Aeronautics and astronautics – Spacecraft – Attitude control
Patent
1993-03-19
1995-03-07
Huppert, Michael S.
Aeronautics and astronautics
Spacecraft
Attitude control
244170, 244171, B64G 126, B64G 138, F03H 500
Patent
active
053950763
ABSTRACT:
A spacecraft uses monopropellant arcjets for velocity change such as for north-south stationkeeping. It has been discovered that, while an arcjet cannot be modulated by pulsing the fuel supply, the amount of thrust can be varied by modulating the power applied to the arc, without extinguishing the arc. While the specific impulse (I.sub.SP) of the arcjet is thereby reduced from the maximum I.sub.SP of which the arcjet is capable, the resulting I.sub.SP may still be larger than the combined I.sub.SP of an unmodulated arcjet in conjunction with a modulated chemical thruster in a typical scenario. According to the invention, attitude control is provided in conjunction with north-south stationkeeping or other velocity change by, in response to an error signal generated by an attitude control system, modulating the arc power(s) of an arcjet thruster(s), which provides the velocity change. The arc is not extinguished during the stationkeeping maneuver, but is varied in magnitude. In addition to improving the overall I.sub.SP, an arrangement according to the invention allows dispensing with the chemical thrusters on the north face, thereby reducing spacecraft weight and complexity. Reliability is not seriously affected, because failure of arc allows an arcjet to continue to be used as a chemical thruster.
REFERENCES:
patent: 3735591 (1973-05-01), Burkhart
patent: 3769792 (1973-11-01), Grey
patent: 4550888 (1985-11-01), Douglass et al.
patent: 4630790 (1986-12-01), Williams, Jr.
patent: 4635885 (1987-01-01), Hujsak
patent: 4767084 (1988-08-01), Chan et al.
patent: 4848706 (1989-07-01), Garg et al.
patent: 4931942 (1990-06-01), Garg et al.
patent: 4961551 (1990-10-01), Rosen
patent: 5098041 (1992-03-01), Uetrecht
patent: 5140525 (1992-08-01), Shanker et al.
patent: 5172876 (1992-12-01), Rahn
patent: 5222023 (1993-06-01), Liu et al.
patent: 5255878 (1993-10-01), Rahn
patent: 5263666 (1993-11-01), Hubert et al.
patent: 5310143 (1994-05-01), Yocum et al.
patent: 5319926 (1994-06-01), Steenborg
AIAA 92-3529, "Power Conditioning Unit for Low-Power Arcjet Flight Application", by Skelly et al, AIAA/SAE/ASME/ASEE 28th Joint Propulsion Conference and Exhibit, Jul. 6-8, 1992, Nashville, TN.
Lichtin Daniel A.
Raman Kidambi V.
Subbarao Vasuki
Ansley Virna Lissi
Berard C. A.
Huppert Michael S.
Martin Marietta Corporation
Meise W. H.
LandOfFree
Spacecraft velocity change maneuvers by variable arcjets does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Spacecraft velocity change maneuvers by variable arcjets, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Spacecraft velocity change maneuvers by variable arcjets will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1401515