Re: National Aerospace Plane (X-30) announced 20 years ago
- From: "tomcat" <jlavine@xxxxxxxxxxxxx>
- Date: 27 Mar 2006 17:38:14 -0800
What's wrong with a SSTO (Single Stage To Orbit) lumbering off a runway
like an old B-29, slowly rising into the sky, gradually climbing to
100,000 feet (20 miles) where thrust to weight should begin approaching
1:1, going transonic, then hypersonic at about 200,000 feet (40 miles),
busting the 300,000 foot Outer Space Marker at mach 25 when it is 2:1
thrust to weight, and doing orbital insertion. And, having at least 8
minutes of burn time remaining. And that 8 minutes would have a thrust
to weight of at least 3:1.
The idea of a low thrust to weight takeoff quadruples the fuel load.
It should allow for 28 minutes of SSME burn time. It give a slow climb
in the thick (under 100,000 feet) atmosphere. With fuel depletion it
becomes a 1:1 thrust to weight (about the same as an F-15). This
approach solves atmospheric hull heating, with most of the speed build
up occuring at the 200,000 foot mark. It would only briefly be in the
atmosphere at all when it reaches hypersonic speed.
Now, planet fall (deorbit) will necessitate high plasma atmospheric
speeds. But, now you can use 'air brakes' to rapidly slow and protect
the vehicle. To do this on insertion would slow the vehicle when you
want it to go fast. Two (or possibly 4) tails with split rudders and
using ailerons, tile covered of course, should slow the vehicle very
quickly. A nose air brake should assist in braking but, more
importantly, give critical protection to the vehicle's skin.
Now, add to all of this the use of 'vacuum panels' for the under the
tile skin area, as well as vacuum with the ship wherever practical to
light the load. Also, compressed air must be used to strengthen the
vehicle instead of mass metal or composite, because it is lighter and
can yield really great strength.
If you don't believe me do this experiment: Take a plastic soda
bottle. Remove the cap. Pound the bottle with your fist. It will
flatten out, crumple if you will, very quickly. Now, use a fresh
plastic bottle. Make sure the cap is tight. Pound the bottle with
your fist. And, it just keeps coming back for more! It's integrity is
scarcely affected by your punches. And, the air pressure used in this
experiment is 1 atmosphere, the same as on the outside. The weight of
the bottle is exactly, except for the cap, the same in both instances.
Imagine what you can do with ten atmospheres!
With proper weight reduction, and blimpification, it may be possible to
achieve lighter than air, at least with the fuel tanks empty and
vacuumed. Make sure you vacuum the fuel tanks with the vehicle tied
down.
Turning an SSTO into a . . . blimp . . . sounds a bit strange. It
conjures up images of the Goodyear Blimp with rockets on it. But, in
fact, it should appear as a nice -- huge -- triangle fully capable of
nearly 'magical' things. Blimpification will provide the crew, fuel
area, and cargo spaces with plenty of room, not to mention additional
weight load capability. And, who says that a blimp can't be built like
a spaceship, with all the proper control surfaces. Now I know that
drag increases with size but the weight reduction of 'vacuum bubbles'
and a nice slow point 25 thrust to weight takeoff, making it slow in
the thick air, should offset additional size induced drag. In Outer
Space (60 miles) size doesn't matter much, except for crew comfort and
bulky cargo capability.
tomcat
.
- References:
- Re: National Aerospace Plane (X-30) announced 20 years ago
- From: ian . woollard
- Re: National Aerospace Plane (X-30) announced 20 years ago
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