Tuesday, April 3, 2012

Paul Allen's rocket plane mistake

F-35 shown obsolete in previous posts

   Paul Allen got together with Burt Rutan to build a plane to carry a rocket aloft for space launch they got it very wrong.  I actually did a thing called Space Launch about two weeks before they announced their exercise in failed engineering.
  Fo0r reasons which I am sure they think are reasonable, they have decided to build an aircraft with two full sized bodies and place the rocket on a wing section connecting the two, B.  This achieves the truly impressive result of increasing weight, increasing the wetted surface and making the entire aircraft heavier and less maneuverable as well as more expensive.  Any reasonable observer would have to conclude that that level of incompetence could not be easily achieved, it would take actual work to equal that degree of failure.
   The correct design procedure is to build a single aircraft body and place the rocket on top, A.  The cockpit would constitute a separate capsule, C.  The cockpit would be on a ring mount that would allow it to rotate from a vertical to an inverted position.  This can be achieved because the aircraft can be built as fly-by-wire, all of the control inputs are electrical so the transmission of signals from the cockpit to control surfaces could be by electrical contact at the ring mount, radio signals across the gap from cockpit capsule to fuselage, by laser signal across the same gap or by mounting a flexible wire bundle from the fuselage to the cockpit for signal transmission.
   The aircraft flies to 10 000 ft (3000 m) and rolls inverted.  A smooth, coordinated roll loads the airframe barely above 1 g, virtually the same as straight line flight.  There is no danger of overstressing the structure.  The cockpit capsule is then rotated 180 degrees returning the pilots to an upright vertical position.  It would be in position G.  In this position the rocket can be smoothly dropped.  The dual tail allow the rocket to extend back further along the fuselage and ensures that there will be a smooth flow of air over the vertical stabilizers after rocket separation.  A single tail would suffer some degree of flow disruption as the rocket falls and the body of the rocket blocks and disrupts the airflow to some extent.
   The cockpit capsule could be built with 2 flight positions like a Gemini capsule or 3 positions like an Apollo capsule if an additional crew member is felt useful for preparing the rocket for launch.  From the front end of the capsule an escape tower of a a pole structure with rocket motors mounted at the end would enable the crew to separate tin the event of a casualty to the aircraft.
   The entire front end could be built into a rotating section, D, is desired.  A crew of up to 8 could be accommodated if additional personnel were needed, although I would not necessarily recommend building that.
   If the rocket were to be used for manned launches, the crew capsule could also be made to rotate on the rocket mounting, although there would be a weight penalty of several hundred pounds.
   To place the rocket on top of the airplane, a tower could be built with an extended arm which would be attached to the rocket carrier, E.  Cables would be used to provide the lifting force.   The tower would have 2 legs to allow th front of the aircraft to be moved under the arm, carrier and rocket for placement of the rocket.  Another method would be to lift the rocket on a giant forklift, F.
the forklift would be built with its supports spaced far enough apart the one could be in front of the wing and the second in back.  It would approach the aircraft from the side.
    By having a single aircraft that rolls inverted, the aircraft would be lighter and less expensive, allowing for a larger rocket to be carried or a higher altitude to be reached before separation.
   If anyone sees Paul Allen, tell him he is wasting hi money, but he has plenty and he won't miss it.  If you meeet Burt Rutan, tell him he botched the engineering.

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