when he was in a formation of planes for an Ad for the general electric engines that all the planes were flying. His "tiny" in comparison jet got too close to the XB-70 bomber (which was suppose to be a Mach 3+ bomber) and it went inverted and smashed into the tail of the bomber, and exploded. Sorry, the early years of test pilots, NASA has always fasinated me, and buddies of mine call me a walking encyclopedia of aircraft knowledge ;)

SCRamjet = Supersonic Combustion Ramjet

[amigoro]

So what's a Ramjet?

There's one fundamental difference between an ordinary jet engine and a scram jet engine: The Ramjet has no moving parts.

The all jet engines,operate according to Newton's Third Law of Motion:
For every action, there's an equal opposite reaction

The standard jet engine, invented by Sir Frank Whittle, sucks in air at the front. Then this air is mixed with fuel, and made to combust. The combustion causes the air to exit the engine at a velocity greater than when it came in, thus creating thrust. The escaping air causes the turbine to spin, and this intern activates the compressor, sucking more air in.

The Ramjet has no turbine and compressor unit. Ramjets fly supersonically and have an inlet which injests subsonic air after it goes through a shock wave in front of the inlet. The intake is slowed down aerodynamically, and then mixed with fuel and made to combust. But after about Mach 5, ramjets don't work so well.

The scramjet is almost but not quite entirely like a ramjet. The only difference being in a scramjet the combustion takes place as the air is travelling through the chamber at supersonic velocities.

More about the scram jet. Or another more concise explanation.

Moderate this comment
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no,

[Anonymous Coward]

the point is to gain the capability to bomb anyone in the world really quickly .

First Mach 10...

[Evanrude]

Then Quantum Leap. Where will Scott Bakula show up next??

It's the engine...

[Kjella]

Yes, we've done Mach 7 before. And the space shuttles & space probes go much faster. The big deal is the engine. It's like comparing a nuke to some kilotons of TNT. Sure they may have the same effect (Mach 7), but one is simply a gigantic waste of resources (fuel), the other is a valuable invention. And considering it's the military, for good or bad...

Kjella

Adtional information on scramjets

[Faith_Healer]

If you want some something that will help understand the scram jet and you have a little aerospace knowledge check out this paper on combustion on a supersonic stream, http://www.anu.edu.au/Physics/aldir/publications/H yslop_hons_thesis_1998.pdf. Its amazeing that this jet can sustain a burn with out a flame holder, at least it looks like it does.

THE PROGRAM IS BEING HALTED!

[wisebabo]

There's an old Airforce saying:
A new plane doesn't make a new engine possible: A new engine makes a new plane possible.

That's why when NASA went for the moon a critical development was the F-1 first stage rocket engine. Capable of 1.5M lbs. of thrust it allowed the Saturn V first stage to be built with only 5 engines. Compare this with the Russian failed manned lunar rocket the N-1 which had 20 engines. They never were able to work all together (vibrational problems) and abandoned it after several launch disasters.

So why is NASA stopping development? (The successor the X-43C will not be flown). Why are we freezing this enabling technology? Are we (under Bush's program) sacrificing everything to plant a flag on Mars and not making space flight practical? It might be worth it if we ever got to Mars but it looks highly doubtful that his proposal is a serious attempt at anything but votes!

Sorry for the (mostly) repost but I really wish we would move "faster" towards developing the technologies towards practical* spaceflight.

*As noted in previous posts, by not carrying the oxygen on board you save a LOT of weight. Remember the reaction is H2 + O = H2O (and energy) and since the atomic weight of oxygen is 16 compared to hydrogen for every kilo of hydrogen you carry you carry EIGHT of oxygen. The weight savings (could be in the millions of pounds) makes up for the turbo-fans/rocket engines you must carry for the takeoff/orbital transition parts of the flight.

Re:THE PROGRAM IS BEING HALTED!

[Krackbaby]

I think this programs future has been uncertain because of the uncertainty of its success. Remember what happened to the first one. Governments tend to be very wary of failure in expensive scientific endeavors, even if those failures teach us lessons necessary to succeed. Now that they've had a pretty stunning success, at the very least the millitary is going to be VERY interested in continuing this project (they're already funding this part) and even if NASA's budget doesn't allow for continuing this program with current priorities, I think the Military has been convinced this is a direction worth pursuing further. Just a guess on my part, but I bet you see new funding quite soon.

Re:THE PROGRAM IS BEING HALTED!

[demachina]

"So why is NASA stopping development?"

I'd rather doubt they are. If it can be made to work and there is a need, either the NASA program will be funded or it will disappear in to an Air Force black program and will just appear to have been killed.

It does appear it can be made to work and it would presumably add a new top end to Aurora or whatever the Air Force's current black program is.

Its use for civilian transportation is dubious. Its pretty dangerous and would take a LONG time to be made safe, cheap and comfortable. I'm also doubtful it will prove to be a great launch vehicle though you never know.

Its military applications are obvious. The DOD has a pretty desperate need to drop bombs on targets of interest that arise quickly and move around like Bin Laden. When they get intelligence he is at a place they need to drop ordinance there as quickly as possible before he moves and with some targeting flexibility. A manned or remotely controlled Mach 11 bomber would seem ideal. An RPV version of this could come to fruition a lot faster than a manned version, Cruise missiles, the stealth bomber etc are to slow to get to the target in time. Using ballistic missiles tends to set of alarm bells in Russia, China and everyplace else where governments have satellites watching for launch signatures. Targeting for ballistic missiles also can't be redirected at or stopped at the last minute.

It would also be priceless for strategic and tactical reconnisance. Spy satellites are to predictable and inflexible since they are locked in to orbits with limited manueverability. Most countries know the schedule and hide stuff when they are overhead. A Scramjet would be flying fast and high enough it would be hard to shoot down, or even detect until after its done the job.

NASA Dryden deserves a huge pat on the back for finally bending metal and flying something. They've been wasting money on computer generated fantasies for this concept for more than a decade and haven't done much to realize it. It would be fantastic if it lead to a better launch vehicle and civilian transport, I just doubt that it will.

Re:THE PROGRAM IS BEING HALTED!

[DerekLyons]

The weight savings (could be in the millions of pounds) makes up for the turbo-fans/rocket engines you must carry for the takeoff/orbital transition parts of the flight.

Actually, the weight savings is non-existent. Sure, you save about 25% of the LOX in your first stage, but that's more than made up by the increased structural weight and thermal protection. Fact is, when the numbers are added up, you frequently come out worse in both weight and cost.

Using a re-useable airbreathing first 'stage' is a powerfully seductive theory, but it simply doesn't work in reality. (Ever wonder why those stages appear now largely only in fiction, and have mostly dissapeared from serious proposals?)

Re:CNN should take a look at the history books...

[wisebabo]

Yeah but they are going the long way around.

Yeah!!

[the eric conspiracy]

NASA overclockers RULE!!

Re:Feasibiliy of High Speed Travel

[mindstrm]

Not that massive.

Shall we calculate?

Let's say for rough estimation purposes mach is about 1000km/h, or 277.8 m/s
So mach 7 is 1944m/s

Let's say that G is 9.8m/s^2 (It is)

1944/9.8= 198.4 seconds

In other words, at 1G, after 3 minutes and a bit ,you will already be cruising at mach 7.

IN that time, you would have gone approximately 193km.

Factor in the same for deceleration... and we could say.

You could comfortably go 400km in about six minutes. Less than that and this speed is not practical.
For that matter, you spend more time in preparation and airports than you do on an aircraft for a 400km flight in the first place... so mach 7 would be really practical for longer flights.

science vs. lay

[MasTRE]

I clicked the first link and saw that NASA only used Mach units to report speed. Then, before clicking the CNN link, I made a bet with myself that they would include mph. Needless to say, I won :)

Armchair physicists are idiots

[Anonymous Coward]

Let's sum it all up. 1) Escape velocity is IRRELEVANT in the discussion. That applies to unpowered vehicles - not a vehicle under constant power such as this one.

2) As has been already posted. The speed record isn't for ANY vehicle. The record is for a vehicle with an air breathing engine (ramjet, scramjet, etc). It doesn't apply to vehicles such as the X-15, Apollo capsules, the space shuttles, etc as their speeds were/are either rocket powered or unpowered reentry.

3) During the first test the scramjet engine did NOT fail. It was never even fired. The booster engine that was supposed to get the scramjet to mach 5 is what failed. If I remember right the fins or something fell off and it went out of control so the remote detonated the booster and consequently the scramjet testbed attached to it.

4) The toyota corolla attachment won't be out until 2006.

Re:Armchair physicists are idiots

[0x0d0a]

4) The toyota corolla attachment won't be out until 2006.

Bullshit. Toyota announced that they will not be selling *any* vehicles with the scramjet until it completes product safety retesting, which will be finished in 2008 at the earliest. Apparently, the flux capacitor doesn't perform as expected above about 88 mph.

Scientists my eye....

[Nick Driver]

good work scientists :)

ENGINEERS had more to do with getting this ship up to Mach 7 that did the scientists!

Not exactly

[HangingChad]

Are we (under Bush's program) sacrificing everything to plant a flag on Mars...

Not exactly. We're sacrificing most everything for the Bush program to plant a flag in Baghdad.

From the CNN article

[badmonkey]

"The space agency's dogged pursuit of extreme speed, officials hope, will ultimately make space flight easier to accomplish.

It also could drastically cut the time of commercial flights -- perhaps shortening the trip between New York and London to less than five hours."

New York to London in less than five hours! That's heresy, that can't be done!

Throwing away information

[jmichaelg]

I'm perplexed by the fact that NASA intentionally threw away the plane before they'd done a post-mortem. The airframe could yield an awful lot of information about how well the craft stood up to the stress and yet they just let it sink in the Pacific. Seems to be either a waste of valuable information or suggests that this is more a publicity stunt than science.

Re:Throwing away information

[KD5YPT]

The reason is that they're not testing the airframe at all (it's built to be as simple and light as possible), they're just testing whether the engine can even light or not. That was their past problem, scramjet in past can't operate past mach 6.

Re:Throwing away information

[No. 24601]

The airframe could yield an awful lot of information

The simulations are probably more precise than getting your hands on the aircraft after flight. In fact, the simulations would not take into account other non-flight stress like hitting the water from that altitude ;)

CNN Errors and the quarter mile

[Wingsy]

Looks like the guy who did this reporting for CNN isn't much of a techie. A few things he got wrong: (1) "scramjet, which uses air for fuel" -- quite a few people will read that as not requiring ANY onboard fuel at all. (2) "shortening the trip between New York and London to less than five hours" -- we can already do that in LESS than 5 hrs. (3) "it flew under its own power for six minutes to do maneuvers over the ocean" -- if you count gravity as its own power. It was only powered for 10 seconds under the scamjet, and "glided" the rest of the way to splashdown.

Now this intrigues me: It was taken to mach 5 by the Pegasus, then it accelerated under the scramjet to mach 7, BUT the engine was only lit for 10 seconds. Does that mean this succer gained nearly 1400mph in 10 seconds???? Wonder what it would do in the quarter? How many Gs is that?

Re:CNN Errors and the quarter mile

[ralphh]

One G is about 22 mph/s, so 1400 mph/10s is a about 6.4 G's.

Re:CNN Errors and the quarter mile

[lfnoise]

It was taken to mach 5 by the Pegasus, then it accelerated under the scramjet to mach 7

This is not true. The pegasus booster took it all the way to mach 7. The scramjet proved it could make positive thrust, but it did not accelerate, it actually decelerated during those 10 seconds. Maximum speed was at booster burn out. This is according to their press conference yesterday.

Also, see this video: (remove the space in the URL)

http://www-pao.ksc.nasa.gov/kscpao/videos/metafi les/ksc_032504_x-43.ram

Uhh guys...this has been done before

[shthd]

From cnn It is the first time a supersonic-combustion ramjet, or scramjet, which uses air for fuel, had traveled so fast, flight engineer Lawrence Huebner told reporters. The University of Queensland Launched the HYSHOT in July 2002. It Hit Mach 7.6. The first people who did this

Re:Uhh guys...this has been done before

[Stregone]

From what I can gather form that site, the HYSHOT only actualy ran for a few seconds. The x-43 apparantly ran for 6 minutes. By 'ran' I mean under its own power.

Re:Uhh guys...this has been done before

[Chairboy]

Nope, the X-43 flew under its own power for 10 seconds.

Re:Uhh guys...this has been done before

[shthd]

Nope, X-43 did not accelerate from Mach 5 to Mach 7. The booster carried it all the way up to that speed. The x-43 got ignition going at mach 7 which is an incredible feat. When you read into the article that it accelerated from mach 5 to 7 it was the fault of crappy reporting.

Re:At the present rate

[alphorn]

it's not impossible, it's just infinitely improbable.

This thing is (*TINY*)

[blair1q]

Take a look at the photo of the actual X-43.

All the pics were of the Pegasus booster rocket which was dropped from a B-52. You can't even resolve the X-43 in those photos.

That X-43 is smaller than most of the bombs that B-52 has dropped in its lifetime.

Re:Mach 10 enough to sail into orbit?

[TheRaven64]

Even if it can't get all of the way into orbit, it could go some of the way. Imagine this:

1. First stage, accelerate vehicle on a long maglev runway. 100% reusable, no fuel carried, speed of about Mach 1 reached.
2. Second stage, SCRAM Jet. Reaches about Mach 10. Then detaches and glides back to Earth on automatic. No oxygen carried, only fuel. Efficient and (apart from the fuel) reusable.
3. Third stage, rocket. Takes the plane the rest of the way into orbit.
4. Fourth stage, ion drive, takes the payload to a different planet (Mars anyone?). This would probably carry the payloads of several launches of a space plane.

Of course, you'll need to build a launcher on the destination planet, if you want to get back. And the SCRAM Jet is not going to be very useful on a planet with a thin atmosphere (but fortunately most such planets have low gravity, so it's less of an issue).

Re:At the present rate

[NeoThermic]

In 1994, a paper was written by Miguel Alcubierre which detailed a possible way of obtaining warp drive.

The current problem is that of relitivty, at which there is a certian point where energy stops creating speed, and goes into increasing the mass of the moving object, thus making light speed impossible.
Alcubierre's idea was that the ship doesn't move. Instead, it modifies the space around it much like an esclator. Since the ship doesn't move in relitive terms, it doesn't gain mass or suffer time dialation.

However, at this time, there was a problem with obtaining the required energy, which was quite alot [think total solar output of the sun in its current life, per second].
In 1999, however, Thomas Valone spotted an answer. Zero Point Energy. In a nutshell, one can theoretically harness the binding energy of a particle. This energy, if harnessed, would be enough energy to power an Alcubierre warp drive.

However, both ideas are still in the working stage, and I think we will see Duke Nukem Forever before we see warp drive from either of these two concepts.

NeoThermic

Perfomance and economy

[soldeed]

Orbital velocity is damn near escape velocity, and thats the whole point. Getting to orbit economically is the key to making space travel pay instead of cost. It takes WAY more energy to get to orbit than to get from orbit to anywhere else in the solar system. Think about the Saturn V moon stack. You needed all the fuel in the 1st and 2nd stages, and most of the fuel in the 3rd, just to make orbit. only a small additional thrust from the third stage was required to send it on its way. We have all sorts of economical solutions for interplanetary travel, such as ion engines, solar sails, and nuclear engines. We need an economical booster technology, and this is it! 3500 mph to 5000+ mph in ten seconds with TWO POUNDS of fuel! Thats outstanding power and fuel economy In my opinion.

Re:Perfomance and economy

[corngrower]

Mod parent up. This is correct. Orbital velocity is the velocity an object needs to maintain an orbit about a planet (or another object). This is a tangential velocity. Escape velocity is the velocity necessary for escaping the gravitational pull of the planet (or other object).
Escape velocity is faster than orbital velocity. But like the parent poster says only a relatively small amount of thrust is needed to gain escape velocity.

Most of the energy in the fuel in a rocket is used to accelerate the remaining fuel in the rocket. Not having to carry along the oxidizer for the lower portion of the flight would save a lot of weight.
And with less oxidizer you need less fuel as well.

Re:At the present rate

[blincoln]

Alcubierre's idea was that the ship doesn't move. Instead, it modifies the space around it much like an esclator.

I'm with you so far.

However, at this time, there was a problem with obtaining the required energy, which was quite alot [think total solar output of the sun in its current life, per second].

The main stumbling block to Alcubierre's drive is that it requires negative energy. My understanding is that the human race can't produce that right now, at least in appreciable quantities.

All of the FTL drive concepts that I've seen involve something currently unobtainable (or outright impossible) like this - infinitely long neutronium rods, creation of a pocket universe to put the ship in, etc.

In 1999, however, Thomas Valone spotted an answer. Zero Point Energy.

No. Pseudo-science can solve lots of problems theoretically, but it is not the answer to real-world problems.

Not exactly the same...

[Dan East]

http://www.mech.uq.edu.au/hyper/hyshot/:
As the spent motor and its attached payload falls back to Earth, they gather speed, and the trajectory is designed so that between 35km and 23km, they are travelling at Mach 7.6

http://www.uq.edu.au/news/index.phtml?article=3469 :
The recent HyShot(TM) launch was designed to take the scramjet engine to a speed of Mach 7.6 (or more than seven times the speed of sound) for the experiment, using a Terrier Orion rocket. The rocket and payload reached an altitude of 314km before the rocket was configured to fly in a new trajectory pointing the payload back down to earth.

HyShot was simply free-falling to earth in order to reach Mach 7.6 so the engine could be ignited. It achieved that speed regardless of whether or not the scramjet fired. The X-43 was flying horizontally, and was actually powered by the scramjet engine during a controlled flight.

So there is a difference between what was accomplished. The distinction is that HyShot achieved combustion, while the X-43 was the first scramjet powered craft to be flown.

Dan East

Doubt it Re:10 seconds

[WolfWithoutAClause]

I've a sneaking suspicion that it would only work for 10 seconds- 'strapping on a bigger tank' would probably result in it melting. They've probably used heatsink materials to soak up some of the awesome heating effects you get at mach 7.

Besides, where would they put the bigger tanks? The thing is tiny; and hydrogen is seriously not dense; meaning very little fits into the vehicle.

Re:Doubt it Re:10 seconds

[WolfWithoutAClause]

Um. No. Density of LH is a tiny fraction of gasoline- just 70kg/m^3.

Compare this to liquid oxygen which is (IRC) more like 1100 kg/m^3; or water 1000kg/m^3. Gasoline or kerosene is slightly lighter than water, but not a lot. Liquid Hydrogen is seriously not dense- that's actually the biggest problem with it.

Re:Feasibiliy of High Speed Travel

[mamba-mamba]

The only thing is, during much of the acceleration time, they will have to use a different type of motor, since a scramjet motor will not work at lower speeds.

However they get up to minimum scramjet ignition speed, there is likely to be a pretty good kick in the pants when the scramjet ignites.

And the question of how they get up to that speed is a very important one to work out. If a rocket is used, then acceleration will be very brisk. Also, if you are going to use a rocket anyway, why bother with the scramjet at all? (In fact, a lot of people feel that scramjets are a solution in search of a problem.)

If a rocket is not used, then what will get you up to that speed? They could climb to 70,000 feet, then go into a power dive to start the scramjet, but can you imagine the G's when you pull out of a dive at hypersonic speed?

I'm not saying it can't work, I'm just pointing out that there are many issues to resolve before commercial flights are remotely feasible.

For very high speed travel, leaving the atmosphere may be the way to go. Hypersonic atmospheric travel is almost like constant re-entry. And designing a craft to get up to those speeds from horizontal takeoff is no joke.

Just some things to think about.

MM
--

12-feet-long. Small in proportion

[johnjay]

I think the X-43 is 12-feet-long. This quote:

"The unpiloted 12-foot-long vehicle, part aircraft and part spacecraft, will be dropped from a B-52,aircraft. It will be boosted to nearly 100,000 feet by a rocket..."

from this NASA page is one source.

I think you are underestimating the size of the Pegasus rocket and B-52 bomber. I know I did. A quick google search found a page on the Pegasus rocket: it is 55.4 feet long and about 4 feet in diameter.

Re:the scramjet did not accelerate to mach 7

[KD5YPT]

You're right, scramjet didn't accerlerate to mach 7, the only thing they're testing is that CAN scramjet operate when the air flowing through it is at mach 7. Because in the past, the major problem with scramjet is that when it approaches mach 6, the speed of the airflow literally snuff out the engine. Now they seems to be able to keep the scram jey burning at mach 7 (now they just need that thrust).

News is supposed to be "PC"

[Jodka]

"News is supposed to be 'PC'"

The term "Politically Correct" (PC) is a satirical epithet applied to liberal doctrine by conservatives. It mocks the presumption that liberal opinions are the "correct" opinions, in an absolute sense, not one perspective among many.

The term "PC" is made more amusing to conservatives by the liberals' conviction of their own political correctness preventing liberals from recognizing the joke that liberals' are unawaredly convinced of their own political correctness. "Of course our beliefs are the correct beliefs, why is that funny ?" ask the liberals.

Which brings us to your assertion that "News is supposed to be PC" What you are telling us ?

1. That news should be reported from a liberal perspective because...
2. Liberals are right and conservatives are wrong.
3. You are blind to the fact that you are promoting your own perspective in absolutist terms.

Note, "PC" denotes both the status of a particular belief as liberal and the associated presumption of correctness. For example, consider the statement "Johnny failed first grade, but he is African-American, therefore holding him back at that grade level would not be PC". In this sentence, "PC" serves to associate with liberals the principle that unqualified indviduals should be promoted if they are members of a particular ethnic group. But "PC" is also meant to characerize the attitude of those who would defend that principle as an absolutist faith that they are "right" and others are "wrong".

Fox News is unpopular with liberals not becuase it sets forth alnternative and consertavie "correct" notions, but because it undermines the very notion of correctnees in political discourse. Fox betrays the news broadcast tradition of delivering news in somber, ministerial tones which close off question and doubt; "Though shalt not question the word of Jennings". "The shalt now question the word of Brokaw." The informal on-air attitude of Fox news is like "Here are our correspondents and here is what they seem to to think is going on." It's more upbeat and friendly. We are allowed to ask questions. Fox news conveys to television viewers the dangerous attitude that what you see on TV is people telling you what they think is going on, not sacred and unquestionable truths. It undermines the notion of TV news as a conduit for absolute and correct truths, subverting the entire system of liberal propagandizing through control of unexamined "correct" news content.

News should not be PC.