Rocket stage and landing method

Abstract

A rocket stage is disclosed that may include a body and a plurality of foldable propulsion units spaced about the body, each propulsion unit including a folding beam, at least one motor attached to the folding beam, and at least one propeller attached to the at least one motor and configured to generate thrust to propel the rocket.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority from Israel Patent Application No. 294757, entitled "ROCKET STAGE AND METHOD OF LANDING THEREOF," filed July 13, 2022, the contents of which are incorporated herein by reference in their entirety. [Technical Field]

[0002] The present invention relates generally to spacecraft, and more particularly to rocket stages and reusable rocket stages with landing capability. [Background technology]

[0003] Advances in commercial spacecraft have led to revolutionary developments in reusable rocketry. Previously, when a rocket was launched into space, its booster was single-use and discarded after each use. In modern times, booster stages (i.e., the stage of the rocket used to propel the launch vehicle into Earth's atmosphere) are reusable and typically use the same fuel for launch and landing. For example, the Falcon™ Heavy booster from SpaceX™ uses a mixture of liquid oxygen (LOX) and rocket-grade kerosene propellant for launch and landing. Therefore, approximately 2% of the total propellant available at liftoff must be saved for use in landing.

[0004] Furthermore, using liquid propellants to land a spacecraft poses additional risks. On the landing trajectory, aerodynamic control (i.e., yaw, pitch, and roll stability) is mostly achieved through aerodynamic control surfaces, and in the art, grids or lattice fins are used for aerodynamic control. For statically mounted thruster engines, the thrust generated by the engine is unidirectional; therefore, the engine must operate simultaneously with the lattice fins to control the landing phase. For thruster engines incorporating thrust vectoring (or TVC, as known in the art), aerodynamic control is limited to the engine's maximum rotational range (i.e., along the pitch and yaw axes) combined with the thrust generated in the desired vector. In such cases, aerodynamic control is further limited by the distance between the engine and the rocket's center of mass, for example, to generate a moment about the rocket's center of mass. In traditional rocketry, the engine's location is limited to the base of the rocket.

[0005] Furthermore, the added complexity of using a single engine as both a thrust vector control and a means of slowing the rocket introduces additional risks. During landing maneuvers, small corrections must be made in fractions of a second to land safely. When engines are utilized for thrust vectoring control, the response time of the actuators that rotate the engines into the desired configuration may be slower than the response time required for corrective maneuvers.

[0006] Another risk of liquid propellant-powered landings is the proximity of the thruster engines to the landing surface (or landing pad). If thrust is miscalculated or the landing gear fails to deploy, the thruster engines may come into direct contact with the landing pad while the engines are generating thrust. This could result in instantaneous, catastrophic damage to the spacecraft and surrounding area (i.e., the exhaust ports being closed by contact with the landing pad, causing a significant amount of backpressure within the engines).

[0007] Furthermore, recovery of liquid propellant rockets must be performed in remote areas, such as areas dedicated to rocket launch and landing. These remote areas must be far from inhabited areas due to safety, noise regulations, and concerns about propellant fumes. With the recent increase in commercial space launch frequency, the availability of these remote areas that can facilitate the launch and landing of liquid propellant rockets can limit launch schedules.

[0008] Therefore, a solution is needed that reduces the risk of a catastrophic rocket landing accident while simultaneously increasing the turnaround time for launch frequency. Summary of the Invention

[0009] Embodiments of the present invention are directed to a rocket stage. An embodiment of the rocket stage may include a body and a plurality of foldable propulsion units spaced about the body, each propulsion unit including a folding beam, at least one motor attached to the folding beam, and at least one propeller attached to the at least one motor and configured to generate thrust for propelling the rocket.

[0010] In some embodiments, the rocket stage may include a plurality of folding air brakes spaced about the body, each air brake comprising at least one air brake actuator configured to actuate the plurality of folding air brakes.

[0011] In some embodiments, the rocket stage may include at least one first sensor configured to measure a value indicative of the altitude of the rocket stage, and the at least one air brake actuator configured to deploy the plurality of folding air brakes in response to receiving the first value indicative of the altitude of the rocket stage from the at least one first sensor.

[0012] In some embodiments, each foldable propulsion unit comprises at least one beam actuator configured to deploy the folding beam.

[0013] In some embodiments, the rocket stage may include at least one second sensor configured to sense at least one flight characteristic of the rocket.

[0014] In some embodiments, the beam actuator is configured to deploy the folding beam in response to receiving a second value indicative of the altitude of the rocket stage from the second sensor or the first sensor, hi some embodiments, the at least one second sensor is selected from an altimeter, a pressure sensor, an accelerometer, a gyroscope, and a magnetometer.

[0015] In some embodiments, the rocket stage may include a controller configured to control folding and unfolding of each foldable propulsion unit based on measurements received from the second sensor or the first sensor. In some embodiments, the controller is configured to control the multiple foldable propulsion units to steer the rocket stage. In some embodiments, the controller is configured to control the multiple foldable propulsion units to change at least one of a pitch angle, a roll angle, and a yaw angle of the rocket.

[0016] In some embodiments, each folding propulsion unit further comprises at least one servo, and the controller is configured to control the at least one servo to vary the pitch of the at least one propeller.

[0017] In some embodiments, the rocket stage may include a plurality of stabilizer fins spaced about the body.

[0018] Embodiments of the present invention are directed to a rocket system that may include a payload, a first stage including a body, a plurality of foldable propulsion units spaced about the body, and a second stage.

[0019] In some embodiments, the first stage of the rocket system further comprises a plurality of folding air brakes spaced about the body, each air brake comprising at least one air brake actuator configured to actuate the plurality of folding air brakes.

[0020] In some embodiments, each first stage foldable propulsion unit comprises a folding beam, at least one motor attached to the folding beam, and at least one propeller attached to the at least one motor and configured to generate thrust for propelling the rocket.

[0021] Embodiments of the present invention are directed to a method for steering a rocket stage, which may include detecting a first altitude and / or speed of the rocket stage, deploying a plurality of foldable propulsion units of the rocket stage, activating at least one motor of the foldable propulsion units, and generating thrust via at least one propeller attached to the at least one motor to steer the rocket stage, the rocket stage comprising a body and a plurality of foldable propulsion units spaced apart around the body, each propulsion unit including a folding beam, at least one motor attached to the folding beam, and at least one propeller attached to the at least one motor and configured to generate thrust to propel the rocket.

[0022] In some embodiments, the method may include detecting a second altitude and / or velocity of the rocket stage and deploying a plurality of folding air brakes, the rocket stage further comprising a plurality of folding air brakes spaced apart around the body.

[0023] In some embodiments, deploying the plurality of folding air brakes is controlled by an air brake actuator of at least one of the folding air brakes.

[0024] In some embodiments, the deployment of the multiple foldable propulsion units is controlled by at least one beam actuator of the foldable propulsion units.

[0025] In some embodiments, the method may include steering the rocket stage via at least one propeller to change at least one of a pitch angle, a roll angle, and a yaw angle of the rocket stage.

[0026] In some embodiments, the method may include steering the rocket stage via a plurality of stabilizer fins located on the rocket stage and configured to actuate relative to a longitudinal axis thereof to change at least one of a pitch angle, a roll angle, and a yaw angle of the rocket stage.

[0027] In some embodiments, the method may include landing the rocket stage via the plurality of foldable propulsion units, hi some embodiments, landing the rocket stage occurs on one of the ground and the watercraft.

[0028] Embodiments of the present invention are directed to a method for launching and landing a rocket. The method may include launching a rocket from one of an aircraft or the ground, controlling the rocket to achieve a desired altitude and / or velocity, separating a first stage of the rocket from a second stage, and landing the first stage via a plurality of foldable propulsion units of the first stage, the rocket comprising a payload, the first stage, and the second stage, the first stage comprising a body and a plurality of foldable propulsion units spaced apart around the body, each propulsion unit comprising a folding beam, at least one motor attached to the folding beam, and at least one propeller attached to the at least one motor and configured to generate thrust to propel the rocket.

[0029] In some embodiments, the first stage further comprises a plurality of folding air brakes spaced about the body, each air brake comprising at least one air brake actuator configured to actuate the plurality of folding air brakes.

[0030] In some embodiments, landing the first stage occurs on one of the ground and the vessel.

[0031] The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of this specification. However, the invention, together with its objects, features, and advantages, both as to organization and method of operation, may best be understood by reference to the following detailed description when read in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0032] [Figure 1] 1 shows a diagram of a rocket stage according to some embodiments of the present invention. [Figure 2] 1 shows a diagram of a rocket stage according to some embodiments of the present invention. [Figure 3A]1 illustrates a top view of a stabilizer fin that may be included in a rocket stage according to some embodiments of the present invention. [Figure 3B] 1 illustrates a side view of a stabilizer fin that may be included in a rocket stage according to some embodiments of the present invention. [Figure 4] FIG. 1 shows a block diagram depicting a control system that may be included in a rocket stage according to some embodiments of the present invention. [Figure 5] 1 shows a block diagram depicting a computing device that may be included in a rocket stage according to some embodiments of the present invention. [Figure 6] 1 shows a block diagram depicting a rocket system according to some embodiments of the present invention. [Figure 7] 1 is a flow diagram of a method for landing a rocket stage according to some embodiments of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0033] It will be understood that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some elements may be exaggerated relative to other elements for clarity. Further, where necessary, reference numerals may be repeated among the figures to indicate corresponding or similar elements.

[0034] Those skilled in the art will recognize that the present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. Accordingly, the foregoing embodiments are to be considered in all respects as illustrative rather than limiting on the invention described herein. The scope of the present invention is, therefore, indicated by the appended claims, rather than the foregoing description, and all changes that come within the meaning and range of equivalency of the claims are intended to be embraced therein.

[0035] In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the present invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the present invention. Some features or elements described with respect to one embodiment may be combined with features or elements described with respect to other embodiments. For clarity, descriptions of the same or similar features or elements may not be repeated.

[0036] Some aspects of the present invention are directed to rocket stages that may have landing capability or may be combined with additional rocket stages (e.g., booster stages) to land the additional rocket stages. In some embodiments, the landing of the rocket stage may be controlled by activating one or more electric motors (also referred to as "drone motors"), which may generate thrust via one or more propellers attached to the one or more drone motors to control the landing of the rocket stage. In some embodiments, landing the rocket stage may include opening multiple air brakes located on the rocket stage body to reduce the speed of the rocket stage.

[0037] Reference is now made to Figure 1, which illustrates a diagram of a rocket stage in a folded state, according to some embodiments of the present invention. Rocket stage 1000 may, in some embodiments, include a body 100. Body 100 may be a conventional rocket body as used in the art, for example, an aluminum alloy shell.

[0038] Rocket stage 1000 may further include a plurality of folding air brakes 20. In some embodiments, the plurality of folding air brakes 20 may be spaced around the circumference of body 100. In some embodiments, the plurality of folding air brakes 20 may be evenly spaced around (e.g., equidistantly spaced from) the circumference of body 100. In a non-limiting example, between 4 and 12 air brakes 20 may be spaced around (e.g., equidistant from) the circumference of body 100.

[0039] The rocket stage 1000 may further include a plurality of foldable propulsion units 30. In the illustration of FIG. 1 , the foldable propulsion units 30 are in a folded state and are not used to propel the rocket stage 1000. In some embodiments, the foldable propulsion units 30 may be spaced apart around the body 100. In some embodiments, the plurality of foldable propulsion units 30 may be evenly spaced apart around the body 100. The foldable propulsion units 30 may be configured to unfold (i.e., extend away from the body 100), as further described herein with respect to FIG. 2 . In a non-limiting example, between 3 and 12 foldable propulsion units 30 may be spaced apart around the body 100.

[0040] The rocket stage 1000 may further include a plurality of stabilizer fins 40. In some embodiments, the stabilizer fins 40 may be spaced apart around the periphery of the body 100. In some embodiments, the plurality of stabilizer fins 40 may be evenly spaced apart (e.g., equidistantly positioned) around the periphery of the body 100. The stabilizer fins 40 may be solid fins, i.e., configured with an airfoil-like shape having an outer "skin" shell. In some embodiments, the stabilizer fins 40 may be or include grid or lattice fins (i.e., fins with a honeycomb-like pattern that allows air to pass through multiple holes along the face of the fin), as is known in the art. The stabilizer fins 40 may be positioned at any predetermined location along the longitudinal length of the body 100, as may be needed based on the desired performance characteristics of the rocket stage 1000.

[0041] Reference is now made to FIG. 2 , which illustrates a diagram of a rocket stage with foldable propulsion units 30 deployed, according to some embodiments of the present invention. In some embodiments, the body 100 may include landing gear (or “legs”) 105 disposed at the bottom of the body 100. The landing gear 105 may be used to stabilize the rocket stage 1000 during landing (e.g., for landing on a landing pad), as is known in the art. Each foldable propulsion unit 30 may include a folding beam 31, at least one motor 32 attached to the folding beam 31, and at least one propeller 34 attached to the at least one motor 32 and configured to generate thrust for propelling the rocket stage 1000.

[0042] Each folding beam 31 may be a structural beam attached to the body 100. In some embodiments, the material composition of each folding beam 31 may be selected from non-limiting examples including carbon fiber, Kevlar®, plastic (e.g., acrylonitrile butadiene styrene or "ABS" plastic), aluminum alloy, and steel alloy.

[0043] The at least one motor 32 may be an electric motor and may be selected based on the requirements of the intended use (e.g., desired propulsive power). Each motor 32 may be powered by a power source (not shown), which may be selected from non-limiting examples including lithium-ion polymer (“LiPo”) batteries, solid-state batteries, supercapacitors, chemical batteries, hybrid systems (e.g., thermal and electric), thermal systems, etc. The selection of the power source may be based on the required specifications of the at least one motor 32, such as the required discharge rate (or “C” rate, as known in the art). At least one propeller 34 may be attached to each of the at least one motor 32 (e.g., two propellers 34 attached to one motor 32).

[0044] Each folding propulsion unit 30 may have a folded state (as shown in FIG. 1 ) and an unfolded state, depending on the orientation of the propulsion unit 30, more specifically, the orientation of the propeller 34. In the folded state, the longitudinal axis A of the folding beam 31 may be parallel to the longitudinal axis J of the main body 100. In the unfolded state, the longitudinal axis A of the folding beam 31 may be at an angle (e.g., 70-110 degrees, 60-90 degrees, 90-100 degrees, and any ranges and values ​​therebetween herein) relative to the longitudinal axis J of the main body 100. In some embodiments, the longitudinal axis A of the folding beam 31 may be perpendicular (i.e., set at 90 degrees) to the longitudinal axis J of the main body 100, as shown in FIG. 2 .

[0045] In the deployed state, the at least one propeller 34 may be configured to generate thrust to propel the rocket stage 1000, for example, to land the rocket stage 1000 on a landing pad. In some embodiments, when each folding beam 31 is set to the deployed state as described herein, the at least one propeller 34 may be configured to rotate along the at least one propeller 34's axis of rotation to generate thrust. In some embodiments, the thrust generated by the at least one propeller 34 may counteract gravity, directing the rocket stage 1000 toward a surface. Each propeller 34 may include a fixed or variable pitch, as is known in the art. If the at least one propeller 34 includes a variable pitch, each folding propulsion unit 30 may include at least one servo 33 (further illustrated and described with respect to FIG. 4 herein) configured to change the pitch of the at least one propeller 34. The at least one servo 33 may be configured to actuate the blades of the at least one propeller 34 relative to the axis of rotation of each propeller 34 and may be selected from non-limiting examples including an electric servo motor, a hydraulic actuator, a pneumatic actuator, etc. In some embodiments, the at least one servo 33 may be configured to prevent rotation of the at least one propeller 34 (i.e., by holding the propeller 34 in a stationary position) to prevent undesired rotation of the at least one propeller 34, as is known in the art.

[0046] In some embodiments, each foldable propulsion unit 30 may include at least one beam actuator 36. In some embodiments, the one or more beam actuators 36 may be configured to deploy the one or more foldable propulsion units 30 (i.e., tilt the longitudinal axis A of the folding beam 31 away from the longitudinal axis J of the main body 100). In some embodiments, the one or more beam actuators 36 may be further configured to fold the one or more foldable propulsion units 30, i.e., tilt the longitudinal axis A of the folding beam 31 toward the longitudinal axis J of the main body 100. The one or more beam actuators 36 may be selected from non-limiting examples including springs, electric actuators, hydraulic actuators, pneumatic actuators, etc. The selection of the beam actuators 36 may be based on the required amount of force needed to deploy the multiple foldable propulsion units 30, i.e., to overcome opposing forces (e.g., drag).

[0047] In some embodiments, each folding air brake 20 may include at least one air brake actuator 26. One or more air brake actuators 26 may be configured to actuate multiple folding air brakes 20. For example, one or more air brake actuators 26 may tilt the multiple folding air brakes 20, i.e., tilt the longitudinal axes of the folding air brakes 20 away from the longitudinal axis J of the body 100.

[0048] In some embodiments, one or more air brake actuators 26 may be configured to actuate the multiple folding air brakes 20 to achieve a desired orientation of the folding air brakes 20. For example, the one or more air brake actuators 26 may set the multiple folding air brakes 20 at an angle (e.g., 0-1 degree, 1-5 degrees, 5-15 degrees, 15-45 degrees, 45-90 degrees, and any ranges and values ​​therebetween herein) relative to the longitudinal axis J of the body 100. The one or more air brake actuators 26 may be selected from non-limiting examples including springs, electric actuators, hydraulic actuators, pneumatic actuators, etc. The selection of the air brake actuator 26 may be based on the required amount of force needed to actuate the multiple folding air brakes 20, i.e., to overcome opposing forces (e.g., drag).

[0049] In some embodiments, rocket stage 1000 may include at least one actuator (not shown) configured to actuate both air brake 20 and folding propulsion unit 30. In such embodiments, at least one actuator may be configured to actuate air brake 20, much like the capabilities disclosed herein for air brake actuator 26. Additionally, at least one actuator may be configured to deploy propulsion unit 30, much like the capabilities disclosed herein for beam actuator 36.

[0050] Reference is now made to FIGS. 3A and 3B, which are top and side views of stabilizer fins that may be included in a rocket stage (e.g., rocket stage 1000) according to some embodiments of the present invention. In some embodiments, stabilizer fin 40 may be configured to rotate (or "tilt") relative to longitudinal axis J of body 100. For example, stabilizer fin 40 may be tilted at angle θ with respect to J, and longitudinal axis J' of stabilizer fin 40 may be set at angle θ with respect to J. In some embodiments, stabilizer fin 40 may be configured to tilt at an angle of 30 degrees, 15 degrees, −15 degrees, −30 degrees, and any range and value therebetween, relative to longitudinal axis J of body 100. In some embodiments, one or more stabilizer fins may be tilted at a predetermined angle, e.g., 5 degrees, to generate at least one of a pitch moment, a roll moment, and a yaw moment on the rocket stage.

[0051] Reference is now made to FIG. 4, which depicts a control system that may be included in a rocket stage (eg, rocket stage 1000) according to some embodiments of the present invention.

[0052] Rocket stage 1000 may further include at least one first sensor 82 and at least one second sensor 84. At least one first sensor 82 or second sensor 84 may be selected from an altimeter, a pressure sensor, an accelerometer, a gyroscope, and a magnetometer. At least one first sensor 82 may be configured to measure a value indicative of the altitude of rocket stage 1000, and at least one second sensor 84 may be configured to sense at least one flight characteristic of rocket stage 1000, as further described herein.

[0053] In some embodiments, the at least one first sensor 82 may be configured to transmit the measured altitude to the at least one air brake actuator 26. In such embodiments, the at least one air brake actuator 26 may activate the plurality of air brakes 20 based on receiving the altitude measurements from the at least one first sensor 82. The altitude measurements that may trigger activation of the air brakes 20 may be predetermined by mission parameters, non-limiting examples of which include the peak altitude of the rocket stage 1000, a velocity measurement of the rocket stage 1000 (e.g., measured by at least one of the first sensor 82, the second sensor 84, and the avionics 80), and an orientation of the rocket stage 1000. In some embodiments, the at least one first sensor 82 may be configured to transmit the measured altitude (or "signal," as referred to herein) to the controller 90, as further described herein.

[0054] In some embodiments, the at least one second sensor 84 may be configured to sense at least one flight characteristic of the rocket stage 1000. As used herein, "flight characteristic" may refer to any attribute of the rocket stage 1000 or its components, including, without limitation, the orientation of one or more of the air brakes 20, the folding propulsion units 30, and the stabilizer fins 40; at least one of the roll rate, pitch rate, and yaw rate of the rocket stage 1000; at least one of the attitude, altitude, velocity vector, heading, specific force, angular velocity, orientation (i.e., relative to a reference frame known in the art), and GPS coordinates of the rocket stage 1000; and indications of the status of the power system (e.g., power source, motor 32, and propeller 34), such as battery capacity, current load, peak load, discharge rate, revolutions per minute of the motor 32, and pitch orientation (or "angle of attack") of the propeller 34. In some embodiments, at least one second sensor 84 may be configured to transmit one or more measured flight characteristics (or "signals" as referred to herein) to controller 90 for controlling rocket stage 1000, as further described herein.

[0055] In some embodiments, the at least one first sensor 82 and the at least one second sensor 84 may be included within avionics 80, which may be configured to transmit at least one signal to controller 90. Avionics 80 may be or include an inertial measurement unit (IMU), as is known in the art. In some embodiments, avionics 80 may include a single sensor (e.g., an IMU) configured to sense at least one flight characteristic of rocket stage 1000 and transmit the sensed flight characteristic (e.g., as a signal) to controller 90.

[0056] Rocket stage 1000 may include controller 90, which may be configured to receive at least one signal from avionics 80. In some embodiments, controller 90 may be configured to receive at least one signal from at least one first sensor 82 or at least one second sensor 84. Controller 90 may control at least one controllable component of rocket stage 1000 based on the one or more received signals. A "controllable component," as referred to herein, may be any mechanism or device included in rocket stage 1000, and non-limiting examples include air brake actuator 26, beam actuator 36, servo 33, motor 32, and stabilizer fin 40.

[0057] The controller 90 may actuate one or more air brake actuators 26 to apply or deploy the multiple air brakes 20. For example, the controller 90 may release one or more air brake actuators 26 (e.g., mechanical springs) to deploy the multiple air brakes 20. In some embodiments, the controller 90 may actuate the air brake actuators 26 (e.g., pneumatic actuators) in a predetermined orientation, for example, to extend the air brakes 20 a predetermined distance away from the body 100. In such embodiments, the predetermined orientation may be based on signals received from the avionics 80, such as altitude measurements.

[0058] The controller 90 may actuate one or more beam actuators 36 to actuate the plurality of folding beams 31. For example, the controller 90 may release one or more beam actuators 36 (e.g., mechanical springs) to deploy the plurality of folding beams 31. In some embodiments, the controller 90 may actuate the beam actuators 36 (e.g., pneumatic actuators) in a predetermined orientation, for example, to extend the folding beams 31 a predetermined distance away from the body 100. In such embodiments, the predetermined orientation may be based on a signal received from the avionics 80, for example, an altitude measurement.

[0059] The controller 90 may control the at least one servo 33 to change the pitch of the at least one propeller 34. In some embodiments, the pitch of the at least one propeller 34 may be controlled by the at least one servo 33 based on signals received from the avionics 80, e.g., a vibration sensor (e.g., a piezoelectric accelerometer) included in the avionics 80 configured to measure vibrations of the propeller 34. In such embodiments, for example, when the controller 90 receives vibrations from the avionics 80 of a significantly higher frequency, the controller 90 may control the at least one servo 33 to change the pitch of the at least one propeller 34.

[0060] The controller 90 may control at least one motor 32 to increase or decrease the rotational speed of the propeller 34. In some embodiments, the controller 90 may increase the rotational speed of all of the motors 32 to generate thrust to propel the rocket stage 1000. As is known in the art, the motors 32 may be counter-rotating, i.e., the multiple motors 32 may have both clockwise and counterclockwise rotational configurations to counteract rotational torque that may be caused by increasing or decreasing the rotational speed of the propeller 34.

[0061] The controller 90 may control the plurality of stabilizer fins 40 to steer the rocket stage 1000. In some embodiments, the controller 90 may actuate the plurality of stabilizer fins 40, and the longitudinal axis of at least one stabilizer fin 40 may be tilted at an angle relative to the longitudinal axis of the body 100, as described herein. The controller 90 may set the at least one stabilizer fin 40 at an inclination angle to induce at least one of a pitch moment, a roll moment, and a yaw moment on the rocket stage 1000.

[0062] 5, which is a block diagram depicting a computing device that may be included in an embodiment of a rocket stage 1000, according to some embodiments of the present invention. In some embodiments, the computing device 1000 is an embodiment of a controller 90 that may be configured to control the folding and unfolding of each propulsion unit 30, control the plurality of foldable propulsion units 30, control at least one servo 33, control at least one air brake actuator 26, control at least one beam actuator 36, control the plurality of stabilizer fins 40, and control at least one motor 32.

[0063] Computing device 1 may include a processor or controller 2, which may be, for example, a central processing unit (CPU) processor, chip, or any suitable computing or computational device, an operating system 3, memory 4, executable code 5, a storage system 6, input devices 7, and output devices 8. Processor 2 (or one or more controllers or processors, possibly across multiple units or devices) may be configured to perform methods described herein and / or to perform or function as various modules, units, etc. More than one computing device 1 may be included in a system according to embodiments of the present invention, and one or more computing devices 1 may function as a component of a system according to embodiments of the present invention.

[0064] Operating system 3 may be or include any code segment (e.g., similar to executable code 5 described herein) designed and / or configured to perform tasks involving coordinating, scheduling, arbitrating, monitoring, controlling, or otherwise managing the operation of computing device 1, such as scheduling the execution of software programs or tasks or enabling communication of software programs or other modules or units. Operating system 3 may be a commercial operating system. Note that operating system 3 may be an optional component; for example, in some embodiments, a system may include a computing device that does not require or include an operating system 3.

[0065] The memory 4 may be or include, for example, random access memory (RAM), read-only memory (ROM), dynamic RAM (DRAM), synchronous DRAM (SD-RAM), double data rate (DDR) memory chips, flash memory, volatile memory, nonvolatile memory, cache memory, buffer, short-term memory unit, long-term memory unit, or other suitable memory or storage unit. The memory 4 may be or include multiple different possible memory units. The memory 4 may be a non-transitory computer or processor-readable medium or a non-transitory computer storage medium, such as RAM. In one embodiment, the non-transitory storage medium, such as the memory 4, a hard disk drive, or another storage device, may store instructions or code that, when executed by the processor, cause the processor to perform methods as described herein.

[0066] Executable code 5 may be any executable code, such as an application, program, process, task, or script. Executable code 5 may be executed by processor or controller 2, possibly under control of operating system 3. For clarity, a single item of executable code 5 is shown in FIG. 5, but systems according to some embodiments of the present invention may include multiple executable code segments similar to executable code 5 that can be loaded into memory 4 and cause processor 2 to perform the methods described herein.

[0067] Storage system 6 may be or include, for example, flash memory known in the art, memory within or embedded in a microcontroller or chip known in the art, a hard disk drive, a CD-Recordable (CD-R) drive, a Blu-ray Disc (BD), a Universal Serial Bus (USB) device, or other suitable removable and / or fixed storage unit. Data related to the AOI may be stored in storage system 6 and loaded from storage system 6 into memory 4, where it may be processed by processor or controller 2. In some embodiments, some of the components shown in FIG. 5 may be omitted. For example, memory 4 may be a non-volatile memory having the storage capacity of storage system 6. Thus, although shown as a separate component, storage system 6 may be embedded in or included in memory 4.

[0068] Input device(s) 7 may be or include any suitable input device, component, or system, such as, for example, a detachable keyboard or keypad, a mouse, etc. Output device(s) 8 may include one or more (possibly detachable) displays or monitors, speakers, and / or any other suitable output device(s). As indicated by blocks 7 and 8, any applicable input / output (I / O) devices may be connected to computing device 1. For example, a wired or wireless network interface card (NIC), a universal serial bus (USB) device, or an external hard drive may be included in input device(s) 7 and / or output device(s) 8. It will be appreciated that any suitable number of input devices 7 and output devices 8 may be operably connected to computing device 1, as indicated by blocks 7 and 8.

[0069] Systems according to some embodiments of the present invention may include components such as, but not limited to, multiple central processing units (CPUs) or any other suitable general-purpose or specific processors or controllers (e.g., similar to element 2), multiple input units, multiple output units, multiple memory units, and multiple storage units.

[0070] In some embodiments, controller 90 may be or include an autonomous flight system (also known as a flight computer). The autonomous flight system may send one or more signals to components or subsystems of rocket stage 1000 to control them. In some embodiments, the autonomous flight system may be configured to operate fully or semi-autonomously. For example, controller 90 may activate multiple air brakes 20 automatically (i.e., without external input) based on receiving a predetermined altitude measurement from at least one first sensor 82.

[0071] Reference is now made to FIG. 6, which is a block diagram depicting a rocket system according to some embodiments of the present invention.

[0072] Rocket system 4000 may include a first stage 1000, a second stage 2000, and a payload 3000. In some embodiments, first stage 1000 may comprise substantially similar elements to rocket stage 1000 described herein, including body 100 and a plurality of foldable propulsion units 30 configured to propel first stage 1000.

[0073] The components of the rocket system 4000 (e.g., payload 3000, and stages 2000, 1000) may be interconnected in any order depending on the desired mission characteristics. For example, in a launch configuration, the first stage 1000 may be located at the bottom of the rocket system 4000 and connected to a second stage 2000 located above the first stage 1000, which in turn may be connected to a payload 3000 located above the second stage 2000.

[0074] In some embodiments, second stage 2000 may include additional thrusters (not shown) configured to propel rocket system 4000 to a desired altitude and / or velocity, as is known in the art. In such embodiments, the additional thrusters may include at least one of liquid propellants, hybrid propellants, and solid propellants, as is known in the art. In some embodiments, second stage 2000 may be configured to separate (or decouple) from first stage 1000, for example, upon reaching a particular altitude and / or velocity.

[0075] In some embodiments, the payload 3000 may include one or more fairings, as is known in the art, to reduce the drag coefficient during flight. In some embodiments, the payload 3000 may be configured to separate from the second stage 2000.

[0076] Reference is now made to FIG. 7, which is a flowchart of a method for landing a rocket stage according to some embodiments of the present invention. In some embodiments, the method of FIG. 7 may also include launching a rocket. In some embodiments, steps S1005-S1050 may be used to control rocket stage 1000. For example, steps S1005-S1050 may be used to steer rocket stage 1000 during flight or landing (e.g., to land rocket stage 1000 on a surface).

[0077] In some embodiments, steps S1005-S1050 may be performed by controller 90 or by any other suitable controller associated with rocket stage 1000. In some embodiments, steps S1001-S1050 may be used to launch and land rocket system 4000. In some embodiments, steps S1001-S1050 may be performed by controller 90 or by any other suitable controller associated with rocket stage 1000 or rocket 4000.

[0078] In step S1001, a rocket (e.g., rocket system 4000) may be launched (or propelled) from one of an aircraft or the ground. For example, rocket system 4000 may be launched via at least one of additional thrusters included in first stage 1000 and second stage 2000 of rocket system 4000 (e.g., conventional propellant rocket thruster engines as known in the art), as described herein with respect to FIG. 6 .

[0079] In step S1002, the rocket may be controlled to achieve a desired altitude and / or velocity of the rocket (e.g., rocket system 4000). For example, controller 90 may monitor the altitude and / or velocity of rocket 4000 (e.g., via avionics 80) until a predetermined measurement of rocket 4000 is reached, as may be determined by performance or mission requirements.

[0080] In step S1003, a first stage (e.g., first stage 1000) of a rocket (e.g., rocket system 4000) may be separated from a second stage (e.g., second stage 2000). For example, controller 90 may separate first stage 1000 and second stage 2000 based on, for example, altitude and / or velocity measurements received via avionics 80. In some embodiments, a payload (e.g., payload 3000) of rocket system 4000 may be separated from second stage 2000 (e.g., via controller 90) based on altitude and / or velocity measurements received via avionics 80.

[0081] In some embodiments, once first stage 1000 separates from second stage 2000, first stage 1000 may be controlled to land on a surface as described herein. For example, steps S1005-S1050 may be used to control first stage 1000 (e.g., via controller 90) to land first stage 1000 as described herein with respect to rocket stage 1000.

[0082] In step S1005, a first altitude of a rocket stage (e.g., rocket stage 1000) may be detected. In some embodiments, the first altitude may be detected by at least one first sensor 82 configured to send a signal to the plurality of air brake actuators 26. In some embodiments, the first altitude may be detected by avionics 80 including at least one first sensor 82 configured to send a signal to controller 90, which is configured to actuate the plurality of air brake actuators 26.

[0083] In step S1010, multiple folding air brakes (e.g., folding air brakes 20) may be deployed (or actuated) based on signals received from at least one of at least one first sensor 82 and avionics 80. For example, multiple folding air brakes 20 may be deployed via air brake actuator 26 based on controller 90 receiving a first altitude measurement from avionics 80. In some embodiments, multiple folding air brakes 20 may be deployed to reduce the speed of rocket stage 1000, for example, during landing of rocket stage 1000.

[0084] In step S1020, a second altitude and / or velocity of a rocket stage (e.g., rocket stage 1000) may be detected. In some embodiments, the second altitude and / or velocity may be detected by at least one second sensor 84. In some embodiments, the second altitude and / or velocity may be detected by avionics 80 including at least one second sensor 84.

[0085] In step S1030, multiple foldable propulsion units (e.g., propulsion units 30) may be deployed (or actuated) based on signals received from at least one of the at least one second sensor 84 and the avionics 80. For example, multiple foldable propulsion units 30 may be deployed via beam actuators 36 based on the controller 90 receiving second altitude and speed measurements from the at least one second sensor 84 and / or the avionics 80.

[0086] In step S1040, at least one motor (e.g., motor 32) included within each folding propulsion unit 30 may be activated. For example, at least one motor 32 may begin to rotate, which in turn may rotate at least one propeller 34 attached to that motor.

[0087] In step S1050, at least one propeller (e.g., propeller 34) may generate thrust to land the rocket stage (e.g., rocket stage 1000). In some embodiments, controller 90 may control at least one propeller 34 via motor 32 to land rocket stage 1000. As is known in the art, powered propellers (e.g., propellers 34) disposed about a body (e.g., body 100) may induce aerodynamic changes in the body based on the rotational speed of the propellers and the net torque about the body. For example, a yaw moment may be induced about body 100 by applying greater thrust to clockwise propellers 34 than to counterclockwise propellers 34. In another example, a pitch or roll moment may be induced on body 100 by applying uneven amounts of thrust via propellers 34. In some embodiments, controller 90 may apply equal thrust to all propellers 34 to induce a net zero torque on body 100. In some embodiments, controller 90 may control one or more propellers 34 to induce aerodynamic changes in rocket stage 1000 based on one or more signals received from avionics 80. For example, controller 90 may induce a pitch moment in rocket stage 1000 via propellers 34 based on one or more signals received from avionics 80 detecting a pitch imbalance. In some embodiments, rocket stage 1000 may land on one of the ground and a watercraft, as may be determined by the mission characteristics of the flight.

[0088] Unless explicitly stated, the method embodiments described herein are not limited to a particular order or sequence. Furthermore, all methods described herein are intended as examples only, and other or different methods may be used. In addition, some of the described method embodiments or elements thereof may occur or be performed at the same time.

[0089] While certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes that fall within the true spirit of the invention.

[0090] Various embodiments are presented, each of which may, of course, include features from the other embodiments presented, and embodiments not specifically described may include various features described herein.

Claims

1. A rocket stage, The main body and a plurality of foldable propulsion units spaced around the body, each propulsion unit comprising: A folding beam; at least one motor attached to the folding beam; at least one propeller attached to the at least one motor and configured to generate thrust for propelling the rocket; a propulsion unit comprising: A rocket stage equipped with

2. 10. The rocket stage of claim 1, further comprising a plurality of folding air brakes spaced about the body, each air brake comprising at least one air brake actuator configured to actuate the plurality of folding air brakes.

3. 3. The rocket stage of claim 2, further comprising at least one first sensor configured to measure a value indicative of the altitude of the rocket stage, and wherein the at least one air brake actuator is configured to deploy the plurality of folding air brakes in response to receiving the first value indicative of the altitude of the rocket stage from the at least one first sensor.

4. 4. The rocket stage of claim 1, wherein each foldable propulsion unit further comprises at least one beam actuator configured to deploy the folded beam.

5. 5. A rocket stage according to any one of claims 1 to 4, further comprising at least one second sensor configured to sense at least one flight characteristic of the rocket.

6. 6. The rocket stage of claim 5, wherein the beam actuator is configured to deploy the folded beam in response to receiving a second value indicative of an altitude of the rocket stage from the second sensor or the first sensor.

7. 7. A rocket stage according to claim 5, wherein the at least one second sensor is selected from an altimeter, a pressure sensor, an accelerometer, a gyroscope, and a magnetometer.

8. 8. The rocket stage of claim 4, further comprising a controller configured to control folding and unfolding of each foldable propulsion unit based on measurements received from the second sensor or the first sensor.

9. 9. The rocket stage of claim 8, wherein the controller is further configured to control the plurality of foldable propulsion units to steer the rocket stage.

10. 10. The rocket stage of claim 9, wherein the controller is configured to control the plurality of foldable propulsion units to change at least one of a pitch angle, a roll angle, and a yaw angle of the rocket.

11. 11. The rocket stage of claim 8, wherein each folding propulsion unit further comprises at least one servo, and wherein the controller is configured to control the at least one servo to vary the pitch of the at least one propeller.

12. 12. A rocket stage according to any one of claims 1 to 11, further comprising a plurality of stabilizer fins spaced about the periphery of the body.

13. 1. A rocket system comprising: A payload; A first stage, The main body and a plurality of foldable propulsion units spaced around the body; a first stage comprising: The second stage, A rocket system comprising:

14. The first stage comprises: a plurality of folding air brakes spaced about the body, each air brake comprising at least one air brake actuator configured to actuate the plurality of folding air brakes; 14. The rocket system of claim 13, further comprising:

15. Each folding propulsion unit of the first stage comprises: A folding beam; at least one motor attached to the folding beam; at least one propeller attached to the at least one motor and configured to generate thrust for propelling the rocket; 15. The rocket system of claim 13, comprising:

16. 1. A method of steering a rocket stage, comprising: Detecting a first altitude and / or velocity of the rocket stage; deploying a plurality of foldable propulsion units of the rocket stage; activating at least one motor of the folding propulsion unit; and generating thrust via at least one propeller attached to the at least one motor to steer the rocket stage, the rocket stage comprising: The main body and a plurality of foldable propulsion units spaced around the body, each propulsion unit comprising: A folding beam; at least one motor attached to the folding beam; at least one propeller attached to the at least one motor and configured to generate thrust for propelling the rocket; a propulsion unit comprising: and A method comprising:

17. detecting a second altitude and / or velocity of the rocket stage; deploying a plurality of folding air brakes, the rocket stage further comprising a plurality of folding air brakes spaced about the body; 17. The method of claim 16, further comprising:

18. 18. The method of claim 17, wherein deploying the plurality of folding air brakes is controlled by an air brake actuator of at least one of the folding air brakes.

19. 19. The method of any one of claims 16 to 18, wherein deploying the plurality of foldable propulsion units is controlled by a beam actuator of at least one of the foldable propulsion units.

20. steering the rocket stage via the at least one propeller to change at least one of a pitch angle, a roll angle, and a yaw angle of the rocket stage. The method of any one of claims 16 to 19, further comprising:

21. steering the rocket stage via a plurality of stabilizer fins located on the rocket stage and configured to actuate relative to a longitudinal axis thereof to change at least one of a pitch angle, a roll angle, and a yaw angle of the rocket stage; The method of any one of claims 16 to 20, further comprising:

22. 22. The method of any one of claims 16 to 21, further comprising landing the rocket stage via the plurality of foldable propulsion units.

23. 23. The method of claim 22, wherein landing the rocket stage occurs on one of the ground and a watercraft.

24. 1. A method of launching and landing a rocket, comprising: launching the rocket from one of an aircraft or the ground; controlling the rocket to achieve a desired altitude and / or velocity; separating a first stage of the rocket from a second stage of the rocket; and landing the first stage via a plurality of folding propulsion units of the first stage, the rocket comprising: A payload; The first stage, A second stage, the first stage comprising: The main body and a plurality of foldable propulsion units spaced around the body, each propulsion unit comprising: A folding beam; at least one motor attached to the folding beam; at least one propeller attached to the at least one motor and configured to generate thrust for propelling the rocket; a propulsion unit comprising: a second stage comprising: and A method comprising:

25. The first stage comprises: a plurality of folding air brakes spaced about the body, each air brake comprising at least one air brake actuator configured to actuate the plurality of folding air brakes; 25. The method of claim 24, further comprising:

26. 26. The method of any one of claims 24 and 25, wherein landing the first stage occurs on one of the ground and a watercraft.

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