Paul Hovnanian P.E. wrote:
tomcat wrote:

Paul Hovnanian P.E. wrote:
tomcat wrote:

[snip]

It is the savings in 'Volume', not weight, that is so important. You
can only make a waverider so big.

Are you planning on using this engine for propulsion during the
waverider's flight? If so, leave the oxygen (or most of it) behind and
use an air breathing engine. You only need the O2 above the atmosphere.

If you are using the waverider for re-entry (like the space shuttle) and
launching with a rocket, then its weight that matters. Particularly if
you can use a multi-stage vehicle, volume isn't nearly as important as
weight.

--
Paul Hovnanian
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Waveriders have to be aerodynamic. If they are too big then they are
apt to have too much drag. In short, they are 'flying gas cans' that
have to be shaped for hypersonic speeds within the atmosphere.

Waveriders, on the other hand, use air pressure underneath the vehicle
to hold the weight. They can be heavier per thrust amount than can a
vertical rise rocket.

The only application I've heard so far for a waverider space vehicle is
for the re-entry phase. Going up isn't a problem of aerodynamics. You
just strap on big fuel tanks and kick them loose at the end of the boost
phase.

To date, I'm unaware of any efficient way to go orbital from aerodynamic
flight with any significant payloads.

--
Paul Hovnanian
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c (velocity of light in a vacuum) = 1.8x10^12 furlongs per fortnight




"To date, I'm unaware of any efficient way to go orbital from
aerodynamic flight with any significant payloads." -- Paul Hovnanian


Just because it hasn't been done doesn't mean that it can't.
Technology has reached the point where waveriders, completely reusuable
rocketry, can be built and reach orbit.

They must, however, carry 10 times their thrust weight in combined dry
weight and fuel (GLOW). It will take roughly 1 hour to reach orbit.
The SSME has proven capable of long burn times. The SSME has the
'punch' to do the job. This may also be the case of the J-1a though
the burn time might exceed it's capability. The J-1a is a kerosone and
lox rocket that would reduce waverider size somewhat.

The SSME (Space Shuttle Main Engine) packs 400 thousand pounds of
thrust at sea level, while consuming 1035 pounds of fuel per second.
The J-1a packs 1.8 million pounds of thrust at sea level, while
consuming 6000 pounds of fuel per second.

The day of the waverider has arrived. One just needs to be built.


tomcat