WO1987007877A1 - Systeme hybride de correction de position pour engin spatial - Google Patents

Systeme hybride de correction de position pour engin spatial Download PDF

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Publication number
WO1987007877A1
WO1987007877A1 PCT/US1987/001073 US8701073W WO8707877A1 WO 1987007877 A1 WO1987007877 A1 WO 1987007877A1 US 8701073 W US8701073 W US 8701073W WO 8707877 A1 WO8707877 A1 WO 8707877A1
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WO
WIPO (PCT)
Prior art keywords
oxidizer
fuel
thrusters
monopropellant
thruster
Prior art date
Application number
PCT/US1987/001073
Other languages
English (en)
Inventor
M. Edmund Ellion
Philip A. Donatelli
Original Assignee
Hughes Aircraft Company
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hughes Aircraft Company filed Critical Hughes Aircraft Company
Publication of WO1987007877A1 publication Critical patent/WO1987007877A1/fr

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B64—AIRCRAFT; AVIATION; COSMONAUTICS
    • B64G—COSMONAUTICS; VEHICLES OR EQUIPMENT THEREFOR
    • B64G1/00—Cosmonautic vehicles
    • B64G1/22—Parts of, or equipment specially adapted for fitting in or to, cosmonautic vehicles
    • B64G1/24—Guiding or controlling apparatus, e.g. for attitude control
    • B64G1/26—Guiding or controlling apparatus, e.g. for attitude control using jets
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B64—AIRCRAFT; AVIATION; COSMONAUTICS
    • B64G—COSMONAUTICS; VEHICLES OR EQUIPMENT THEREFOR
    • B64G1/00—Cosmonautic vehicles
    • B64G1/22—Parts of, or equipment specially adapted for fitting in or to, cosmonautic vehicles
    • B64G1/40—Arrangements or adaptations of propulsion systems
    • B64G1/401—Liquid propellant rocket engines
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B64—AIRCRAFT; AVIATION; COSMONAUTICS
    • B64G—COSMONAUTICS; VEHICLES OR EQUIPMENT THEREFOR
    • B64G1/00—Cosmonautic vehicles
    • B64G1/22—Parts of, or equipment specially adapted for fitting in or to, cosmonautic vehicles
    • B64G1/40—Arrangements or adaptations of propulsion systems
    • B64G1/402—Propellant tanks; Feeding propellants
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02K—JET-PROPULSION PLANTS
    • F02K9/00—Rocket-engine plants, i.e. plants carrying both fuel and oxidant therefor; Control thereof
    • F02K9/42—Rocket-engine plants, i.e. plants carrying both fuel and oxidant therefor; Control thereof using liquid or gaseous propellants
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B64—AIRCRAFT; AVIATION; COSMONAUTICS
    • B64G—COSMONAUTICS; VEHICLES OR EQUIPMENT THEREFOR
    • B64G1/00—Cosmonautic vehicles
    • B64G1/22—Parts of, or equipment specially adapted for fitting in or to, cosmonautic vehicles
    • B64G1/24—Guiding or controlling apparatus, e.g. for attitude control
    • B64G1/242—Orbits and trajectories
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B64—AIRCRAFT; AVIATION; COSMONAUTICS
    • B64G—COSMONAUTICS; VEHICLES OR EQUIPMENT THEREFOR
    • B64G1/00—Cosmonautic vehicles
    • B64G1/22—Parts of, or equipment specially adapted for fitting in or to, cosmonautic vehicles
    • B64G1/24—Guiding or controlling apparatus, e.g. for attitude control
    • B64G1/242—Orbits and trajectories
    • B64G1/2427—Transfer orbits

Definitions

  • This invention relates to spacecraft, and, more particularly, to the control system used in spacecraft.
  • a spacecraft such as a satellite depends upon several types of propulsion and control systems during its life. For example, in the case of a spacecraft launched by the space shuttle, a powerful combination of main and booster engines lifts the entire shuttle orbiter into a low orbit around the earth. A spacecraft or satellite to be placed into a permanent or semi-permanent orbit is carried aloft in the payload bay of the orbiter, and then is launched into its own orbit from the orbiter with additional rocket thrusters.
  • the communications satellite acts as a relay station for transmitted signals.
  • An earth station transmits a television, telephone, data or other signal to the satellite, which in turn relays the signal to- another earth station, possibly ' after amplifying or otherwise modifying it.
  • the earth stations are a key part of the overall system, and it is commercially important to minimize their cost.
  • One approach to minimizing cost is to position the communications satellite at a fixed location in the sky relative to the earth stations, so that the sending and receiving antennas of the earth - stations can remain stationary and pointed at the fixed location, avoiding the need for tracking electronics and mechanisms that would otherwise be necessary for the ground antennas to continuously point at a satellite that moves relative to the earth stations. While this approach minimizes the cost of the earth station, it adds complexity to the requirements of the satellite control system.
  • the satellite After the satellite is ' transported into space by the space shuttle or an expendable rocket, it is then boosted into a highly elliptical orbit by a thruster termed a perigee motor. When the elliptical orbit intercepts the altitude required for " the geosynchronous orbit, another thruster termed the apogee motor is fired to cause the satellite to enter the circular geosynchronous orbit. Once the satellite is in geosynchronous orbit, smaller thrusters are used . to position it precisely at the desired orbital station and with the proper orientation. This description has been presented for a communications satellite in geosynchronous orbit, but the same principles apply for other types of satellites in low-earth orbit, polar orbit, inclined orbit, etc.
  • the spacecraft must be provided with the means to control its attitude and orbital position relative to the intended position in orbit, also termed the station, so that minor deviations from the intended position can be corrected.
  • the attitude and station of a communications satellite in geosynchronous orbit must be maintained precisely, so that communications links with the ground are not broken.
  • the spacecraft is therefore provided with its own built-in control system, including thrust.ers which can propel the spacecraft in various modes.
  • thrust.ers which can propel the spacecraft in various modes.
  • the thrusters control the attitude or orientation of the spacecraft with respect to the earth or other reference points. They also shift the position of the spacecraft in a north-south or east-west direction, should the spacecraft stray from its intended station in orbit, in maneuvers termed stationkeeping.
  • the control system may also provide propulsion to move the spacecraft to an orbit of slightly different altitude above the earth.
  • attitude control and stationkeeping functions are usually provided by a single type of thruster, although there are numerous thrusters of that single type located at various positions on the spacecraft to allow combinations of thrusters to be fired to achieve the desired control movements.
  • Attitude control usually requires more frequent, shorter pulses of thrust, while north-south and east-west stationkeeping and orbital changes require less frequent, longer pulses of thrust.
  • Monopropellant thrusters generate hot gas by passing a fuel such as hydrazine over a catalyst such as iridium to decompose the fuel into a hot gaseous mixture, ana then direct the gas through a nozzle to provide thrust.
  • Bipropellant thrusters generate gas by reacting a fuel such as hydrazine or the less-energetic monomethylhydrazine with an oxidizer such as nitrogen tetroxide, and then direct the hot gas through a nozzle to provide thrust.
  • monopropellant thrusters are most favored for small, inexpensive satellites because of their simplicity.
  • Bipropellant thrusters are more favored when, used for the control of larger satellites and consequently greater propellant loads because of their greater efficiency. The selection of the particular thrusters for the control system depends upon the exact mission of the spacecraft.
  • the present invention resides in a spacecraft control system which utilizes a hybrid monopropellant and bipropellant approach to providing .thrust for attitude control and stationkeeping, and for apogee boost.
  • the control system achieves significantly improved spacecraft efficiency, without requiring major modifications to spacecraft procedures.
  • a spacecraft control system comprises a bipropellant thruster operating from a fuel and an oxidizer; a monopropellant thruster operating from the same type of fuel as said bipropellant thruster; a supply of oxidizer communicating with the bipropellant thruster; and a supply of fuel communicating with the bipropellant thruster and the monopropellant thruster, the amount of fuel being greater than the amount required to react with all of the oxidizer.
  • the fuel is preferably hydrazine and the oxidizer is preferably nitrogen tetroxide.
  • the apogee motor can alsq be operated as a bipropellant thruster using the common fuel and oxidizer.
  • the monopropellant thruster is preferably initially used for maneuvers requiring short pulses of thrust which require a small percentage of the total propellant and consequently its lower performance 'is of little signi icance.
  • the bipropellant thruster is preferably used for maneuvers requiring long pulses of thrust, which require the majority of the total propellant. Because the bipropellant thruster only has to operate in the steady state mode, its design can be optimized for that single type of operation, so that it is more efficient than the conventional thrusters that must operate in both the steady state and pulsing modes. • The fuel is provided in excess, so that the oxidizer is exhausted first. When the oxidizer is depleted, the bipropellant thruster no longer functions. The monopropellant thruster can then be used for . both short and long duration firings, even though the monopropellant thruster is somewhat less efficient than the bipropellant thruster. An overall advantage is gained by using the otherwise unusable residual propellant.
  • two sets of monopropellant thrusters and a bipropellant thruster are provided for attitude control and stationkeeping maneuvers.
  • Radial monopropellant thrusters are positioned for performing attitude control and east-west stationkeeping, and the bipropellant thrusters are positioned for north-south stationkeeping in their normal operation. These thrusters are used in the early part of the life of the satellite, while both fuel and oxidizer are available.
  • Axial monopropellant thrusters are . positioned for north-south stationkeeping when the oxidizer is depleted.
  • both the radial and axial monopropellant thrusters are used to control the satellite, expending the remainder of the fuel excess completely.
  • the amount of fuel carried is therefore greater than the sum of the amount required to react with all of the oxidizer, plus the expected consumption of fuel by the monopropellant thrusters prior to the time that the oxidizer is expended.
  • a method for controlling a spacecraft comprises providing the spacecraft with at least one bipropellant thruster and at least one monopropellant thruster; providing the spacecraft with a fuel storage tank communicating with the bipropellant thruster and the monopropellant thruster; providing the spacecraft with am oxidizer storage tank communicating with the bipropellant thruster; loading the oxidizer storage tank with an amount f 5" 5 of oxidizer; and loading the fuel storage tank with an amount of fuel in excess of the amount required to react with the available oxidizer in the oxidizer storage tank.
  • Bipropellant and monopropellant thrusters can *>e designed ⁇ and used optimally, and
  • the onboard fuel and oxidizer may be pr.ovided. in quantities that will allow the spacecraft to function for the greatest possible time before exhaustion of these consumables.
  • Figure 1 is a schematic view of a typical communications satellite in relation to the earth and two earth stations;
  • Figure 2 is a schematic view of three types of satellite orbits in relation to the earth
  • Figure 3 is a schematic view of a communications satellite in geosynchronous orbit, illustrating different types of movement induced by operation of the thrusters;
  • Figure 4 is a sectional elevational view of a communications satellite, illustrating the control system;
  • FIG. 5 is a schematic diagram of the control system.
  • Spacecraft are often placed into orbit as satellites in approximately the desired a -titude and orbit by a launch vehicle such as a dedicated booster rocket or the reusable space shuttle.
  • the ' attitude and orbit must often then be refined by the control system of the spacecraft, using the propulsion thrusters located on the spacecraft.
  • the attitude of the spacecraft can change slightly, but even a few degrees of misorientation may be sufficient to render the spacecraft ineffective in performing its mission unless the attitude is corrected.
  • small changes in the orbital station must also be corrected. Both attitude and station corrections are achieved using the control system of the spacecraft.
  • the control system of a spacecraft includes its propellant supply, the thrusters, and the associated propellant lines to provide propellant to the thrusters. It does not include the control apparatus required to command firings of the thrusters.
  • Figure 1 depicts a satellite 10 in orbit about the earth, acting as a relay station.
  • a first earth station 12 transmits a signal to the satellite 10, where the signal may be amplified and modified for transmission to the second earth station 14.
  • the ground antennas 16 located at the earth stations 12 and 14
  • the orbit of the satellite 10 is one key factor in the ability to position the satell ' ite so that it appears to be fixed in space at its station.
  • a satellite 10 may be launched into an equatorial orbit 20 lying in the equatorial plane of the earth, an inclined orbit 22, or a polar orbit 24 that takes it over the poles of the earth.
  • a satellite 10 in an equatorial orbit 20 that is circular at an altitude of about 22,235 statute miles moves at just the right velocity to maintain an essentially stationary position above a selected point on the earth as the earth rotates, in a geosynchronous orbit.
  • geosynchronous orbit provides the capability of placing a satellite at a fixed station in space
  • a satellite in geosynchronous orbit tends to move slightly from its assigned station due to various forces.
  • Geosynchronous satellites must therefore have control systems to maintain them continuously on station, and such a control system is the subject of the present invention.
  • .satellites such as those in low earth orbit or in inclined orbits can also make use of the control system of the present invention, but the presently preferred embodiment is used in conjunction with geosynchronous communications satellites.
  • Figure 3 depicts a satellite 10 in orbit about the earth, with superimposed coordinates corresponding to control functions. Three coordinates are shown, corresponding to an above/below direction 26, an east/west direction 28, and a north/south direction 30.
  • the satellite 10 must maintain the proper attitude or angular orientation with respect to these coordinates, with respect to reference points such as the earth, certain stars, or other bodies, this angular orientation being termed its attitude.
  • the satellite 10 must also stay fixed with respect to a desired location in the orbit, termed the station X.
  • the spacecraft 10 may deviate from the desired station by being north or south (relative to the earth) of the desired station along axis 30, by being east or west (relative to the earth) of the desired station along axis 28, or by being at a greater or lesser altitude (relative to the earth) than the desired station along the axis 26.
  • Attitude control is therefore understood to relate to the angular orientation of the satellite relative to the proper station X, while stationkeeping is understood to relate to a movement of the entire satellite 10 away from its proper station.
  • Deviations of attitude or station can arise for a number of reasons, including solar pressure, gravitational forces of other bodies such as the sun or moon, drag, thermal effects, electromagnetic effects, imprecision in prior corrective maneuvers, or other external and internal factors.
  • spacecraft as satellites is closely linked to their economics, particularly the weight and . size of the spacecraft when launched and the expected, effective life of the satellite in its mission. It is desirable to reduce size and weight by reducing the amount of propellant carried on the spacecraft, but a reduction in the amount of onboard propellant used for attitude control and stationkeeping maneuvers limits the number of corrective maneuvers and thence the useful life of the satellite. It is therefore highly important to optimize the control system to avoid wasted propellant and minimize inefficiencies in the operation of the thrusters used in the control system.
  • FIG. 4 illustrates a satellite 10 in greater detail, emphasizing elements of its control system 32.
  • the illustrated satellite 10 includes a body 34 that supports a platform 36.
  • the body 34 is generally cylindrical and rotates about its cylindrical axis at a rate of about 60 revolutions per minute. This rotation causes the entire satellite 10 to behave somewhat as a large gyroscope and maintain a generally constant attitude or angular orientation relative to the axes 26, 28 and 30.
  • the platform 36 does not rotate at the same rate as the body 34, but instead remains relatively fixed so that the satellite antennas 18 can continuously point at the ground antennas 16. The platform 36 is thus said to be despun to have only that rotation necessary to permit the satellite antennas to be properly pointed.
  • the control system 32 is positioned within the body 34, and includes a propellant supply 38, thrusters 40, and propellant lines 42 that deliver propellant from the supply 38 to the thrusters 40.
  • the control system 32 is indicated generally, and Figure 5 presents a detailed schematic illustration of the manner of conducting propellant to the thrusters.
  • FIG. 5 schematically illustrates the control . system 32 in accordance with the present invention.
  • the control system 32 utilizes two propellants, contained in a fuel tank 44 and an oxidizer tank 46.
  • the fuel presently preferred is hydrazine, having the chemical compo ' sition N2H4, which can be used either as a bipropellant fuel or a monopropellant. That is, hydrazine can be used to generate gas in a thruster by reacting the hydrazine with a proper oxidizer, or to generate hot gas in a thruster by passing the hydrazine over a catalyst to decompose it to nitrogen and hydrogen gasses. See U.S.
  • Patents 3,871,828; 4,069,664; 4,324,096; and 4,490,972 by Ellion, et al. whose disclosures are herein incorporated by reference.
  • the oxidizer presently preferred is nitrogen tetroxide, having the chemical composition N2O4. Hydrazine and nitrogen tetroxide react spontaneously to generate hot gas, in the bipropellant thruster. Hydrazine decomposes exothermally in a catalytic bed such as iridium coated alumina oxide to produce hot gas, in a monopropellant thruster.
  • the technology for using these propellants in thrusters is known, both for the fuel as a monopropellant and the fuel and oxidizer as bipropellants.
  • the fuel from the tank 44 and the oxidizer from the tank 46 are delivered to the thrusters 40 through piping collectively termed the propellant lines 42.
  • Lines are provided to conduct both fuel and oxidizer to the bipropellant thrusters, and fuel to the monopropellant thrusters.
  • the tanks 44 and 46 are typically pressurized with a sufficient pressure to deliver the fuel and oxidizer as needed, without the need for pumps.
  • propellant pumps can be provided for specific applications.
  • Fuel only is delivered to a monopropellant thruster 48._
  • Fuel and oxidizer are delivered to a bipropellant thruster 50.
  • the fuel and oxidizer are also provided to an apogee motor 52.
  • the apogee motor 52 is typically a much larger rocket engine than thrusters 48 and 50. It is sometimes provided as a solid rocket motor, or a cryogenic rocket motor that is fired only to establish the orbit at the beginning of the mission and then not used again.
  • the use of the hybrid monopropellant and -bipropellant approach of the present invention is therefore optional as applied to- the apogee motor 52, and its use depends upon the mission and type of , spacecraft. In a preferred approach wherein the present invention is applied to a spacecraft in geosynchronous .
  • the monopropellant thrusters 48 are positioned for attitude control, for east-west stationkeeping, and for north-south stationkeeping.
  • the bipropellant thrusters 50 are positioned only for north-south stationkeeping. The mode of using the thrusters varies with the stage in the life of the satellite, and the amount of oxidizer remaining.
  • a set of radial monopropellant thrusters 54 are operated for attitude control and for east-west stationkeeping, for which a relatively small proportion of the total propellant is used.
  • the bipropellant thrusters 50 are operated for north-south stationkeeping, for which the majority of the propellant. is used.
  • the amount of fuel initially loaded into the fuel tank 44 is greater than the sum of the amount required to react with the oxidizer in the oxidizer tank 46, plus the "expected consumption” of fuel required to perform the attitude control and east-west stationkeeping functions of the radial monopropellant thrusters 54 during the period prior to exhaustion of the oxidizer in the tank 46.
  • the "expected consumption” is defined as the amount of fuel required to operate the monopropellant thrusters during the period prior to exhaustion of the oxidizer initially loaded into the spacecraft. This expected consumption of fuel is a value which can be estimated during design of the satellite, and is usually based on data from prior operations of other satellites used for similar missions.
  • the expected consumption cannot be determined exactly beforehand, but an advantage of the present approach is that, as long as an excess of fuel is provided, small errors _in estimating expected consumption do not result in supplies of unconsumed and unusable propellants. Of course, it is still desirable to estimate the expected consumption as closely as possible to maximize the period during which the efficient bipropellant thrusters are used for north-south stationkeeping maneuvers.
  • the bipropellant thrusters 50 no longer can be operated for north-south stationkeeping, and a set of axial monopropellant thrusters 56 assume this function.
  • the propulsion functions of the control system 32 therefore are accomplished jointly by the monopropellant thrusters 54 and the bipropellant thrusters 50 early in the life of the satellite ' , and solely by the monopropellant thrusters 54 and 56 during .the later stages of the life of the satellite 10.
  • all of the propellant is used to advantage, wasting none and leaving no potentially dangerous propellants in storage.
  • the apogee motor 52 is also a liquid fueled thruster of the bipropellant type, and operates from the common fuel tank 44 and oxidizer tank 46 prior to exhaustion of the oxidizer, according to the principles just described.
  • the bipropellant thrusters 50 operate in their most efficient mode of long duration firings for north-south stationkeeping, the firings typically lasting 50-200 seconds.
  • the monopropellant thrusters 48 operate in pulsed or short duration firings over most of the life of the satellite, and consume a small fraction of the propellant.
  • the oxidizer used in the bipropellant thrusters 50 is expended and the axial monopropellant thrusters 56 assume the north-south stationkeeping functions, they are used in place of the more efficient bipropellant thrusters, for long duration firings for north-south stationkeeping.
  • the overall control system efficiency is thereby improved through full use of the available propellants and extended life of the satellite.
  • the amount of fuel initially loaded into the fuel tank 44 and provided for consumption by the hybrid monopropellant and bipropellant control system 32 is in all cases greater than the amount required to react with the oxidizer contained within the oxidizer tank 46.
  • the amount of fuel is greater than the sum of the amount required to react with the oxidizer plus the amount required for the expected consumption of fuel, by the monopropellant thrusters . prior to the exhaustion of the oxidizer. It is known from prior geosynchronous communications satellites that approximately 1056 of the propellant is expended in pulsed discharges * for attitude control and east-west stationkeeping, while 9056 is expended on north-south stationkeeping, primarily in long bursts of 50 to 200 seconds duration for the correction of north-south drift.
  • the amount of fuel initially loaded into the fuel tank of the satellite is determined to be at least about 1056 (that is, an expected consumption value of 1056) greater ' than the amount of fuel required to react with all of the oxidizer initially loaded into the oxidizer tank of the satellite.
  • the precise fuel load would be chosen using a similar of calculation to that just discussed. It is projected that use of the present hybrid monopropellant and bipropellant control system can increase the efficiency of spacecraft significantly, thereby increasing their payloads.
  • replacing an all-monopropellant system with the present hybrid control system results in a net reduction of the end-of-life weight of a Hughes Aircraft Co. type HS 376 class geosynchronous satellite, normally having a payload of 350 pounds, by as much as about 106 pounds.
  • This weight savings allows an equal increase in the payload, thus achieving a 3056 increase in payload through improvement of the control system.
  • the present invention represents an important ' advance in spacecraft * control systems such as used in geosynchronous communications satellites. Efficiency of the control system is improved, resulting in increased payload for the spacecraft. The propellants are fully consumed, leaving no wasted residual propellant that causes a weight penalty and might be dangerous. No major changes in spacecraft operating and preparation procedures are required.

Abstract

Système de correction de position (32) pour engin spatial possédant des propulseurs (54, 50) à monopropergol et bipropergol, les deux types de propulseurs étant alimentés par le même carburant. Le carburant sélectionné peut subir une réaction catalytique dans les propulseurs (54) à monopropergol, ou alors il peut être oxydé à l'aide d'un oxydant injecté séparément dans les propulseurs (50) à bi-propergol, produisant dans les deux cas un gaz chaud qui est expulsé du propulseur pour créer la force de poussée. Le carburant est fourni en quantité excédentaire par rapport à la quantité requise pour la réaction avec l'oxydant disponible, de sorte que les propulseurs (54) à monopropergol peuvent continuer à fonctionner même après l'épuisement de la quantité d'oxydant fournie aux propulseurs (50) à bipropergol. Il n'y a pas de propergols non utilisables, et le rendement plus élevé des propulseurs à bipropergol continue à être pleinement exploité. Le carburant préféré est l'hydrazine et l'oxydant préféré est le tétroxyde d'azote.
PCT/US1987/001073 1986-06-19 1987-05-12 Systeme hybride de correction de position pour engin spatial WO1987007877A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US87605986A 1986-06-19 1986-06-19
US876,059 1986-06-19

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WO1987007877A1 true WO1987007877A1 (fr) 1987-12-30

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EP (1) EP0272284A1 (fr)
JP (1) JPH01500531A (fr)
CN (1) CN87104290A (fr)
WO (1) WO1987007877A1 (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2640579A1 (fr) * 1988-12-16 1990-06-22 Gen Electric Engin spatial a charge en carburant accrue pour maintien en position et procede de lancement
US5282357A (en) * 1990-04-19 1994-02-01 Trw Inc. High-performance dual-mode integral propulsion system
US5417049A (en) * 1990-04-19 1995-05-23 Trw Inc. Satellite propulsion and power system
EP0727403A1 (fr) * 1995-02-09 1996-08-21 State Of Israel, Ministry Of Defence, Rafael-Armaments Development Authority Système de propulsion hybride inversé
EP0919464A1 (fr) * 1997-11-25 1999-06-02 TRW Inc. Système de contrÔle d'attitude et vitesse d'un engin spatial avec propulseurs
FR2828524A1 (fr) * 2001-08-07 2003-02-14 Air Liquide Systeme propulsif annexe d'etage cryotechnique de lanceur et etage de lanceur comprenant un tel systeme

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2019018826A1 (fr) * 2017-07-21 2019-01-24 Nicholson James Garret Dispositifs d'entretien de véhicule spatial et ensembles, systèmes et procédés associés

Citations (3)

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Publication number Priority date Publication date Assignee Title
US3514953A (en) * 1968-10-21 1970-06-02 Us Air Force Trimode rocket engine
FR2197118A1 (fr) * 1972-08-23 1974-03-22 Messerschmitt Boelkow Blohm
US3955784A (en) * 1972-02-22 1976-05-11 Salkeld Robert J Mixed mode propulsion aerospace vehicles

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3514953A (en) * 1968-10-21 1970-06-02 Us Air Force Trimode rocket engine
US3955784A (en) * 1972-02-22 1976-05-11 Salkeld Robert J Mixed mode propulsion aerospace vehicles
FR2197118A1 (fr) * 1972-08-23 1974-03-22 Messerschmitt Boelkow Blohm

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2640579A1 (fr) * 1988-12-16 1990-06-22 Gen Electric Engin spatial a charge en carburant accrue pour maintien en position et procede de lancement
GB2226999A (en) * 1988-12-16 1990-07-18 Gen Electric Spacecraft with increased stationkeeping fuel load
GB2226999B (en) * 1988-12-16 1992-05-27 Gen Electric Spacecraft with increased stationkeeping fuel load
US5263666A (en) * 1988-12-16 1993-11-23 General Electric Co. Spacecraft with increased stationkeeping fuel load
GB2293627B (en) * 1990-04-19 1996-08-21 Trw Inc High performance dual mode rocket propulsion system
US5417049A (en) * 1990-04-19 1995-05-23 Trw Inc. Satellite propulsion and power system
GB2293627A (en) * 1990-04-19 1996-04-03 Trw Inc High performance dual mode rocket propulsion system
US5282357A (en) * 1990-04-19 1994-02-01 Trw Inc. High-performance dual-mode integral propulsion system
US5572865A (en) * 1990-04-19 1996-11-12 Trw Inc. Satellite propulsion and power system
AU663095B2 (en) * 1991-08-21 1995-09-28 Trw Inc. Satellite propulsion and power system
EP0727403A1 (fr) * 1995-02-09 1996-08-21 State Of Israel, Ministry Of Defence, Rafael-Armaments Development Authority Système de propulsion hybride inversé
EP0919464A1 (fr) * 1997-11-25 1999-06-02 TRW Inc. Système de contrÔle d'attitude et vitesse d'un engin spatial avec propulseurs
FR2828524A1 (fr) * 2001-08-07 2003-02-14 Air Liquide Systeme propulsif annexe d'etage cryotechnique de lanceur et etage de lanceur comprenant un tel systeme

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EP0272284A1 (fr) 1988-06-29
JPH01500531A (ja) 1989-02-23
CN87104290A (zh) 1988-02-24

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