DE10230350B4 - Spacecraft with a position control device - Google Patents

Abstract

spacecraft with a device for position control on a given orbital Railway, wherein the location optionally at least on a given spacecraft axis is alignable, containing at least one angular momentum generating Means and at least one parent Control and regulation device associated with position sensors stands, wherein the means for position control as angular momentum generating Means at least one annular Conduit with a channel-flowing liquid therein has, at least electrically conductive and magnetically influenced is, wherein the duct at least one magnetohydrodynamic Pump for the circulation of the liquid is assigned, characterized in that in the magnetohydrodynamic Pump (21, 22, 42, 43, 44, 45, 51, 52, 53, 54) is a thermoelectric Unit (48, 49, 62) with a block of material (27, 57) available is connected to the duct (19, 40, 55), electrically and heat is conductive as well as a thermoelectric power over the liquid (20), wherein the material block (27, 57) with an associated heat source (11, 12, 56, 65) for training ...

Description

The The invention relates to a spacecraft with a position control device on a given orbital path, the position optionally at least can be aligned with a given spacecraft axis, containing at least one angular momentum generating means and at least one parent Control and regulation device associated with position sensors stands, wherein the means for position control as angular momentum generating Means at least one annular Conduit with a channel-flowing liquid therein has, at least electrically conductive and magnetically influenced is, wherein the duct at least one magnetohydrodynamic Pump for the circulation of the liquid assigned.

Such a position control device for a spacecraft is in the document US 2,856,142 described and has at least three annular ducts, in particular pipelines, each with a channel-flowing liquid, which is influenced electrically and magnetically on. Each conduit is associated with a pump, in particular a magnetohydrodynamic pump, which is provided for the controlled rotation of the liquid in the conduit. For this purpose, the respective pump is connected by means of electrical lines to a control and regulation system (box), in which position sensors can be located. The magnetohydrodynamic pump has a magnetic device for generating a magnetic field and a perpendicularly arranged pair of electrodes (cathode, anode) for generating an electric field, wherein the pair of electrodes is isolated from the pipeline in the liquid.

One Position sensor within the box registers the position / position deviation of the vehicle e.g. on its roll axis and produced after a reasonable reinforcement an electrical signal over the electrical line to the electrode pair. This signal operates the pump, which is connected to the pipeline, around the liquid to accelerate within the pipeline such that a reaction / a Swirl inside the vehicle is developed, which should be enough to counteract the Ausgangsstörgröße and to return the vehicle to its predetermined position. The can be done equally well for the other axes as well. The electrically conductive liquid may be mercury or a low-melting metal, which can be moved by the magnetohydrodynamic pump.

each These pumps can also be individually via the lines by signals turned from suitable position sensors who the who within of the vehicle, in particular in the box are introduced.

The Pumps for controlling the liquid flow rate and the direction through the pipes have in detail each a magnetic device, the at least one pair from each other having spaced magnetic poles, wherein the magnetic field transverse for extending between the poles in an air gap pipe is oriented to the liquid to superimpose a flow of force in a transverse direction. The Magnetic field is adjusted by means of a coil when connected Voltage source generated. Between the pair of magnetic poles within the air gap and on the opposite sides the pipeline immersed in the conductive liquid are two electrodes attached, suitably spaced from the pipe wall are electrically isolated. The electrodes are in relation to the magnetic poles arranged such that after connection of the voltage potential across the Conduct a current through the conductive liquid in one Direction flows, which is perpendicular to the magnetic field. The transverse current generates a motor / drive effect for the liquid in conjunction with the magnetic field and thus forms a magnetohydrodynamic Pump out in intensity and direction the voltage amplitude and voltage phase to the energy-carrying Electrodes changeable is.

The Pipelines are preferably within the vehicle in geometric surfaces arranged, each perpendicular to the roll, pitch or Yaw axis lie.

One Problem of the position control device is that on the one hand the magnetohydrodynamic pumps with the pair of electrodes for generating of setting moments that compensate for disturbances should, are relatively underachieving. In case of use in spacecraft, on the other hand the known magnetohydrodynamic pumps the installed supply systems for Generation of setting torques for position control is too high in terms of energy or power requirement strain.

Another spacecraft with a device for controlling a 3-axis stabilization is in the document EP 0 260 957 B1 in which at least one or preferably three momentum / reaction wheels (swirl wheels), a series of thrusters for changing in speed maneuvers mounted around the circumference of the spacecraft and other means for balancing positions are provided. On Spacecraft in orbit have thermal effects due to direct solar radiation (solar heat), heat radiation into space, and the heat released from the inside of the enclosure by electronic devices and components (internal heat). The solar radiation and the heat radiation generate disturbing moments that can change the predetermined position of the spacecraft on its orbital orbit. By using the known spin wheels to compensate for the attacking disturbances.

One Problem is that the position control at least one momentum wheel attached, which requires relatively much energy for its operation. Are located If there are more spin wheels on / in the spacecraft, then the mass balance becomes shifted to the detriment of the payload mass.

One Another problem is that in small satellites (about 100 kg mass) a high energy requirement for the operation of swirl wheels and at the same time for activity the pumps to the flow of liquid inside the heat pipes to reduce the heat accumulation at the hot zones is required.

Another spacecraft is in the document US 5,211,360 described, in which a device for position control with a reaction wheel (impeller) or with a reaction wheel arrangement is provided to compensate for the heat disturbances from the sun's rays. The solar radiation, which manifests itself in particular by resulting temperature gradients, also generate disturbance torques due to the radiation pressure, which attaches to the main body of the spacecraft and changes its position. The temperature gradients are registered by a variety of temperature sensors and forwarded to the connected microcomputer / on-board computer and processed. With the microcomputer, which is the central part of the position control device, and the spin wheel is connected, which receives signals from the microcomputer for rotation and thus correcting the position, wherein a counter-torque generated by the temperature gradient resulting by means of the impeller spin wheel and the spacecraft again the original position, in particular the given spacecraft axis is aligned.

It is further a device for position and Nutationsregelung for a spin-controlled spacecraft having rolling, pitching and yaw axes, in the document EP 0 460 935 B1 has, in addition to a sensor device for measuring the instantaneous roll, an estimating device, a logic device, at least one pusher in the form of mini-nozzle drives and a swirl wheel as position correction means. The mini-nozzle drives or the momentum wheel can generate torques in order to return the position values with respect to the given spacecraft axes to predetermined limits in the event of deviations from the original position values. The associated control and regulating device includes a microcomputer which transmits the appropriate correction signals to the position correcting means. Again, the mass cost - the attitude stabilization mass - high and reduces the mass balance to the detriment of the payload mass of the spacecraft.

Furthermore, a reaction system (swirl system) with fluid circulation in the document US 5,026,008 described, which also serves to exercise a movement on a spacecraft. The reaction system contains at least one liquid line in which the flow of the liquid can be regulated. For complete control of the attitude of the spacecraft, the reaction system includes a plurality of fluid conduits. The liquid lines may be arranged as pipelines in a circular or disordered manner and inside or outside the spacecraft. In particular, in the spacecraft in the region of a predetermined center of mass or in the central body, a pump, which may also be a magnetohydrodynamic pump, as well as the piping associated liquid storage and associated valves available, from the central pump, the pipes can run in the form of loops.

Preferably the pump is arranged substantially in the center of mass of the central body, around the moment of inertia of the non-liquid part of the Reaktionssytems to minimize. The liquid is controlled by the pipeline moves, with a torque at the mass of the gravity axis is to be generated, which exerts a rotation on the spacecraft.

On the objects / objects in the spacecraft, the torque is transferred from the liquid, which in at least one of the predetermined arranged liquid loops flows in the spacecraft body to the To control body angle orientation. The liquid circulated by means of a pump or a plurality of pumps.

in the Area of the piping can thermosensitive Arrangements may be arranged as heat sinks and / or heat sources across from the liquid are formed, resulting in heat exchange between the liquid and the heat sensitive Allows facilities, without the position control device being supported.

One problem is that the Re Action system generally relates to a torque transmission system and more particularly to a fluid behavior system for a motion to be transmitted to the spacecraft, in particular on the three predetermined axes. In particular, the reaction system requires a higher electrical power requirement from the associated installed supply system for the respective operation of the magnetic direction and the associated electrode pair, in particular for the operation of the pumps for the formation of large actuating torques.

Of the Invention is therefore the object of a spacecraft with to specify a location control facility in which at least a magnetohydrodynamic pump designed so suitable and is arranged that heat areas of the spacecraft body to generate electricity and thus to circulate the liquid used and the electrical load of the central and / or the decentralized Energy supply systems are to be reduced.

The The object is solved by the features of claim 1. In the spacecraft with a device for position control according to the preamble of the claim 1 is a thermoelectric in the magnetohydrodynamic pump Unit with a block of material present with the duct is connected, electric and heat is conductive as well as a thermoelectric power over the liquid wherein the block of material with an associated heat source to form a block internal temperature gradient in conjunction through which a current flow in the channel cross-sectional plane of Can be reached in such a way that with the help of the control and control device a moment-forming and optionally thermocontrolling circulation of the liquid can be achieved.

The ducts can a closed hollow ring casing as a channel housing, in particular a steel pipe ring exhibit.

The channel flowing through liquid may be metallic or saline-like liquid be.

The liquid has a temperature that is preferably adjusted in the range below the average operating temperature in the spacecraft housing.

The Torque axis of at least one hollow-ring-shaped duct can preferably with one of the predetermined spacecraft axes, in particular coincide with the yaw, pitch or roll axis.

Of the hollow ring Conduit can be cross-sectionally round, be oval, square or rectangular.

To a predetermined spacecraft axis, a plurality of ducts axially superimposed and / or be arranged radially in one another.

To a MHD pump can at least one magnet spaced from the duct, whose magnetic flux density cross-sectioned the duct penetrates at least with a vertically directed component, and the thermoelectric unit for generating an electric Stromes, the channel passage cross-section perpendicular to the Conduit and at the same time directed directed perpendicular to the magnetic flux density is, belong and be arranged such that along the duct a driving the fluid Force is present.

The Magnets or the magnet arrangement of a MHD pump can permanent magnets and / or Be electromagnets.

The Magnets of a MHD pump can spaced from the walls of the duct and in guideways be arranged movably to the duct, wherein the respective Distance to the duct by existing means for moving or twisting of the magnets in the associated guideway is variable.

Of the Conduit can at least partially with at least one heat (solar heat) receiving Wall of the spacecraft housing and / or one or more assembly complexes / devices or components within of the spacecraft housing (Indoor heat) keep in touch.

The electrically conductive liquid especially liquid, represent metallic gallium or a gallium alloy.

At the thermoelectrically formed block of material are a einendbereichsseitige hot zone and another end-zone-side cold zone such that between the two temperature value ranges in cross section to the duct directed a temperature gradient is present, resulting in a circulating, thermoelectrically generated current flow cross-sectionally through the liquid and forms through the block of material.

The channel housing is a metal with sufficient electrical and thermal conductivity, which has no reaction with the liquid and of the Magnetic flux density is penetrable.

Of the Material block can be a part body represent.

Of the provided for the formation of the temperature gradient block of material can in the intended heat absorption area (Hot zone) voluminous be formed as in the heat dissipation area (cold zone).

Of the with the annular, preferably rectangular in cross-section Conduit associated material block may preferably be annular and can be influenced in the radial direction by a temperature gradient be.

Of the Material block can be made of a material that is liquid a high thermoelectric power is formed and preferably is a cobalt alloy.

In the areas of the hot zones and the cold zones can Temperature sensors may be arranged, which are connected to the control and regulating device are those with the means for shifting and / or twisting the Magnets for changing the Magnetic flux density is related.

The Means for shifting the magnets may be, in particular, linear motors be that are firmly installed.

In the areas of the hot zones and cold zones can be arranged the heating element associated with the duct, the to maintain or maintain a constant temperature gradient are provided, wherein the heating elements with the control and regulating device keep in touch.

The Control and regulating device can for the position control a proportional-integral controller, a Engine displacement module, a fluid-related accuracy comparison module and include a location navigation module.

The Arrangement for position control, in particular by a MHD pump driven, an angular momentum generating metalli cal liquid in the hollow ring-shaped Cable duct with optional field variable thermoelectric and magnetic elements can simultaneously heat transport and thus for heat regulation be used, resulting in a cost-saving thermal control in the Spacecraft leads.

The Invention opened the possibility, that in the presence of hot and cold zones in the region of the duct a thermal control over the Exchange of heat between the liquid and the Leitungskanalwandungen and by the transport of heat with the liquid can be done.

The Invention allows it, that heat and Performance surpluses for Generation of thermoelectricity be used, reducing the amount of electrical energy for the entire Spacecraft can be reduced. This also attracts savings at the spacecraft power supply system.

The Arrangement for position control, in particular by a MHD pump driven, angular momentum generating liquid in the hollow annular duct with optional field variable thermoelectric and magnetic elements is thus simultaneously for heat transport and Can also be used if there is direct contact and / or between the hot zones and the channel housing heat transfer Contact elements are provided.

The Invention allows it is that the device for position control with the heat distribution over the common working medium, an electrically conductive and magnetic influenceable liquid, which is driven by at least one MHD pump, coupled is.

further developments and improved additional Embodiments of the invention are described in further subclaims.

The Invention is described by means of several embodiments with reference to Drawings closer explained.

It demonstrate:

1 a schematic representation of an earth-oriented spacecraft with a device for position control,

2 a cross-sectional view through a duct and a block of material in thermoelectrically supported MHD pumps after 1 and

3 a schematic representation of a provided with magnetohydrodynamic (MHD) pumping duct for determining the liquid movement direction,

4 a schematic representation of thermoelectrically supported MHD pumps on a sun-oriented spacecraft,

5 a cross-sectional view through a duct and a block of material in a thermoelectrically supported MHD pump according to 4 and

6 a schematic representation of the functional sequence of the position control in the event of disturbances.

For explanation, the 1 and 2 considered together below.

In 1 is the overall view of a spacecraft 1 represented with a device for position control. The spacecraft 1 essentially comprises a spacecraft housing 2 with six outer walls 3 . 4 . 5 . 6 . 7 . 8th , which preferably form a cube, two power modules 9 . 10 , which are representative of other devices, assemblies, components and other power and heat generating sources and at least surface area hot zones (hot spots) 11 . 12 have, the hot zones 11 . 12 associated temperature sensors 13 . 14 as well as an on-board computer 15 on, taking the location of the spacecraft 1 by three optionally given spacecraft axes - eg, the yaw axis 16 , the pitch axis 17 and the roll axis 18 - is defined.

The spacecraft 1 with a device for position control on a predetermined orbital path, wherein the position optionally at least on a given spacecraft axis 16 . 17 . 18 can be aligned, contains at least one angular momentum generating means and at least one higher-level control and regulating device, in which the on-board computer 15 is integrated and the with position sensors 70 . 81 is connected, wherein the means for position control as an angular momentum generating means at least one annular duct 19 with a channel-flowing liquid therein 20 has, which is at least electrically conductive and magnetically influenced, wherein the duct 19 at least one magnetohydrodynamic pump 21 . 22 to the circulation of the liquid 20 assigned.

According to the invention, as well as in 2 is shown in a magnetohydrodynamic pump 21 ; 22 a thermoelectric unit 48 ; 49 with a block of material 27 present with the duct 19 is connected, electrically and thermally conductive and a thermoelectric power to the liquid 20 having, wherein the material block 27 with an associated heat source 11 . 12 to form a block internal temperature gradient .DELTA.T is connected, through which a current flow 25 . 26 in the channel cross-sectional plane 64 of the duct 19 can be reached so that with the help of the control and regulating a moment-forming and possibly thermally controlling circulation of the liquid 20 is reachable.

The MHD pumps 21 . 22 each contain a magnet arrangement, in particular a magnet 23 respectively. 24 and a thermoelectric unit 48 respectively. 49 for generating an electric current.

The magnets 23 . 24 are preferably permanent magnets, but may also be electromagnets or combinations of permanent magnet and electromagnet. The permanent magnets 23 . 24 are located at a distance d from the duct housing of the duct 19 , The permanent magnet 23 . 24 in 1 is always an engine 28 . 29 with an associated engine control 30 . 31 and an associated guideway 32 . 33 to shift or twist the magnets 23 . 24 assigned.

Inside the thermoelectric units 48 . 49 is a first block of material 27 provided, which consists of a material, in relation to the liquid 20 in the first conduit 19 has a considerable thermal power, the formation of a hot and a cold electrode (a temperature gradient .DELTA.T) is used.

In the annular first duct 19 can be at least one liquid speedometer 34 located, which measures the actual values of the rotational speed v and in particular via a line 39 to the control and regulating device 79 ( 6 ). The first line channel 19 can by holding elements 71 . 72 on the housing 2 of the first spacecraft 1 be attached. This can also contact points 73 to the outer walls 3 . 4 . 5 . 6 form, which can become hot zones with corresponding direct sunlight.

Inside the spacecraft housing 1 At least one can be a hot zone 84 generating device 83 located, with his hot zone 84 on the wall of the duct 19 can be present.

The engine controls 30 . 31 , the temperature sensors 13 . 14 and the liquid velocity meter 34 are via associated signal / supply lines 37 . 38 ; 35 . 36 ; 39 with the on-board computer 15 connected.

In the first spacecraft 1 there are position sensors 70 . 81 that with the on-board computer 15 especially via lines 82 . 63 are connected and the actual values of the location of the first spacecraft 1 measure and forward for processing.

In 3 is a schematic representation for determining the rotational speed direction 46 the liquid 20 or the direction of the rotational speed v in an annular, rectangular in cross-section, second conduit 40 shown.

The second line channel 40 in the second spacecraft 41 preferably consists of a steel pipe ring (ring radius R) with a rectangular cross section (height h, width b) and has four MHD pump in each case 42 . 43 . 44 . 45 , The liquid 20 in the steel pipe ring 40 is preferably metallic gallium. The steel pipe ring 40 can also be the outer walls of the two-th spacecraft 41 touch. The MHD pumps 42 to 45 each contain permanent magnets 47 and in each case a thermoelectric unit 48 ,

The rotational speed v of the gallium can be determined by varying the electric current I in the channel cross-sectional plane 64 through the liquid 20 or the magnetic flux density B of the permanent magnets 47 to be influenced.

Are at contact of the steel pipe ring 40 With the outer walls there there are hot zones, then the surplus heat existing there from the liquid 20 can be removed. In essence, depending on the rotational speed v at a ring radius R (FIG. 3 ) An actuating torque T _{S are} generated, which can be used for position control. As a result, the spacecraft rotates due to the rotation speed v and an angular momentum T _S 41 with a number of revolutions / time unit ω. In order to increase the rotational speed v, substantially the thermoelectric current I 25 (arrow) and / or the magnetic flux density B can be increased, which is achieved by connecting the MHD pumps 42 to 45 with the associated control and regulating device 79 ( 6 ) including the on-board computer 15 or the number of MHD pumps can be increased.

For the on the liquid 20 acting normal to the cross section A = h · b normally oriented Lorentz force FL - 80 - arrow direction ( 3 ) - in the direction of the flow: FL = hIB when the magnetic flux density B and the current I (along the height h) are perpendicular to each other.

The mass of the steel pipe ring housing 40 , the permanent magnets 47 and the thermoelectric units 48 . 49 may be about 25% of the total makeup mass, with the remainder of the furnish being primarily from the bulk of the liquid 20 is determined. With the rotating mass of liquid 20 can the corrective angular momentum, a control torque T _S ( 3 ) to the given spacecraft axis 17 be generated.

Based on 4 and 5 another embodiment will be explained. This is in 4 a schematic representation of thermoelectrically supported MHD pumps 51 . 52 . 53 . 54 on a sun-oriented third spacecraft 50 shown. In 5 is a cross-sectional view through a third conduit 55 in the seventh MHD pump 51 (representative of all thermoelectrically supported MHD pumps 52 . 53 . 54 ), the explanation of which is also shown 2 includes.

These are the 4 and 5 explained together.

On the outer wall 56 of the third spacecraft 50 is an annular second block of material 57 such by means of fasteners 77 . 78 attached that a direct contact between by a solar radiation 58 high-temperature outer wall 56 and the second block of material 57 is available. The third spacecraft 50 has the spacecraft axes 59 . 60 . 61 taking it with one of its spacecraft axes 59 is aligned with the sun. The solar radiation 58 and thus the solar heat bounces on the outer wall 56 , There is a hot zone. On the annular second block of material 57 is the annular third duct 55 attached. The ring-shaped third duct 55 has four MHD pumps 51 . 52 . 53 . 54 on.

In the MHD pumps 51 to 54 is as a means for generating a respective thermoelectric current 67 within a duct 55 a third thermoelectric unit 62 (representing all four MHD pumps) provided from the third duct 55 , the liquid 20 and the second block of material 57 exists, wherein the second block of material 57 with the third duct 55 is connected, electrically and heat is conductive and to the liquid 20 is formed with a thermoelectric power.

The with the annular, preferably rectangular cross-section duct 55 connected second material block 57 is preferably also annular and can be influenced in the radial direction by a temperature gradient .DELTA.T.

At the second block of material 57 are to the outer wall 56 directed Einendbereichzusitig a hot zone and other end area a cold zone 66 present, wherein the temperature gradient .DELTA.T in 5 between the two different temperature value ranges 65 / 66 in cross-section to the duct 55 directed, whereby a circulating current flow 67 cross-sectioned by the liquid 20 and through the second block of material 57 is present through.

The duct housing 55 is a metal with sufficient electrical and thermal conductivity that does not react with the liquid 20 and penetrable by the magnetic flux density B.

The second block of material 57 may be interrupted and each also represent a block body in the range of the magnetic flux density B and the temperature gradient .DELTA.T.

For the formation of the temperature gradient .DELTA.T is the intended second block of material 57 in the intended heat absorption area (hot zone) 65 preferably voluminous and bulkier formed than in the heat dissipation area (cold zone) 66 ,

The second block of material 57 consists of a material that is liquid 20 , Gallium for example, forms a sufficiently high thermoelectric power and may preferably be a cobalt alloy.

In the areas of hot zones 65 and the cold zones 66 Temperature sensors can be arranged in the control and regulating device 79 ( 6 ) are involved with the means 69 (Move arrow) for the displacement and / or rotation of the magnets 68 for changing the magnetic flux density B is connected, wherein the means 69 for shifting the magnets 68 In particular, fixed-mounted, linear motors can be. In the control and regulation device 79 is preferably the on-board computer 15 contain.

Is due to the train no sunlight on the outer wall 56 present, so in the areas of hot zones 65 and cold zones 66 the duct 55 assigned and switchable heating elements can be arranged, which are provided for maintaining or maintaining constant the temperature gradient .DELTA.T, wherein the heating elements with the control and regulating device 79 can be connected.

The operation is in both spacecraft 1 and 50 almost the same with thermo-electrically assisted MHD pumps: the electrically conductive metallic fluid 20 is in the duct 19 . 55 included, that with a cobalt ring 27 . 57 is connected adjacent. Due to the different electron levels in the neighboring metals 20 . 27 and 20 . 57 If there is a temperature gradient .DELTA.T in the radial direction, there is a flow of current 25 . 26 . 67 , Due to the interaction with the magnetic field of the permanent magnet 23 . 24 ; 68 the Lorentz force arises on the liquid 20 which is thus moved and around the given axes 17 . 59 rotates. The resulting movement of the liquid 20 can in their strength by the intensity of the magnetic field, in particular the magnetic flux density B on the shift 69 the magnet 23 . 24 ; 68 changed. become. The magnets 23 . 24 ; 68 can eg by linear motors 28 . 29 ; 69 to be moved.

In 6 is a schematic representation of the functional sequence of the attitude control for stabilizing a spacecraft in the occurrence of disturbance torques T _D with reference to 1 shown.

One on the first spacecraft 1 acting disturbance torque T _D causes the change in the position of the first spacecraft 1 that at least with a thermoelectrically supported MHD pump 21 . 22 is working. The change of position can be done with the help of position sensors (eg gyroscopes, star sensors, etc.) 70 . 81 measured and via the associated signal / supply lines 82 . 63 to the connected on-board computer 15 be reported. In the on-board computer 15 Then, the necessary for a position correction actuating torque T _{S is determined} via a comparison processing. Together with the information on current Temperaturgra served ΔT along the first duct 19 can the on-board computer 15 calculate the control signals sent to the control units 30 . 31 and finally to the linear motors 28 . 29 the permanent magnets 23 . 24 be sent. Then the distance d of the permanent magnets 23 . 24 to the channel housing of the first duct 19 changed, whereby the magnetic flux density B in the channel cross section 64 can be varied. The magnetic flux density change, in turn, has a change in the Lorentz force and, finally, the circulation velocity v of the liquid 20 result. The way through the first line channel 19 rotating liquid 20 caused torques T _S are on the channel support elements 71 . 72 on the first spacecraft 1 transferred to counteract the disturbance torques T _D partially or completely.

The six outer walls 3 . 4 . 5 . 6 . 7 . 8th of the first spacecraft 1 are heated or cooled by various effects (eg solar radiation, albedo, etc.). About the contact points 73 and / or support elements 71 . 72 may be the first conduit 19 with the outer walls 3 to 6 be thermally conductively connected. Furthermore, exist inside the spacecraft 1 the hot zones or heating elements 11 . 12 , in particular electrical and electronic components 9 . 10 in which a lot of heat is released. The components 9 . 10 are thus thermally conductive with the first conduit 19 over the first block of material 27 (eg made of cobalt alloy) connected. About the temperature sensors 13 . 14 The current temperatures are recorded and sent to the on-board computer 15 transfer. If too large deviations occur in the temperature gradient ΔT over the channel cross-section 64 on, the temperature at the hot zones becomes 11 . 12 - the power module contact points or heating elements - by additional heating or use of other internal sources of heat 75 raised. Regulation takes place via the on-board computer 15 , By the circulation of the liquid 20 through the first conduit 19 is also a uniform temperature distribution or thermal control of the adjacent outer walls 3 to 8th reached. Next there is a heat transfer from the hot zones / heating elements 11 . 12 to the channel housing 19 , The heat transfer is on the one hand driving force for the emergence of the electric field or current over the channel cross section 64 and on the other hand ensures a desired cooling of the components in question 9 . 10 , At the same time there is a comprehensive thermal control.

The power supply for all named components 9 . 10 done as in 6 is shown via a spacecraft internal power supply unit 76 by a battery 74 or by other power generation facilities.

The control and regulating device 79 to which the on-board computer 15 may include, for the thermoelectric mode attitude control of the MHD pumps, a proportional-integral controller, an engine displacement module, a fluid-related accuracy comparison module, and a position navigation module.

There the heat transport not like the known heat pipe system dependent on the convection is, but over the liquid-based mass flow can be done in the hot zones disturbing Heat faster be transported to the cold zones. The use of thermoelectric gestützen MHD pumps, which are essentially undesirable temperature gradients within the spacecraft can, in particular, primarily for attitude control a spacecraft and at the same time secondary to the constancy of the internal operating temperature in the spacecraft and thus cost-effective for thermal control be used.

1

first spacecraft

2

Spacecraft housing

3

First outer wall

4

Second outer wall

5

third outer wall

6

Fourth outer wall

7

Fifth outer wall

8th

Sixth outer wall

9

first power device

10

second power device

11

First Hot Zone / heating element

12

Second Hot Zone / heating element

13

first temperature sensor

14

second temperature Senor

15

board computer

16

yaw axis

17

pitch axis

18

roll axis

19

first duct

20

liquid

21

First MHD pump

22

Second MHD pump

23

first magnet

24

second magnet

25

first electricity

26

second electricity

27

first material block

28

first engine

29

second engine

30

First motor control

31

Second motor control

32

First guideway

33

Second guideway

34

Liquid speedometer

35

first Supply / signal line

36

second Supply / signal line

37

third Supply / signal line

38

fourth Supply / signal line

39

fifth supply / signal line

40

second duct

41

second spacecraft

42

third MHD pump

43

Fourth MHD pump

44

Fifth MHD pump

45

Sixth MHD pump

46

Speed of rotation direction

47

permanent magnets

48

First thermoelectric unit

49

Second thermoelectric unit

50

third spacecraft

51

seventh MHD pump

52

Eighth MHD pump

53

Ninth MHD pump

54

Tenth MHD pump

55

third duct

56

seventh outer wall

57

second material block

58

solar radiation

59

First Spacecraft axis

60

Second Spacecraft axis

61

third Spacecraft axis

62

third thermoelectric unit

63

seventh Signal / supply line

64

Channel cross-sectional plane

65

third hot zone

66

First cold zone

67

current flow

68

permanent magnet

69

shift direction

70

First position sensors

71

first supporting member

72

second supporting member

73

contact point

74

battery

75

internal heating sources

76

Power supply unit

77

first fastener

78

second fastener

79

Tax- and control device

80

Lorentz force direction

81

second position sensor

82

Eighth Signal / supply line

83

device

84

Fourth hot zone

v

rotation speed

I

electricity

B

Magnetic flux density

T _s

Angular momentum / righting moment

R ₁₇

Radius of the duct 19 around the pitch axis 17

R ₅₉

Radius of the duct 55 around the axis 59

H

Height of the duct

b

width of the duct

T _D

Disturbing torque

.DELTA.T

temperature gradient

S

South Pole

N

North Pole

M

engine

ω

Revolution / unit of time

F _L

Lorentz force

Claims (21)

Spacecraft with a device for position control on a predetermined orbital path, wherein the position is selectively alignable at least on a given spacecraft axis containing at least one angular momentum generating means and at least one higher-level control and regulating device, which is in communication with position sensors, wherein the means for Position control as an angular momentum generating means has at least one annular duct with a channel flowing therein liquid, which is at least electrically conductive and magnetically influenced, wherein the duct at least one magnetohydrodynamic pump for the circulation of the liquid is associated, characterized in that in the magnetohydrodynamic pump ( 21 . 22 . 42 . 43 . 44 . 45 . 51 . 52 . 53 . 54 ) a thermoelectric unit ( 48 . 49 . 62 ) with a material block ( 27 . 57 ), which is connected to the duct ( 19 . 40 . 55 ) is electrically and thermally conductive and a thermoelectric power to the liquid ( 20 ), wherein the material block ( 27 . 57 ) with an associated heat source ( 11 . 12 . 56 . 65 ) is connected to form a block-internal temperature gradient (ΔT) through which a current flow ( 25 . 26 . 67 ) in the channel cross-sectional plane ( 64 ) of the duct ( 19 . 40 . 55 ) is reached in such a way that with the aid of the control and regulating device ( 15 . 79 ) a moment-forming and optionally thermal-controlling circulation of the liquid ( 20 ) is reachable. Spacecraft according to claim 1, characterized in that the channel-flowing liquid ( 20 ) metallic, in particular liquid, metallic gallium or a gallium alloy or a salt solution-like liquid. Spacecraft according to claim 2, characterized in that the liquid ( 20 ) has a temperature adjusted in the range below the average operating temperature in the spacecraft housing ( 2 ) lies. Spacecraft according to at least one of the preceding claims, characterized in that the ducts ( 19 ; 40 ; 55 ) have a closed hollow ring casing as a channel housing, preferably a steel pipe ring. Spacecraft according to at least one of the preceding claims, characterized in that the annular duct ( 19 ; 40 ; 55 ) is cross-sectionally round, oval, square or rectangular. Spacecraft according to at least one of the preceding claims, characterized in that to a given spacecraft axis ( 16 . 17 . 18 ; 59 . 60 . 61 ) a plurality of ducts are axially superimposed and / or radially arranged one inside the other. Spacecraft according to at least one of the preceding claims, characterized in that to a MHD pump ( 21 . 22 ;; 42 to 45 ; 51 to 54 ) at least one of the duct ( 19 ; 40 ; 55 ) spaced magnet ( 23 . 24 ; 47 ; 68 ), the magnetic flux density (B) of the duct ( 19 ; 40 ; 55 ) cross-sectionally penetrates at least with a vertically directed magnetic flux density component, and the thermoelectric unit ( 48 . 49 . 62 ) for generating an electric current, the channel passage cross-section perpendicular to the duct ( 19 ; 40 ; 55 ) and at the same time oriented perpendicularly to the magnetic flux density (B) belong, which are arranged such that along the duct ( 19 ; 40 ; 55 ) one the liquid ( 20 ) driving force is present. Spacecraft according to claim 7, characterized in that the magnets or the magnet arrangement ( 23 . 24 ; 47 ; 68 ) an MHD pump ( 21 . 22 ;; 42 to 45 ; 51 to 54 ) Are permanent magnets and / or electromagnets. Spacecraft according to claim 7 or 8, characterized in that the magnets ( 23 . 24 . 47 . 68 ) an MHD pump ( 21 . 22 . 42 to 45 . 51 to 54 ) from the walls of the duct ( 19 . 40 . 55 ) and in guideways ( 32 ; 33 ) to the duct ( 19 . 40 . 55 ) are arranged movable, wherein the respective distance (d) to the duct ( 19 . 40 . 55 ) by existing resources ( 28 . 30 ; 29 . 31 ) for moving or rotating the magnets in the associated guideway ( 32 ; 33 ) is variable. Spacecraft according to at least one of the preceding claims, characterized in that the duct ( 19 ; 40 ; 55 ) at least partially with at least one heat-absorbing outer wall ( 3 ) of the spacecraft housing ( 2 ) and / or one or more assembly complexes / devices ( 83 ) and / or components ( 9 . 10 ) within the spacecraft housing ( 2 ). Spacecraft according to claim 1 to 10, characterized in that the material block ( 27 . 57 ) a single-zone hot zone ( 11 . 12 . 65 ) and another end-zone-side cold zone ( 66 ) and that between the two temperature value ranges ( 11 . 12 . 65 . 66 ) in cross section to the duct ( 19 . 40 . 55 ) a temperature gradient (ΔT) is present, whereby a circulating current flow ( 25 . 26 . 67 ) cross-sectioned by the liquid ( 20 ) and through the material block ( 27 . 57 ) is present. Spacecraft according to at least one of the preceding claims, characterized in that the channel housing of the duct ( 19 ; 40 ; 55 ) is a metal with sufficient electrical conductivity and thermal conductivity that has no reaction with the liquid and that of the magnets ( 23 . 24 ; 47 ; 68 ) outgoing magnetic flux density (B) is penetrable. Spacecraft according to at least one of the preceding claims, characterized in that the one MHD pump ( 21 . 22 ; 42 . 43 . 44 . 45 ; 51 to 54 ) assigned material block ( 27 ; 57 ) represents a block part. Spacecraft according to at least one of the preceding claims, characterized in that the material block (ΔT) provided for forming the temperature gradient ( 27 ; 57 ) in the intended heat absorption area (hot zone) ( 11 . 12 . 65 ) is made more voluminous and bulkier than in the heat release area (cold zone) ( 66 ). Spacecraft according to at least one of the preceding claims, characterized in that in a thermoelectric unit ( 48 . 49 . 62 ) an MHD pump ( 21 . 22 . 42 . 43 . 44 . 45 . 51 . 52 . 53 . 54 ) of the annular, preferably rectangular cross-section duct ( 19 ; 40 ; 55 ) assigned material block ( 27 ; 57 ) is preferably contiguous ring-shaped and in the radial direction of a local temperature gradient (.DELTA.T) can be influenced. Spacecraft according to at least one of the preceding claims, characterized in that the material block ( 27 ; 57 ) consists of a material that is a liquid ( 20 ) forms a high thermoelectric power and is preferably a cobalt alloy. Spacecraft according to one of claims 11-16, characterized in that in the regions of the hot zones ( 11 . 12 ) and the cold zone temperature sensors ( 13 . 14 ) arranged in the control and regulation device ( 79 ) are integrated with the means ( 28 . 30 ; 29 . 31 ; 69 ) for the displacement and / or rotation of the magnets ( 23 . 24 ; 47 ; 68 ) for changing the magnetic flux density (B) is in communication. Spacecraft according to claim 17, characterized in that the means for displacing the magnets are in particular linear motors ( 28 . 29 ) are firmly installed. Spacecraft according to one of claims 11-18, characterized in that in the regions of the hot zones ( 11 . 12 ) and cold zones the duct ( 19 ) associated heating elements ( 73 ) are arranged, which are provided for maintaining or keeping constant the temperature gradient (.DELTA.T), wherein the heating elements to the control and regulating device ( 79 ) belong. Spacecraft according to at least one of the preceding claims, characterized in that the control and regulating device ( 79 ) For the position control, a proportional-integral controller, a motor-displacement module, a fluid-related accuracy comparison module and a position navigation module contains. Spacecraft according to at least one of the preceding claims, characterized in that the device for position control, in particular by a MHD pump ( 21 . 22 ; 42 to 45 ; 51 to 54 ) driven, rotational pulses (T _S ) generating liquid ( 20 ) in the hollow-ringed lei channel ( 19 ; 40 ; 55 ) with optionally field variable thermoelectric and magnetic elements at the same time for heat transfer, for heat regulation and thus for thermal control within the spacecraft housing ( 2 ) can be used.