AU2012101948A4

AU2012101948A4 - A method of launching an object

Info

Publication number: AU2012101948A4
Application number: AU2012101948A
Authority: AU
Inventors: John Scott
Original assignee: Individual
Current assignee: Individual
Priority date: 2012-06-26
Filing date: 2012-06-26
Publication date: 2016-01-07
Anticipated expiration: 2020-06-26
Also published as: AU2012101948B4

Abstract

A method of launching an object comprising: a) arranging a carriage such that it can run along a track while substantially levitated by magnetic force within an evacuated launch 5 enclosure to move: i. a vehicle; ii. a booster; and iii. a protective shield; b) providing propulsive force to the carriage so that it moves the vehicle, 10 booster and shield along the track within the evacuated enclosure; c) activating the booster to burn fuel while within the enclosure and opening exit doors of the enclosure such that the vehicle and booster achieve sufficient speed for a successful launch and such that the protective shield protects at least a braking mechanism and/or parts of 15 the carriage from the booster; d) causing the vehicle and booster to detach from the carriage; and e) activating the braking mechanism to slow and/or stop the carriage outside the enclosure.

Description

1 TITLE A method of launching an object. FIELD OF INVENTION 5 This invention relates to a method of launching an object. A preferred form of the invention relates to a method of launching a vehicle into orbit around the earth. BACKGROUND It is known to launch vehicles, for example satellites, into orbit around the earth or into 10 space generally. A problem with known methods is that they can be very expensive and involve the use of plant or substantial parts that cannot be re-used. It is an object of the present invention to go at least some way towards addressing this or to at least provide the public with a useful choice. 15 SUMMARY OF THE INVENTION According to one aspect of the invention there is provided a method of launching an object comprising: a) arranging a carriage such that it can run along a track while substantially levitated by magnetic force within an evacuated launch enclosure to move: 20 i) a vehicle; ii) a booster; and iii) a protective shield; b) providing propulsive force to the carriage so that it moves the vehicle, booster and shield along the track within the evacuated enclosure; 25 c) activating the booster to burn fuel while within the enclosure and opening exit doors of the enclosure such that the vehicle and booster achieve sufficient speed for a successful launch and such that the protective shield protects at least a braking mechanism and/or parts of the carriage from the booster; 30 d) causing the vehicle and booster to detach from the carriage; and e) activating the braking mechanism to slow and/or stop the carriage outside the enclosure. Preferably the propulsive force mentioned at step b) is provided by electricity. 35 2 Preferably the launch enclosure has vents which open at approximately the same time the booster burns fuel to allow exhaust from the booster to vent from the launch enclosure. 5 Preferably the booster activates when it enters a substantially widened part of the launch enclosure. Preferably the booster provides in-flight thrust to at least assist in causing the vehicle to fly towards space. 10 Preferably after the vehicle has received in-flight thrust from the booster it detaches from the booster and travels further upwards under its own driving force. Optionally the launch enclosure comprises a launch tube. 15 Optionally the launch enclosure is associated with an airlock and the carriage, vehicle and booster are within the airlock prior to being propelled along the enclosure. Optionally protective shield provides braking for the carriage as a result of air 20 resistance from the shield when the carriage has exited the launch enclosure. Optionally the protective shield has a series of petals which open to provide braking air resistance to slow or stop the carriage outside the launch enclosure. 25 Optionally the breaking mechanism comprises a paddle which extends into liquid in a channel alongside the track outside the launch enclosure so that friction between the paddle and the liquid slows or stops the carriage. Optionally the braking mechanism comprises friction means which engages the track 30 to cause the carriage to slow or stop. Optionally the protective shield is of a generally dome shape. Optionally a coolant is applied to the surface of the protective shield as it moves along 35 the track.

3 BRIEF DESCRIPTION OF THE DRAWINGS Some preferred embodiments of the invention will now be described by way or example and with reference to accompanying drawings, of which: Figure 1 is a side view of plant for use in launching a vehicle into space; 5 Figure 2 is an isometric view showing various details of the plant; Figure 3 is a part cutaway side view of the plant; Figure 4 is an end view of a vehicle, carriage and track forming part of the plant; Figure 4a is an end view of a vehicle, carriage and track forming part of an alternative embodiment of the plant; 10 Figure 5 is a cutaway side view showing detail of the carriage and vehicle when in use; Figure 6 is an isometric view showing a braking mechanism forming part of the plant; Figure 7 is an isometric view illustrating a petal protective shield according to a 15 particular embodiment of the plant; and Figure 8 schematically illustrates the launching of a vehicle as above. DETAILED DESCRIPTION Figure 1 illustrates plant for use in launching an object into orbit around the earth. This 20 comprises a hangar 1, a work area airlock 2, a launch tube 3 and a track 4. The airlock 2, launch tube 3 and track 4 are shown in more detail in figure 2. The drawings only show part of the length of the launch tube 3 which, in a preferred embodiment, is approximately 23 kilometres long although it may be shorter or longer in other embodiments. The first 20 km of the tube 3 have a diameter of approximately 7 m and 25 the final 3 km have a diameter of approximately 10 m. The track 4 runs inside and along the entire length of the launch tube 3 and also extends outside the launch tube. Figure 3 shows a launch vehicle 5 and rocket booster 6 within the airlock 2 above the track 4, ready for launch. An ablative blast shield 7 is similarly arranged immediately 30 behind the booster 6. Referring to figure 4, the vehicle 5 and booster 6 do not engage the track 4 directly but rather sit on a carriage 8 which in turn engages the track. The engagement is such 4 that the carriage 8 is caused, by way of magnetic force, to levitate over the track. This assists the carriage 8 to run along the track 4 without touching it, therefore reducing frictional forces which may otherwise undesirably hinder forward movement. The track illustrated in figure 4 comprises a monorail arrangement however in alternative 5 embodiments, as illustrated in figure 4a, the track may comprise a dual rail arrangement. To launch the vehicle 5 it is positioned with its carriage 8 within the airlock 2. A vacuum is created within the launch tube 3 and then within the airlock 2. The airlock 10 is then opened to the launch tube and electrical power is used to propel the carriage, and therefore the vehicle generally horizontally along the track. Because these move within an evacuated environment there is minimal or no air drag. When the carriage and vehicle have reached the desired speed the booster 6 is 15 activated to give even more velocity to the carriage and vehicle. As mentioned above, in a preferred embodiment the latter part of the launch tube 3 (eg the last 3 km) is widened (eg to 10 m) to facilitate safe firing of the booster 6. Momentarily after activation of the booster the exit doors 9 at the end of the launch open, as do launch tube vent doors 10, the vehicle 5 and booster 6 exit the tube detach from the carriage 8 20 and are directed upwards to begin a journey towards space. The exit and vent doors 9, 10 are arranged to open very rapidly by way of pneumatic rams 26 (see figure 1) and rocket powered openers 27 (see figure 1). The vent doors 10 are preferably situated along the last 3 km of the launch tube 3. Preferably the thrust provided by the booster 6 is sufficient to offset the negative forces inclement on the vehicle and booster 25 when they are exposed to the atmosphere outside the tube. This may be particularly advantageous when the vehicle is manned. The booster 6 subsequently provides further thrust (eg 4 g to 6 g) and, while still in flight, eventually detaches from the vehicle 5 and drops to the earth. Parachutes are deployed to slow descent of the booster so that it can be re-used if desired. The vehicle 5 has its own driving source 30 so that after release from the booster 6 it is able to continue upward travel, and does so, until it reaches the desired orbital path with respect to the earth. It will be appreciated that at the point the vehicle 5 and booster 6 leave the carriage 8 the carriage is moving at very high velocity, for example approximately 4,800 - 8,000 35 km/hr depending on the size and weight of the vehicle and its contents. However a braking system is deployed to bring the carriage 8 to a stop along the part of the track 5 outside the launch tube. The braking system preferably comprises air brakes, water 5 brakes and friction brakes. The carriage is then returned to the hangar 1 for future use. In the event of a launch malfunction, for example insufficient initial thrust, the vehicle 5 5 and booster 6 do not separate from the carriage 8 but rather come to a stop along the track outside the tube 3 due to the braking system. Referring to figure 5, when the vehicle 5 and booster 6 are mounted to and move along the track by way of the carriage 8, the blast shield 7 and braking system 11 move with 10 them. The braking system comprises a water brake and a friction brake. Preferably the blast shield 7 is approximately 5m from the booster 6 and protects the carriage and braking system 11 from the booster 6 when it fires. Referring to figure 6, because the ablative blast shield 7 has a significant surface area, 15 when it is exposed to the atmosphere outside the tube 3 it serves as an air brake for the carriage 8. The shield 7 comprises a shell structure (eg 40-80 mm thick) formed from filament (eg a tape) wound composite material made from a suitable fibre (eg Aramid) and thermoplastic resin (eg Bismaleimide) in, for example, a 1:1 ratio. The blast shield has an intermediate layer (eg 10 mm thick of carbon/graphite and a 20 suitable phenolic resin) which provides thermal protection comprising filament (eg tape) wound on the outer surface of the shell structure. The outer surface of the shield 7 comprises thermal tiles, for example of a suitable silicon foam with a metallic coating. The tiles are preferably 25 mm thick. Preferably the blast shield is generally dome shaped and extends across virtually the whole diameter of the launch tube, except for 25 a nominal clearance. The shield 7 incorporates stiffening webs and inner and aft bulkheads to give a good degree of rigidity. The shield incorporates spray holes 21 and means to spray water through them over its external surface to cool the shield when exposed to air. 30 The blast shield preferably incorporates an open honeycomb shaped seal at an aft major circumference. The seal may be in a close fit (eg 4.5 mm clearance) within the launch tube. In some embodiments the pressurised air may provide thrust in relation to the shield. 35 With further reference to figure 6, when the air braking by the blast shield 7 has slowed the carriage 8 sufficiently the water brake is activated. This comprises a pair of paddles 12 moved by hydraulic rams to engage water 13 contained in channels 14 6 adjacent to each side of the track outside the launch tube. The rams are programmed to progressively lower the paddles to control the braking effect while keeping stress within the water brake to an acceptable level. In preferred embodiments of the invention the water brake will be sufficient, in association with the blast shield, to slow 5 the carriage 8 to approximately 60 km/hr. With further reference to figure 5, after the water brake has been activated and the carriage 8 has slowed sufficiently the friction brake is activated. The friction brakes 15 may comprise aluminium hinged panels with heat resistant carbon material at their 10 track contacting parts. These panels are moved by a pneumatic ram 16 to progressively engage the track until the carriage 8 has stopped. The panels are formed to provide heat sinks to absorb heat generated when they contact the track 4. High tensile steel pins may be used to transfer breaking loads from the panels to the carriage 8 generally. 15 Referring to figure 7, in an alternative embodiment of the invention the ablative blast shield is substituted by a petal blast shield 17. This provides air braking and is made from similar materials and of a similar shape, however it differs in that it has a series of hinged petals 18 which open outwards to produce more air resistance to slow the 20 carriage when it has exited the launch tube 3. Water is sprayed onto the shield 17 via spray holes 22 to help cool the shield when exposed to air. Referring to figure 6, preferably the carriage 8 has a series of horizontally and vertically oriented wheels 19, 20 which can be moved by pneumatic rams to contact the track 4. 25 Covers (not shown) are provided to protect the wheels from the blast of the booster 6 when the wheels are recessed and not in use. The wheels 19, 20 engage the track to prevent undesired friction between it and the carriage when the magnetic levitation force separating the track and carriage is deactivated. In some embodiments of the invention, for example when a permanent magnetic levitation force is used, the wheels 30 may be dispensed with. With reference to figure 2, in some embodiments of the invention the airlock 2 and launch tube 3 are evacuated and kept in that state by suitable gas turbines 23 and vacuum pumps 24, or when pressurising the airlock, compressors 25. Initially the gas 35 turbines draw their air needs directly from the launch tube. In this way the launch tube may be rapidly evacuated to around 10% of the sea level pressure. To complete the evacuation the gas turbines supply electrical power to drive two types of conventional 7 vacuum pumps. At this stage of evacuation the gas turbines draw their air requirements from the ambient atmosphere through a valve controlled intake. It should be understood that references to an evacuated launch tube or state, etc, do not necessarily mean that the tube is completely evacuated, but rather at least sufficiently 5 evacuated to enable an effective launch. In preferred embodiments of the invention the airlock 2 may be used to contain pressurised air. For a short period during the start phase this pressurised air may act on the aft area of the blast shield to provide thrust in the direction of launch. This may 10 assist in overcoming the inertia of the carriage at the start phase and thus reduce the amount of electrical power needed. The compressors 25 may supply compressed air to assist with this. Electrical power for the compressors may be supplied supplied by the gas turbines. 15 It will be appreciated that an advantage of preferred embodiments of the invention is that it can be employed to do away with the necessity for a two stage rocket booster arrangement. For example, in some prior art arrangements a vehicle is launched using a large stage one rocket booster and a smaller stage two booster. The stage one booster involves significant expense and is jettisoned in-flight to release the stage two 20 booster and the vehicle. Recovery of the stage one booster can be difficult. The stage one booster is used to get the vehicle to a sufficient speed to enable the stage two booster to take over. In preferred embodiments of the present invention, as described above, the booster and vehicle are provided with sufficient launch and initial flight speed by the carriage moving at high speed within the launch tube. 25 While some preferred embodiments of the invention have been described by way of example it should be understood that modifications and improvements can occur without departing from the scope of the following claims. 30 35

Claims

1. A method of launching an object comprising: a) arranging a carriage such that it can run along a track while substantially levitated by magnetic force within an evacuated launch 5 enclosure to move: i. a vehicle; ii. a booster; and iii. a protective shield; b) providing propulsive force to the carriage so that it moves the vehicle, 10 booster and shield along the track within the evacuated enclosure; c) activating the booster to burn fuel while within the enclosure and opening exit doors of the enclosure such that the vehicle and booster achieve sufficient speed for a successful launch and such that the protective shield protects at least a braking mechanism and/or parts of 15 the carriage from the booster; d) causing the vehicle and booster to detach from the carriage; and e) activating the braking mechanism to slow and/or stop the carriage outside the enclosure. 20

2. A method according to claim 1, wherein the propulsive force mentioned at step b) is provided by electricity.

3. A method according to claim 1 or 2, wherein the launch enclosure has vents which open at approximately the same time the booster burns fuel to allow exhaust from 25 the booster to vent from the launch enclosure.

4. A method according to claim 1, 2 or 3, wherein the booster activates when it enters a substantially widened part of the launch enclosure. 30

5. A method according to any one of the preceding claims, wherein the booster provides in-flight thrust to at least assist in causing the vehicle to fly towards space. 9

6. A method according to claim 5, wherein after the vehicle has received in-flight thrust from the booster it detaches from the booster and travels further upwards under its own driving force. 5

7. A method according to any one of the preceding claims, wherein the launch enclosure comprises a launch tube.

8. A method according to any one of the preceding claims, wherein the launch enclosure is associated with an airlock and the carriage, vehicle and booster are 10 within the airlock prior to being propelled along the enclosure.

9. A method according to any one of the preceding claims, wherein protective shield provides braking for the carriage as a result of air resistance from the shield when the carriage has exited the launch enclosure. 15

10. A method according to any one of the preceding claims, wherein the protective shield has a series of petals which open to provide braking air resistance to slow or stop the carriage outside the launch enclosure. 20

11. A method according to any one of the preceding claims, wherein the breaking mechanism comprises a paddle which extends into liquid in a channel alongside the track outside the launch enclosure so that friction between the paddle and the liquid slows or stops the carriage. 25

12. A method according to any one of the preceding claims, wherein the braking mechanism comprises friction means which engages the track to cause the carriage to slow or stop.

13. A method according to any one of the preceding claims, wherein the protective 30 shield is of a generally dome shape.

14. A method according to any one of the preceding claims, wherein a coolant is applied to the surface of the protective shield as it moves along the track. 35

15. A method according to claim 1, substantially as herein described. 10

16. A method of launching an object substantially as herein described with reference to the accompanying drawings.

17. Plant arranged for launching an object according to any one of the preceding 5 claims, the plant comprising the launch enclosure, the track, means for evacuating the enclosure, means for causing the carriage to be levitated by the magnetic force, the protective shield and the braking mechanism. 10 15 20 25