At Wed, 21 Mar 2012 20:47:09 EDT Justin wrote:


On 3/12/12 8:34 AM, wrote:
On Mar 7, 2:26 am, wrote:
Let's bring SABRE into the mix. Would it be possible to desich a rocke
t
to use the atmospheric O2 when available and then switch to an on board
supply?

Yes, it is possible. It won't be competitive with turbofans for
atmospheric cruising, though. Rockets and turbojets waste a lot of
horsepower that turbofans and turboprops capture.

Sorry for the delay, been traveling for job interviews!

I think I understand. A rocket wouldn't be cost effective for
atmospheric travel - even those SABRE's that I just wikied!
Why carry your O2 when you can pull it out of the air?


It might help to have some more explanation. I read your initial post
asking for a usable range, normal cruise speed, size, etc. But what do
you want to do with this rocket plane? (Don't hold back - I've posed
some odd thought experiments on usenet, too.)

It's embarrassing... But here goes!
I was at an interview in February and the guy I interviewed with has a
model plane on hie desk. It looked like a mini space shuttle. It turns
out it was a "Farscape" toy! I downloaded a few episodes and I have to
say the show sucked, but that rocket plane mini shuttle thing looked
pretty neat.
From what you, Dave and Jeff said, something that small wouldn't be
able to carry enough fuel and O2. I was just wondering if we were even
remotely capable of a craft that small capable of air and space flight.
There was a scene where the pilot took the craft into an atmosphere and
did a dogfight.

Basically, given current tech and limiting ourselves to basic chemical
engines (air breathers or not), what you see in the movies or on TV
just does not work well in reality (or not as well as the special
effects people make it look like it does), at least not with a
'typical' Earth atomosphere or gravity. The only way around this is
some sort of craft with something like anti-gravity or some sort of
mini fusion power plant or something else current tech cannot do (or
else they violate one or more laws of physics or something). The craft
is either pure rocket and only really works well in a vacuum or a pure
air-breather, like you basic fighter jet (which won't work well without
air). For example, the real space shuttles flew like 'bricks', not
like the X-Wing Luke Skywalker flew or the Colonial Vipers Apolo and
Starbuck flew. :-)





--
Robert Heller -- 978-544-6933 /
Deepwoods Software -- http://www.deepsoft.com/
() ascii ribbon campaign -- against html e-mail
/\ www.asciiribbon.org -- against proprietary attachments