Patent Abstract:
A winged hybrid airship (dynastat) combining the advantages of lighter-than-air (LTA) and heavier-than-air (HTA) aircrafts is disclosed. By combining the dynamic lift of low drag, high aspect ration airfoils (e.g., length over chord &gt;10) with the static lift of low drag, laminar-airflow airships, a platform is formed which is capable of prolonged high altitude flight, maintaining station over a given point on the earth, carrying a payload of communications, reconnaissance or meteorological equipment. Solar collection cells and microwave antennas allow for recharging of on board batteries/fuel cells for powering both the airship and on board avionics computers and reconnaissance or meteorological equipment. An alternate embodiment, having strengthened structural members, is able to provide low altitude heavy cargo lift in remote regions regions or cross country transport of goods.

Full Description:
This application is related to Provisional U.S. Patent Application Serial No. 60/262,364, filed on Jan. 19, 2001. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to aircraft, and more specifically to high altitude (stratoshperic), extended flight aircraft with variants capable of medium to low altitude flight for cargo transport or other tasks. More particularly, the invention comprises an unmanned hybrid winged airship (dynastat) designed for sustained flight utilizing electrically powered engines deriving electrical energy from on board solar collection cells and/or radio frequency (RF) energy collected by on board microwave antennas receiving RF signals from RF transmitters on the ground specifically located for this purpose. 
     2. Description of the Prior Art 
     Over time, airships have been developed in a variety of configurations ranging from the earliest hot air balloons to the great airships of the 1930s. The era of great transport airships was interrupted with the crash of the Hindenburg in 1937, and the development larger versions of the faster, fixed wing transport planes. More recently, relatively small blimps have been the predominant airship in use, being used primarily for promotional purposes and as short term platforms for camera equipment for sporting events. 
     Long term, high altitude (stratospheric) flight, either straight line or fixed position is desirable for a variety of reasons, including communications, weather monitoring and intelligence surveillance. Orbital satellites are expensive to put into place and, once in place, maintenance or modifications are difficult or impractical to carry out. Fixed winged (aerodyne) heavier-than-air (HTA) aircraft are more economical to operate and can be easily put into place, but altitude and flight duration limitations do not make them practical for long term communications, environmental sampling and monitoring, or imaging applications. Lighter-than-air (LTA) airships (aerostat), such as blimps and dirigibles, while able to maintain more prolonged flight durations, lack the stability to effectively maintain a fixed position relative to the earth&#39;s surface. A hybrid aerodyne/aerostat (dynastat) provides the best of both technologies, and a number of dynastat forms have been suggested in more recent years. None of these, however, has, singly or collectively, demonstrated the essential ingredients of the present invention, that is, multiple, low-drag, laminar-flow aerostats connected together with low-drag, high aspect ration airfoils (e.g., length over chord &gt;10), in a tensegrity structure that allows aerostats containing patches of solar cells on their outer surface to rotate, thus maximizing exposure to the sun. 
     U.S. Pat. No. 5,581,205, issued to Stephen G. Wurst, et. al., on May 21, 1996, presents a HIGH ALTITUDE, LONG DURATION SURVEILLANCE SYSTEM comprising a pair of aerostats connected by rigid fore and aft wing assemblies. While a suspended gondola may be shifted to alter the center of gravity in a manner similar to the present invention, Wurst&#39;s wings are of a heavy design, providing the rigidity that is provided by a light weight tetrahedral stabilizer and cables system of the present invention, linking high aspect ration airfoils to laminar-flow aerostats in a manner that allows rotation of the aerostats about their longitudinal axis. 
     U.S. Pat. No. 5,425,515, issued to Tokuzo Hirose on Jun. 20, 1995, presents an AIRCRAFT and U.S. Pat. No. 5,383,627, issued to Matsuro Bundo on Jan. 25, 1995, presents an OMNIDIRECTIONAL PROPELLING TYPE AIRSHIP, each having a plurality of aerostats joined by fore and aft wings. Both Hirose and Bundo utilize wings of a heavy, rigid construction to provide rigidity to the craft which is provided by the light weight tetrahedral system of the present invention, linking high aspect ration airfoils to laminar-flow aerostates in a manner that allows rotation of the aerostats about their longitudinal axis. 
     U.S. Pat. No. 5,240,206, issued to Sousuke Omiya on Aug. 31, 1993, presents an AIRSHIP, an aerostat having wing type control surfaces attached thereto. Omiya does not have the stability in flight of the present winged hybrid airship. 
     U.S. Pat. No. 3,856,238, issued to Frank S. Malvestuto, Jr., on Dec. 24, 1974, presents an AIRCRAFT TRANSPORTER comprising a plurality of aerostats joined by heavy wings segments placed at intervals along their length. Additional rigid fuselage members are spaced between the airships providing payload space. Again, all rigidity of the aircraft is provided by the wing/fuselage structure, as opposed to the light weight tetrahedral structure of the present invention, linking high aspect ratio airfoils to laminar-flow aerostats in a manner that allows rotation of the aerostats about their longitudinal axis. 
     U.S. Pat. No. 3,180,588, issued to J. R. Fitzpatrick on Apr. 27, 1965, presents a RIGID TYPE LIGHTER-THAN-AIR CRAFT wherein a plurality of aerostats are joined, side by side, by a rigid framework. Fitzpatrick is principally a large aerostat, presenting none of the control of a winged craft provided by the present winged hybrid. 
     None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed. 
     SUMMARY OF THE INVENTION 
     The present invention presents a hybrid winged airship (dynastat) which is capable of sustained high altitude (stratospheric) flight, either straight line or over a fixed geographic position. The present invention is designed to be able to loiter at approximately 65,000 feet and remain stationary, relative to the earth&#39;s surface, in head winds of 65-70 knots. The combination of the low drag laminar-airflow aerostat and ultra lightweight high aspect ratio aerodyne technologies provides a platform for long term, electrically powered flight and the mounting of a diversity of monitoring devices thereon. Generation of electrical energy through solar collectors and/or Radio Frequency (RF) antennas and electrical storage in on board batteries and/or fuel cells allows electrical regeneration to sustain long term flight, while variants of the dynastat capable of medium to low altitude flight may be powered by conventional power sources, such as diesel. 
     Accordingly, it is a principal object of the invention to provide a dynastat which is lightweight, low drag and stable in flight. 
     Another object of the invention is to provide a dynastat which combines the advantages of lighter-than-air (LTA)(aerostat) and heavier-than-air (HTA)(aerodyne) aircraft. 
     It is another object of the invention to provide a dynastat which is modular in design and may be constructed in varying sizes and configurations. 
     It is a further object of the invention to provide a dynastat which is structurally stable through principles of tensegrity, and at least partially maneuverable through active manipulation of the center of gravity. 
     Yet another object of the invention is to provide a dynastat which is capable of high altitude flight, with variants capable of medium to low altitude flight for cargo transport or other tasks. 
     It is a further object of the invention to provide a dynastat which is capable of long term flight. 
     Still another object of the invention is to provide a dynastat which has a renewable power source (conversion to electrical energy of solar and/or RF waves). 
     Another object of the invention is to provide a dynastat which is capable of autonomous flight and payload control through on board sensors, including global positioning via satellites (e.g. GPS). 
     An additional object of the invention is to provide a dynastat which is maneuverable by remote control through earth based transmissions. 
     It is again an object of the invention to provide a dynastat which is of lightweight construction. 
     Yet another object of the invention is to provide a dynastat which is capable of carrying and powering an array of devices thereon which may be monitored from a ground station. 
     Still another object of the invention is to provide a dynastat wherein solar collectors may be either fixed position or adapted to track the sun for maximum harvesting of solar energy, or both. 
     Another object of the invention is to provide a dynastat capable of receiving RF energy from an earth station to supplement or replace solar energy, as needed. 
     It is another object of the invention to provide a dynastat having microwave antennas which are either fixed position or adapted to track RF transmitters on the earth&#39;s surface, or both. 
     It is again an object of the invention to provide a dynastat with efficient means for descent back to earth, including safe return to earth from stratospheric altitudes without heavy or costly mechanism for facilitating that process in the event of failure of the aerostat (loss of helium) at operational altitude. 
     Still another object of the invention is to provide a dynastat, solar or non-solar powered, which, at low altitudes, derives primary lift from the aerostats and maneuverability from the airfoils, thereby allowing uses as a lift vehicle. 
     It is again an object of the invention to provide a dynastat capable of tracking its location relative to the surface of the earth and making corrections in course to maintain a designated position. 
     It is an object of the invention to provide improved elements and arrangements thereof in an apparatus for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes. 
     These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Various other objects, features, and attendant advantages of the present invention will become more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein: 
     FIG. 1 a  is a perspective view of a first embodiment of the central beam structure used in construction of the airfoils, struts, booms and airships. 
     FIG. 1 b  is a perspective view of a second embodiment of the central beam structure used in construction of the airfoils, struts, booms and airships. 
     FIG. 1 c  is a front view of a variant of the second embodiment of FIG. 1 b.    
     FIG. 2 a  is a perspective view of an airfoil segment using the first embodiment of the central beam structure of FIG. 1 a.    
     FIG. 2 b  is a perspective view of an airfoil segment using the second embodiment of the central beam structure of FIG. 1 b.    
     FIG. 3 a  is a side view of the Goldschmied laminar flow aerostat with midsection gas containment system, solar cell panels on the airship skin surface, and aft propulsion. 
     FIG. 3 b  is a side view of an alternate laminar-flow aerostat having a different mode of boundary layer control using a low drag streamlined shape and an external, ducted fan. 
     FIG. 3 c  is a side view of an aerostat having additional solar cells fore and aft. 
     FIG. 3 d  is a front view of the alternate laminar-flow aerostat of FIG. 3 c.    
     FIG. 4 a  is a perspective view of an alternate, oblate, aerostat configuration. 
     FIG. 4 b  is a front view of the alternate aerostat configuration of FIG. 4 a.    
     FIG. 5 a  is a side view of an alternate, flat aerostat configuration. 
     FIG. 5 b  is a front view of the alternate aerostat configuration of FIG. 5 a.    
     FIG. 6 a  is a side view of an alternate, non-aerostat fuselage structure. 
     FIG. 6 b  is a front view of the alternate, non-aerostat fuselage structure of FIG. 6 a.    
     FIG. 7 a  is a top view of an aerostat structure having an internal, flat-panel, tracking, solar collection system. 
     FIG. 7 b  is a side view of the aerostat structure and solar collection system of FIG. 7 a.    
     FIG. 7 c  is a front view of the aerostat structure and solar collection system of FIGS. 7 a  and  7   b.    
     FIG. 8 is a vector diagram illustrating the forces exerted on the dynastat. 
     FIG. 9 is a perspective view of a twin aerostat/mono-airfoil version of the dynastat. 
     FIG. 10 is a perspective view of an expanded, triple aerostat/bi-airfoil embodiment of the dynastat. 
     FIG. 11 is a non-aerostat embodiment of the dynastat. 
     FIG. 12 a  is a perspective view of a twin aerostat/monoairfoil version of the dynastat, lacking the vertical stabilizer and tensioning cables. 
     FIG. 12 b  is a perspective view of a non-aerostat version of FIG. 12 a.    
     FIG. 13 is a schematic of the control strategies for the dynastat. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the interest of simplicity, initial discussion will be of individual elements of the invention which will later be combined to form a whole. 
     FIG. 1 a  presents a first embodiment of the central beam structure  10  for the ultra-light airfoils, struts and airship framework. A plurality of rigid, lightweight longitudinal rods or hollow tubes  12  are arranged parallel to one another, preferably in a rectangular configuration. Hereinafter, the term rod will be used to represent either a solid rod or hollow tube. Longitudinal rods  12  are connected at regular intervals by rigid cross rods  14 , normal to the longitudinal rods  12 . Beam cables  16  of steel or other high strength fiber, as are known in the art, connecting each diagonally opposite pair of junctures  18  of longitudinal rods  12  and adjacent pairs of cross rods  14  provide structural stability against axial compressive forces, vertical bending moments due to aerodynamic lift, and lateral bending or torsion moments due to stresses of flight. 
     FIG. 1 b  presents an alternative central beam structure  10   a  consisting of a single rigid, lightweight central rod  20 . A plurality of rigid stays or stand off members  22  are affixed to central rod  20  at regular intervals, such that each set of stand off members  22  is normal to central rod  20  and substantially parallel with one another. Cables  16  again provide structural stability, connecting the free ends  24  of each stand off member  22  within a set of stand off members  22 , the free ends  24  of corresponding stand off members  22  in succeeding sets of stand off members  22 , and diagonally opposite free ends  24  of stand off members  22  in succeeding sets of stand off members  22 , thereby forming a substantially rectilinear framework. As illustrated in FIG. 1 c , stand off members  22  could optionally be longer at the central portion of central rod  20  than those at the ends of central rod  20 , thus increasing the resistence against bending of central rod  20 . 
     The longitudinal rods  12 , cross rods  14 , central rods  20  and stand off members  22  illustrated in FIGS. 1 a ,  1   b  and  1   c  are of a material such as, but not limited to, a graphite fiber or Kevlar® in a polymeric matrix, as are known in the art, while cables  16  are of steel or other high tensile strength fibers as are known in the art. 
     FIGS. 2 a  and  2   b  illustrate the airfoil substructure constructed around the central beam structure  10  and  10   a  of FIGS. 1 a  and  1   b , respectively, with airfoil ribs  26 , leading airfoil frame  28  and trailing airfoil frame  30  attached thereto. Airfoil ribs  26 , leading airfoil frame  28  and trailing airfoil frame  30  are of a lightweight foam or other composite material, as are well known in the art, having sufficient rigidity for attachment of an outer membrane (not shown) such as TEDLAR® or other polymeric material as are known to the art. Airfoils ribs  26  are shaped to create an aerodynamic shape as are well known in the aviation art. 
     As stated heretofore, a variety of aerostat designs have been developed over the years and are well known to the airship art. Any number of these aerostat designs could be modified for use in the present invention, and the specifics of the aerostat construction will not be discussed herein. Several alternative aerostat embodiments will be discussed, however, without limiting the aerostats to these designs. 
     A smooth laminar air flow (flow of air around the surface of the aerostat and away from the aft end of the aerostat) is of major importance in order to minimize turbulence of flow or wake drag which might impair smooth flight of the dynastat  1 . Several existing, preferred airflow devices, as are well known in the aerostat art, will be presented hereinbelow, without detailing the exact construction thereof or limiting design to these specific devices, as others are well known in the art. 
     FIG. 3 a  depicts the Goldschmeid laminar flow aerostat  100   a , without the typical tail boom and tail assembly, but rather having an aft suction slot (to be discussed later). As is typical of LTA craft, the aerostat  100   a  is comprised primarily of a gas containment bag  110 , formed of TEDLAR® or other polymeric material, as are known to the art, defining the overall shape of the craft. Mounted at the rear of gas containment bag  110  is an aft section housing  112   a  containing an electric motor (not shown) with a propeller or fan (not shown) for propulsion. An aft suction slot  114  formed between gas containment bag  110  and aft section housing  112   a  provides boundary layer air flow control. Arrows  116  illustrate air flow around the airship  100   a , through the suction slot  114  and out the exit nozzle  118 . An array of solar collection cells  40  may be disposed on the outer surface of aerostat  100   a  in any of a variety of configurations to optimize the collection of solar energy. The solar collection cells  40  are composed of thin, interconnected solar cells made from silicon, gallium arsenide or other material as are known in the solar energy collection art, and sandwiched between sheets of TEDLAR® or other polymeric material as are known to the art. Surface mounted microwave antennas  50  may be mounted in lieu of or in addition to solar collection cells  40 , the microwave antennas  50  for receiving RF energy from ground transmitters for supplimenting/replacing solar collected energy. 
     FIG. 3 b  is a side view of an alternative laminar airflow aerostat  100   b , similar in design to that of FIG. 3 a , having a gas containment bag  110  of TEDLAR® or other polymeric material, as are known to the art, defining its overall shape. In lieu of aft section housing  112   a , however, a more open aft housing  112   b , having one or more ducted fans/propellers  113  enhances laminar air flow over the gas containment bag  110 . 
     FIGS. 3 c  and  3   d  illustrate optional arrangements of solar collector cells  40  and/or microwave antennas  50  at the fore and aft ends of aerostat  100   c  to optimize collection when the sun is in a nose on/tail on attitude. 
     FIGS. 4 a  and  4   b  illustrate an additional laminar flow aerostat  100   d  design in which the gas containment bag  110  has a flattened, oblate configuration which provides added surface for exposure of solar collection cells  40  and/or microwave antennas  50  normal to the sun/transmitter, but at the expense of gas containment volume. Due to the reduced gas containment volume, this embodiment must rely more on the airfoils (to be discussed later) for lift than the previously discussed aerostat designs. 
     FIGS. 5 a  and  5   b ,  6   a  and  6   b  present non-airship fuselage structures  100   e  and  100   f , respectively, which rely solely on the airfoils (to be discussed later) for lift, but provide surface area for solar collection cells  40  and/or microwave antennas  50 . 
     In each embodiment presented in FIGS. 3,  4 ,  5 , and  6 , the aerostat  100   a, b, c, d  or  e  or non-airship fuselage  100   f  may be rotated about its longitudinal axis, as indicated by arrows of FIGS. 3 c ,  4   b ,  5   b , and  6   b , to present the solar collections cells  40  and/or microwave antennas  50  to the sun/transmitter at the most direct angle for reception. 
     Referring now to FIGS. 7 a ,  7   b , and  7   c , an alternative to or addition to surface mounted solar collection cells  40  and/or microwave antennas  50  is presented. Gas containment bag  110  is formed of a transparent or highly translucent TEDLAR® or other polymeric film, as are known in the art, which would allow the solar rays or microwave/RF waves to pass therethrough. A rotatable central beam  10  runs along the longitudinal axis of aerostat  100 . A plurality of arrays  42  of solar collection cells  40  and/or microwave antennas  50  are mounted along the length of central beam  10  by array hinges  44 . Each array  42  of solar cells  40  and/or microwave antennas  50  is rotatable at array hinge  44  about an axis normal to central beam  10 . By the compounded rotation of central beam  10  and arrays  42 , solar cells  40  and/or microwave antennas  50  may be aligned in virtually any direction for line of sight tracking of either the sun or ground transmitters. 
     FIG. 8 presents a vector diagram illustrating the forces exerted on dual aerostat  100  embodiment of dynastat  1 . This same vector diagram applies to each dual aerostat  100  segments of any embodiment having more than the basic two aerostat  100  components. Airfoils  120  connect aerostats  100  at their fore and aft ends. Typically the aerostats  100  are attached to airfoils  120  at the ends of their central beams  10  (FIGS. 7 a ,  7   b ), although airfoils  120  could penetrate the gas containment bag  110  of aerostat  100  to be attached to the central beam  10  of aerostat  100  along its length. A vertical stabilizer  130  rises at the center of the aperture formed by the pairs of aerostats  100  and airfoils  120 . Vertical stabilizer  130  is attached to aerostats  100  and airfoils  120  at each of their junctures by cables  132  running from each of the two ends of vertical stabilizer  130 . A payload pod  140  may be suspended, either by direct attachment or by suspension, from the lower end of vertical stabilizer  130 , or be contained within vertical stabilizer  130 . As illustrated by FIG. 8, aerostats  100 , airfoils  120  and vertical stabilizer  140  act as compressive members while cables  132  act as tension members, forming a tetrahedral shaped structure capable, as a unified platform, to withstand sheer forces and other stresses encountered in flight. This tetrahedral structure comprises the CG Trim package, as will be referred to later. Aerostats  100  exert static lift on dynastat  1 , while airfoils  120  exert dynamic lift and payload pod  140  exerts a static load. The dynastat  1  is designed to fly like an aerodyne, or fixed wing aircraft, while utilizing the buoyance of the aerostats  100  to aid in the ascent to altitude and enhance the payload carrying capacity at altitude. 
     FIG. 8 further illustrates an added feature of the dynastat  1 , especially at stratospheric altitudes, which is important from a safety and/or a systems-engineering point of view. In ordinary aerostat operation, during ascent the ballonet empties as the volume of helium expands to compensate for lower pressure on the exterior of gas containment bag  10  (the exterior and internal pressures must be at or near equilibrium). Alternatively, in the absence of a ballonet, the helium must be vented from the gas containment bag  10  or compressed into a tank/liquified to cryogenic temperatures as the aerostat rises. At stratospheric altitudes, the lifting power of helium in its gaseous form is minimal. 
     The high altitude embodiment of dynastat  1  has a significant design advantage over conventional aerostats in ability to descend safely and economically to earth after the mission, for replenishment and recycling. For conventional aerostats, the helium or other LTA gas is the only means of lift ({fraction (1/20)}th lift at stratoshperic altitudes versus sea level). For a conventional aerostat to descend and maintain an approximate equilibrium between interior gas pressure and the external atmosphere, helium or hydrogen gases must be introduced from on-board sources (stored compressed gas, cryogenic liquid), or the aerostat&#39;s gas bag must be super heated to maintain pressure equilibrium, with an internal gas that is still lighter than air. Otherwise, the constantly increasing weight of the descending aerostat, without a compensating increase in lift, would ultimately lead to a catastrophic, uncontrollable plunge to earth. 
     The hybrid dynastat  1  requires no such equipment (compressors, cryogenic storage, re-heaters), since the loss in lift of the aerostats  100  during descent can be more than compensated for by the increasing dynamic lift of the airfoils  120 , by a controlled increase in velocity translating potential energy into kinetic energy. The dynastat  1  literally flies to the ground in a controlled descent. Even if there were a catastrophic failure of the gas containment bag  110  of one of the aerostats  100 , and a total venting of the helium therein, there would still remain a fail-safe way to return to earth with an adjustment of the CG Trim mechanism and reliance on the airfoils  120  for a controlled descent. 
     Now that the various elements of the dynastat  1  have been described, attention will be turned to the specific composition of various embodiments of the dynastat  1 . 
     FIG. 9 is a perspective view of the twin-aerostat  100 , monoairfoil  120  version of the dynastat  1 . As pointed out hereinabove, a pair of aerostats  100  are attached, fore and aft by airfoils  120  and a vertical stabilizer  130  and payload pod  140  are suspended by cables  132  within the aperture formed between aerostats  100  and airfoils  120 . Outer airfoil segments  122  extend outboard of aerostats  100  at the ends of airfoils  120 . The top surface of airfoils  120  may be covered with solar collection cells  40  and/or microwave antennas  50  similar to those mounted on the aerostats  100  (FIGS. 3 thru  4 ). 
     The cables  132  of the lower part of the structure can be adjusted through mechanisms in the payload pod  140  at the bottom of vertical stabilizer  130  to adjust the length of each cable  132  such that the payload pod  140 , as well as vertical stabilizer  130 , pivots about a pivot point relative to aerostats  100  and airfoils  120 . The center of gravity of the payload can thereby be moved in any direction about the base of vertical stabilizer  130 . 
     The payload pod  140  contains the heaviest components of the platform, such as an avionics computer (not shown), energy storage system (batteries and/or fuel cells) (not shown), communications electronics (not shown) and other hardware (not shown). The repositioning of the payload by the CG Trim system changes the center of gravity of the entire platform relative to the center of lift of the aerostats  100  and airfoils  120 , thus effecting gradual turns and altitude adjustments. 
     Referring now to FIG. 10, a triple aerostat  100 , bi-airfoil  120  embodiment of the dynastat  1  is depicted, illustrating that modular construction may be utilized to expand the dynastat  1  for larger payloads. Additional aerostats  100  provide added static lift to the dynastat  1  while additional airfoil  120  segments and the addition of bi-wing airfoils  120  increase dynamic lift pressures. The added vertical stabilizers  130  and payload pods  140  increase payload capacity. 
     In FIG. 11, a non-airship fuselage  100  embodiment of the dynastat  1 , having a twin, rigid fuselage  100 , is presented. Although lacking the static lift of the aerostats  100  of other embodiments, the non-airship fuselage  100  is constructed of the lightweight components set forth hereinbefore, creating an extremely lightweight fuselage  100 . Also set forth in FIG. 11 is the application of an airfoil hinge  124  at the juncture of outboard airfoil segments  122 , airfoils  120  and aerostats  100 . Airfoil hinge  124  allows the outboard airfoil segments  124  to be folded downward by gearing to form landing gear. Lightweight wheels and/or skids (not shown) on the tips of outboard airfoil segments  124  allow for rolling or skidding of dynastat  1  during takeoff and landings. All four outboard airfoil segments  124  could drop for landings, or only those on the fore or aft airfoil  120 , using the lower end of vertical stabilizer  130  or payload pod  140  as a third point for a three point landing, as illustrated. Placements for electric engines  150  are also illustrated, with either pusher engines  150   a  or puller engines  150   b  being applicable in varying locations, such as leading airfoil  120  edges, trailing airfoil  120  edges, vertical stabilizer  130  edges, or payload pod  140 . 
     FIGS. 12 a  and  12   b  depict aerostat  100  and non-aerostat fuselage  100  embodiments of dynastat  1  without the tensegrity structure of the vertical stabilizer  130  and cables  132 . Lacking the tensegrity structure, the aerostats  100  or non-aerostat fuselages  100  must be rigidly attached to the airfoils  120  through the central beam  10  structure, as has previously been suggested. These joints must be sufficiently strong to withstand torque and other stresses of flight. Since these versions do not have the CG Trim referred to previously, additional outer airfoil segments  122  are added in the aft of the dynastat  1 , to provide yaw stability as well as a means for achieving roll, pitch and yaw movements of the dynastat  1 . This is achieved by rotating outer airfoil segments  124  around their vertical axis to achieve yaw control. Turns are also accomplished, in all embodiments, by differential adjustment of engine  150  speeds, creating additional thrust in the engines outboard of the turn. Lightweight wheels or skids (not shown) provide for takeoff/landing, as previously disclosed. Payload, including batteries or fuel cells (not shown), communications equipment (not shown), etc., is distributed throughout the platform, internal to aerostats  100  and airfoils  120 . Liquid payloads may be stored within hollow longitudinal rods  12 , cross rods  14 , or stand off members  12 , as well as pods added to the structure for that purpose. 
     In FIG. 13 the control strategies for control of the dynastat  1  using the on board avionics computers  200 , on board platform sensors  202 , external Global Positioning System (GPS)  204  input,; and ground control command input  206  are described. These strategies support the autonomous navigation and station keeping functions; energy production, storage and utilization; and in transit flight functions. The parameters for these strategies include: 
     Platform Location and Orientation  210 : Longitude, latitude and altitude of the platform, as well as roll, pitch and yaw of the platform as determined by on board platform sensors  202  and GPS  204 ; 
     Platform Heading and Velocity  212 : Heading (direction of flight relative to North) as determined by on board sensors  202  as well as computed change of position over time by GPS  204 ; 
     Estimated wind direction and velocity  214 : Computed by avionics computer  200  utilizing input from on board sensors  202  (apparent wind speed and direction) as adjusted by Platform Heading and Velocity  212 . These estimates can be supplemented by estimates of platform speed in ambient air, at altitude, based on model of thrust and drag as a function of electrical energy expended on the electric engines  150 ; 
     Solar Line-of-Sight (SUN-LOS) Computation  216 : Computation by avionics computer  200  of the direction of the sun relative to the position and orientation of the platform given latitude, longitude, date, and time of day, with a look up table or algorithm in avionics computer  200 ; 
     Radio Frequency (RF) Line-of-Sight (RF-LOS) Computation  218 : Computation by avionics computer  200  of the direction of ground based RF transmitters relative to the position and orientation of the platform; 
     Solar Collection Efficiency  220 : Computation of appropriate angle of rotation of aerostats  100  having surface mounted solar collection cells  40  or other rotatable solar collection cells  40 , in order to maximize the amount of solar energy collected, given the current SUN-LOS  216 ; 
     RF Transmission/Collection System Efficiency  222 : Computation by avionics computer  200  of the appropriate angel of rotation of aerostats  100  having surface mounted microwave antennas  50  or other rotatable microwave antennas  50 , in order to maximize the amount of RF energy collected, given the current RFLOS  218 ; 
     Energy Storage System Charge/Discharge Efficiency  224 : Computations by avionics computer  200  assessing the appropriate charge and discharge rates of the energy storage system  152  to assure charge/discharge efficiency and prolong battery life. 
     Propulsion System/Thrust Efficiency  226 : Computations by the avionics computer  200  which assess the appropriate RPM settings of the electric engines  150  to assure adequate thrust to maintain altitude and make course corrections to perform the mission with minimal expenditure of energy from the solar or RF collection systems and/or battery stored energy. Thrust efficiency may vary from engine to engine depending on location on the platform and maneuver being performed. 
     Platform Drag/Displacement  228 : All structures of the dynastat  1  contribute to the platform drag in the direction of motion, as well as to the displacement of the dynastat  1  by cross winds. This drag and displacement is highly dependent on the aspect angle between the platform heading and the wind direction and increases in severity with increased platform velocity and wind intensity. A computation is made by the avionics computer  200  assessing the appropriate angle of rotation of the solar collection panels  50  in order to maximize the amount of solar energy collected while minimizing the adverse effects of drag and displacement cross section of the platform. 
     Route Planner  230 : As has previously been stated, the hybrid platform can be used for a number of different missions, including telecommunications, high altitude environmental sampling, platform to platform information/data relay, and remote imaging/surveillance and sensing. The route planner, using input from GPS  204  and look up tables, logic trees or other algorithms, optimizes the best route or orbit (for stationary positioning) based on wind, available energy, and time allowed for point to point transitions by automatically adjusting CG-Trim settings  234 , engine Propulsion/Thrust Settings  236  and Other Aerodynamic Control Settings  238 . These adjustment may also be effected through External commands  206  from earth based transmissions. 
     Energy Manager  232 : A program within the avionics computer  200  which monitors Energy Storage System Charge/Discharge Efficiency  224 , Solar Collection Efficiency  220 , RF Collection Efficiency  222  and projected future energy requirements based on inputs from the Route Planner  230 . The program directs the Solar Collector Rotation Settings  240 , RF Collector Rotation Settings  242 , and Charge/Discharge Rate Settings  244  to make necessary adjustments for maximal alignment for energy acquisition, optimal storage and minimal expenditures to the electric engines  150  to achieve the necessary platform velocity required by the Route Planner  230  with look up tables or other algorithms in the avionics computer  200  providing data on total time of isolation and angle of sun for any particular day or location (longitude, latitude, date, and time of day). 
     In an alternate, low altitude, heavy payload version of the dynastat  1  having strengthened structural members, the principal lift may be buoyancy of the aerostats, supplemented by the airfoils when the airship is in transit. This low altitude embodiment relies on the fact that the lifting power of aerostats is 15 to 20 times greater at lower altitudes (hundreds to thousands of feet) than at stratospheric altitudes (tens of thousands of feet) because of the density of air at lower altitudes. The weight of the cargo is distributed throughout the dynastat  1  by the cables of the tetrahedral structure of the central vertical stabilizer. A low altitude, heavy payload version would probably not be solar powered, but rather could be diesel powered, either directly or by electrical generation. 
     The mode of operation for the low altitude embodiment would differ from that of the high altitude embodiment. In the high altitude embodiment the aerostats would be only partially filled with helium, maintaining a large ballonet filled with air. As the airship ascends, the helium will expand, forcing the air out of the ballonet, until operational altitude is achieved, when the aerostat will be filled, volumetrically, with helium, but at a much lower density than at sea level. In the low altitude embodiment the aerostats would be filled almost completely with helium, with a small ballonet containing ambient air. This maximizes the lift of the aerostats. The payload could be matched to the weight of the airship such that the combined weight would be lighter-than-air and the dynastat  1  could ascend vertically, or if slightly heavier-than-air, require only a short powered runway takeoff. 
     If the low altitude embodiment were to be used for heavy lift in a remote region (e.g. extraction of forestry products from a forest) sections of the payload pod  140  could be filled with water for ballast during transit to the site, then off loaded gradually as the cargo is brought aboard. In this manner a moderate lighter-than-air configuration can be maintained so the airship can ascend after loading for transit to an unloading point. 
     It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.

Technology Classification (CPC): 8