Heater apparatus and method for heating a component of a spacecraft, and spacecraft comprising a heater apparatus

Abstract

A heater apparatus configured to provide heat to at least one component of a spacecraft. The heater apparatus comprises a combustion chamber for a hypergolic propellant, and a heat radiator configured to radiate heat from the combustion chamber towards the at least one component to be heated. A spacecraft comprises at least one component to be heated and a heater apparatus configured to heat the at least one component to be heated. A method for heating at least one component of a spacecraft. The method comprises generating heat in a combustion chamber for a hypergolic propellant, and radiating at least a portion of the heat towards the at least one component.

Claims

1. An assembly comprising: an avionics box containing at least one avionics device for a spacecraft, and a heater apparatus to provide heat to the at least one avionics device, wherein the heater apparatus comprises: a combustion chamber for a hypergolic propellant, and a heat radiator configured to radiate heat originating from the combustion chamber towards the at least one avionics device to be heated, wherein the combustion chamber is arranged in a heat conducting block at least partially attached to a surface of the heat radiator, and wherein the heat radiator is attached to the avionics box.

2. The assembly according to claim 1, wherein the heater apparatus further comprises an exhaust duct configured to discharge exhaust fumes from the combustion chamber, wherein at least a portion of the exhaust duct is configured to deliver heat absorbed from exhaust fumes to the heat radiator.

3. The assembly according to claim 2, wherein the exhaust duct forms at least one loop along a surface of the heat radiator.

4. The assembly according to claim 2, wherein the exhaust duct forms at least one loop within the heat radiator.

5. The assembly according to claim 2, wherein the exhaust duct comprises at least two branches.

6. The assembly according to claim 1, wherein the heater apparatus further comprises a heat insulation block enclosing a portion of the combustion chamber.

7. The assembly according to claim 1, wherein the heater apparatus is further configured to operate as a thruster.

8. The assembly according to claim 1, wherein the heater apparatus further comprises at least one adjustable valve configured to control a supply of the hypergolic propellant into the combustion chamber.

9. The assembly according to claim 1, wherein the heater apparatus further comprises at least one pressure reducer configured to control a supply of the hypergolic propellant into the combustion chamber.

10. A spacecraft comprising the assembly according to claim 1.

11. A method for heating at least one avionics device of a spacecraft, the method comprising: generating heat by combustion of a hypergolic propellant in a combustion chamber for a hypergolic propellant, and radiating at least a portion of the heat towards the at least one avionics device, wherein the combustion chamber is arranged in a heat conducting block at least partially attached to a surface of a heat radiator, said heat radiator being attached to an avionics box containing the at least one avionics device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Shown is schematically in

(2) FIG. 1a, a first sectional view of an exemplary embodiment of a heater apparatus according to the present invention;

(3) FIG. 1b: a second sectional view of the heater apparatus shown in FIG. 1a;

(4) FIG. 2a a side view of an exemplary heat radiator of an embodiment of a heater apparatus according to the present invention;

(5) FIG. 2b a plan view of the heat radiator shown in FIG. 2a; and

(6) FIG. 3 a spacecraft according to an exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(7) In FIG. 1a, an exemplary heater apparatus 1 according to an embodiment of the present invention is shown; the heater apparatus 1 is devised for heating at least one component of a spacecraft (not shown).

(8) The heater apparatus 1 comprises a combustion chamber 10 for a hypergolic propellant combination (which may, for instance, contain hydrazine, a derivate of hydrazine, nitric acid, dinitrogen tetroxide and/or hydrogen peroxide), and a heat radiator 20 configured to radiate heat from the combustion chamber 10 towards the component to be heated.

(9) A fuel pipe 30 is devised to form part of a fuel supply line connected with at least one fuel tank (not shown) containing a component of the hypergolic propellant (combination), to be fed into the combustion chamber 10. Valves 31, which in the example shown, are configured to be electromechanically operated by means of respective solenoids 32, are configured to control the component flow.

(10) According to a preferred embodiment, at least one of the valves 31 is adjustable, such that it may be selectively closed, or opened at one of at least two possible opening levels. As a consequence, the valves and, therewith, the propellant component supply, may be tunable. In particular, in applications where the heater is further adapted to operate as a thruster as mentioned above, by means of the adjustable valves, feeding the propellant component may be adapted to whether the heater apparatus 1 is used, in a particular situation, as a heater only or whether it is additionally employed as a thruster.

(11) The heat radiator 20 comprises a plate 21 with a flat surface facing the combustion chamber 10. At the opposite surface of the plate 21, the heat radiator 20 comprises a plurality of fins 22 protruding from the plate 21. In application of the heater apparatus, the fins 22 are preferably arranged so as to face the at least one component to be heated; a more detailed view of a heat radiator 20 is given in FIGS. 2a, 2b. Preferably, at least a portion of the heat radiator 20 is (nearly) a black body. In particular, at least a portion of the heat radiator may preferably be coated with lamp-black or with vertically aligned carbon nanotube arrays (VANTAs).

(12) As further illustrated in FIG. 1a, a casing of the combustion chamber 10 is formed by a heat conducting block 11 which may be at least partially formed from aluminum or titanium. In the example shown, the heat conducting block 11 is essentially shaped as a cuboid. A flat surface of the heat conducting block 11 is entirely arranged on the flat surface of the plate 21 of heat radiator 20. A preheater element 33 is arranged on the heat conducting block 11; the preheater element 33 may provide for an advantageous ignition temperature in the combustion chamber 10.

(13) Both the heat conducting block 11 (with the combustion chamber 10) and the preheater element 33 are arranged in a cavity, which is formed in a heat insulation block 50 and covered by the heat radiator 20. The heat insulation block 50 preferably contains insulation material.

(14) An exhaust duct 40 comprising a duct inlet 41 and a duct outlet 42 is configured to discharge exhaust from the combustion chamber 10. Between the duct inlet and the duct outlet, the exhaust duct runs along the flat surface of the plate 21 of the heat conductor means. The exhaust duct 40 serves to transfer heat of conducted exhaust fumes to the heat conductor means 20.

(15) In FIG. 1b, the heater apparatus 1 depicted in FIG. 1a is shown in another sectional view; as compared to FIG. 1a, the heater apparatus is turned by 90° around the longitudinal axis X. Thereby, FIG. 1b, in particular, gives an insight into the heat insulation block 50, thus providing a view onto the flat surface 23 of plate 21 of the heat radiator 20 with the exhaust duct 40 arranged thereon.

(16) As can be seen in FIG. 1b, the exemplary exhaust duct 40 depicted comprises two branches 43, 44. With regard to a dedicated exhaust flow direction (indicated in FIGS. 1a and 1b by respective arrows), the branches 43, 44 separate behind the inlet 41, they each form a loop along the flat surface 23 of the plate 21, and then they join before the outlet 42. A length of each branch (between the separation and the joining) may be at least 50 mm, at least 75 mm or at least 90 mm. Additionally or alternatively, the length may be at most 150 mm or at most 125 mm or at most 110 mm.

(17) In FIGS. 2a, 2b, a heat radiator 20 is shown which comprises a plate 21 and a plurality of fins 22 protruding, by a protrusion dimension d4, at a side opposite to a flat surface 23 of the plate 21. According to preferred embodiments, 3 mm≤d4≤7 mm or 4 mm≤d4≤6 mm holds true.

(18) As indicated by arrows, the heat radiator is configured to produce a radiant flux L in a protrusion direction of the fins 22.

(19) As can be seen in FIG. 2b, the plate 21 is shaped as rectangle, and the fins 22 extend straight and parallel to one another, with a respective distance d5. According to alternative (not shown) embodiments, the plate may be shaped as a disk, and/or the fins may, for instance, extend along (preferably parallel) curves, or they may extend as concentric rings.

(20) In the exemplary embodiment depicted in FIGS. 2a, 2b, the plate 21 has a first extension d1 and a second extension d2 (which is orthogonal to the first extension).

(21) According to exemplary advantageous embodiments, 70 mm≤d1≤140 mm or 90 mm≤d1≤120 mm holds true, and/or 70 mm≤d2≤140 mm or 90 mm≤d2≤120 mm. In particular, d1 and d2 may be equal, or they may differ by at most 10 mm or at most 5 mm.

(22) A thickness d3 of the plate 21 may preferably comply with 2 mm≤d3≤6 mm or even 3 mm≤d3≤5 mm.

(23) In the exemplary embodiment shown in FIG. 2b, the fins 22 are arranged side by side along d1, while their lengths extend in the same direction as d2. In the example depicted, d2 coincides with the respective lengths of the fins 22.

(24) A thickness d6 of the fins (measured in parallel to the surface 23 of the plate 21 and orthogonally to a lengths of the fins) may preferably comply with 1 mm≤d6≤3 mm or even 1.5 mm≤d6≤2.5 mm.

(25) In preferable embodiments, the heat radiator 20 may comprise at least ten fins 22 or at least twelve fins 22, and/or at most twenty-five fins 22 or at most twenty fins 22. In the exemplary embodiment shown, the heat radiator 20 comprises fourteen fins 22.

(26) FIG. 3 provides an insight into a schematically depicted exemplary spacecraft 100 (being a landing vehicle) according to an embodiment of the present invention. The spacecraft comprises a shell 110 with a payload platform 120, an engine platform 130 (with an engine 140 mounted thereto) and support legs 150.

(27) A fuel tank 160 (preferably containing a hypergolic propellant component such as hydrazine or a derivative thereof) and an oxidizer tank 161 are each connected, by a respective supply line 180, 181, with an engine 140. Both tanks 160, 161 are connected to a pressure tank 170 which can be used to control the discharge of the fuel tank 160 and the oxidizer tank 161 into the respective supply lines 180, 181.

(28) Moreover, the spacecraft 100 comprises at least one avionics device contained in an avionic box 190, which in the exemplary embodiment depicted is mounted to the payload platform.

(29) A heater apparatus 1 according to an embodiment of the present invention is provided to heat the avionic box 190. The heater apparatus 1 comprises a combustion chamber 10 connected, via the fuel supply line 180 and the oxidizer supply line 181, with the fuel tank 160 and the oxidizer tank 161. Heat which may be generated in the combustion chamber 10 can be transmitted to a heat radiator 20 mounted to the avionic box 190. An exhaust duct 40 is configured to duct exhaust fumes caused by the combustion from an inlet (not shown) within the combustion chamber 10 along a surface of the heat radiator 20 to an outlet 42.

(30) According to alternative embodiments of the present invention, at least one thruster (not shown) may be mounted, adjacent the avionic box 190, to the payload platform 120. The thruster may then be used both to provide thrust, e.g., to fine-tune a position and/or an orientation of the spacecraft, and to heat the avionic box 190.

(31) Disclosed is a heater apparatus 1 configured to provide heat to at least one component of a spacecraft. The heater apparatus 1 comprises a combustion chamber 10 for a hypergolic propellant, and a heat radiator 20 configured to radiate heat from the combustion chamber 10 towards the at least one component to be heated.

(32) Further disclosed is a spacecraft 100 comprising at least one component 190 to be heated and a heater apparatus 1 configured to heat the at least one component to be heated.

(33) Further disclosed is a method for heating at least one component 190 of a spacecraft 100. The method comprises generating heat in a combustion chamber 10 for a hypergolic propellant, and radiating at least a portion of the heat towards the at least one component 190.

(34) While at least one exemplary embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). In addition, in this disclosure, the terms “comprise” or “comprising” do not exclude other elements or steps, the terms “a” or “one” do not exclude a plural number, and the term “or” means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.

REFERENCE SIGNS

(35) 1 heater apparatus 10 combustion chamber 11 heat conducting block 20 heat radiator 21 plate 22 fin 23 flat surface of the plate 30 fuel pipe 31 valve 32 solenoid 33 preheater element 40 exhaust duct 41 inlet of exhaust duct 42 outlet of exhaust duct 43, 44 branch of exhaust duct 50 insulation block 51 insulation material 100 spacecraft 110 shell 120 payload platform 130 engine platform 140 engine 150 support leg 160 fuel tank 161 oxidizer tank 170 pressure tank 180 fuel supply line 181 oxidizer supply line 190 avionic box L radiant flux X center axis of heater apparatus