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Nonchemical Rocket Engine
Published in D.P. Mishra, Fundamentals of Rocket Propulsion, 2017
The performance of ion thruster can be evaluated in terms of thrust per unit area, specific impulse, and power efficiency. We can use the expression Equation 11.33 for determining the thrust per unit area. The specific impulse of this kind of thruster can be expressed in terms of charge-to-mass ratio and voltage using Equation 11.20, as follows: Isp=Vqg=2(q/mq)Vg The specific impulse Isp is dependent on charge-to-mass ratio and voltage, which can be enhanced for obtaining higher performance. The charge-to-mass ratio is dependent on the type of propellant. Generally, cesium is preferred, as already discussed. The practical limit of the voltage that can be used for this kind of thruster is 50,000 V, with field strength of 107 V/m. The specific impulse in the range of 20–10,000 can be achieved for ion thruster.
How Do Rockets Work?
Published in Travis S. Taylor, Introduction to Rocket Science and Engineering, 2017
On the other hand, interplanetary missions (after launch) typically need to apply thrust continuously for a long period of time. These are usually the small payloads that are atop the launch vehicles; thus, they have very little mass budget for fuel. This means that they cannot apply large thrusts for long periods of time, or they will run out of fuel. Hence, a more propellant-efficient engine, such as an ion thruster, is needed. The ion thrusters use small amounts of propellant mass at a time, but accelerate that mass to very high equivalent velocities. Figure 3.2 illustrates images of NASA’s Deep Space Probe 1 that used an ion engine that only generated 0.09 N of thrust but had an Isp of over 3,100 sec.
Rocketry
Published in Jonathan Allday, Apollo in Perspective, 2019
The Solar Technology Application Readiness (NSTAR) ion thruster ran in testing for over 30,000 hours of continuous use, mostly at full power, without showing serious signs of wear. The engine works at a power level between 0.5 and 2.3 kW and produces 19 mN of thrust at a specific impulse of 1,900 s in low power mode, rising to 92 mN and 3,100 s at high power level.
Nuclear Power Concepts and Development Strategies for High-Power Electric Propulsion Missions to Mars
Published in Nuclear Technology, 2022
Lee Mason, Steve Oleson, David Jacobson, Paul Schmitz, Lou Qualls, Michael Smith, Brian Ade, Jorge Navarro
Nuclear power systems for NEP applications have been studied extensively, dating back to 1955 when Stuhlinger published “Electrical Propulsion System for Space Ships with Nuclear Power Source” in the Journal of the Astronautical Sciences.2 In the late 1950s and 1960s, the U.S. Atomic Energy Commission developed both radioisotope and fission nuclear power sources under the Systems for Nuclear Auxiliary Power (SNAP) Program.3 In 1965, the SNAP10A reactor was launched from Vandenberg Air Force Base as part of the U.S. Air Force SNAPSHOT mission, which included a 500-W reactor power system and a 400-W cesium ion thruster—the first and only NEP space flight mission performed by the United States. In the 1980s, the SP-100 Program, involving NASA, the U.S. Department of Energy (DOE), and the Strategic Defense Initiative Organization (SDIO), sought to develop a 2.5-MW(thermal) lithium-cooled, fast-spectrum reactor using 93%-enriched uranium nitride (UN) fuel pins with refractory alloy cladding coupled to SiGe thermoelectric conversion to produce 100-kW(electric) net output.4 Among the applications studied for SP-100 were EP missions for outer planet science and Mars. Although detailed designs were generated and considerable component testing was performed, the SP-100 system was never completed.
Research Trends on Separation and Extraction of Rare Alkali Metal from Salt Lake Brine: Rubidium and Cesium
Published in Solvent Extraction and Ion Exchange, 2020
Li Gao, Guihua Ma, Youxiong Zheng, Yan Tang, Guanshun Xie, Jianwei Yu, Bingxin Liu, Junyuan Duan
Rubidium and cesium are important and rare alkali metals. They possess excellent physical, chemical, and photoelectric properties, which have attracted the interest of nations worldwide.[1] Moreover, these metals are utilized for many traditional applications (Table 1). Recently, with the rapid global development of high-tech industries, rubidium, cesium, and their compounds have been used extensively in high-tech applications such as perovskite solar cells,[2–7] magnetohydrodynamic power generation,[8,9] ion thruster propellant,[8] energy conversion,[10] and cesium atomic clocks.[11] The international demand for these metals is also growing.