Patent Publication Number: US-2023150676-A1

Title: Drogue parachute system for spacecraft

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of U.S. Pat. application Ser. No. 17/355,176 filed on Jun. 23, 2021. The above application is incorporated by reference herein. 
    
    
     BACKGROUND 
     Field of the Invention 
     The present invention relates to a spacecraft recovery technology, and more particularly to a drogue parachute system for a spacecraft. 
     Description of Related Art 
     Conventional launch vehicles are designed to have their upper stage reenter the Earth atmosphere after launch vehicles deliver satellite payload into orbit. The upper stage is then burned away through the reentry flight because hypersonic flight speed and increasing air density led to extremely high heating rates. For spacecraft reentry and recovery operations for crew or payload return to Earth safely, heat shields designed to handle the aerothermodynamic effects are employed to pass through the reentry flight high-heating phase without damaging the payload and/or putting the crew at risk. Spacecraft and upper stage recovery technology present high added value to the overall space launch system. 
     SUMMARY 
     One objective of the present invention is to provide a drogue parachute system for a spacecraft, and the drogue parachute system is capable of preventing the spacecraft from experiencing the aerothermal heat impact in the reentry flight of the spacecraft to the Earth so that a safe and stable reentry flight is possibly achieved for spacecraft recovery. 
     Another objective of the present invention is to provide a drogue parachute system for a spacecraft, and the drogue parachute system is capable of inducing a safe and stable reentry flight by slowing down the spacecraft during the reentry flight. 
     To achieve the foregoing or other objectives, the present invention provides a drogue parachute system for a spacecraft according to an embodiment, and the drogue parachute system includes a first parachute, a first set of connection lines, an extension device, a second set of connection lines that is inflatable, at least one inflating device that is connected to the first parachute and configured to inflate the first parachute, a second parachute and a third set of connection lines. Each connection line of the first set of connection lines includes two opposite ends respectively connected to the first parachute and the spacecraft. Each connection line of the second set of connection lines includes two opposite ends respectively connected to the extension device and the first parachute. Each connection line of the third set of connection lines includes two opposite ends respectively connected to the second parachute and the extension device. The first parachute fully deployed is reverse umbrella-shaped with respect to the spacecraft. 
     Optionally, a distance between a periphery of the first parachute in operation and the spacecraft is longer than a distance between a center of the first parachute in operation and the spacecraft. 
     Optionally, a distance between a periphery of the second parachute in operation and the spacecraft is shorter than a distance between a center of the second parachute in operation and the spacecraft. 
     Optionally, the extension device comprises an inner space for accommodating the second parachute and the third set of connection lines. 
     Optionally, the drogue parachute system further includes a housing for accommodating the first parachute, the first set of connection lines, the second set of connection lines, the extension device, the second parachute and the third set of connection lines. 
     Optionally, the second parachute and the third set of connection lines are released from the extension device after the extension device is pushed out from the spacecraft, and then the second set of connection lines, the first parachute and the first set of connection lines are released from the spacecraft. 
     Optionally, at least a part of the extension device is flexible. 
     Optionally, the first, second and third sets of connection lines are made of at least a bulletproof material. 
     Optionally, the second parachute is smaller than the first parachute. 
     Optionally, connection lines of the first set of connection lines connected to a central portion of the first parachute are shorter than connection lines of the first set of connection lines connected to a periphery portion of the first parachute. 
     Optionally, a central portion of the first parachute is thicker than a periphery portion of the first parachute when the first parachute is fully deployed. 
     Optionally, the second set of connection lines, the first parachute and the first set of connection lines are pulled out from the spacecraft by a drag force of the second parachute after the second parachute is deployed. 
     Optionally, the second set of connection lines, the extension device, the third set of connection lines and the second parachute are lay idle after the first parachute is fully deployed. 
     Optionally, the first parachute comprises a first surface and a second surface opposite to the first surface, one of the first and second surfaces is disposed with at least one pressure regulator connected to the at least one inflating device, and the at least one inflating device inflates the first parachute with compressed gas stored in the inflating device, through the at least one pressure regulator. 
     Optionally, the first parachute comprises at least one gas chamber for being inflated by the compressed gas. 
     Optionally, an amount of gas chambers in the first parachute is plural, and every two adjacent ones of the gas chambers are connected to each other and have vents on a connection therebetween. 
     Optionally, the first parachute comprises a first surface and a second surface opposite to the first surface, a part of the first set of connection lines is connected to the first surface in a central portion of the first parachute, another part of the first set of connection lines is connected to the first surface in a periphery portion of the first parachute, and the second set of connection lines is connected to the second surface in the central portion of the first parachute. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       After studying the detailed description in conjunction with the following drawings, other aspects and advantages of the present invention will be discovered: 
         FIGS.  1  to  4    are schematic diagrams illustrating steps of the process of releasing a drogue parachute system for a spacecraft according to an embodiment of the present invention; 
         FIG.  5    is a schematic diagram illustrating a part of the drogue parachute system fully released from the spacecraft, at a view point according to an embodiment of the present invention, to mainly show the full deployment of the first parachute; 
         FIG.  6    is a schematic diagram illustrating a part of the drogue parachute system fully released from the spacecraft, at another view point according to an embodiment of the present invention, to mainly show the full deployment of the first parachute; 
         FIG.  7    is a side view of a part of the drogue parachute system fully released from the spacecraft according to an embodiment of the present invention, to mainly show the full deployment of the first parachute; and 
         FIG.  8    is a cross-section view of a part of the drogue parachute system of  FIG.  7    according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Please refer to  FIGS.  1  to  8   , illustrating a drogue parachute system  2  and the process of releasing the drogue parachute system  2  from a payload  11  of a spacecraft  1  according to an embodiment of the present invention. The drogue parachute system  2  is suitable to be disposed to the spacecraft  1 . The drogue parachute system  2  includes a housing (not shown), a circuit board with a timer (not shown), a first parachute  21 , a first set of connection lines  22 , an extension device  23 , a second set of connection lines  24 , a second parachute  25 , a third set of connection lines  26 , and an inflating device  27 . 
     The housing has an inner space for accommodating the circuit board, the first parachute  21 , the first set of connection lines  22 , the extension device  23 , the second set of connection lines  24 , the second parachute  25  and the third set of connection lines  26 , and is contained in the payload  11  of the spacecraft  1 , for example. The circuit board is communicable with an avionics system of the spacecraft  1 , so as to program a parashell deployment signal according to the altitude data provided by the avionics system, and trigger an inflation sequence of the drogue parachute system  2  according to the parashell deployment signal. 
     The first parachute  21  is an inflatable parachute contained in a fabric container stored in the housing. The central portion of the first parachute  21  is, for example but not limited to, thicker than the periphery portion of the first parachute  21  when the first parachute  21  is fully inflated, so that the cross-section shape of the first parachute  21  fully inflated is approximately a crescent moon shape. This is conducive to preventing the fully-inflated first parachute  21  from deformation during the reentry flight of the spacecraft  1  to the Earth. 
     The first parachute  21  includes a first surface  211 , a second surface  212  opposite to the first surface  211 , and includes, for example but not limited to, gas chambers  213  therein, and a pressure regulator  214  mounted on the first surface  211  in the central portion of the first parachute  21  at the center and connected to the inflating device  27 . Every two adjacent gas chambers  213  are connected to each other and have vents  216  on the connection therebetween, so all the gas chambers  213  are communicable with each other. The pressure regulator  214  has an air channel therein for gas inflation and deflation, and the air channel is operationally communicable with the gas chambers  213 , so the pressure regulator  214  can control the pressure level of the first parachute  21 . 
     The inflating device  27  has a compact size, is lightweight, and includes a gas storage  271  (ex., one or more gas bottles) for storing compressed gas, and is communicable with the circuit board. The gas storage  271  is affixed to the first surface  211  in the central portion of the first parachute  21  at the center by a fixture made of a bulletproof material, such as KEVLAR fiber, is connected to the pressure regulator  214  and operationally communicable with the air channel of the pressure regulator  214 , and is triggerable by the circuit board according to the inflation sequence to inflate the gas chambers  213  with the compressed gas stored therein, through the pressure regulator  214 . The pressure regulator  214  automatically stops the flow of the compressed gas from the gas storage  271  into the gas chambers  213  when the pressure level of the first parachute  21  achieves a desired value that all the gas chambers  213  are fully inflated. 
     Each connection line of the first set of connection lines  22  includes two opposite ends respectively connected to the payload  11  and the first parachute  21 . Some connection lines  22  of the first set of connection lines  22  are connected to the first surface  211  in the central portion of the first parachute  21 , and some connection lines  22  of the first set of connection lines  22  are connected to the first surface  211  in the periphery portion of the first parachute  21 . The connection lines  22  connected to the central portion of the first parachute  21  are shorter than the connection lines  22  connected to the periphery portion of the first parachute  21 . Each connection line of the second set of connection lines  24  includes two opposite ends respectively connected to the first parachute  21  and the extension device  23 . The second set of connection lines  24  is connected to the second surface  212  in the central portion of the first parachute  21 . Each connection line of the third set of connection lines  26  includes two opposite ends respectively connected to the extension device  23  and the second parachute  25 . The first, second and third sets of connection lines are made of at least a bulletproof material, such as KEVLAR fiber. 
     At least a part of the extension device  23  is flexible and is a lightweight passive extension teleport so that it is easy to receive the extension device  23  into the housing. The extension device  23  is tube-shaped and includes an inner space (not shown) for accommodating the second parachute  25  and the third set of connection lines  26 . 
     The second parachute  25  is, for example but not limited to, a drogue chute, and is smaller than the first parachute  21  when they are fully inflated and deployed. The second parachute  25  is spring-loaded and contained in the extension device  23 , and can be pushed out from the extension device  23  when the spring releases according to the control of the circuit board, thereby functioning to pull out the first parachute  21  from the fabric container of the first parachute  21 . 
     In the inflation sequence, the drogue parachute system  2  except the housing is released from the payload  11  by the following steps: (1) pushing out the extension device  23  from the housing contained in the payload  11  before the spacecraft  1  enters its reentry flight that can be initiated by the deorbiting maneuver of the spacecraft  1 , as shown in  FIG.  1   ; (2) pushing out the second parachute  25  and the third set of connection lines  26  from the extension device  23  before the spacecraft  1  enters its reentry flight and after the extension device  23  is pushed out; (3) inflating the second parachute  25  in the beginning of the reentry flight of the spacecraft  1 , as shown in  FIG.  2   ; (4) pulling out the first parachute  21 , the first set of connection lines  22  and the second set of connection lines  24  from the housing by the drag force of the fully-deployed second parachute  25 , as shown in  FIG.  3   ; and (5) inflating the first parachute  21  with the compressed gas stored in the inflating device  27  after the first parachute  21  and the second set of connection lines  24  are pulled out, as shown in  FIG.  4   . The extension device  23 , the second set of connection lines  24 , the second parachute  25  and the third set of connection lines  26  are lay idle after the second parachute  25  and the third set of connection lines  26  are pulled out. 
     In the process of releasing the drogue parachute system  2  except the housing, the releasing of the extension device  23  is prior to the releasing of the second parachute  25  so that the third set of connection lines  26  is possibly prevented from fouling each other and entangling with the spacecraft  1 . In the opening state of the second parachute  25 , a distance between a periphery of the second parachute  25  and the spacecraft  1  is shorter than a distance between a center of the second parachute  25  and the spacecraft  1 . 
     When the first parachute  21  is fully inflated and deployed, the first parachute  21  possibly maintains its reverse umbrella shape with respect to the spacecraft  1  during the descending of the spacecraft  1  since in addition to the crescent-moon shaped cross section of the first parachute  21 , the compressed gas within the gas chambers  213  makes the first parachute  21  maintain fully spread out and the first set of connection lines  22  pulls on the first parachute  21 . In the opening state of the first parachute  21 , a distance between a periphery of the first parachute  21  and the spacecraft  1  is longer than a distance between a center of the first parachute  21  and the spacecraft  1 . Through the opened first parachute  21  as an aeroshell, the spacecraft  1  is possibly slowed down gradually when passing through the thin-air region of the reentry flight. When the spacecraft  1  reaches the denser part of the atmosphere, the flight speed of the spacecraft  1  has already become low enough. In this way, there would be no aerothermal heating imposed on the spacecraft  1  throughout the reentry flight, and the spacecraft  1  possibly returns to the earth surface safely. 
     Although the forgoing embodiment is exemplarily described based on a case of the housing disposed in the payload  11 , the present invention is not limited to this example. In other embodiments, the housing containing the first parachute  21 , the first set of connection lines  22 , the extension device  23 , the second set of connection lines  24 , the second parachute  25  and the third set of connection lines  26  may be disposed in another part of the spacecraft  1  instead of the payload  11 . 
     Although there are more than one gas chambers  213  in the first parachute  21 , the present invention is not limited to this example; and in other embodiments, the first parachute  21  can be modified to have only one gas chamber  213  therein. Likewise, although one inflating device  27  is utilized to inflate more than one gas chambers  213  of the first parachute  21 , the present invention is not limited to this example; and in other embodiments, the drogue parachute system  2  can be modified to have more inflating devices  27  for inflating the gas chambers  213 . Similarly, the pressure regulator  214  and the inflating device  27  are disposed to the first surface  211  as shown in  FIGS.  6  to  8   , the present invention is not limited to this example; and in other embodiments, it may be contemplated that the pressure regulator  214  and the inflating device  27  are disposed to the second surface  212 . 
     While we have shown and described various embodiments in accordance with the present invention, it is clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.