NASA pondering electro-hypersonic jet boosters

NASA will revisit an engineering technique which could solve many of the problems associated with hypersonic flight, according to reports. The research might offer genuinely re-usable space launch vehicles, among other benefits. At present, the only method humanity has to accelerate things up to the Mach 25+ speeds required to …

[Chris Morrison]

Or...

It could give me the billions of pounds it spends on this venture and end up with the exact same results as they will if they attempt this.

Chris

[Anonymous Coward]

MHD

Anyone curios at how odd MHD really is should wander over to Jean Lous Naudins (http://jnaudin.free.fr/lifters/main.htm) website for some freaky demos.

PS. dont try the Microwave plasma balls in the missus cooker she wont like it!

[Anonymous Coward]

War rocket Ajax?!

Wasn't that going to be used to 'Bring back his [flash gordon's body]?'

[Graham Dawson]

re: War rocket Ajax?!

I always *thought* she sounded Russian. Now we know!

[Anonymous Coward]

What's the point?

Great, London to New York in 3 days and a few minutes (3 days pre notice), then 3 days in customs because your teddy bears name is NOT Mohammed, so clearly you are terrorist!

[Joe Cooper]

Uhh...Ramjets???

"conventional (but brutal) J-58 turbojets"

What???

The J-58 is a turbofan-ramjet hybrid engine and is anything but conventional.

You're thinking of the MiG-25 which has "conventional but brutal", enormous turbojets that would fuck themselves to pieces at mach 3 speeds, ruining the jet.

[Sam]

Plumbing the depths

Wasn't the Caterpillar Drive on Red Oktober a form of MHD?

[Androski]

Don't need to accelerate!

You don't need to accelerate to "Mach 25+" to reach orbit. In fact, you don't need to accelerate at all. As long as your craft can get you off the ground and can maintain a steady push, you can reach orbit at any speed. The issue is what speed you attain when in orbit, to stop yourself from being pulled back down to earth and being reduced to a hot, steaming, metal lump.

[lucmars]

the lifter

Yes, it's impressive. That remembers me how Jean-Pierre Petit, a french physician, explained the possible use of the MHD by the flying-saucer.

[Paul Smith]

Perpetual Motion

"...So, like, we ionise the air infront of the intake with this, like, device, yea? Then we take the ions back out of the air with this other device, yea, which makes electricty, right, yea, and we use the electricty to power the first device, ok? And your, like, going to pay me lots of money, yea? Cool!"

[Epimenide]

Re: Plumbing the depths

That was fiction (and, BTW, only in the movie, the novel used a different technique), but they've done it for real:

http://en.wikipedia.org/wiki/Yamato_1

[Dom]

Nuclear warheads?

What's this about putting nuclear warheads in orbit? Sheesh, let's have some accurate reporting, eh? There is a limited history of weapons in space - the Soviets put some on the Almaz military stations. And the Soyuz capsule is always equipped with a triple-barreled "survival gun".

@Androski - if you're not going fast enough to miss the ground as you get pulled back down to earth, you're not in orbit. It's very simple.

[Eileen Bach]

@Stu Reeves

I don't suppose they can make a case for commercial applications as they would lose the drinks trolley sales.

[Michael]

@Dom

They don't get the survival gun anymore. They ran out of ammunition for it.

They just get a normal pistol now.

[Michael Greenhill]

@Dom

It's called "taking the piss", mate.

[JeffyPooh]

Hmmm...

@Androski - 'Orbiting' is different than hovering-really-high. And hovering is typically more more energy intensive than standing on a table.

Are they claiming that they can extract the energy from the front and use it at the back?

These boffins should perhaps review Thermodynamics 101:

1. You can't win.

2. You can't break even.

3. You can't quit.

[Lee Humphries]

Just too easy

If you want to make your own plasma the simple answer is fire two 5000w microwave emitters at each other (roughly), the atmosphere at the point(s) in space where they are in phase will be reduced to plasma - actually it forms into plasma balls, but who's counting. Normally these man made lightening balls will seek out something earthed and/or metallic, but a few good magnets/electromagnetic fields should keep them in check - plus moving forward very quickly.

Actually another option if you're moving forward very fast is to push something sacrificial into the shock front (or whatever the term is) with the aim that the heat generated will convert it to a plasma stream. Think along the lines of a MIG welder.

Now what I really want to see is someone do a proper pulse detonation engine (that I can make in my backyard) not just a run of the mill pulsejet. Personally I think scramjets are overrated.

[Pascal Monett]

If access to space is ever to become easier

Then Earth's orbit is going to need a serious cleaning. The thousands of nuts, bolts and assorted debris that are floating around up there will be a navigational hazard of much greater importance if the traffic is multiplied by civilian activity.

[Anonymous Coward]

Thermodynamics

@JeffyPoo

Quite right about not being able to get something for nothing, but I think your interpretation is slightly off.

What happens in a normal jet engine is that the airflow is "slowed down" relative to the plane, which converts some of the planes kinetic energy into heat.

What they are trying to do here is convert some of it into electricity instead, which they can then convert back to kinetic energy by using it to boosting the exhaust.

Each step will cost energy, as you can't get anything for free, but they are hoping that they will be able to make it efficient enough to be worth the effort.

To summarise: the energy they are trying to tap is in the system already, and it is only going to be lost as heat anyway.

[Mike Flugennock]

re: JeffyPooh

JeffyPooh writes:

> These boffins should perhaps review Thermodynamics 101:

> 1. You can't win.

> 2. You can't break even.

> 3. You can't quit.

or:

"the wheel is turnin' and you can't slow down,

you can't let go and you can't hold on;

you can't go back and you can't stand still..."

--jerry garcia.

Uhm, yeah; mine's the big tie-dyed mohair one, thanks.