Rocket

About: Rocket is a research topic. Over the lifetime, 14018 publications have been published within this topic receiving 95852 citations. The topic is also known as: rockets.

The physics and engineering of the vasimr engine

Abstract: The Variable Specific Impulse Magnetoplasma Rocket (VASIMR) is a high power, radio frequency-driven magnetoplasma rocket, capable of I s]/thrust modulation at constant power. The physics and engineering of this device have been under study since 1980. The plasma is produced in an integrated plasma injector by a helicon discharge. However, the bulk of the plasma energy is added downstream by ion cyclotron resonance. The system features a magnetic nozzle, which accelerates the plasma particles by converting their azimuthal energy into directed momentum. A NASA-led, research effort, involving several teams in the United States, continues to explore the physics and engineering of the VASIMR, and its extrapolation as a high power, in-space propulsion system. These studies have produced attractive results in a number of areas, involving plasma theory and experiments, systems engineering and mission analysis. A conceptual point design for a 10 kW space demonstrator experiment has been completed.

Chemical erosion of carbon-phenolic rocket nozzles with finite-rate surface chemistry

Abstract: Ablative materials are commonly used to protect the nozzle metallic housing and to provide the internal contour to expand the exhaust gases in solid rocket motors. Because of the extremely harsh environment in which these materials operate, they are eroded during motor firing with a resulting nominal performance reduction. The objective of the present work is to study the thermochemical erosion behavior of carbon-phenolic material in solid rocket motor nozzles. The adopted approach relies on a validated full Navier–Stokes flow solver coupled with a thermochemical ablation model, which takes into account finite-rate heterogeneous chemical reactions at the nozzle surface, rate of diffusion of the species through the boundary layer, pyrolysis gas and char-oxidation product species injection in the boundary layer, heat conduction inside the nozzle material, and variable multispecies thermophysical properties. The results obtained with the proposed approach are compared with two sets of experimental data: subs...

An overview of the VASIMR engine: High power space propulsion with RF plasma generation and heating

Abstract: The Variable Specific Impulse Magnetoplasma Rocket (VASIMR) is a high power, radio frequency-driven magnetoplasma rocket, capable of exhaust modulation at constant power. While the plasma is produced by a helicon discharge, the bulk of the energy is added in a separate downstream stage by ion cyclotron resonance heating (ICRH). Axial momentum is obtained by the adiabatic expansion of the plasma in a magnetic nozzle. Exhaust variation in the VASIMR is primarily achieved by the selective partitioning of the RF power to the helicon and ICRH systems, with the proper adjustment of the propellant flow. However, other complementary techniques are also being studied. Operational and performance considerations favor the light gases. The physics and engineering of this device have been under study since the late 1970s. A NASA-led, research effort, involving several terms in the United States, continues to explore the scientific and technological foundations of this concept. The research involves theory, experiment, engineering design, mission analysis, and technology development. Experimentally, high density, stable plasma discharges have been generated in Helium, Hydrogen and Deuterium, as well as mixtures of these gases. Key issues involve the optimization of the helicon discharge for high-density operation and the efficient coupling of ICRH to the plasma, prior to acceleration by the magnetic nozzle. Theoretically, the dynamics of the magnetized plasma are being studied from kinetic and fluid perspectives. Plasma acceleration by the magnetic nozzle and subsequent detachment has been demonstrated in numerical simulations. These results are presently undergoing experimental verification. A brisk technology development effort for space-qualified, compact, solid-state RF equipment, and high temperature superconducting magnets is under way in support of this project. A conceptual point design for an early space demonstrator on the International Space Station has been defined. Also, a parametric study of a fast (115 day,) VASIMR-driven human Mars mission has been completed. This paper reviews the progress obtained in all these areas and outlines plans and strategies for continued research.

Rocket measurement of midlatitude airglow and particle precipitation

Abstract: Rocket measurements of midlatitude nightglow and particle fluxes indicate different sources for aurorae and 5577 angstrom line