DE10230350A1 - Spacecraft attitude control system has electrically and thermally conducting magnetic fluid rotated in rings by magneto hydrodynamic pump - Google Patents

Abstract

A spacecraft attitude control system has pipe rings (19) with Gallium alloy electrically conducting magnetic fluid (20) rotated by a magneto hydrodynamic pump with magnets (21, 22) in guides (32) to give torque impulses about the three axes (16 - 18) and temperature gradients created by cobalt alloy blocks (27) to provide heat transfer.

Description

The invention relates to a spacecraft with a means for position control, the at least one angular momenta generating means for stabilizing the position at a predetermined orbital orbit, the location optionally at least at a given is alignable spacecraft axis, and at least one parent includes control and regulation means connected to position sensors in Connection is established.

Such a space vehicle with a device for controlling a 3-axis stabilizer is in the publication EP 0260957 B1 described in the or three momentum / reaction wheels (reaction wheels), a number of thrusters to a change in velocity maneuvers, which are mounted around the periphery of the spacecraft, as well as further means for compensating positions are at least one preferably present. thermal stresses due to the direct solar radiation (solar heat), by radiation into space, and by the liberated heat in the interior of the housing part of electronic equipment and devices (indoor heat) acting on the spacecraft in orbit. All of these energy influences generate disturbing torques that can change the predefined position of the spacecraft on its orbital orbit.

intended by the use of known momentum wheels done to compensate for the disturbance torques acting.

One problem is that Position control a momentum wheel mounted at least, the relative much energy its operating needs. If there are further swirl wheels on / in the spacecraft, then the mass balance shifted to the disadvantage of the payload mass.

Another problem is that in small satellites (approx 100 kg Mass), a high energy requirement for the operation of swirl wheels and at the same time for activity the pump to the flow of the liquid inside the heat pipes to reduce the heat build-up at the hot zones is required.

Another spacecraft is in the publication US 5,211,360 described in which a device for position control is provided with a reaction wheel (swirl wheel) or with a reaction wheel arrangement in order to compensate for the heat disturbances on the part of solar radiation. The solar radiation, which is manifested in particular by the resulting temperature gradients, also generate disturbing torques from the radiation pressure, which is applied to the base body of the spacecraft and changes its position. The temperature gradient to be registered by a plurality of temperature sensors and forwarded to the connected microcomputer / on-board computer and processed. With the microcomputer, which central part of the position control device, the momentum wheel is also connected to the up of the micro-computer signals to the rotation, and thus obtained for correcting the position, in which generates a counter torque to the resultant by the temperature disturbance torque by means of the momentum wheel and the spacecraft again the original position, in particular aligned with the predetermined spacecraft axis.

It is further comprising means for position and for a spin nutation controlled spacecraft roll, pitch and yaw axes in the publication EP 0460935 B1 described, which in addition to a sensor device for measuring the instantaneous roll attitude, an estimator, a logic device, at least one pushing device in the form of mini jet engines as well as a momentum wheel as an attitude correcting means. The mini-jet engines or the momentum wheel can generate torques to return the event of deviations from the original position values the position values relating to the predetermined spacecraft axes in predetermined limits. The associated control and regulating device contains a microcomputer, which transmits the relevant correcting signals to the position correcting means. Again, the mass effort - the Lagestabilierungsmasse - very high and reduces the mass balance the disadvantage of the payload mass of the spacecraft.

The object of the invention is therefore to provide a spacecraft with a device for position control specify that is formed in such a suitable that under reduced Mass and energy use in relation to at least one defined spacecraft axis Angular momentum can be generated. In addition to on any, caused in particular by heat disorders and disturbing moments generating positional changes be reacted in such a way that at least part of the disruptive heat for position correcting Angular momentum changes used can be.

The task is characterized by the characteristics of claim 1 solved. In the spacecraft with a device for position control according to the preamble of Claim 1, the means for position control as the angular momenta generating means at least one annular duct system with a liquid flowing through it, which at least can be influenced electrically and magnetically, the conduit system at least one magnetohydrodynamic (MHD) pump for rotation the liquid is assigned such that for position control rotational pulses by at least one of the predetermined spacecraft axes are generated.

The liquid can be conductive and heat be that the liquid-filled duct system optionally at the same time for heat control can be used.

The duct system may comprise at least Line duct with a closed hollow ring jacket as a duct housing, in particular a tubular steel ring included.

The channel-flowing liquid can metallic Kind or a saline-like liquid his.

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

The duct system may comprise at least hollow annular Have conduit, the torque axis preferably with one of the predetermined space vehicle axles, in particular with the Yaw, pitch or roll axis coincides.

The hollow annular duct can be round in cross section, oval, square or rectangular.

To a predetermined axis of the spacecraft can be more ducts axially one above the other and / or radially be arranged into one another.

At least one can be used for a MHD pump magnet spaced from the conduit, its magnetic flux density the line channel cross-sectional at least with a vertical directed component pierces, and at least one means for Generation of an electric current, the channel passage of which is cross-sectional perpendicular to the duct and at the same time perpendicular to the magnetic flux density is directed, belong and be arranged such that along the duct a the liquid driving force is present.

The magnets or magnet assembly an MHD pump can Permanent magnets and / or electromagnets.

The means of generating an electric current may be in the MHD pump, at least one of an existing electrical Power supply unit having powered electrode pair whose Electrodes, opposite each other, in the walls of the duct are inserted and with the liquid are so connected that, in operation transverse to the duct and through the liquid there is a current flow through it.

The magnets an MHD pump may differ from the Walls of the conduit spaced and in guideways be arranged to be movable to the conduction channel, wherein the respective Distance from the conduction channel by existing means for displacing or rotating the magnets in the associated guideway is variable.

The cable channel can at least partially with at least one heat (Solar heat) receiving wall of the spacecraft housing and / or one or more Complex assemblies / devices or components within the spacecraft housing (internal heat) in Connect.

The electrically conductive liquid may, in particular liquid, represent metallic gallium or a gallium alloy.

In the MHD pump can be used as a means to generate an electrical current within a conduit a thermoelectric unit can be provided, which essentially from the conduit, the liquid and a material block, wherein the block of material with the is duct connected, electrically and heat as well as to the conductive liquid is designed with a thermoelectric power such that in the presence of a temperature gradient within the block of material a current flow in the channel cross-sectional plane through the liquid is passed to reach.

On thermoelectric trained Material block are a einendbereichsseitige hot zone and a cold zone on the other end region in such a way that between the two temperature value ranges in cross section to the duct directed, a temperature gradient is present, thus forming a Circulating, thermoelectrically generated current flow cross-sectional through the liquid and through the block of material therethrough is formed.

The channel housing is a metal having sufficient electrical and thermal conductivity, the no reaction with the liquid and being penetrated by the magnetic flux density.

The block of material may be part of the body.

Of the formation of the temperature gradient The proposed block of material can be made more voluminous in the intended heat absorption area (hot zone) be than in the heat-dissipating area (cold zone).

The rectangular with the annular, preferably cross-sectionally Duct associated block of material may be formed preferably annularly and can be influenced in the radial direction by a temperature gradient his.

The block of material can be made from one Material consist of liquid a high thermoelectric power, and preferably forms is a cobalt alloy.

In the areas of the hot zones and of the cold zones Temperature sensors can be arranged, which are connected to the control and regulating device are provided with the means for displacement and / or rotation of the Magnet amending the magnetic flux density is in communication.

The means for moving the magnets can in particular be linear motors, which are fixedly installed.

In the areas of the hot zones and Cold zones the conduction channel associated heating elements may be arranged that to maintain or maintain a constant temperature gradient are provided, the heating elements with the control and regulating device stay in contact.

The control and regulating device for the Position control can preferably the thermoelectric mode of operation is a proportional-integral controller, one Motor displacement module, a liquid-associated accuracy comparison module and a location-navigation module included.

The position control device, in particular driven by an MHD pump, an angular momentum generating metallic liquid in the hollow annular Duct with optional field varying electric and magnetic elements can be used for heat transport and thus for thermal control be usable, resulting in a cost-saving thermal control in the Spacecraft leads.

The invention opens up the possibility that in the presence of hot and cold zones in the area of the duct a heat control over the Exchange of heat between the liquid and the Leitungskanalwandungen as well as by the transport of heat the liquid can be done.

The invention allows heat and Power surpluses Generation of thermoelectricity are used, whereby the cost of electrical energy for the entire Spacecraft can be reduced. This also draws savings on the spacecraft power supply system itself.

The position control device, in particular, an angular momentum driven by a MHD pump generating liquid in the hollow ring Duct with optional field varying electric and magnetic elements is thus the same for heat transport and exchange can be used if there is direct contact and / or between the hot zones and the duct housing heat transfer Contact elements are provided.

The invention enables the device for position control with 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 the further subclaims.

The invention is achieved by means of several embodiments based on drawings explained.

Show it:

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

2 a schematic representation of a pair of electrodes supported by the magneto-hydrodynamic (MHD) pumps provided duct laying down the liquid movement direction,

3 a perspective cut-away view of the duct according to 2 .

4 a schematic representation of thermoelectrically based MHD pumps to a sun-oriented spacecraft,

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

6 a schematic representation of the operational sequence of the position control in the event of disturbing torques.

In 1 is the overall view of a spacecraft 1 represented with a means for position control. The spacecraft 1 has substantially a spacecraft housing 2 six outer walls 3 . 4 . 5 . 6 . 7 . 8th , Which preferably form a cube, two power modules 9 . 10 Which is representative of other devices, assemblies, components, and other power and heat generating sources are shown and at least surface region side hot zones (hot spots) 11 . 12 having the hot zone 11 . 12 assigned temperature sensors 13 . 14 and an onboard computer 15 , whereby the attitude of the spacecraft 1 by three selectively predetermined spacecraft axes - z. B. the yaw axis 16 , The pitch axis 17 and the roll axis 18 - is defined.

According to the invention, the device for position control essentially contains at least one annular conduit system as a means generating angular momentum 19 with therein befindlicher, channel by flowing liquid 20 That is at least electrically conducting and magnetically influenced, wherein the duct system 19 at least one, here two magneto-hydrodynamic pump (MHD pumps) 21 . 22 the rotation of the liquid 20 are assigned such that for position control, the liquid 20 in the duct system 19 unidirectionally to one of the predetermined spacecraft axes 16 . 17 . 18 is circumferentially controlled movable and generates rotation pulses.

The liquid 20 such heat may be conductive, and storing that the liquid-filled duct system 19 is optionally simultaneously used for heat control.

The MHD pumps 21 . 22 each contain a magnet assembly, in particular a magnet 23 or 24 and a system 25 and 26 for generating an electric current.

The magnets 23 . 24 are preferably permanent magnets, but can also be electromagnets his or combinations of permanent and electromagnet. The permanent magnets 23 . 24 located at a distance d from the channel housing of the duct 19 , The permanent magnets 23 . 24 in 1 is in each case a motor 28 . 29 with an associated motor control 30 . 31 and an associated guideway 32 . 33 the displacement or rotation of the magnets 23 . 24 assigned.

The respective system 25 . 26 for generating an electric current, a pair of electrodes of cathode and anode or a thermoelectric unit can display. Within the thermoelectric unit is a first block of material 27 provided, which consists of a material that is related to the liquid 20 in the first line channel 19 has a considerable thermal power, using the formation of a hot and a cold electrode (a temperature gradient ΔT).

In the ring-shaped first conduit 19 there may be at least one liquid speed meter 34 which measures the actual values of the rotational speed v and in particular via a line 39 to the control and regulation device 79 ( 6 ) forwards. The first duct 19 can by mounting elements 71 . 72 on the housing 2 of the first spacecraft 1 be attached. This can also be used for contact points 73 to the outer walls 3 4 5 . 6 form, which can be directed in accordance with sunlight to hot zones.

Inside the spacecraft housing 1 can be at least one a hot zone 84 generating device 83 are that with his hot zone 84 on the wall of the duct system 19 can concern.

The engine controls 30 . 31 , The temperature sensors 13 . 14 and the liquid speedometer 34 are connected via associated signal / power 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 onboard computer 15 especially via lines 82 . 63 are connected and the actual values of the position of the first spacecraft 1 measure and forward for processing.

In 2 is a schematic diagram for determining the direction of rotation speed 46 the liquid 20 or the direction of the rotational speed v shown. In 3 is a perspective cut-away view of the annular, rectangular in cross-section, the second duct 40 shown. Both 2 . 3 are described together below.

The second duct 40 in the second spacecraft 41 preferably consists of a tubular steel ring (ring radius R) with a rectangular cross-section (height h, width b) and has in each case at four positions a MHD pump 42 . 43 . 44 . 45 , The liquid 20 in steel pipe ring 40 is preferably metallic gallium. The tubular steel ring 40 can also the outer walls of the two th spacecraft 41 touch. The MHD pumps 42 to 45 each containing permanent magnets 47 and an electrode assembly 48 (Cathode / anode), being outside the electrode arrangement 48 the duct housing 40 by an insulating jacket 49 ( 3 can surround). The rotational speed v of the gallium, by varying the electric current I between the electrodes of the electrode assembly 48 or the magnetic flux density B of the permanent magnets 47 to be influenced.

Are in contact with the steel tube ring 40 present with the outer walls there hot zone, then the presence of excess heat can there from the liquid 20 can be transported away. Essentially, depending on the speed of rotation v with a ring radius R ( 2 ) an actuating torque T _{S is} generated which can be used for position control. Characterized v rotates due to the rotation speed and angular momentum T _S the spacecraft 41 with a number of revolutions / unit of time ω. v may for increasing the rotational speed substantially equal to the electric current I and / or the magnetic flux density B be increased, by a compound of MHD pumps 42 to 45 with the associated control and regulating device 79 ( 6 ) Including the on-board computer 15 can take place, or the number of MHD pumps can be increased.

For those in the liquid 20 acting normal to the cross section A = h · b normal directed Lorentz force F _L - 80 - direction of the arrow ( 2 ) - in the direction of flow, the following applies: F L = HLB when the magnetic flux density B and the current I (along the height h) are directed perpendicularly to each other.

The mass of steel pipe ring case 40 , the permanent magnet 47 and an associated power supply for the electrode arrangement 48 can be about 25% of the total device mass, wherein the remainder mainly means the mass of the mass of the liquid 20 is determined. With the rotating mass of the liquid 20 can the corrective angular momentum, an actuating torque T _S ( 2 ) To the predetermined space vehicle axle 17 be generated.

Based on 4 and 5 is on when appended 1 a further embodiment, particularly illustrated for the angular momentum increase. 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 duct 55 That in the seventh MHD pump 51 (representative of all thermoelectrically supported MHD pumps) is shown, the explanation of which also 1 includes. To do this, the 4 and 5 explained together.

On the outer wall 56 of the third spacecraft 50 is an annular second material block 57 so by means of fasteners 77 . 78 appropriate that a direct contact between the solar radiation by an 58 high-temperature outer wall 56 and the second material block 57 is available. The third spacecraft 50 has the spacecraft axes 59 . 60 . 61 , Which is with one of its spacecraft axes 59 is aimed at the sun. Solar radiation 58 and thus the heat of the sun hits the outer wall 56 , A hot zone is created there. The annular second material block 57 is the ring-shaped third conduit 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 provided as a means for generating a respective one electric current I within a duct 55 a second thermoelectric unit 62 (Representative of all four MHD pumps) provided from the third duct 55 , the liquid 20 and the second material block 57 , wherein the second material block 57 with the third duct 55 is connected, electrically and heat is conductive as well as to the liquid 20 is formed with a thermoelectric power.

The one with the ring-shaped, preferably cross-sectional rectangular duct 55 connected second block of material 57 is preferably also annular and influenced in the radial direction of a temperature gradient .DELTA.T.

On the second block of material 57 is the outer wall 56 directed a hot zone on one end area and a cold zone on the other end area 66 present, wherein the temperature gradient in .DELTA.T 5 between the two different temperature value areas 65/66 in cross-section to conduit 55 directional is present, which creates a circulating current flow 67 cross-section directed through the liquid 20 and through the second block of material 57 passes available.

The channel box 55 is a metal having sufficient electrical and thermal conductivity, no reaction with the liquid 20 and being penetrated by the magnetic flux density B.

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

For the formation of the temperature gradient AT is the intended second material block 57 in the intended heat absorption area (hot zone) 65 preferably more voluminous and bulky than in the heat dissipation area (cold zone) 66 ,

The second block of material 57 consists of a material to liquid 20 , e.g. As gallium, forms a sufficiently high thermoelectric power, and preferably a cobalt alloy can be.

In the regions of hot zones 65 and the cold zones 66 Temperature sensors may be arranged that in the control and regulating device 79 ( 6 ) are involved with the means 69 (Displacement arrow) for displacement and / or rotation of the magnets 68 stands for changing the magnetic flux density B in combination, said means 69 to move the magnets 68 in particular can be firmly mounted, linear motors. In the control and regulating device 79 is preferably the on-board computer 15 contain.

Is groundbreaking due no sunlight on the outer wall 56 available, so in the areas of the hot zones 65 and cold zones 66 the conduction channel 55 assigned and switchable heating elements can be arranged, which are provided for maintaining or maintaining the temperature gradient ΔT, the heating elements with the control and regulating device 79 may be associated.

The way it works is with both spacecraft 1 and 50 with thermoelectrically MHD pumps supported almost the same: the electrically conductive metallic liquid 20 is in the cable duct 19 . 55 Included, with a cobalt ring 27 . 57 adjacent connected. Because of the different electron levels in the neighboring metals 20-27 . 20-57 If there is a temperature gradient ΔT in the radial direction, there is a current flow 67 , By the interaction with the magnetic field of the permanent magnet 23 . 24 ; 68 creates the Lorentz force on the liquid 20 Which is thus moved and around the predetermined axis 17 . 59 rotates. The resulting motion 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 be changed. The magnets 23 . 24 ; 68 can e.g. For example, by linear motors 28 . 29 ; 69 be moved.

In 6 is a schematic representation of the operational sequence of the position control for the stabilization of a spacecraft in the event of disturbing torques T _D with reference to 1 shown.

A first on the spacecraft 1 Attacking disturbance torque T _D changes the position of the first spacecraft 1 Comprising at least a thermo-electrically assisted MHD pump 21 . 22 is working. The change in position can be measured with the help of position sensors (e.g. gyroscopes, star sensors, etc.) 70 , 81 and via the associated signal / supply lines 82 , 63 to the connected on-board computer 15 be reported. In the on-board computer 15 that is necessary for a position correction aligning torque T _S is then determined by a comparison processing. Along with the information about current Temperaturgra served .DELTA.T along the first conduit 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 of permanent magnets 23 . 24 be sent. Then, the distance d of the permanent magnets 23 . 24 to the duct housing of the first duct 19 changed, causing the magnetic flux density B in the channel cross section 64 can be varied. The magnetic flux density change in turn results in a change of the Lorentz force, and finally the circulation velocity v of the liquid 20 result. The so through the first duct 19 rotating liquid 20 induced torques T _S be the channel support members 71 . 72 on the first spacecraft 1 transmitted in order to partially or completely counteract the disturbing torques T _D.

The six outer walls 3 . 4 . 5 . 6 . 7 . 8th of the first spacecraft 1 be different effects (eg. B. sunlight, albedo, etc.) to heat up or cool down. Via the contact points 73 and / or support members 71 . 72 can be the first conduit 19 with the outer walls 3 to 6 be thermally connected. Furthermore, inside the existing spacecraft 1 the hot zones or heating elements 11 . 12 , especially electrical and electronic components 9 . 10 where a lot of heat is released. The components 9 . 10 are thus thermally conductive with the first duct 19 on the first block of material 27 (e.g. consisting of cobalt alloy). About the temperature sensors 13 . 14 the current temperatures are recorded and to the on-board computer 15 transfer. If excessively high variations in temperature gradient .DELTA.T across the channel cross-section 64 on, the temperature at the hot zone is 11 . 12 - The power module contact points or heating elements - by additional heating or by using other internal heating sources 73 raised. The regulation is done by the onboard computer 15 , By the circulation of the liquid 20 through the first duct 19 there is also an even temperature distribution or heat control of the adjacent outer walls 3 to 8th reached. Next occurs a heat transfer from the hot zones / heating elements 11, 12 to the channel housing 19 , The heat transport is on the one hand the driving force for the creation of the electric field or current across the channel cross-section 64 and on the other hand ensures a desired cooling of the relevant components 9 . 10 , This means that comprehensive thermal control is also available.

The power supply for all named components 9 . 10 via a spacecraft internal power supply unit 76 , By a battery 74 and is supported by other generating facilities.

The control and regulating device 79 to which the on-board computer 15 belongs to the position control of the MHD pumps can proportional integral regulator, contain a engines a shift module, a liquid-associated accuracy comparison module as well as a location navigation module preferably for the thermoelectric mode.

Since the heat transport do not like the known heat pipe system depends on the convection is, but on the liquid-based mass flow in the hot zones disturbing heat faster be transported to the cold zones. The use of thermoelectric gestützen MHD pumps, substantially undesirable temperature gradients Recycle within the spacecraft, in particular, primarily for position control of a spacecraft and at the same time secondary for the constancy of the internal operating temperature in the spacecraft and therefore inexpensive 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 electrode pair

26

second electrode pair

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

electrode assembly

49

insulator

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

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 means

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

radius the duct

H

Height of the duct

b

width the duct

T _D

Disturbing torque

.DELTA.T

temperature gradient

S

South Pole

N

North Pole

M

engine

ω

Revolution / unit time

F _L

Lorentz force

Claims (25)

Space vehicle having a device for position control, comprising at least one rotational pulse generating means for stabilizing the position at a predetermined orbital path, the position is selectively alignable at least at a given spacecraft axis, and at least one superordinate control and regulating device which is connected to position sensors in conjunction characterized in that the device generating the position control means as the rotation pulses at least one annular duct system ( 19 ; 40 ; 55 located) with a fact liquid flowing through channel ( 20 has) which is at least electrically conducting and magnetically influenced, wherein the duct system ( 19 ; 40 ; 55 ) At least one magneto-hydrodynamic (MHD) pump ( 21 . 22 ; 42 . 43 . 44 . 45 ; 51 . 52 . 53 . 54 ) For rotation of the liquid ( 20 is) assigned such that for position control rotational pulses by at least one of the predetermined spacecraft axes ( 16 . 17 . 18 ; 59 . 60 . 61 ) can be generated. Spacecraft according to claim 1, characterized in that the liquid ( 20 ) Is conductive and such heat retentive that the fluid-filled line channel system ( 19 ; 40 ; 55 can be used) optionally, for heat control. A spacecraft according to claim 1 and 2, characterized in that the channel through-flowing liquid ( 20 ) metallic type, in particular liquid, metallic gallium or a gallium alloy or a saline-like liquid. A spacecraft according to claim 3, characterized in that the liquid ( 20 Having) a temperature adjusted in the range below the average operating temperature in the spacecraft body ( 2 ) lies. Spacecraft according to at least one of the preceding claims, characterized in that the duct system ( 19 ; 40 ; 55 ) At least a duct having a closed hollow annular casing as a duct housing, preferably a tubular steel ring contains. A spacecraft as claimed in any one of the preceding claims, that the duct system ( 19 ; 40 ; 55 ) has at least one hollow annular duct, the torque axis preferably with one of the predetermined spacecraft axes ( 16 . 17 . 18 ; 59 . 60 . 61 ), especially with the yaw, pitch or roll axis ( 16 ; 17 ; 18 ) matches. A spacecraft according to at least one of preceding claims, characterized in that the hollow annular duct ( 19 ; 40 ; 55 is) cross-sectionally round, oval, square or rectangular. A spacecraft as claimed in any one of the preceding claims, that for a given spacecraft axis ( 16 . 17 . 18 ; 59 . 60 . 61 ) Axially over each other a plurality of line channels and / or are arranged radially in one another. Spacecraft according to at least one of the preceding claims, characterized in that an MHD pump ( 21 . 22 ; 42 to 45 ; 51 to 54) from the at least one duct ( 19 ; 40 ; 55 ) spaced magnet ( 23 . 24 ; 47 ; 68 ), whose magnetic flux density (B) 19 ; 40 ; 55 ) Directed cross-section with at least one vertically directed magnetic flux density component penetrates, and at least one means for generating an electric current whose channel passage cross-section directed perpendicular to the conduit ( 19 ; 40 ; 55 ) and at the same time is directed perpendicular to the magnetic flux density (B), which are arranged such that along the conduit ( 19 ; 40 ; 55 ) Is a liquid ( 20 ) Driving force is present. A spacecraft as claimed in any one of the preceding claims, that the magnets and the magnet arrangement ( 23 . 24 ; 47 ; 68 ) a MHD pump ( 21 . 22 ; 42 to 45; 51 to 54) are permanent magnets and / or electromagnets. Spacecraft according to at least one of the preceding claims, characterized in that the means for generating an electrical current in the MHD pump ( 41 to 45 ) At least one electrical from an existing energy supply unit ( 76 ) fed pair of electrodes ( 48 Having) the electrodes of which, in each case opposite, in the walls of the duct ( 40 ) Are introduced, and with the liquid ( 20 ) Are connected in such a way that in operation transverse to the duct ( 40 ) And the liquid ( 20 ) there is a current flow through it. A spacecraft as claimed in any one of the preceding claims, that the magnets ( 23 ; 24 ) a MHD pump ( 21 ; 22 ) from the walls of the conduit ( 19 ) Are spaced apart and in guideways ( 32 ; 33 ) to the trunking ( 19 ) are arranged movable, wherein the respective distance (d) to the duct ( 19 ) By known means ( 28 . 30 ; 29 . 31 ) For displacement or rotation of the magnets in the associated guideway ( 32 ; 33 ) is variable. Spacecraft according to at least one of the preceding claims, characterized in that the conduit ( 19 ; 55 ) At least partially receiving at least one heat outer wall ( 3 ) Of the spacecraft body ( 2 ) And / or one or more complexes assemblies / devices (83) and / or components ( 9 . 10 ) Within the spacecraft body ( 2 ) is connected. Spacecraft according to claim 1 to 13, characterized in that in the MHD pump ( 21 . 22 ; 51 to 54 ) As a means for generating an electric current ( 67 ) Within a duct ( 19 ; 55 ) a thermoelectric unit ( 62 is provided) consisting of the duct ( 19 ; 55 ), The liquid ( 20 ) And a block of material ( 27 ; 57 ), whereby the material block ( 27 ; 57 ) With the duct ( 19 ; 55 is) connected electrically and heat is conductive and formed from the liquid with a thermoelectric power in such a manner that in the presence of a temperature gradient (.DELTA.T) within the block of material ( 27 ; 57 ) Of the current flow ( 67 ) In the channel cross-sectional plane ( 64 ) Through the liquid ( 20 ) can be reached through. A spacecraft according to claim 14, characterized in that the block of material ( 57 ) a hot zone on the one-end area ( 65 ) And a cold zone anderenendbereichsseitige ( 66 are present) and that between the two temperature ranges of information ( 65 . 66 ) In cross-section to conduit ( 55 directed) a temperature gradient (.DELTA.T) is provided, whereby a circumferential current flow ( 67 ) Cross-section directed through the liquid ( 20 ) and through the block of material ( 57 ) Therethrough is provided. A spacecraft as claimed in any one of the preceding claims, that the channel housing of the duct ( 19 ; 40 ; 55 Is) a metal having sufficient electrical conductivity and thermal conductivity having no reaction with the liquid and that of the magnets ( 23 . 24 ; ; 68 ) Outgoing magnetic flux density (B) can be penetrated. Spacecraft according to at least one of the preceding claims, characterized in that the one MHD pump ( 21 . 22 ; 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 block of material provided for forming the temperature gradient (ΔT) ( 27 ; 57 ) In the provided heat receiving area (hot-zone) ( 65 ) Is formed of bulky and massive than in the heat-dissipating area (cold area) ( 66 ). A spacecraft as claimed in any one of the preceding claims, in that a thermoelectric unit of an MHD pump ( 21 . 22 ) the ring-shaped, preferably cross-sectionally rectangular duct ( 19 ; 55 ) assigned material block ( 27 ; 57 is formed preferably) contiguous annular and can be influenced in a radial direction by a local temperature gradient (.DELTA.T). Spacecraft according to at least one of the preceding claims, characterized in that the block of material ( 27 ; 57 ) Is made of a material to liquid ( 20 ) forms a high thermoelectric power and is preferably a cobalt alloy. A spacecraft as claimed in any one of the preceding claims, that in the areas of the hot zones ( 11 . 12 ) and the cold zone temperature sensors ( 13 . 14 ) are arranged in the control and regulating 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 ) Is related to the change of the magnetic flux density (B). A spacecraft as claimed in any one of the preceding claims, wherein the means for displacement of the magnet particularly linear motors ( 28 . 29 ) that are permanently installed. A spacecraft as claimed in any one of the preceding claims, that in the areas of the hot zones ( 11 . 12 ) and cold zones the line duct ( 19 ) assigned heating elements ( 73 ) are arranged, which are provided to maintain or maintain a constant temperature gradient (.DELTA.T), wherein the heating elements to the control and regulating device ( 79 ) belong. A spacecraft as claimed in any one of the preceding claims, that the control and regulating device ( 79 ) For the position control, preferably for the thermoelectric mode includes a proportional-integral regulator, a displacement engine module, a liquid-associated accuracy comparison module as well as a location navigation module. Spacecraft according to at least one of the preceding claims, characterized in that the device for position control, in particular by an MHD pump ( 21 . 22 ; 42 to 45 ; 51 to 54 ) Driven, rotational pulses (T _S) generating liquid ( 20 ) In the hollow ring-shaped duct ( 19 ; 40 ; 55 ) Simultaneously, lung with optional field varying electric and magnetic elements for heat transfer to heat Rege and thus to thermal control within the spacecraft body ( 2 ) can be used.