Reaction Engines To Fly Reusable Spaceplane

See:

http://science.slashdot.org/science/.../0135200.shtml

wrote:
See:

http://science.slashdot.org/science/.../0135200.shtml

I don't understand the obsession/fascination with LH2/LOX systems.
A good chuck of this craft seems dedicated to tankage.

Kelly Johnson and Ben Rich both wrote extensively on this topic.
Their fuel of choice? Liquid methane/LOX.

Now methane might not be ideal for this type of engine, but I'm
surprised by the dearth of systems using this given the extensive
work/testing done by Lockheed in this area dating back to the 50s.

Dave

On Mon, 12 Jan 2009 12:13:08 -0500, in a place far, far away, David
Spain made the phosphor on my monitor glow in such
a way as to indicate that:

wrote:
See:

http://science.slashdot.org/science/.../0135200.shtml

I don't understand the obsession/fascination with LH2/LOX systems.
A good chuck of this craft seems dedicated to tankage.

It's an obsession/fascination with Isp.

Rand Simberg wrote:
On Mon, 12 Jan 2009 12:13:08 -0500, in a place far, far away, David
Spain made the phosphor on my monitor glow in such
a way as to indicate that:

wrote:
See:

http://science.slashdot.org/science/.../0135200.shtml
I don't understand the obsession/fascination with LH2/LOX systems.
A good chuck of this craft seems dedicated to tankage.

It's an obsession/fascination with Isp.

Understood. But is it really worth the trade-off?
I keep hearing the phrase "wide-bodied dog" in the back of my head....

Dave

On Mon, 12 Jan 2009 12:45:49 -0500, in a place far, far away, David
Spain made the phosphor on my monitor glow in such
a way as to indicate that:

Rand Simberg wrote:
On Mon, 12 Jan 2009 12:13:08 -0500, in a place far, far away, David
Spain made the phosphor on my monitor glow in such
a way as to indicate that:

wrote:
See:

http://science.slashdot.org/science/.../0135200.shtml
I don't understand the obsession/fascination with LH2/LOX systems.
A good chuck of this craft seems dedicated to tankage.

It's an obsession/fascination with Isp.

Understood. But is it really worth the trade-off?

No. In my opinion, at least. And that of a lot smarter people than
me on such matters (e.g., Max Hunter). It's particularly crazy for
air breathers (which are crazy enough on their own, for space launch).

Rand Simberg wrote:
On Mon, 12 Jan 2009 12:13:08 -0500, in a place far, far away, David
Spain made the phosphor on my monitor glow in such
a way as to indicate that:

wrote:
See:

http://science.slashdot.org/science/.../0135200.shtml
I don't understand the obsession/fascination with LH2/LOX systems.
A good chuck of this craft seems dedicated to tankage.

It's an obsession/fascination with Isp.

That, and clean, efficient, non-polluting energy conversion processes.

But we know how you think profit trumps reality.

kT wrote:
Rand Simberg wrote:
On Mon, 12 Jan 2009 12:13:08 -0500, in a place far, far away, David
Spain made the phosphor on my monitor glow in such
a way as to indicate that:

wrote:
See:

http://science.slashdot.org/science/.../0135200.shtml
I don't understand the obsession/fascination with LH2/LOX systems.
A good chuck of this craft seems dedicated to tankage.

It's an obsession/fascination with Isp.

That, and clean, efficient, non-polluting energy conversion processes.

But we know how you think profit trumps reality.

Regards clean:
Water vapor, such as you get from LH2/LOX combustion, is the #1 Greenhouse gas.
Above even CO2. Unless there is a good way to get this out of the upper atmosphere
I wouldn't call it non-polluting.

Regards efficient:
You have to trade off the best Isp from a chemical engine against the
size/bulk/drag of the tankage needed to keep the chemicals in a state+place
where they can be combusted. LH2/LOX are not the most efficient designs.
That was Kelly's/Ben's whole point!

wrote in message
...
See:

http://science.slashdot.org/science/.../0135200.shtml

This is simply a paper airplane. If you read their site carefully you will
notice that they need $5 billion to develop and fly this thing. The British
government is never going to fund it, so there's no chance of it ever
flying.

In message
David Spain wrote:

wrote:
See:

http://science.slashdot.org/science/.../0135200.shtml

I don't understand the obsession/fascination with LH2/LOX systems.
A good chuck of this craft seems dedicated to tankage.

Kelly Johnson and Ben Rich both wrote extensively on this topic.
Their fuel of choice? Liquid methane/LOX.

Now methane might not be ideal for this type of engine,

Methane is far too warm for this type of engine.

Anthony

Anthony Frost writes:


Methane is far too warm for this type of engine.

Anthony

Yeah I suspected as such. Perhaps there are better engines?

Dave