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Results for “NUCLEAR PROPULSION”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 253 records · Page 14
All sourcesNASA NTRSDOE OSTI
NASA NTRS1986

Nuclear electric propulsion

We investigate the feasibility of using nuclear electric propulsion (NEP) for slow "freighter" ships traveling from a 500 km low Earth orbit {LEO) to the Moon's orbit about the Earth, and on to Mars. NEP is also shown to be feasible for transporting people to Mars on long conjunction-class missions lasting about nine months one way, and on short "sprint" missions lasting four months one way. Generally, we have not attempted to optimize ion exhaust velocities, but rather we have chosen suitable parameters to demonstrate NEP feasibility. Various combinations of missions are compared with chemical and nuclear thermal propulsion (NTR) systems. Typically, NEP and NTR can accomplish the same lifting task with similar mass in LEO. When compared to chemical propulsion, NEP was found to accomplish the same missions with 40% less mass in LEO. These findings are sufficiently encouraging as to merit further studies with optimum systems.

Paul W Keaton↗
NASA NTRS1978

Optimize out-of-core thermionic energy conversion for nuclear electric propulsion

Thermionic energy conversion (TEC) potentialities for nuclear electric propulsion (NEP) are examined. Considering current designs, their limitations, and risks raises critical questions about the use of TEC for NEP. Apparently a reactor cooled by hotter-than-1675 K heat pipes has good potentialities. TEC with higher temperatures and greater power densities than the currently proposed 1650 K, 5-to-6 W/sq cm version offers substantial gains. Other approaches to high-temperature electric isolation appear also promising. A high-power-density, high-temperature TEC for NEP appears, therefore, attainable. It is recommended to optimize out-of-core thermionic energy conversion for nuclear electric propulsion. Although current TEC designs for NEP seem unnecessary compared with Brayton versions, large gains are apparently possible with increased temperatures and greater power densities.

Morris, J. F.↗
NASA NTRSDate not supplied

Nuclear Thermal Propulsion (NTP) Fission Product and Source Term Analysis

Nuclear thermal propulsion (NTP) is an in-space propulsion technology that uses a nuclear reactor to directly heat a propellant to provide high thrust, at higher efficiencies than achievable with conventional chemical propulsion systems. Due to the ability of NTP rockets to efficiently provide high thrust, this technology has been proposed for long duration space missions such as crewed missions to Mars and beyond. A primary hurdle for NTP technology development is the demonstration of an integrated reactor engine system to verify its functionality and performance. This primarily requires the manufacture and testing of candidate reactor and engine technologies to demonstrate the proposed design enables desired performance and exhibits acceptable response under all known operation modes. A major component in this testing is fission product accumulation, since after operation radioactive isotopes can be produced and pose radiological dose concerns. This paper explains the background behind fission product analysis and the methodology used to evaluate current reactor designs and identify the amount of fission products present and their radiological impact. Results of multiple thrust level engines at different time periods are discussed and highlight the need for additional experimental testing to confirm fractional release levels of fission products out of the system. Benchmarking of models and future paths of analysis are also discussed.

Nuclear Thermal Propulsion↗
NASA NTRSDate not supplied

Nuclear Thermal Propulsion (NTP) Fission Product and Source Term Analysis

Nuclear thermal propulsion (NTP) is an in-space propulsion technology that uses a nuclear reactor to directly heat a propellant to provide high thrust, at higher efficiencies than achievable with conventional chemical propulsion systems. Due to the ability of NTP rockets to efficiently provide high thrust, this technology has been proposed for long duration space missions such as crewed missions to Mars and beyond. A primary hurdle for NTP technology development is the demonstration of an integrated reactor engine system to verify its functionality and performance. This primarily requires the manufacture and testing of candidate reactor and engine technologies to demonstrate the proposed design enables desired performance and exhibits acceptable response under all known operation modes. A major component in this testing is fission product accumulation, since after operation radioactive isotopes can be produced and pose radiological dose concerns. This paper explains the background behind fission product analysis and the methodology used to evaluate current reactor designs and identify the amount of fission products present and their radiological impact. Results of multiple thrust level engines at different time periods are discussed and highlight the need for additional experimental testing to confirm fractional release levels of fission products out of the system. Benchmarking of models and future paths of analysis are also discussed.

Fission↗
NASA NTRS1990

Overview of Mars transportation options and issues

The transportation options for manned Mars missions being considered for the Space Exploration Initiative are discussed. Seven candidate architectures are examined and compared: cryogenic/aerobraking, nuclear-electric propulsion, solar electric propulsion, nuclear rocket propulsion, L-based cryogenic/aerobraking, direct cryogenic/aerobraking, and cycler orbits. The rationales for choosing each one are presented, and cost considerations are addressed.

Adams, Alan↗
NASA NTRS1992

Near term NEP missions and systems

The topics covered are presented in viewgraph form and include the following: Nuclear Propulsion Office Nuclear Electric Propulsion (NEP) goals; near term systems definition, representative near term NEP systems; demonstration missions; primary missions; near term NEP Mars cargo mission; near term NEP Mars mission analysis; and near term NEP mars mission.

Gilland, Jim↗
NASA NTRS2011

Z-Pinch Fusion Propulsion

Fusion-based nuclear propulsion has the potential to enable fast interplanetary transportation. Shorter trips are better for humans in the harmful radiation environment of deep space. Nuclear propulsion and power plants can enable high Ispand payload mass fractions because they require less fuel mass. Fusion energy research has characterized the Z-Pinch dense plasma focus method. (1) Lightning is form of pinched plasma electrical discharge phenomena. (2) Wire array Z-Pinch experiments are commonly studied and nuclear power plant configurations have been proposed. (3) Used in the field of Nuclear Weapons Effects (NWE) testing in the defense industry, nuclear weapon x-rays are simulated through Z-Pinch phenomena.

Miernik, Janie↗
NASA NTRS1992

Nuclear thermal propulsion transportation systems for lunar/Mars exploration

Nuclear thermal propulsion technology development is underway at NASA and DoE for Space Exploration Initiative (SEI) missions to Mars, with initial near-earth flights to validate flight readiness. Several reactor concepts are being considered for these missions, and important selection criteria will be evaluated before final selection of a system. These criteria include: safety and reliability, technical risk, cost, and performance, in that order. Of the concepts evaluated to date, the Nuclear Engine for Rocket Vehicle Applications (NERVA) derivative (NDR) is the only concept that has demonstrated full power, life, and performance in actual reactor tests. Other concepts will require significant design work and must demonstrate proof-of-concept. Technical risk, and hence, development cost should therefore be lowest for the concept, and the NDR concept is currently being considered for the initial SEI missions. As lighter weight, higher performance systems are developed and validated, including appropriate safety and astronaut-rating requirements, they will be considered to support future SEI application. A space transportation system using a modular nuclear thermal rocket (NTR) system for lunar and Mars missions is expected to result in significant life cycle cost savings. Finally, several key issues remain for NTR's, including public acceptance and operational issues. Nonetheless, NTR's are believed to be the 'next generation' of space propulsion systems - the key to space exploration.

Clark, John S.↗
NASA NTRS2019

Fission Reactor Inadvertent Reentry: A Report to the Nuclear Power & Propulsion Technical Discipline Team

The Nuclear Power and Propulsion Technical Discipline Team has directed an effort to consider possible improvements to the launch approval process as it relates to fission reactors. To that end, Reference 1 described possible general design criteria and risk criteria for fission reactors. At the time that Reference 1 was completed, it was felt that additional examination of reentry issues was warranted. This paper presents the next step in that examination, which is to accurately describe and frame the problem and suggest safety criteria that might apply to inadvertent reentry. The report includes a discussion of the issues associated with different types of inadvertent reentry, the possible consequences of those events, a review of previous work in the area, security and nonproliferation issues, and options for safety requirements that might be considered. Note that safety requirements can have significant mission implications, e.g., no operation below a certain orbit.

Camp, Allen↗
NASA NTRS2012

Nuclear Cryogenic Propulsion Stage Fuel Design and Fabrication

Nuclear Cryogenic Propulsion Stage (NCPS) is a game changing technology for space exploration. Goal of assessing the affordability and viability of an NCPS includes thses overall tasks: (1) Pre-conceptual design of the NCPS and architecture integration (2) NCPS Fuel Design and Testing (3) Nuclear Thermal Rocket Element Environmental Simulator (NTREES) (4) Affordable NCPS Development and Qualification Strategy (5) Second Generation NCPS Concepts. There is a critical need for fuels development. Fuel task objectives are to demonstrate capabilities and critical technologies using full scale element fabrication and testing.

Hickman, Robert↗
NASA NTRS2012

Nuclear Cryogenic Propulsion Stage Fuel Design and Fabrication

Nuclear Cryogenic Propulsion Stage (NCPS) is a game changing technology for space exploration. Goal of assessing the affordability and viability of an NCPS includes these overall tasks: (1) Pre-conceptual design of the NCPS and architecture integration (2) NCPS Fuel Design and Testing (3) Nuclear Thermal Rocket Element Environmental Simulator (NTREES) (4) Affordable NCPS Development and Qualification Strategy (5) Second Generation NCPS Concepts. There is a critical need for fuels development. Fuel task objectives are to demonstrate capabilities and critical technologies using full scale element fabrication and testing.

Hickman, Robert↗
NASA NTRS2014

Nuclear Cryogenic Propulsion Stage Affordable Development Strategy

The development of nuclear power for space use in nuclear thermal propulsion (NTP) systems will involve significant expenditures of funds and require major technology development efforts. The development effort must be economically viable yet sufficient to validate the systems designed. Efforts are underway within the National Aeronautics and Space Administration's (NASA) Nuclear Cryogenic Propulsion Stage Project (NCPS) to study what a viable program would entail. The study will produce an integrated schedule, cost estimate and technology development plan. This will include the evaluation of various options for test facilities, types of testing and use of the engine, components, and technology developed. A "Human Rating" approach will also be developed and factored into the schedule, budget and technology development approach.

Doughty, Glen E.↗
NASA NTRS2014

Nuclear Cryogenic Propulsion Stage Conceptual Design and Mission Analysis

The Nuclear Cryogenic Propulsion Stage (NCPS) is an in-space transportation vehicle, comprised of three main elements, designed to support a long-stay human Mars mission architecture beginning in 2035. The stage conceptual design and the mission analysis discussed here support the current nuclear thermal propulsion going on within partnership activity of NASA and the Department of Energy (DOE). The transportation system consists of three elements: 1) the Core Stage, 2) the In-line Tank, and 3) the Drop Tank. The driving mission case is the piloted flight to Mars in 2037 and will be the main point design shown and discussed. The corresponding Space Launch System (SLS) launch vehicle (LV) is also presented due to it being a very critical aspect of the NCPS Human Mars Mission architecture due to the strong relationship between LV lift capability and LV volume capacity.

Kos, Larry D.↗
NASA NTRS1992

Nuclear Electric Propulsion Technology Panel findings and recommendations

Summarized are the findings and recommendations of a triagency (NASA/DOE/DOD) panel on Nuclear Electric Propulsion (NEP) Technology. NEP has been identified as a candidate nuclear propulsion technology for exploration of the Moon and Mars as part of the Space Exploration Initiative (SEI). The findings are stated in areas of system and subsystem considerations, technology readiness, and ground test facilities. Recommendations made by the panel are summarized concerning: (1) existing space nuclear power and propulsion programs, and (2) the proposed multiagency NEP technology development program.

Doherty, Michael P.↗
NASA NTRSDate not supplied

Nuclear Electric Propulsion for Outer Planet Science Missions

Nuclear electric propulsion (NEP) combines the high specific impulse of electric thrusters with a constant power source that can operate anywhere in the solar system. Current investments in fission surface power offer a starting point for development of an NEP capability for deep space science missions, with a mission to the Saturn system illustrating the potential of such a system. Minimum time of flight transits, maximum payload delivery, and a sample return from Enceladus are considered. The NEP system can deliver payloads to the Saturn system with similar transit times to the Cassini spacecraft without requiring the planetary flyby maneuvers, and when coupled with a heavy-lift launch vehicle an NEP-powered spacecraft can complete a Saturn transit significantly faster than Cassini. High payload masses can be delivered on a longer trajectory at the expense of transit time. Replacing a portion of the payload with propellant allows for a high degree of maneuverability upon reaching the Saturn system. An Enceladus sample return mission closes when utilizing the NEP system for the Saturn departure and Earth return burns.

Matthew E Duchek↗
NASA NTRS1990

Advanced propulsion options for human exploration of Mars

The various propulsion options that can meet NASA's primary mission objectives of the Space Exploration Initiative are discussed. Technology developments and projections are considered for solar electric propulsion, nuclear electric propulsion, solid core nuclear thermal rockets, and gas core nuclear thermal rockets. Mission scenarios appropriate to the individual propulsion options are presented, and the advantages and drawbacks of each option are described.

Cothran, B. R.↗
NASA NTRS2015

Shielding Development for Nuclear Thermal Propulsion

Radiation shielding analysis and development for the Nuclear Cryogenic Propulsion Stage (NCPS) effort is currently in progress and preliminary results have enabled consideration for critical interfaces in the reactor and propulsion stage systems. Early analyses have highlighted a number of engineering constraints, challenges, and possible mitigating solutions. Performance constraints include permissible crew dose rates (shared with expected cosmic ray dose), radiation heating flux into cryogenic propellant, and material radiation damage in critical components. Design strategies in staging can serve to reduce radiation scatter and enhance the effectiveness of inherent shielding within the spacecraft while minimizing the required mass of shielding in the reactor system. Within the reactor system, shield design is further constrained by the need for active cooling with minimal radiation streaming through flow channels. Material selection and thermal design must maximize the reliability of the shield to survive the extreme environment through a long duration mission with multiple engine restarts. A discussion of these challenges and relevant design strategies are provided for the mitigation of radiation in nuclear thermal propulsion.

Caffrey, Jarvis A.↗