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Record 5 of 82
Fusion for Space Propulsion
Author and Affiliation:
Thio, Y. C. Francis(NASA Marshall Space Flight Center, Huntsville, AL United States)
Schmidt, George R.(NASA Marshall Space Flight Center, Huntsville, AL United States)
Santarius, John F.(Wisconsin Univ., Madison, WI United States)
Turchi, Peter J.(Air Force Research Lab., Kirkland AFB, NM United States)
Siemon, Richard E.(Los Alamos National Lab., NM United States)
Rodgers, Stephen L. [Technical Monitor]
Abstract: The need for fusion propulsion for interplanetary flights is discussed. For a propulsion system, there are three important system attributes: (1) The absolute amount of energy available, (2) the propellant exhaust velocity, and (3) the jet power per unit mass of the propulsion system (specific power). For efficient and affordable human exploration of the solar system, propellant exhaust velocity in excess of 100 km/s and specific power in excess of 10 kW/kg are required. Chemical combustion obviously cannot meet the requirement in propellant exhaust velocity. Nuclear fission processes typically result in producing energy in the form of heat that needs to be manipulated at temperatures limited by materials to about 2,800 K. Using the fission energy to heat a low atomic weight propellant produces propellant velocity of the order of 10 kinds. Alternatively the fission energy can be converted into electricity that is used to accelerate particles to high exhaust velocity. However, the necessary power conversion and conditioning equipment greatly increases the mass of the propulsion system. Fundamental considerations in waste heat rejection and power conditioning in a fission electric propulsion system place a limit on its jet specific power to the order of about 0.2 kW/kg. If fusion can be developed for propulsion, it appears to have the best of all worlds - it can provide the largest absolute amount of energy, the propellant exhaust velocity (> 100 km/s), and the high specific jet power (> 10 kW/kg). An intermediate step towards fusion propulsion might be a bimodal system in which a fission reactor is used to provide some of the energy to drive a fusion propulsion unit. There are similarities as well as differences between applying fusion to propulsion and to terrestrial electrical power generation. The similarities are the underlying plasma and fusion physics, the enabling component technologies, the computational and the diagnostics capabilities. These physics and engineering capabilities have been demonstrated for a fusion reactor gain (Q) of the order of unity (TFTR: 0.25, JET: 0.65, JT-60: Q(sub eq) approx. 1.25). These technological advances made it compelling for considering fusion for propulsion.
Publication Date: Jan 01, 2002
Document ID:
20020067391
(Acquired Aug 30, 2002)
Subject Category: SPACECRAFT PROPULSION AND POWER
Document Type: Preprint
Meeting Information: American Nuclear Society (ANS); 3-9 Jun. 2002; Hollywood, FL; United States
Meeting Sponsor: American Nuclear Society; United States
Financial Sponsor: NASA Marshall Space Flight Center; Huntsville, AL United States
Organization Source: NASA Marshall Space Flight Center; Huntsville, AL United States
Description: 2p; In English
Distribution Limits: Unclassified; Publicly available; Unlimited
Rights: No Copyright
NASA Terms: FUSION PROPULSION; CONTROLLED FUSION; EXHAUST VELOCITY; POWER CONDITIONING; INTERPLANETARY FLIGHT; FUSION REACTORS; ELECTRIC PROPULSION
Availability Source: Other Sources
Availability Notes: Abstract Only
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