X-43A Hits Mach 7 405
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."
Re:sublight speed ;) (Score:4, Insightful)
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 ;) (Score:5, Insightful)
Re:At the present rate (Score:5, Insightful)
Re:Stupid, Slightly OT Question (Score:5, Insightful)
Damn gravity.
no, (Score:2, Insightful)
It's the engine... (Score:5, Insightful)
Kjella
Re:sublight speed ;) (Score:2, Insightful)
Re:Mach 10 (Score:3, Insightful)
Re:sublight speed ;) (Score:4, Insightful)
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:10 seconds (Score:3, Insightful)
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:Mach10?! (Score:3, Insightful)
Scientists my eye.... (Score:5, Insightful)
ENGINEERS had more to do with getting this ship up to Mach 7 that did the scientists!
Not exactly (Score:2, Insightful)
Not exactly. We're sacrificing most everything for the Bush program to plant a flag in Baghdad.
Throwing away information (Score:3, Insightful)
Re:THE PROGRAM IS BEING HALTED! (Score:2, Insightful)
CNN Errors and the quarter mile (Score:3, Insightful)
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:sublight speed ;) (Score:2, Insightful)
Re:But at that speed... (Score:3, Insightful)
Re:At the present rate (Score:5, Insightful)
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... (Score:5, Insightful)
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=346
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
Re:Feasibiliy of High Speed Travel (Score:3, Insightful)
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
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Re:Throwing away information (Score:2, Insightful)
News is supposed to be "PC" (Score:4, Insightful)
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.