Devices and method for rocket booster vectoring to provide stability augmentation during a booster launch phase

Rocket booster motor vectoring system and method for shortening take-off distance of aircraft, the aircraft being airborne before it is going fast enough for its conventional controls to provide adequate stability and control. A rocket booster motor (52) is coupled to aircraft (50) by means of thrust arm link (56) is pivotal engagement with the aircraft and fixed to the booster, and coupled by rearwardly positioned links (62, 64, 66) having ball and socket joints at both ends, one end being connected to the aircraft through aerodynamic surfaces (68, 70) or through actuators (124, 126), the aerodynamic surfaces being operable by conventional systems within the basic aircraft, and the actuators also being operated by motion sensing systems within the aircraft to vector the thrust of the booster to provide stability augmentation of the aircraft during the boosted launch phase to provide pitch, roll, and yaw control. The thrust vector is rotated or directed in response to signals generated in the basic aircraft control systems.

DESCRIPTION 
1. Technical Field 
The invention relates to the use and combination of a rocket booster motor 
for providing additional stability and control required during a booster 
launch phase of an aircraft. Aircraft is defined as including airplanes, 
missiles, and airborne vehicles. 
2. Background Art 
In the prior art, during rocket assisted take-offs of aircraft, ther have 
been problems of thrust misalignment, stability, and control of the 
aircraft. Auxiliary rocket engines or jato bottles have been provided for 
additional acceleration when flying speed must be attained in very short 
distances. The aircraft flies before it is going fast enough for its 
conventional controls to provide adequate stability and control. If the 
vehicle has aerodynamic controls only, the following problems tend to 
occur: 
1. The center of gravity of the combined vehicle plus a booster is 
generally farther aft than for the basic vehicle. This results in reduced 
stability or an unstable vehicle. Both of these conditions demand 
additional control power. 
2. If the booster thrust is not precisely aligned to pass very close to the 
center of gravity, large torques are generated, placing additional demands 
on the control system. 
3. The available aerodynamic control is severely limited at the low launch 
speeds. 
In the prior art to avoid or solve the above problems, the practice for 
controlling booster vehicles varied depending upon the mission and 
configuration. For space vehicles some form of reaction control was 
generally used and stabilizing fins may have been added to the booster. 
For airplanes and airborne missiles, of particular concern in this 
application, the solutions have been a mix of the following: 
1. The size of the aerodynamic controls have been increased over that 
required for flight after boost. 
2. Stabilizing fins have been added to the booster. 
3. The manufacturing tolerances on booster rocket nozzles have been limited 
to provide a precision installation. 
4. A separate, self-contained stability and control unit has been provided 
in the booster and either a jet defletor vane or a gimballed nozzle has 
been incororated. 
The first, second, and last solutions, listed above, burden either the 
basic, non-boosted, vehicle or the booster. The third and fourth, listed 
solutions, are very costly. Further, the above solutions have resulted in 
penalties of either reduced performance of the basic vehicle, increased 
weight and/or increased cost, and complexity. 
A search of the patent literature including rocket motor boost systems has 
revealed the following. For example, U.S. Pat. No. 3,897,030, to Cors et 
al discloses a rocket motor attached to the aircraft and which is 
responsive to changes which occur in a control system so as to move the 
motor in response to the changes. 
The following patents disclose systems of general interest: 
U.S. Pat. No. 2,544,830--Grill et al. 
U.S. Pat. No. 2,745,347--Lightbody et al. 
U.S. Pat. No. 2,776,622--Robert, 
U.S. Pat. No. 2,814,453--Trimble, Jr. et al., 
U.S. Pat. No. 2,971,725--Jakimiuk, 
U.S. Pat. No. 3,070,329--Hasbrouck, 
U.S. Pat. No. 3,114,520--Finvold. 
DISCLOSURE OF THE INVENTION 
Modern aircraft have motion sensors and required logic coupled to 
aerodynamic controls, such as elevons, ailerons, elevators, and rudder, 
for augmenting stability in post launch phases of climb, high speed 
flight, and landings. the aerodynamic controls are sized to provide 
sufficient control power at these speeds. 
According to the invention, rocket motors are attached to the aircraft by 
supporting members or links that are connected by shear pins or other 
self-releasable means so that the rocket motors are released from the 
aircraft after take-off. The invention is comprised of means and a method 
for coupling a rocket booster motor to an aircraft, or for an aircraft in 
combination therewith, so that the rocket booster thrust vector is 
directed as a single unit by the aerodynamic controls in the basic 
aircraft to provide the additional stability and control required during a 
boosted launch phase. Relatively small motions are required because large 
torques are generated at low speed. 
These torques are generated by the relatively large and constant thrust 
vector moved by the aerodynamic controls to control the pitch, roll, and 
yaw of the aircraft, as well as to provide the acceleration forces 
required to achieve unboosted flight. This is accomplished with no changes 
required in the flight control logic or system. 
The means for coupling the rocket booster motor to at least some of the 
aerodymanic surfaces of the controls are operated in accordance with 
signals from motion sensors and/or logic in the aircraft to the controls, 
so that the rocket thrust vector is directed as a single unit into 
automatic alignment in direct proportion to the signals and relative to 
the center of gravity of the aircraft so that travel of the aircraft is 
commanded through the flight control and logic system to prevent genertion 
of excessive torques, to avoid placing additional demands on the controls, 
to aovid severely limiting of available aerodynamic control at low launch 
speeds, and to provide pitch, roll, and yaw control. 
The means for coupling may be in the form of supporting links having ball 
joints at at least one end. A forward link of the supportin glinks has a 
forward end for pivotal connection to the aircraft aft of tis center of 
gravity and has a rearward end fixed to the rocket motor. There is a first 
rear link having ball joints at both ends, one of said ends of the first 
rear link being connectable to a control on one side of the aircraft, and 
the other end of the first rear link is connected to a corresponding one 
side of the rocket motor. Second and third rear links have ball joints at 
both ends, one of the ends of each second and third rear links being 
connectable to a control on the other side of the aircraft. The other ends 
of the second and third links are spacedly connected to a corresponding 
other side of the rocket motor. 
In another embodiment, an actuator is connected to supporting links and to 
the rocket motor to move the motor transversely with respect to the 
aircraft to provie for roll-yaw control. 
For missiles in which no aerodynamic control surfaces are available for 
actuation of the rocket booster, a separate system is used. For example, 
the coupling means include a forward link having a spherical roller on its 
forward end for rollable contact on a concave spherical member securable 
to the aircraft and having a rearward end fixed to the rocket motor. There 
is a first rear link having ball joints at both ends, one of the ends of 
said first rear link being connectable to the aircraft and th other end of 
the first rear link being connectd to the rocket motor. There are a pair 
of actuators having one end of each joining the forward link between the 
spherical roller and its fixed end. The actuators are angularly positioned 
so that their other ends are spaced and are connectable to the aircraft 
whereby a forward thrust point in the spherical roller is movable on the 
concave spherical member by the actuators to provide pitch, roll, and yaw 
control to the aircraft through the thrust vector of the rocket motor. 
One benefit of the booster vectoring, according to the invention, is that 
the alignment of the thrust vector to the aircraft center of gravity is 
not critical. Normal production tolerances are sufficient. The flight 
control system moes the thrust vector to yield the required moments and 
forces for controlled flight. 
The invention provides the following advantages: 
1. Additional control power is made available for manging thrust 
misalignment and instability during rocket boost. 
2. This additional control power is obtained with little penalty or change 
to either the basic aircraft or the booster. 
3. Elements of the basic aircraft stability augmentation system are used. 
4. The additional control power is gained with a relatively simple system 
and small weight penalty. 
5. The system shall cost less in terms of dollars and performance penalties 
than competitive systems. 
Further advantages of the invention may be brought out in the following 
part of the specification wherein small details have been described for 
the competence of the disclosure, without intending to limit the scope of 
the invention which is set forth in the appended claims.

BEST MODE FOR CARRYING OUT THE INVENTION 
Referring again to the drawings, there is shown in FIGS. 1-4 a delta wing 
type aircraft 10 having elevons 12 and 14 adjacent the tail of the 
aircraft, the elevons being normally adapted to be operted by motion 
sensors and required logic for augmenting stability in post launch phases 
of flight, high speed flight, and landings. Such aerodynamic controls are 
sized to provide sufficient control power at these speeds. The present 
invention solves the stability and control problems encountered when 
boosters are used to shorten take-off distance. That is, the airplane 
flies before it is going fast enough for its conventional control, 
including the elevons 12 and 14, to provide adequate stability and 
control. 
The solution of the problem is the use of a rocket booster motor 18, 
coupled to the elevons by supports or links 20 on one side and links 22 
and 24 on the other side. Each of the links has ball joint ends as shown, 
FIG. 4, at 26, 28, 30, 32 and 34. This provides for the ability of 
universal movement. The links are connected to slip clamps 36 and 38 on 
the end of the aerodynamic surfaces of the elevons and which slide off of 
the elevons after take-off when the booster 18 is being detached. The 
booster is connected forwardly by a support member or link 40. At its 
forward end it is pivotally connected to the aircraft by a shear pin 42. 
Thus, after take-off the pin 42 is sheared and the rocket booster and the 
supporting links are disengaged from the aircraft, the clamps 36 and 38 
slipping off of the elevons. 
The invention provides that the booster be coupled to the aircraft, as 
described, and steerable by the conventional controls, such as the elevon 
surfaces 12 and 14 so that the booster thrust produces moments around the 
center of gravity 44 which supplement those produced by the conventional 
controls such as the elevons 12 and 14. 
In FIG. 1 when the elevon is in the horizontal position the rocket motor 
thrust takes the direction of the arrow T.sub.1 in alignment with the 
support 40 and the direction of thrust provided by the motor. By 
deflecting the elevons downwardlyl, the rocket motor is moved downwardly 
as shown by the broken lines and the thrust takes the direction of T.sub.3 
below the null position T.sub.1. As shown in the downward position the 
thrust vector T.sub.3 is directed above the center of gravity 44 so as to 
pitch the nose of the aircraft downwardly. Similarly, by directing the 
elevons upwardly as indicated by the thrust position of T.sub.2, an upward 
pitch occurs. 
Three supporting links as 20, 22, and 24 are required to ensure a unique 
rocket motor position and orientation for each elevon position. The 
retainer shear pin 42 releases the thrust arm 40 on the ignition of the 
rocket motor 18. 
In FIGS. 5-9 the arrangements are similar to those shown in FIGS. 1-4, but 
in greater detail. An aircraft 50 is shown fragmentarily and has a booster 
rocket 52, shown schematically, coupled to the aircraft rearwardly of the 
center of gravity 54 by means of a detachable thrust arm 56 pivotally 
engaged to the aircrat at 58. The rear end 60 of the link or thrust arm 56 
is fixed to the forward end of the rocket motor in alignment withthe 
thrust. The rear end of the booster is supported on one side by two links 
62, 64, FIG. 6, th links being connected to the aerodynamic surface of the 
elevon and the motor by ball and socket joints. On the other side of the 
aircraft and booster, there is a supporting link 66 also connected to the 
elevon 70 and booster by ball and socket joints. The rocket booster is 
connected to the aircraft, as indicated with respect to FIGS. 1-4, and 
when the rocket is ignited at take-off, it applies its thrust to the 
aircraft. After rocket motor burnout the total system disengages and falls 
away from the aircraft. 
As shown in FIG. 7, by deflecting the elevons down in their conventional 
operation, the thrust vector from the booster is directed above the center 
of gravity so as to pitch the nose downwardly as indicated by the moment 
arrow. Similarly, as shown in FIG. 8, by deflecting the elevon upwardly, 
the thrust vector being directed below the center of gravity and the 
pitch-up being indicated by the moment arrow. 
As shown in FIG. 9, if the elevon 68 on one side of the aircraft is down 
and the other elevon 70 on the other side is up, a roll-yaw couple results 
as indicated by the arrows. As should be noted, this method of coupling, 
to the flight control surfaces and basic aircraft control system, requires 
no additional actuators; that is, other than in the basic aircrat system. 
Another method of actution, where only elevators are available, that is, 
typically in an airplane 84 having a forwardly positioed wing, is 
illustrated in FIGS. 10-12. A rocket booster 80 is connectd forwardly to 
the aircraft by a detachable thrust arm or link 82 having a ball joint 
connection at the forward end and having its rearward end fixed to the 
rocket motor and in the direction of the thrust. There are two rearward 
supporting links 86 and 88, one on each side of the aircraft and each 
having a pivotal joint at both ends, one end being connectd to an elevator 
90 on one side and an elevator 92 on the other side. Pivotal joints are 
connected to the aerodynamic surfaces of the elevators by means of 
slip-off clamps 94 and 96, FIG. 12, that are detached from the elevators 
when a shear pin in the forward end of the link 82 detaches the booster 
from the aircraft. 
The links 86 and 88 are in respective pivot planes, FIG. 11, and their 
lower ends are pivotally connected to joints on a transverse link 98 which 
is slidably and rotatably engaged in a pivot-slide sleeve 100 fixed to the 
booster. An actuator 102, connected to the flight control system of the 
aircraft, by means not shown, for its operation, has one end pivotally 
connected to the link 88 and its other end connected by a ball and socket 
joint to the rocket booster 80. Pitch control for the aircraft is created 
in the same manner as shown in FIGS. 1-8 by raising and lowering the 
elevators to move the links 86 and 88 upwardly and downwardly to change 
the thrust vector, and the operation of the actuator 102 provides roll-yaw 
control by changing the direction of the thrust vector by moving the 
rocket to booster transversely with respect to the link 98 and the 
aircraft. 
In FIGS. 13 and 14 an aircraft 110 having no aerodynamic control surfaces 
for actuation by the booster is provided with a separate system, according 
to the invention. In this embodiment a block 112 is secured to the 
underside of the aircraft and has a rearwardly directed concave spherical 
face 114. A thrust arm 116 has a spherical roller 118 at its forward end, 
the roller being adapted to move on the spherical face 114. The rearward 
end of the link or arm 116 is secured to a rocket booster 120 in alignment 
with the thrust. 
A pair of angularly spaced actuators 124 and 126 have ball and socket 
joints at both ends and one end of each is joined to the thrust arm 116 
between the spherical roller 118 and the rocket booster 120. The actuators 
are about 90.degree. to each other and their respective ends 130 and 132 
have ball and socket joints connected to the aircraft. The actuators are 
operated by motion sensing or other conventional means within the 
aircraft, not shown. The rear end of the booster is supported by two links 
136 and 138 having ball and socket joints at both ends. 
Operation of the actuators by the motion sensing means in the aircraft moes 
the forward thrust point formed by the spherical roller and thus, vectors 
the thrust as required by the actuators to provide pitch, roll, and yaw 
control which is developed by the thrust vectoring as in the other 
embodiments of the invention. Shear pins or other means are provided to 
disengage the rocket booster on ignition after it has functioned during 
the take-off phase. 
The invention and its attendant advantages will be understood from the 
foregoing description and it will be apparent that various changes may be 
made in the form, construction, and arrangements of the parts of the 
invention without departing from the spirit and scope thereof or 
sacrificing its material advantages, the arrangements hereinbefore 
described being merely by way of example. We do not wish to be restricted 
to the specific forms shown or uses mentioned except as defined in the 
accompanying claims.