1,403 research outputs found
High-temperature LM cathode ion thrusters Quarterly progress report, 5 Aug. - 4 Nov. 1968
Thermodynamic and operating characteristics of high temperature liquid mercury cathode ion thruster
Procedures and requirements for testing in the Langley Research Center unitary plan wind tunnel
Information is presented to assist those interested in conducting wind-tunnel testing within the Langley Unitary Plan Wind Tunnel. Procedures, requirements, forms and examples necessary for tunnel entry are included
High-temperature LM cathode ion thrusters Quarterly progress report, 5 May - 4 Aug. 1968
Design and operation of high temperature liquid mercury cathode ion thruster
Design and development of a small structurally integrated ion thruster system
A 5 cm structurally integrated ion thruster has been developed for attitude control and stationkeeping of synchronous satellites. With 2-D vectorable grids, thrust is 0.56 mlb at a beam voltage of 1200 V, total mass efficiency is 64%, and electrical efficiency is 46.8%. Nonvectoring thrust of 0.41 is demonstrated at very low specific impulse with dielectric coated grids. Structural integrity is demonstrated with dielectric coated grids for shock (30 G), sinusoidal (9 G), and random (19 G squared/Hz) accelerations. System envelope is 31.6 cm long by 14 cm flange B.C. with a mass of 8.5 kg including 6.2 Kg mercury propellant
Eight cm technology thruster development
A structural integrated ion thruster with 8-cm beam diameter (SIT-8) was developed for attitude control and stationkeeping of synchronous satellites. As optimized, the system demonstrates a thrust T=1.14 mlb (not corrected for beam V sub B = 1200 V (I sub sp = 2200 sec) total propellant utilization efficiency nu sub u = 59.8% (is approximately 72% without auxiliary pulse-igniter electrode), and electrical efficiency n sub E 61.9%. The thruster incorporates a wire-mesh anode and tantalum cover surfaces to control discharge chamber flake formation and employs an auxiliary pulse-igniter electrode for hollow-cathode ignition. When the SIT-8 is integrated with the compatible SIT-5 propellant tankage, the system envelope is 35 cm long by 13 cm flange bolt circle with a mass of 9.8 kg including 6.8 kg of mercury propellant. Two thrust vectoring systems which generate beam deflections in two orthogonal directions were also developed under the program and tested with the 8-cm thruster. One system vectors the beam over + or - 10 degrees by gimbaling of the entire thruster (not including tankage), while the other system vectors the beam over + or - 7 degrees by translating the accel electrode relative to the screen electrode
An approach to the parametric design of ion thrusters
A methodology that can be used to determine which of several physical constraints can limit ion thruster power and thrust, under various design and operating conditions, is presented. The methodology is exercised to demonstrate typical limitations imposed by grid system span-to-gap ratio, intragrid electric field, discharge chamber power per unit beam area, screen grid lifetime, and accelerator grid lifetime constraints. Limitations on power and thrust for a thruster defined by typical discharge chamber and grid system parameters when it is operated at maximum thrust-to-power are discussed. It is pointed out that other operational objectives such as optimization of payload fraction or mission duration can be substituted for the thrust-to-power objective and that the methodology can be used as a tool for mission analysis
LM cathode thruster system Quarterly progress report, 4 Jan. 1969 - 4 Apr. 1970
Development of 20 cm liquid metal cathode thruster syste
High-temperature LM cathode ion thrusters Quarterly progress report, 5 Feb. - 4 May 1968
Poiseuille flow measurements for high temperature liquid metal cathode ion thruster
LM cathode thruster system Quarterly progress report, 4 Oct. 1969 - 4 Jan. 1970
Optimization testing of thermally integrated liquid mercury cathode thruster syste
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