DE102017203303A1 - Drop-down hull structure for hypersonic spacecraft vehicles - Google Patents

Abstract

The present application relates to a drop-down hull structure (10) for a lift-assisted abutment trajectory following hypersonic spacecraft (12), the hull structure (10) for disguising a hull (26) and / or hydrofoil (28) of the spacecraft (12). supported payload (20) is attachable to the space transport vehicle (12) and wherein the sub-hull structure (10) is shaped so that compression shocks (14, 18) in the supersonic or hypersonic flight through the below the fuselage (26) and / or wing ( 28) attached lower body structure (10) arise, an increase in pressure under the wing (28) and thereby generate compression buoyancy.

Description

TECHNICAL AREA

The present invention relates to a drop-down hull structure for a hypersonic space transport vehicle following a lift assisted lift trajectory. Further, the invention relates to a spacecraft having a fuselage and a wing configured to follow a lift-assisted, hypersonic-speed ascent trajectory and having a drop-down hull structure.

STATE OF THE ART

In order to enable a broad use and development of the space, it is imperative that the transport of payloads into the orbit of earth much cheaper than previously possible. Efforts have already been made to improve, in particular, conventional launchers. In this way, however, only limited cost reductions are possible, but fundamental breakthroughs in space transportation are not expected.

A regularly proposed alternative approach is fully reusable single-stage-to-orbit or two-stage-to-orbit hyperspace transport systems, also known as spaceplanes. Such space transport vehicles should in principle be suitable for enabling drastic cost reductions and were therefore intensively studied, especially in the 1980s and 1990s. So far, however, none of these concepts could achieve a real breakthrough because either the engines did not meet the expectations or the respective empty mass of the space transport system was too high.

However, the distance to a technically feasible and economically viable system was not very large. Consequently, it is believed that even relatively small improvements in the prior art could be sufficient to realize space plans.

In particular from military aviation it is known to use compression buoyancy in lift-assisted supersonic flight or hypersonic flight. By a special contouring of the aircraft geometry in the area under the wing of the aircraft, the pressure increase generated by compression shocks can be used specifically to increase the buoyancy of an aircraft in addition. This principle was realized, for example, in the 1960s in the US in the form of the XB-70 bomber, the lower hull, in which the engines were housed, was shaped so that the heights generated by supersonic cruise compressions significantly increased the pressure on the underside of the wing , This resulted in a significantly higher lift with consistent resistance with a corresponding increase in the glide ratio and thus the range of the aircraft.

Geometrical configurations that can generate compression buoyancy by creating an increase in pressure under the wing of an aircraft are known in the art. An example of this is in US 3 137 460 from 1964 described.

However, the sub-hull structure geometries of known aircraft, such as the XB-70 bomber, are not suitable for use in spacecraft vehicles, particularly because they can not be protected from aerothermodynamic loading upon re-entry into the earth's atmosphere.

PRESENTATION OF THE INVENTION

In the light of the prior art, the object of the present invention is first of all to provide a space transport system which enables a more efficient transport of payloads into earth orbit and, above all, the cost advantages of a lift-assisted ascent trajectory following, because reusable and possibly Single-stage hypersonic spacecraft uses. In particular, the object of the present invention is also to provide a hypersonic space transport vehicle that is suitable as a reusable and ideally single-stage-to-orbit hypersonic space transport system and thus can lead to a drastic reduction in the cost of transport of payloads in Earth orbit.

The object of the present invention is achieved by a drop-down hull structure according to claim 1 or by a space transport vehicle according to claim 6. Advantageous features and further developments of the invention emerge from the respective subclaims.

A drop-down hull structure according to the invention for a hypersonic space transport vehicle following a lift-assisted ascent trajectory can be attached to the space transport vehicle for disguising a payload carried under a fuselage and / or under a wing of the space transport vehicle. The lower hull structure is shaped so that compression impacts arising in supersonic flight or hypersonic flight through the lower hull structure mounted below the fuselage and / or the wing increase the pressure under the wing and thereby create compression buoyancy.

A first aspect of the invention is to downsize the hull of the spacecraft and attach the payload to the hull rather than in a cargo hold. As a result, the hull of the space transport vehicle can be made much smaller and lighter than previously known space transport vehicles with a cargo space.

Payload means in the present context, in particular, the load to be transported in earth orbit (payload). In addition, the term "payload" in the present context may also comprise at least part of the fuel required for driving the space transport vehicle and a fuel tank used for this purpose.

In addition to the aspect of attaching the payload to the spacecraft to make the fuselage smaller and lighter, the in-hull structure recognizes that skilful geometric design of the hull structure creates additional compression buoyancy and thereby reduces aerodynamic drag of the spacecraft due to a reduction in pitch can be. As a result, the need for atmospheric acceleration fuel consumption can be significantly reduced, which in turn increases the performance of the spacecraft.

A further advantage of the lower-hull structure according to the invention is that the geometry of the lower-hull structure can be varied within certain limits and can thus be adapted to different sizes and geometries of the payload and possibly to variable amounts of additional fuel. In contrast to a spacecraft with a cargo compartment inside the fuselage designed for a particular payload or versatility such as standard dimensions, a spacecraft of the present invention can transport a variety of payloads optimally into Earth orbit because the sub-hull structure can be geometrically optimized for any payload, thereby minimizing mass and drag of the spacecraft.

Another advantage of the invention is that by attaching the payload to the spacecraft, the possibility of easier integration of the payload on the spacecraft is provided. The payload, for example, can be easily pushed under the floor-standing space transport vehicle and attached to it. Conventionally, previous spaceplane concepts provide for a payload bay within the vehicle which is accessible via swing-open doors on the back of the fuselage; a crane required for this purpose is not required in the proposed invention.

With regard to the design of the lower hull structure, so that compression shocks, which occur in supersonic flight or hypersonic flight through the lower body structure, generate an increase in pressure under the wing and thereby compression buoyancy, it should be noted that the position of the compression shocks in particular depends on the airspeed. The speed of flight of a spacecraft varies on its way from the earth to the edge of the atmosphere, unlike an airplane always flying within the atmosphere, over a very large speed range. The geometry of the bottom hull structure can be optimized for relatively low speeds in the low supersonic range or for high speeds in the hypersonic range. For the present invention, an average value between low and high supersonic speeds (or low-average hypersonic velocities) of the geometry of the undershirt structure is preferably used. This is possible by basically known simulations of compaction collisions and is fundamentally within the scope of expert knowledge. For example, the system can be tuned to Mach numbers of 1-6 ... 10, from supersonic to low-mid hypersonic, and the actual design of the system may depend heavily on the overall system design.

A further advantage of the invention's under-hull structure is that the under-hull structure can be dropped after leaving the denser atmosphere layers, thereby releasing the payload and further reducing mass loss due to the dropping of the hull structure further reduces the mass to be accelerated into orbit and thus additionally performance the space transport vehicle improved.

Unless the discarded hull structure can not be reused, it can be made from relatively simple and inexpensive materials and with low safety factors, since in most cases the hull structure only needs to maintain a given contouring but does not carry vehicle loads. Therefore, damage such as creep, oxidation or limited plastic deformation can be tolerated. This further leads to an improved cost efficiency of the transport of the payload.

According to a preferred embodiment, the lower body structure comprises a fuel tank. This may in particular be an additional tank to a main tank of the spacecraft, the content of which was used up within the denser atmosphere layers and thus can be discarded after leaving these denser layers of atmosphere. Although such a fuel tank basically increases the complexity and thus the cost of the lower body structure, but at the same time allows a further reduction in the earth orbit to be accelerated mass.

According to a further preferred embodiment, the lower body structure further comprises a flap, preferably a plurality of flaps, which can be extended such that the compression impacts under the wing can be influenced by the flap or the flaps. In particular, such a displacement of a position of a pressure point of the compression buoyancy by the operation of the flap or flaps is feasible, i. the pressure point of the compression buoyancy can be shifted by the flap or the flaps. Preferably, the flap or the flaps are arranged laterally on the lower body structure.

The preferred flap or flaps of the lower body structure may maintain and / or vary the intensity of the compression buoyancy over a wider range of speeds, which is advantageous in a spacecraft that does not occupy a particular cruising speed but is accelerating as it travels through the earth's atmosphere becomes. In addition, in this way, the pressure point position can be adjusted not only with regard to the speed range to be traveled, but also to a possible change in the center of gravity.

According to a further preferred embodiment, the lower-hull structure further comprises a wheeled chassis which is suitable for supporting the space-transporting vehicle during its take-off run. In this embodiment, the sub-hull structure not only performs a fairing function, but also carries loads of the hull structure and / or other parts of the spacecraft during take-off. The sub-hull structure may be made somewhat more stable and solid in this case, which may result in a higher mass of the hull structure. On the other hand, thus at least a portion of the mass of a separate starting chassis can be saved, the additional mass of the lower body structure with this dropped in the course of the flight and the mass to be accelerated in orbit can thus be further reduced compared to the take-off mass.

In an advantageous embodiment, the under-hull structure further comprises a parachute for a smooth landing of the dropped lower body structure on the ground, such a parachute is particularly important in embodiments in which the sub-hull structure makes a significant contribution to the flight into the Earth orbit in which the lower body structure their impact on the earth could pose a danger to living beings or objects. However, it is also possible to dispense with such a parachute, in particular when the trajectory of the space transport vehicle is planned so that the sub-hull structure is at sea or in a non-populated area, such as a low-hull structure merely serving as a fairing a desert will hit the earth.

A spacecraft of the present invention having a fuselage and a wing configured to follow a buoyancy-assisted supersonic or hypersonic ascending trajectory includes a drop-down hull structure releasably mounted beneath the spacecraft for disguiding a payload carried beneath the fuselage and / or under the wing is. In this case, the lower body structure is shaped and arranged on the space transport vehicle that the compression shocks that occur in supersonic flight and hypersonic flight through the lower body structure, an increase in pressure under the wing and thereby generate compression buoyancy.

Advantageously, the sub-hull structure is a sub-hull structure as described above.

Such a spacecraft makes it possible to transport payloads into earth orbit much more efficiently than is possible with conventional carrier systems, and can thus represent a realization of the concept of a fully reusable single-stage-to-orbit spacecraft.

The space transport vehicle preferably has a flat underside after the lower hull structure has been dropped off. Such a flat underside is particularly advantageous in terms of the re-entry into the earth's atmosphere, in which very high thermal loads on the space transport vehicle caused by the friction of the air at space transport vehicle. For example, a flat bottom causes a heat shield or similar devices to be effectively attached and used to protect the spacecraft. Furthermore, a flat underside prevents the formation of secondary compression shocks on flow obstacles, which are too local Temperature increases and corresponding additional loads of the heat shield would lead.

According to a further preferred embodiment, the space transport vehicle further comprises a heat protection panel, which is extendable from the fuselage and / or wing, in particular to protect the payload after an ejection of the sub-fuselage structure from an aerodynamomechanical load, and is retractable to the fuselage and / or the wing, in particular in order to record an aerothermodynamic load on the space transport vehicle when the space transport vehicle re-enters the earth's atmosphere.

Preferably, the space transport vehicle comprises several heat protection panels, which are preferably arranged frontally and laterally with respect to the payload and are correspondingly extendable. Also only frontally or only laterally with respect to the payload arranged extendable heat protection panels are conceivable within the scope of the present invention. The heat protection panel or the heat protection panels are used in particular to protect the payload after the lower body structure has been dropped and come for this purpose rather in atmospheres with very thin air used. In these layers of atmosphere, the space transport vehicle hardly flies due to aerodynamic lift, so that the lack of support by the compression buoyancy and the optionally increasing coefficient of resistance of the space transport vehicle are also negligible with the dropping of the lower body structure. However, the lower mass of the spacecraft after ejection of the sub-hull structure improves the efficiency of further rocket-propelled acceleration, and the heat-shield panels required for re-entry may protect the payload in the extended state, for example, from pressure surges and aerothermodynamic loads.

By the present invention, existing concepts in space transportation vehicles can be further developed so that the potential payload increases and thus the cost of transporting the payload into earth orbit can be significantly reduced.

Further features of the invention will become apparent from the following description of the figures and the totality of the claims.

list of figures

• 1a and 1b Figure 11 is a view of a spacecraft from below a fuselage and wing with a preferred sub-hull structure.
• 2 shows a view of a spacecraft from below the fuselage and the wing with another preferred sub-hull structure.
• 3a to 3c each show a schematic side view of a space transport vehicle with ejectable lower body structure.
• 3d shows a schematic side view of a spacecraft with attached payload after dropping the lower body structure.
• 4a and 4b show a front view of a space transport vehicle with underneath structure attached underneath.
• 5a and 5b show a schematic side view of a space transport vehicle with frontally mounted in front of the payload heat protection panel to protect the payload.
• 6a and 6b show a schematic front view of a space transport vehicle with side mounted to the payload heat protection panels to protect the payload.
• 7 shows a schematic side view of a spacecraft with another preferred sub-hull structure.

WAYS FOR CARRYING OUT THE INVENTION

1a and 1b show a schematic view from below of a space transport vehicle 12 according to a preferred embodiment. The space transport vehicle 12 has a thrown-down hull structure 10 on, under the fuselage or wing of the spacecraft 12 is appropriate. The lower body structure 10 is shaped so that compression shocks 14 in supersonic flight and hypersonic flight at the sub-hull structure 10 arise, an increase in pressure under the wing and thereby generate compression buoyancy. As a result, the gliding ratio of the space transport vehicle in flight conditions, in which the space transport vehicle follows a lift-assisted ascending trajectory, increases in basically known manner. Thus, the compression buoyancy can reduce the drag of the spacecraft, resulting in lower energy required to accelerate Earth orbit than previous Spacecraft vehicles.

Various forms of sub-hull structures are generally suitable for creating such a pressure increase under the wing and thereby compression buoyancy. 1a and 1b schematically show two different examples, wherein in 1a a rounded tip and in 1b a sharp point indicated are. The sub-hull structures can also have different opening angles and at least partially concave on their surface, at least partially convex and / or at least partially planar design.

2 shows a further preferred embodiment of a space transport vehicle 12 with lower body structure 10 , Unlike in the 1a and 1b embodiment shown has the lower body structure 10 out 2 two flaps 16 on their sides, which by extending and retracting the shape and arrangement and the strength of the compression joints 14 . 18 in supersonic flight or hypersonic flight influence.

In particular, by extending the flaps 16 a secondary compression shock 18 generates, which causes an additional, secondary compression buoyancy in a certain speed range, which serves primarily to control the pressure point position and thus the aerodynamic trim of the spacecraft. Unless this secondary compression buoyancy can or should not be generated, for example because the spacecraft is traveling 12 in an unsuitable speed range or the additional compression buoyancy would lead to unwanted displacement of the pressure point position, the flaps 16 be retracted to reduce air resistance. In addition, the flaps 16 also be extended in the course of the flight to the air resistance of the space transport vehicle in an initial phase of the flight 12 to minimize.

The 3a to 3c show a schematic side view of a space transport vehicle 12 with a drop-down hull structure 10 , There are different geometric configurations of the lower body structure 10 which are intended to illustrate that there are various possibilities for increasing the pressure under the wing and thereby increasing the compression caused by the collisions in supersonic flight and hypersonic flight.

3d shows a schematic side view of the space transport vehicle 12 with the payload no longer covered by a sub-hull structure 20 , The payload 20 It obviously takes up a smaller space than the ejectable lower-hull structure, but is not particularly well-designed with regard to the targeted influencing of the compression shocks and thus the generation of the compression buoyancy and also with regard to its air resistance.

4a and 4b show a schematic front view of a space transport vehicle 12 with a hull 26 and a wing 28 as well as the under the wing 28 attached sub-hull structure 10 , These figures in turn show various possible embodiments of the geometry of the lower body structure 10 ,

5a and 5b show a selective, schematic side view of another preferred embodiment of a space transport vehicle 12 , The in the 5a and 5b The configuration shown may be after the lower hull structure has dropped 10 to adjust. The payload 20 is substantially exposed, but after the casting of the lower body structure is still through a heat protection panel 22 especially protected against an aerothermomechanical load.

In 5a is the heat protection panel 22 frontal in front of the payload 20 arranged. After the payload 20 from the spaceport vehicle 12 has solved the heat protection panel 22 back to the surface of the underside of the spacecraft 12 be retracted to re-enter the spacecraft 12 into the earth's atmosphere an aerothermodynamic load on the spacecraft 12 take. The heat protection panel 22 may already be under the hull structure 10 have been extended or extended only after the dropping of the lower body structure 10.

6a and 6b show the configurations similar to those 5a and 5b in a schematic front view. 6b shows how heat protection panels 22 can be retracted to the wing 28. The front heat protection panel 22 , this in 5a and 5b is shown in is 6a and 6b been omitted. Similarly, the in 6a and 6b shown side heat protection panels 22 in the 5a and 5b Not shown.

According to a preferred embodiment, heat protection panels 22 arranged both in front of and next to the payload 20 to protect against aerothermomechanical loads and other external influences. The space transport vehicle 12 But also with only one or more frontal payload 20 arranged heat protection panel or heat protection panels or with only one or more laterally to the payload 20 be arranged heat protection panel or heat protection panels equipped.

7 shows a further preferred embodiment of a space transport vehicle 12 with a lower body structure 10 , where the in 7 shown lower body structure 10 a wheel drive 24 that includes in support of the spacecraft 12 during his run is suitable. The wheel drive 24 May prefer separately according to the Take-off of the lower hull structure and the spacecraft 12 be solved or after leaving the Earth's atmosphere together the lower body structure 10 from the spacecraft 12 be dropped. In particular, in this second case, it is advantageous if the lower body structure 10 a parachute for a smooth landing of the dropped lower body structure 10 has on the ground, because especially the wheel gear 24 Hereditary mass may cause collateral damage on impact with the earth. Furthermore, in a parachute landing, the suspected undamaged hull structure can be recovered and reused.

The above described examples are merely illustrative of the invention in some preferred embodiments and are not intended to be limiting. Moreover, it is possible to combine individual features of individual embodiments with other features of other embodiments.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 3,137,460 [0006]

Claims (9)

A drop-on hull structure (10) for a hypersonic spacecraft (12) following a lift assisted climb trajectory, the underbody structure (10) being adapted to be clad to the spacecraft (12) for disguising a payload (20) carried under a hull (26) and / or wing (28) of the spacecraft (12); and the underfinger structure (10) being shaped such that compression impacts (14, 18) arising in supersonic flight or hypersonic flight through the lower body structure (10) mounted below the fuselage (26) and / or hydrofoil (28) increase the pressure under the hydrofoil (28) and thereby generate compression buoyancy. Lower hull structure (10) after Claim 1 further comprising a fuel tank. Lower hull structure (10) after Claim 1 or 2 further comprising a flap (16) which is extendable such that the compression joints (14, 18) under the wing (28) can be influenced by the flap (16), wherein in particular a displacement of a position of a pressure point of the compression buoyancy by the flap (16) 16) is achievable, wherein the flap (16) is preferably arranged laterally on the lower body structure (10). The underbody structure (10) of any one of the preceding claims further comprising a wheeled chassis (24) adapted to support the spacecraft (12) during takeoff. The lower hull structure (10) of any one of the preceding claims further comprising a parachute for gently landing the dropped hull structure (10) on the ground. A spacecraft (12) having a fuselage (26) and a wing (28) configured to follow a buoyancy assisted supersonic or hypersonic ascending trajectory, comprising a drop-down hull structure (10) releasably mounted beneath the spacecraft (12) for cladding a payload (20) carried under the fuselage (26) and / or wing (28), the underfinger structure (10) being shaped and disposed on the spacecraft (12) such that compression impacts (14, 18) arising in supersonic flight or hypersonic flight through the hull structure create an increase in pressure under the wing (28) and thereby compression lift. Space transport vehicle (12) after Claim 6 wherein the lower body structure (10) according to any one of Claims 1 to 5 is trained. Space transport vehicle (12) according to one of Claims 6 and 7 wherein the space transport vehicle (12) has a flat underside after the lower structure (10) has been dropped. Space transport vehicle (12) according to one of Claims 6 to 8th further comprising a heat protection panel (22) extendible from the fuselage (26) and / or hydrofoil (28) to protect the payload (20) from ejection of the sub-fuselage structure (10) from an aerothermo-mechanical load and to the fuselage (10). 26) and / or the wing (28) can be retracted, in particular in order to re-enter the space transport vehicle (12) into the earth's atmosphere to record an aerothermodynamic load on the space-transport vehicle (12).

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