h a l f b a k e r yFutility is persistent.
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How about a laser mounted on the tip of a rocket to heat
the air. This would make the air less dense and allow the rocket to slip faster into orbit/ or use less fuel.
[link]
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Whats with the tube? [wjt] |
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If you're talking about lugging a payload into LEO, the atmosphere gets fairly thin quite quickly if you're heading vertically upwards, and by the time the rocket is really starting to pick up speed, aerodynamic drag is much less of an issue than at sea level. |
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(1) Windshear - beyond the first few inches, the air vaporized won't be the air the rocket passes through |
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(2) The vacuum window won't stay open long enough |
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(3) The heating is not effective, as laser light won't heat the air fast enough |
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(4) The apparatus would consume more energy and payload than that saved |
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(5) 8 th's point about air density |
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(6) Danger factor of a laser on the nose of the rocket |
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(7) The pressure wave gets hot from frictional forces anyway |
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(8) Low efficiency would mean the laser would heat up the rocket |
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(9) Additional complexity would increase lauch failure risk |
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I got bored when I reached double digits, but there's plenty more. |
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Your idea does have merit, just not in the application you describe. A rocket delivery system could raise an energy weapon to a height where it could reach targets over the horizon, and by passing through less atmosphere, would be less detectable and less lossy. I believe Regan's Star Wars plan included X-Ray devices of this sort, but AFAIK they were banned under START. |
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Oops, looks like I scared him off....come back wjt! |
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Bully,...and not the 'pickled beef' variety..sheez i didn't know it meant that as well,sounds disgusting. |
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This might work slightly better if WJT would sit on the nose-cone, and breathed his favorite allergen. Forthwith he would inhale mightily (while facing skyward), then sneeze downward. |
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So to get this right
getting a rocket into "LEO" is all about blindly burning energy to fight for a gain against gravity
not about constructing a climb by moving the stuff that is infront out of the way and building a more rigid platform below.
technically the more knowledge about air the better
a tread a can be designed to grip and maniulate the air. |
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This is a mechanism used to clear the path for particle beam weapons. So I don't think it's totally impractical. Might be useful for high speed planes, too. Perhaps the shuttle could use it to clear a path as it bangs into the atmosphere. |
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I read about an experimental craft (don't know if it was ever built) propelled by microwaves (something like this idea, but different). It accelerated much too fast to be manned, and had an estimated top speed of Mach 25 (!). |
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Anyway, the article mentioned a microwave 'aerospike' which would keep its nose from being smashed from the fast-moving air. Most fighter jets have metal aerospikes. |
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I am wrong,
If the space machine has enough grip in the air to control hovering and motion in the atmosphere from ground to space then an aerospike does not really matter.
So engineering more controlled force is what really matters |
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I must have misread your concept. I thought you were trying to create a vacuum pocket for a distance in front of the rocket. |
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Is this instead like the ribs on the bottom of speedboats that generate bubbles to reduce fluid friction? |
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If so, would there be a better way of reducing atmospheric pressure directly ahead of the rocket? |
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Initially, yes, the laser was to reduce friction infront of the rocket by making a tube of less dense air.
(If the laser/beam could make a vacuum all the better)Rethinking, rocketry is about making a force in a volume that can be stood on and position held.
If this can be done powerfully and cheaply, density of air/substance above is of little importance.
##maybe the laser/beam may help in the construction of fuel burn giving a more solid air brick to stand on. |
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How about that panel ultrasound gun thingy being used to mold the structure of the rocket flare?
This would try and make stable platforms of rocket plasma to force off.
A bit like blowing plasma smoke rings. |
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Acoustic pulsejets? While on the subject, what about shaping the rocket flare using electrostatic charge found at border of laser image, like that stungun thingie? |
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Let's say you use a pulsed later and create a pocket of superheated air of low density in front of your rocket. All you've done is replace compressive heating due to collisions with the craft with laser heating, losing some efficiency in the process ;-) |
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The concept has some merit, however I agree that ultrasound would work better. Maybe well enough to make the payload tradeoff worthwhile. New high freq work in ultra sound offers the best chance. On the other hand decent aerodynamics and a good wax job will probally work just as well.
Spaceship One shows that there other ways to launch a payload. |
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I you are going supersonic
(and that happens pretty
quickly with a rocket) the
ultrasound waves will not
travel forward.
I too have once read about
this (russian?) craft that
used a plasma and a magnetic
field to overcome friction and
add to the propulsion.
The magnetic field would push
away the ions (more precise
electrons and nuclei) as they
entered the field.
This may be needed too for leo
coilguns or railguns that have
a muzzle velocity of tens of
machs, but that is another
matter. |
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