Engine for a spacecraft, spacecraft having an engine, and method for operating the spacecraft
Patent Information
- Application Number
- PCT/EP2026/060753
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2025-04-17
- Filing Date
- 2026-04-14
- Publication Date
- 2026-10-22
Smart Images
Figure EP2026060753_22102026_PF_FP_ABST
Abstract
Description
[0001] JECK, FLECK & PARTNER mbB P.O. Box 1469 • D-71657 Vaihingen / Enz PATENTA NWÄ LTE Telephone (07042) 9728 - 0
[0002] Fax (07042) 9728 - 11
[0003] A25792-PCT - JF / construction April 14, 2026
[0004] German Aerospace Center (DLR)
[0005] Königswinterer Str. 522 - 524
[0006] 53227 Bonn
[0007] - 1 -
[0008] Engine for a spacecraft and spacecraft with an engine, as well as methods for operating the spacecraft
[0009] The invention relates to an engine and a spacecraft with the engine, as well as a method for operating the spacecraft.
[0010] A spacecraft includes, among other things, a propulsion system with an engine that accelerates the spacecraft, as well as a propellant system with an injection device for the propellant into the engine. The spacecraft can be, for example, a satellite and / or a space probe, particularly a lander. The spacecraft's engine typically has at least one combustion chamber and a thruster for accelerating the spacecraft. In chemical propulsion systems, hot, especially pressurized, combustion gases are accelerated to supersonic speeds, for example, through a usually convergent-divergent nozzle. The combustion gas is directed locally at the respective pressure against the engine's inner wall and generates thrust on the spacecraft in the opposite direction to the flow direction. A25792-PCT - JF / bau -2 - April 14, 2026
[0011] From DE 10 2008 022 289 A1, a missile with an engine is known. The engine comprises a combustion chamber with a combustion chamber and a nozzle with a nozzle chamber, the nozzle being arranged downstream of the combustion chamber and in the main flow direction of the hot combustion gases exiting the engine, so that during engine operation, the hot combustion gases generated in the combustion chamber flow axially out of the engine through the nozzle. A transition between the combustion chamber and the nozzle lies in a plane in which the combustion chamber narrows.
[0012] Furthermore, EP 4202 200 A1 discloses a rocket propulsion system with detonation chambers that can be operated in a rotating detonation mode. The rocket propulsion system is designed for multi-stage combustion. The detonation chambers can have a disc-shaped or conical structure. Thrust is generated by means of a downstream nozzle that is arranged symmetrically along a longitudinal axis.
[0013] The publication “KAWALEC, Michal; WOLANSKI, Piotr: Development of rocket engine with continuously rotating detonation supplied by liquid propellants. In: 9th European Conference for Aeronautics and Space Science, 27 June - 1 July 2022, Lille, France. 8 pp.” describes a rocket propulsion system with a combustion chamber for operation with a continuously rotating detonation wave and a disc-shaped and / or conical structure. In the combustion chamber with the disc-shaped and / or conical structure, thrust is generated by means of a downstream nozzle that is arranged symmetrically along a longitudinal axis.
[0014] The invention is based on the objective of providing an efficient engine of the type mentioned above. Furthermore, the invention is based on the objective of providing an efficient spacecraft. A further objective of the invention is be-A 25792-PCT - JF / bau - 3 - April 14, 2026
[0015] Its purpose is to enable a method for the efficient operation of the spacecraft.
[0016] The problem is solved for the engine with the features of claim 1 and for the spacecraft with the features of claim 12 and for the method with the features of claim 13.
[0017] Favorable embodiments and advantages of the invention will become apparent from the further claims, the description and the drawing.
[0018] The engine for a spacecraft, with an axis of symmetry, comprises a combustion chamber, a squash plate, and an engine exhaust port, wherein the combustion chamber has a combustion chamber, in particular symmetrically, annularly surrounding the axis of symmetry and radially outward around the squash plate, oriented along a longitudinal axis, which is bounded by an upper combustion chamber wall (axially with respect to the axis of symmetry) and a lower combustion chamber wall (axially with respect to the axis of symmetry), and has at least one combustion chamber outlet arranged at the downstream end of the combustion chamber, for example, a continuous annularly surrounding the axis of symmetry, wherein the combustion chamber and / or the combustion chamber outlet is for the radial discharge of combustion gases in the direction of the axis of symmetry, i.e.with a radial directional component inwards, in particular towards the flow along the baffle plate, is / are arranged and designed, wherein the baffle plate is radially surrounded by the combustion chamber downstream of the combustion chamber outlet and is arranged symmetrically to the axis of symmetry on it, and wherein the engine exhaust opening for the discharge of the combustion gases from the engine is arranged on the axis of symmetry and axially opposite to the axis of symmetry of the baffle plate.
[0019] Combustion products or combustion gases generated in the combustion chamber are carried radially inwards, particularly in the direction of A25792-PCT - JF / bau -4 - April 14, 2026
[0020] The combustion products accumulate along the axis of symmetry, preferably accelerating to supersonic speeds, i.e., not parallel to the spacecraft's direction of motion. They are deflected by the stagnation plate, under the influence of dynamic pressure, to exit the engine, generating thrust. The combustion gases then flow out of the engine through the exhaust port, exhibiting a predominantly axial directional component (with respect to the axis of symmetry). The generated thrust propels or accelerates the spacecraft. The engine is thus a stagnation plate engine, in which thrust is generated by dynamic pressure. The outflow of combustion gases creates a continuous flow accompanied by continuous thrust.
[0021] The axis of symmetry forms, in particular, the central axis of the baffle plate.
[0022] The longitudinal axis of the combustion chamber forms, in particular, a central axis of the combustion chamber, which extends, in particular, from an inlet side of the combustion chamber to the combustion chamber outlet opposite the inlet side. The longitudinal axis has, in particular (e.g., exclusively), a radial component with respect to the axis of symmetry of the engine; that is, the combustion chamber is oriented, at least with a radial component, e.g., exclusively, orthogonally (radially) to the axis of symmetry. If the combustion chamber is annular, the longitudinal axis lies, in particular, in a longitudinal plane that rotates around the combustion chamber.
[0023] The upper and / or lower combustion chamber wall(s) is / are aligned, for example, with a radial and circumferential directional component with respect to the longitudinal axis, e.g., orthogonally to it. The lower combustion chamber wall can advantageously be arranged axially at the lower end of the engine. The combustion chamber outlet is preferably located between the upper combustion chamber wall and the lower one. A25792-PCT - JF / bau - 5 - April 14, 2026
[0024] The combustion chamber wall is arranged. The upper and lower combustion chamber walls are connected, for example, on the combustion chamber inlet side by means of a circumferential combustion chamber (end) wall. The circumferential combustion chamber wall can be oriented essentially parallel to the axis of symmetry. The circumferential combustion chamber wall delimits the combustion chamber, particularly on its radial outer side, wherein an outer contour of the annular combustion chamber or of multiple annularly arranged combustion chambers, delimited by the circumferential combustion chamber wall, is, for example, circular or polygonal. If multiple combustion chambers are present, their combustion chamber outlets are preferably arranged symmetrically to each other around the axis of symmetry.
[0025] The combustion chamber outlet is preferably designed as a single opening, thus forming a continuous open surface, or it can comprise multiple openings and, for example, intervening struts. The sum of the multiple openings can constitute the open surface. In the case of multiple openings, these can advantageously be arranged symmetrically around the engine's axis of symmetry. Support structures with struts extending radially and orthogonally to the longitudinal axis of the combustion chamber can be provided. In the area of the engine outlet opening, support structures, for example, to reinforce the lower combustion chamber wall, can thus limit or reduce the size of the engine outlet opening. These support structures can be delicate and advantageously do not significantly affect the flow of combustion gases from the combustion chamber and / or the engine.
[0026] The combustion chamber can have a circular outer contour. Alternatively, the combustion chamber can have a polygonal outer contour. In this case, the outer contour can extend along the surrounding combustion chamber wall from the upper to the lower combustion chamber wall. A25792-PCT - JF / bau -6 - April 14, 2026
[0027] The engine can be a chemical engine, in which a hot, pressurized combustion gas is produced in the combustion chamber by burning at least one propellant. A monopropanoid or bipropanoid can be used as the propellant. Examples include hydrazine, nitrous oxide, etc. The pressures generated can be in the range of several tens of bar, typically between 20 and 50 bar.
[0028] In one embodiment of the engine, the engine exhaust opening can be radially bounded on its outer side, at least in sections, by the lower combustion chamber wall. In particular, the downstream end of the lower combustion chamber wall forms the boundary of the engine exhaust opening. For example, the radial extent of the engine exhaust opening corresponds to the radial extent of the baffle plate.
[0029] In one embodiment of the engine, the upper combustion chamber wall can transition directly into the baffle plate immediately downstream of the combustion chamber outlet. In this configuration, the upper combustion chamber wall is integrally manufactured with the baffle plate (as a single, continuous component), and / or the baffle plate is attached to the upper combustion chamber wall by means of a suitable support. Advantageously, the baffle plate and the upper combustion chamber wall can form a single, flat component of the engine. Conventional fasteners, including those made of materials suitable for the operating temperature conditions in the region of the upper combustion chamber wall, can be used as the support. The support may include detachable or non-detachable fasteners.The fastening means are advantageously adapted to the material of the combustion chamber wall and can include, for example, welding and / or bonding and / or riveting. The baffle plate can be rigidly connected to the combustion chamber, in particular to the upper combustion chamber wall. This enables cost-effective manufacturing of the engine. A 25792-PCT - JF / bau - 7 - April 14, 2026.
[0030] In one embodiment of the engine, the baffle plate can be arranged in a plane orthogonal to the axis of symmetry, e.g. exclusively in the plane orthogonal to the axis of symmetry, in an axial position constant over its radial extent, wherein it is planar.
[0031] Particularly in this context, it can be advantageous for the combustion chamber to be arranged with its longitudinal axis (especially exclusively) orthogonal to the axis of symmetry. The lower and upper combustion chamber walls can also be arranged at least largely (over the majority of their surface area) orthogonal to the axis of symmetry.
[0032] The upper combustion chamber wall and the lower combustion chamber wall are arranged, for example, in the area of the combustion chamber, at least essentially parallel to each other.
[0033] Furthermore, the baffle plate can be curved, in particular at the point lying on the axis of symmetry the baffle plate is aligned orthogonally to the axis of symmetry, i.e. at this point a virtual tangent plane of the baffle plate is aligned orthogonally to the axis of symmetry.
[0034] Particularly in this context, it is advantageous to arrange the combustion chamber with its longitudinal axis inclined relative to the engine's axis of symmetry, with an axial directional component. The inclination is such that the axial (pointing towards the axis of symmetry) directional component of the longitudinal axis is aligned towards the engine exhaust opening. The plane in which the combustion chamber (with its longitudinal axis or longitudinal plane) is arranged and the axis of symmetry are not orthogonal to each other; rather, the longitudinal axis and the orthogonal (to the axis of symmetry) form an angle of inclination. The angle of inclination (between the orthogonal to the axis of symmetry and the longitudinal axis) can be, for example, up to 50°, preferably between 5° and 50°.
[0035] The tilt angle is typically between 20° and 30°. For the Mars lander and the Apollo capsule, the tilt angle can be greater than 25°. The tilt angle is preferably such that there is a continuous transition (without edges and / or jumps that would induce flow separation) between the combustion chamber and the (especially curved) baffle plate.
[0036] In one embodiment, the baffle plate for closing the engine exhaust opening can be designed and / or arranged to be axially displaceable. In this case, the baffle plate can be displaceable relative to the axial position of the upper combustion chamber wall and / or the lower combustion chamber wall.
[0037] In one embodiment of the engine, in a first configuration the engine, in particular the engine exhaust port, can be closed by means of the blast plate, whereby the blast plate acts as a heat shield when required (without engine thrust, e.g., during a landing approach and / or entry into the atmosphere of a celestial body), and / or in a second configuration the engine can be open, whereby the blast plate (during engine thrust operation, with combustion gas generation) serves to generate thrust in conjunction with the rest of the engine. In this case, the engine exhaust port must be open so that the combustion gases can escape.Preferably, at least in this embodiment, the baffle plate has a shape that corresponds essentially to the radial extent and shape of the engine exhaust opening, such that the baffle plate can be positioned in the engine exhaust opening in a sealing manner, for example, positively interlocking, optionally with the intermediate arrangement of any sealing elements, or (in the first configuration) is positioned.
[0038] The interaction of the inclined combustion chamber and the curved baffle plate can enhance the effectiveness of the protective shield, particularly the heat shield, and / or stabilize the spacecraft. A25792-PCT - JF / bau - 9 - April 14, 2026
[0039] In a further embodiment of the engine, the combustion chamber outlet can have a nozzle neck for generating a sonic and / or supersonic flow of the combustion gases during operation. The nozzle neck is formed, in particular (for example, exclusively), by means of the lower combustion chamber wall (a bulge formed therein in the area of the nozzle neck to narrow the flow cross-section). The upper combustion chamber wall can transition smoothly, without a bulge, into the baffle plate. Alternatively, the nozzle neck (as a separate, attached component) can be arranged on the lower combustion chamber wall, or the lower combustion chamber wall can transition into the nozzle neck. The nozzle neck is thus, in particular, annular, rotating continuously around the axis of symmetry and does not lie on the axis of symmetry. Therefore, the combustion chamber rotating around the axis of symmetry forms a thrust chamber, with the nozzle, also annular and rotating around the axis of symmetry, located downstream of the combustion chamber.There is no central nozzle located on the axis of symmetry.
[0040] In another design variant, the combustion chamber can be designed for combustion by means of a rotating detonation wave, for the design of the engine as a "Rotating Detonation Engine" (RDE), whereby in particular no narrowing of the flow cross-section at the combustion chamber outlet is provided.
[0041] In a further aspect of the invention, a spacecraft is proposed. The spacecraft comprises an engine according to the invention and a propellant periphery. The engine, with an axis of symmetry, has a combustion chamber, an engine exhaust port, and a baffle plate. The combustion chamber has a combustion chamber, in particular symmetrically, annularly extending around the axis of symmetry and radially outward around the baffle plate, oriented along a longitudinal axis and bounded by an upper combustion chamber wall and a lower combustion chamber wall. The combustion chamber also has at least one combustion chamber outlet arranged at the downstream end of the combustion chamber, for example, a continuous annularly extending around the axis of symmetry. The combustion chamber outlet is located at the end of the combustion chamber.
[0042] The combustion chamber and / or the combustion chamber outlet are arranged and configured for the radial discharge of combustion gases in the direction of the axis of symmetry, particularly in relation to the flow along the baffle plate, wherein the baffle plate is radially surrounded by the combustion chamber downstream of the combustion chamber outlet and arranged symmetrically to the axis of symmetry on the combustion chamber, and wherein the engine exhaust opening for the discharge of combustion gases from the engine is arranged on the axis of symmetry and axially opposite the baffle plate with respect to the axis of symmetry. The baffle plate can be arranged downstream, at least temporarily, in the direction of gas flow. The baffle plate can be arranged axially downstream of the combustion chamber outlet in the direction of flow. The baffle plate can cause a deflection of the combustion gases.
[0043] This allows the spacecraft to be axially more compact and have a shorter length along its axis of symmetry. The resulting weight savings enable a more efficient spacecraft to be provided.
[0044] The spacecraft could be, for example, a lander, such as the European Large Lander (EL3). The spacecraft could also be a satellite.
[0045] In another aspect of the invention, the use of an engine according to the invention in a spacecraft is proposed.
[0046] In a further aspect of the invention, a method for operating a spacecraft is proposed, wherein thrust is generated in an engine by means of ram pressure, wherein hot combustion gases are generated by means of a combustion chamber and these are accelerated radially inwards, in the direction of an axis of symmetry of the engine, wherein the combustion gases accumulate on the axis of symmetry and thereby generate a ram pressure which acts on a ram plate of the engine and thus accelerates the spacecraft, wherein A 25792-PCT - JF / bau - 11 - April 14, 2026
[0047] The combustion gases are redirected and escape from the engine via an engine exhaust port. The spacecraft features the engine according to the invention, in which a propellant is burned in the combustion chamber, producing combustion gases that are accelerated in the direction of the combustion chamber's axis of symmetry and undergo a change in direction by the ram plate. The ram plate can thus change the radial direction of the combustion gases, allowing them to flow essentially along and parallel to the axis of symmetry. This enables thrust to be generated in a direction opposite to the flow direction of the combustion gases.
[0048] In one embodiment of the method, the engine's baffle plate can be moved relative to the combustion chamber, thus closing the engine exhaust port. In this configuration, the baffle plate can act as a heat shield. The baffle plate can be moved essentially axially, along its axis of symmetry. This allows for the modification of the baffle plate's axial position.
[0049] The features listed individually in the patent claims can be combined in a technologically meaningful way and can be supplemented by explanatory facts from the description and by details from the figures, showing further embodiment variants of the invention.
[0050] The invention is explained in more detail below with reference to exemplary embodiments and the drawings. The drawings depict exemplary embodiments of the invention. The drawings, the description, and the claims contain numerous features in combination. A person skilled in the art will expediently consider the features individually and combine them into meaningful further combinations. The drawings show:
[0051] Fig. 1 shows an engine with a combustion chamber and a nozzle according to the state of the art.
[0052] Technology; A25792-PCT - JF / bau - 12 - 14 April 2026
[0053] Fig. 2 shows an engine with a combustion chamber with an internal aerospike nozzle according to the prior art;
[0054] Fig. 3 shows an engine with a combustion chamber with an expansion-deflection nozzle according to the prior art;
[0055] Fig. 4 shows an embodiment of an engine according to the invention for a spacecraft with an annular combustion chamber, a squash plate and an engine exhaust opening;
[0056] Fig. 5 shows another embodiment of the engine according to the invention;
[0057] Fig. 6 shows a drive unit according to a further embodiment;
[0058] Fig. 7 shows a first embodiment of the baffle plate;
[0059] Fig. 8 shows another embodiment of the baffle plate;
[0060] Fig. 9 shows a drive unit according to a further embodiment;
[0061] Fig. 10 shows a spacecraft with a ring-shaped combustion chamber;
[0062] Fig. 11 shows a flowchart of a procedure for operating a spacecraft.
[0063] Fig. 1 shows a schematic sectional view of a conventional chemical engine 10, in particular a rocket engine with a cylindrical combustion chamber 12 with a combustion chamber 14 and a nozzle 16 according to the prior art. Combustion products are formed in the combustion chamber 14, in particular a hei-A25792-PCT - JF / bau - 13 - 14 April 2026
[0064] The combustion gas is pressurized. It exits the nozzle 16, which has a convergent-divergent shape, and acts locally with its respective pressure on an inner engine wall 18. For propulsion, thrust is generated against the flow direction of the combustion gas from the combustion chamber 12 (see arrow 20).
[0065] Fig. 2 shows a schematic sectional view of a conventional engine 22 according to the prior art with an annular combustion chamber 24 and an internal aerospike nozzle 26. The combustion gas exits the annular combustion chamber 24 in the flow direction indicated by the respective arrow 28.
[0066] The expansion-deflection engine 30 shown in schematic sectional view in Fig. 3 according to the prior art has an annular combustion chamber 32 and a plow 34 which deflects the flow direction of the combustion gas indicated by the arrow 36 towards a nozzle wall 38 of a nozzle 40.
[0067] In the engines 10, 22 and / or 30 shown in Figures 1, 2 and 3, the combustion gases are accelerated axially away from the respective spacecraft body. The engine 10, 22 or 30 has a sufficient length to generate the required thrust. In particular, a certain axial length of the respective nozzle 16, 26 and / or 40 is required, with the divergent portion of the nozzle 16, 26 or 40 being decisive: the longer the nozzle 16, 26 or 40 and thus the larger its end diameter, the greater the thrust that can be generated.
[0068] Fig. 4 shows a schematic sectional view of an engine 50 according to the invention. The engine 50 has an annular combustion chamber 52 with a combustion chamber 54, an engine exhaust opening 55, and a baffle plate 56. The engine 50 is designed to be symmetrical about an axis of symmetry 58. The plane of the sectional view is defined by the axis of symmetry 58. A25792-PCT - JF / bau - 14 - April 14, 2026
[0069] Combustion chamber 52 has a longitudinal axis L, which in particular forms a central axis of the combustion chamber 54. In the embodiment shown in Fig. 4, the longitudinal axis L is arranged essentially orthogonally to the axis of symmetry 58.
[0070] The combustion chamber 54 of the combustion chamber 52 is, in particular, symmetrically, annular around the axis of symmetry 58 and radially circumferential around the baffle plate 56, oriented along the longitudinal axis L. The combustion chamber 54 is axially bounded by an upper combustion chamber wall 52.1 and a lower combustion chamber wall 52.2, and radially bounded by an inlet-side, circumferential combustion chamber wall 52.3. The combustion chamber 52 has at least one combustion chamber outlet 51 arranged at the downstream end of the combustion chamber 54, for example, a continuous annular outlet 51 circumferentially around the axis of symmetry 58. The combustion chamber 54 and / or the combustion chamber outlet 51 is / are arranged and designed for the radial discharge of combustion gases in the direction of the axis of symmetry 58, in particular for the flow of combustion gases along the baffle plate 56.The baffle plate 56 is radially surrounded by the combustion chamber 52 downstream of the combustion chamber outlet 51 and is arranged symmetrically on the axis of symmetry 58. The combustion chamber outlet 51 is located between the upper combustion chamber wall 52.1 and the lower combustion chamber wall 52.2. The combustion chamber outlet 51 is circular, in particular cylindrical, and points in the direction of the axis of symmetry 58.
[0071] The engine exhaust port 55 serves to discharge the combustion gases from the engine 50. The engine exhaust port 55 is arranged on the axis of symmetry 58 and is axially opposite the baffle plate 56 with respect to the axis of symmetry 58. The engine exhaust port 55 is radially bounded on the outside, at least partially, by the lower combustion chamber wall 52.2. A25792-PCT - JF / bau - 15 - April 14, 2026
[0072] In the embodiment shown in Fig. 4, the baffle plate 56 is rigidly connected to the upper combustion chamber wall 52.1 of the combustion chamber 52. The upper combustion chamber wall 52.1 transitions into the baffle plate 56 immediately after the combustion chamber outlet 51, and in particular after an upper section of the combustion chamber outlet 51. The baffle plate 56 and the upper combustion chamber wall 52.1 are preferably manufactured integrally as a single piece. Alternatively, the baffle plate 56 can be connected to and / or attached to the upper combustion chamber wall 52.1 by means of suitable supports or connecting elements (not shown in Fig. 4). The baffle plate 56 is arranged in a plane orthogonal to the axis of symmetry 58. In Fig. 4, the baffle plate 56 is shown by way of example to extend exclusively in this plane and is thus arranged in an axially constant position.
[0073] As further shown in Fig. 4, the combustion chamber 52 has a nozzle neck 53, which is formed, for example, by means of the lower combustion chamber wall 52.2, or is integrally formed with it. The nozzle neck 53 connects directly to the combustion chamber 54.
[0074] During operation of the engine 50, hereinafter also referred to as "thrust mode," combustion products, in particular combustion gases, are generated in the combustion chamber 54 by burning a propellant. The hot combustion gases generated in the combustion chamber 54 flow radially out of the combustion chamber outlet 51 in the direction of the axis of symmetry 58 (see arrow 64 in the direction of flow). The combustion gases accumulate on the axis of symmetry 58 and generate a dynamic pressure acting on the stagnation plate 56. This dynamic pressure causes thrust in the direction of arrow 62, which accelerates the spacecraft. The accumulating combustion gases are deflected at the stagnation plate 56 and escape from the engine 50 through the engine exhaust opening 55 opposite the stagnation plate 56 (see arrow 60).
[0075] The engine exhaust port 55 is typically located on and symmetrically to the axis of symmetry 58. Engine exhaust port 55A25792-PCT - JF / bau - 16 - April 14, 2026
[0076] It may have a support structure (not shown), for example with struts, which can have a stabilizing effect. Typical dimensions for a (conventional) combustion chamber with nozzle are approximately 0.4–0.5 m. The diameter of a lander is a maximum of 5 m. The blast plate 56 typically comprises about 80% of the engine diameter. Thus, the diameter of the blast plate 56 is a maximum of 4 m. The range here is between 50% and 85% and depends on the size of the combustion chamber.
[0077] The engine 50 shown in Fig. 4 can be used in any spacecraft that uses one of the conventional engines shown in Figs. 1 to 3. One example of such a spacecraft is the European Large Logistics Lander, designated EL3.
[0078] Fig. 5 shows a schematic sectional view of an engine 66, which is a modified embodiment of the engine 50 shown in Fig. 4. The engine 66 has the annular combustion chamber 52 with the combustion chamber 54. The combustion chamber 52 is arranged symmetrically with respect to the axis of symmetry 58. A baffle plate 68 is arranged to be axially movable along the axis of symmetry 58. The movable baffle plate 68 is arranged to be displaceable in the axial direction between the upper combustion chamber wall 52.1 and the lower combustion chamber wall 52.2.
[0079] The axial displacement or adjustment of the baffle plate 68 is achieved in particular via an adjustment mechanism (not shown). The adjustment mechanism can be, for example, a purely mechanical mechanism such as a scissor mechanism or a rail, or a hydraulically and / or pneumatically operated mechanism. Hybrid mechanisms for adjusting the baffle plate 68 are also possible.
[0080] In the upper part of Fig. 5, the engine 66 assumes a second configuration, with the combustion chamber 52 open and the squash plate 68 in an upper position.-A25792-PCT - JF / bau - 17 - 14 April 2026
[0081] The arrangement is such that the engine exhaust port 55 is open. In the upper position, the baffle plate 68, functioning as a baffle plate 68 for thrust generation when the engine 66 is operating ("thrust mode"), is axially arranged at the level of the upper combustion chamber wall 52.1. The engine 66 is ready for operation in thrust mode or is operating in this mode, whereby the combustion gases generated in the combustion chamber 52 initially flow in the direction of the axis of symmetry 58 and can then leave the combustion chamber 52 in the direction indicated by the arrow 60, generating thrust in the opposite direction.
[0082] In the lower part of Fig. 5, the engine 66 assumes a first configuration, in which at least the engine exhaust port 55 is closed by means of the baffle plate 68. The baffle plate 68 is arranged in a lower position, at the axial height of the lower combustion chamber wall 52.2. The engine 66 is closed by means of the baffle plate 68 by closing the engine exhaust port 55. The first configuration is assumed particularly when the engine 66 is not in thrust operation, e.g., during entry into the atmosphere of a celestial body. In this case, the baffle plate 68 acts as a heat shield for the spacecraft.
[0083] The baffle plate 68 thus has a dual function: as heat protection (first configuration) and as baffle plate 68 (second configuration) during thrust generation. In this second configuration and upper position of the baffle plate 68, the function of the engine 66 is comparable to that of the engine 50. For this purpose, the baffle plate 68 has a size and shape approximately corresponding to (or slightly smaller than) that of the engine exhaust opening 55, in order to be able to seal it at least substantially tightly, possibly with the intermediate use of at least one sealing agent (not shown in Fig. 5).
[0084] The material of the baffle plate 56, 68 is preferably a ceramic or ceramic compound. Alternatively, the baffle plate 56, 68 may have a metallic body with a ceramic coating. Furthermore, materials such as cork are also used. (A 25792-PCT - JF / bau - 18 - 14 April 2026)
[0085] Fiberglass composites, synthetic resin and a specific material from the company Brandenburger, known as S 5000, were used.
[0086] Fig. 6 shows a schematic sectional view of another embodiment of the engine, designated by reference numeral 72. Engine 72 is shown in the first configuration as an example, although it can also assume the second configuration.
[0087] The annular combustion chamber 52 is arranged in an inclined position. Inclined here means that the combustion chamber 52 is inclined with its longitudinal axis L at an angle of inclination 76 with respect to the perpendicular to the axis of symmetry 58 (corresponding to the orientation of the combustion chamber 52 in the non-inclined arrangement, see, for example, Fig. 5), with an axial component in the direction of the engine exhaust opening 55 (not shown in Fig. 6). The angle of inclination 76 can be, for example, up to 50°, approximately between 5° and 50°, and in particular between 20° and 30°. In the Mars lander and / or the Apollo capsule, the angle of inclination is greater than 25°. The upper combustion chamber wall 52.1 and the lower combustion chamber wall 52.2 are, for example, arranged essentially parallel to each other and form a concave shape with respect to the axis of symmetry 58.
[0088] A curved baffle plate 78 is arranged in the area of the combustion chamber 52. The curved baffle plate 78 is designed such that, particularly at the point lying on the axis of symmetry 58, the baffle plate 78 is aligned orthogonally to the axis of symmetry 58 and / or arranged symmetrically to the axis of symmetry 58. The curvature of the baffle plate 78 stabilizes the spacecraft and / or enhances its effect as a protective shield in the lower position (second configuration), more precisely in the axial position of the lower combustion chamber wall 52.2. A25792-PCT - JF / bau - 19 - April 14, 2026
[0089] Figures 7 and 8 show a schematic top view of the combustion chamber 52 with a radially bounding outer contour 57. The outer contour 57 can be circular, as shown in Figure 7, or polygonal, as shown in Figure 8. The outer contour 57 is formed by the circumferential combustion chamber wall 52.3. The circumferential combustion chamber wall 52.3 is also shown in the sectional view of the engine 50, 66, and 72 in Figures 4 to 6 and connects the upper combustion chamber wall 52.1 and the lower combustion chamber wall 52.2.
[0090] Fig. 9 shows a schematic sectional view of an engine 84 based on the combustion principle of the Rotating Detonation Engine (RDE). The engine 84 has an annular combustion chamber 86 with an upper combustion chamber wall 86.1, a lower combustion chamber wall 86.2, a circumferential combustion chamber wall 86.3, and a combustion chamber 88, as well as a ram plate 90. Due to its design and dimensions, one or more rotating detonation waves 92 are generated in the combustion chamber 88 during combustion. The propellant is burned and the combustion gases are generated by means of the rotating detonation waves 92. The combustion gases flow out of the combustion chamber 86 and are accelerated in the direction indicated by arrow 94 towards the axis of symmetry 58, creating ram pressure. The combustion gases are deflected at the baffle plate 90 under thrust generation and flow through an engine exhaust opening 97 (see arrow 96).The advantage of this embodiment is that the detonation waves achieve a pressure increase in the combustion chamber and a convergent-divergent nozzle throat area is not necessarily required.
[0091] Fig. 10 shows a spacecraft 98 in which a thruster 50, 66 or 84 according to the invention is used. Typically, the combustion chamber 52, 86 is arranged on the underside of a body 99 of the spacecraft 98. The representation labeled “I” in Fig. 10 shows the spacecraft 98 in the first configuration in flight without thrust during entry into the atmosphere of a planet, for example in A 25792-PCT - JF / bau - 20 - April 14, 2026
[0092] The atmosphere of Mars. Here, spacecraft 98 is shown at an angle and with its combustion chamber 52, 86 closed. The stasis plate 68, 78 acts as a heat shield.
[0093] In Fig. 10, labelled “II”, the spacecraft 98 is shown in the second configuration, i.e. in landing configuration with legs 89 extended under thrust generation and combustion chamber 52, 86 visible, with the engine exhaust opening 55 not closed.
[0094] The spacecraft 98 can be a lander or space probe intended to land on a celestial body, for example, Mars. An example of a space probe is the European Large Logistic Lander (EL3). The spacecraft 98 can also be a satellite or a probe. The engine 50, 66, or 84 according to the invention, which is a blast plate engine, allows the spacecraft 98 to be significantly shorter axially, thus optimizing its weight and increasing its efficiency. The combustion chamber 52, positioned at the lower end of the spacecraft 98, is shown schematically. If the movable blast plate 68 or 78 is used, it can be positioned to serve as a heat shield on the underside of the spacecraft 98.
[0095] In addition to the respective engine 50, 66 and 84, the spacecraft 98 includes a propellant supply system with at least one propellant tank and an injection system by means of which the propellant enters the combustion chamber 54, 88.
[0096] Fig. 11 shows a method 100 for operating a spacecraft 98 in the form of a flowchart of the method steps. The essential method steps are:
[0097] - 110: Ignition and stable combustion of a propellant in a combustion chamber 54 of an engine 50, 66, 84,
[0098] - 112: Flow of combustion gases in the direction of the axis of symmetry 58 of engine 50, 66 or 84 of spacecraft 98,A25792-PCT - JF / bau - 21 - 14 April 2026
[0099] - 114: Deflecting the combustion gases at the baffle plate 56, 68, 78 or 90 - 116: Generating a thrust 62 in a direction opposite to the direction 60, 96 in which the combustion gases flow out.
[0100] In the method for operating the spacecraft 98 with the engine 50, 66 or 84, thrust is generated by ram pressure, whereby hot combustion gases are generated by means of the combustion chamber 52 and these are accelerated radially inwards, in the direction of the axis of symmetry 58 of the engine 50, 66 or 84, whereby the combustion gases accumulate on the axis of symmetry 58 and thereby generate the ram pressure which acts on the ram plate 56, 68, 78 or 90 of the engine 50, 66 or 84 and in this way accelerates the spacecraft 98, whereby the combustion gases are deflected and escape from the engine 50, 66 or 84 via an engine exhaust opening 55, 97.
[0101] The blast plate 68, 78, or 90 of the engine 66 or 84 can be moved relative to the combustion chamber 86, thus closing the engine exhaust port 55, 97. The blast plate 68, 78, and / or 90 is positioned in an upper position to redirect the combustion gases during thrust operation (second configuration). In a lower position (first configuration), the blast plate 68, 78 acts as a heat shield, for example, during atmospheric entry into a planet without thrust generation. The transition from the first to the second configuration occurs particularly when switching to thrust operation, e.g., for the landing approach after the spacecraft enters a planet's atmosphere. A25792-PCT - JF / bau - 22 - April 14, 2026
[0102] Reference symbol list
[0103] 10 engines
[0104] 12 cylindrical combustion chamber 14 combustion chamber
[0105] 16 nozzle
[0106] 18 Engine inner wall
[0107] 20 Arrow
[0108] 22 Engine
[0109] 24 ring combustion chamber
[0110] 26 nozzle
[0111] 28 Arrow
[0112] 30 engine
[0113] 32 Ring combustion chamber
[0114] 34 Plug
[0115] 36 Arrow
[0116] 38 Nozzle wall
[0117] 40 nozzle
[0118] 50 engine
[0119] 51 Combustion chamber outlet
[0120] 52 Combustion chamber
[0121] 52.1 Upper combustion chamber wall 52.2 Lower combustion chamber wall 52.3 Circumferential combustion chamber wall 53 Nozzle neck
[0122] 54 Combustion chamber
[0123] 55 T engine outlet opening
[0124] 56 Stowage plate
[0125] 57 Outer contour of the combustion chamber 52 58 Axis of symmetry A25792-PCT - JF / bau - 23 - April 14, 2026
[0126] 60 Arrow
[0127] 62 Arrow in thrust direction
[0128] 64 Arrow in the direction of flow
[0129] 66 engine
[0130] 68 movable dust plate
[0131] 72 engine
[0132] Level 74
[0133] 76 tilt angles
[0134] 78 Stowage plate
[0135] 84 engine
[0136] 86 Combustion chamber
[0137] 86.1 upper combustion chamber wall 86.2 lower combustion chamber wall 86.3 circumferential combustion chamber wall 88 combustion chamber
[0138] 89 leg
[0139] 90 Stowage plate
[0140] 92 rotating detonation wave 94 arrow
[0141] 96 Arrow
[0142] 97 Engine exhaust opening
[0143] 98 Spacecraft
[0144] 99 Spacecraft body 100 Procedures
[0145] 110, 112, 114, 116 Process steps L Longitudinal axis
Claims
A25792-PCT - JF / bau - April 24 - 14, 2026 Claims 1. Engine (50, 66, 72, 84) for a spacecraft (98), with an axis of symmetry (58), comprising a combustion chamber (52, 86), a stasis plate (56, 68, 78, 90) and an engine exhaust port (55, 97), wherein the combustion chamber (52, 86) has a combustion chamber (54) which is oriented along a longitudinal axis (L) and is in particular symmetrical, annular around the axis of symmetry (58) and radially outside around the baffle plate (56, 68, 78), and which is bounded by an upper combustion chamber wall (52.1, 86.1) and a lower combustion chamber wall (52.2, 86.2), and which has at least one combustion chamber outlet (51) arranged at the downstream end of the combustion chamber (54, 88), e.g. continuously annular around the axis of symmetry (58), wherein the combustion chamber (54) and / or the combustion chamber outlet (51) is / are arranged and designed for the radial discharge of combustion gases in the direction of the axis of symmetry (58), in particular for the flow along the baffle plate (56, 68, 78, 90), wherein the baffle plate (56, 68, 78, 90) is radially surrounded by the combustion chamber (52, 86) downstream of the combustion chamber outlet (51) and is arranged symmetrically to the axis of symmetry (58) on it, and wherein the engine exhaust opening (55, 97) for the discharge of combustion gases from the engine is arranged on the axis of symmetry (58) and axially opposite the squash plate (56, 68, 78, 90) with respect to the axis of symmetry (58).
2. Engine (50, 66, 72, 84) according to claim 1 , characterized by that the engine exhaust opening (55, 97) is radially bounded on the outside, at least partially, by the lower combustion chamber wall (52.2, 86.2). A25792-PCT - JF / bau - 25 - April 14, 2026 3. Engine (50, 66, 72, 84) according to claim 1 or 2, characterized by that the upper combustion chamber wall (52.1, 86.1) transitions into the baffle plate (56, 68, 78, 90) after the combustion chamber outlet (51), wherein the upper combustion chamber wall (52.1, 86.1) is integrally manufactured with the baffle plate (56, 68, 78, 90) and / or the baffle plate (56, 68, 78, 90) is attached to the upper combustion chamber wall (52.1, 86.1) by means of a suitable holder.
4. Engine (50, 66, 72, 84) according to one of the preceding claims, characterized in that that the baffle plate (56, 68, 78, 90) is arranged in a plane orthogonal to the axis of symmetry (58).
5. Engine (50) according to any one of the preceding claims, characterized by that the combustion chamber (52, 86) is arranged with the longitudinal axis (L) orthogonal to the axis of symmetry (58).
6. Engine (50, 66, 72, 84) according to one of the preceding claims, characterized in that that the baffle plate (56, 68, 78, 90) is curved, wherein in particular at the point lying on the axis of symmetry (58) the baffle plate (56, 68, 78, 90) is aligned orthogonally to the axis of symmetry (58).
7. Engine (50) according to any one of the preceding claims, characterized by that the combustion chamber (52, 86) is arranged with the longitudinal axis (L) inclined at an angle (76) with an axial directional component. A25792-PCT - JF / bau - 26 - April 14, 2026 8. Engine (50, 66, 72, 84) according to one of the preceding claims, characterized in that that the baffle plate (68, 78, 90) is designed and / or arranged to be axially displaceable for closing the engine exhaust opening (55, 97).
9. Engine (50, 66, 72, 84) according to one of the preceding claims, characterized in that that in a first configuration the engine (50, 66, 72, 84), in particular the engine exhaust port (55, 97), is closed by means of the blast plate (56, 68, 78, 90), the blast plate (56, 68, 78, 90) acting as a heat shield when required, and / or that in a second configuration the engine (50, 66, 72, 84) is open, with the ram plate (56, 68, 78, 90) serving to generate thrust in conjunction with the rest of the engine (50, 66, 72, 84).
10. Engine (50, 66, 72) according to one of the preceding claims, characterized in that that the combustion chamber outlet (51) has a nozzle neck (53) for generating a sonic and / or supersonic flow of the combustion gases during operation, wherein the nozzle neck (53) is formed in particular by means of the lower combustion chamber wall (52.2).
11. Engine (84) according to any one of the preceding claims, characterized by that the combustion chamber (52, 86) is designed for combustion by means of a rotating detonation wave.
12. Spacecraft (98) with a propulsion system comprising a propellant periphery and an engine (50, 66, 72, 84) according to any one of the preceding claims. A25792-PCT - JF / bau - 27 - April 14, 2026 13. Method for operating a spacecraft (98), in particular according to claim 12, in which thrust is generated in an engine (50, 66, 72, 84) by means of a combustion chamber (52, 86) and is accelerated radially inwards in the direction of an axis of symmetry (58) of the engine (50, 66, 72, 84), wherein the combustion gases accumulate on the axis of symmetry (58) and thereby generate a stagnation pressure which acts on a stagnation plate (56, 68, 78, 90) of the engine (50, 66, 72, 84) and thus accelerates the spacecraft (98), wherein the combustion gases are deflected and discharged from the engine (50, 66, 72, 84) via an engine exhaust opening (55, 97) escape.
14. Method according to claim 13, wherein a baffle plate (68, 78) of the engine (66, 72, 84) is moved relative to the combustion chamber (52, 86) and can thus close the engine outlet opening (55, 97).