NewMarsWiki - User contributions [en]

User:Mweiss

2009-03-03T17:40:21Z

Mweiss: /* User Profile for Mweiss */

== User Profile for Mweiss==
Moishe Weiss

Phoenix, Arizona

United States

== Interests ==
I am interest in anything related to science and technology, but mostly things with near-term application. For example I am not really very interested in faster-than-light travel, since we have no tested theories on how that might be done. I am very interested in interplanetary travel and nuclear power, because those are the items most immediately on our horizon.

== Education ==
Associate Degree from Phoenix College (with high distinction). Major in math.
Associate Degree from DeVry in Electronics and Computer Technology.
Bachelor Degree from Excelsior College (magna cum laude) in Computer Information Systems.

== Employment ==
I worked my way through college working mainly in libraries, first at DeVry and then with the City of Phoenix. Since then I have been a substitute teacher for the Phoenix Union High School District. I started doing this as a temporary source of income while I looked for a job in the computer field, but it has turned into a long-term job instead.

User:Mweiss

2009-03-03T17:39:52Z

Mweiss:

== User Profile for Mweiss==
Moishe Weiss
Phoenix, Arizona
United States

== Interests ==
I am interest in anything related to science and technology, but mostly things with near-term application. For example I am not really very interested in faster-than-light travel, since we have no tested theories on how that might be done. I am very interested in interplanetary travel and nuclear power, because those are the items most immediately on our horizon.

== Education ==
Associate Degree from Phoenix College (with high distinction). Major in math.
Associate Degree from DeVry in Electronics and Computer Technology.
Bachelor Degree from Excelsior College (magna cum laude) in Computer Information Systems.

== Employment ==
I worked my way through college working mainly in libraries, first at DeVry and then with the City of Phoenix. Since then I have been a substitute teacher for the Phoenix Union High School District. I started doing this as a temporary source of income while I looked for a job in the computer field, but it has turned into a long-term job instead.

VASIMR

2009-03-03T17:30:14Z

Mweiss:

{{stub}}

==Intro==
VASIMR stand for Variable-Specific-Impulse Magnetoplasmadynamic Rocket. It is a type of electric propulsion that is efficient over a large range of specific impulses. This allows specific impulse to be exchanged for thrust. It is a marginal improvement over ion engines or Hall thrusters in terms of thrust for any given power level but will allow much faster transit times once much higher power levels are implemented. The VASIMR is very important in this respect because it is deemed much more scalable to these higher power levels than are most other types of electric propulsion. In the above respects, the VASIMR is qualitatively similar to the [[Pulsed Inductive Thruster (PIT)]] from a standpoint of most promising future technologies in electric propulsion.

Currently the only company working on the VASIMR is the [http://www.adastrarocket.com Ad Astra Rocket Company], owned and run by its inventor. From the web site:

"Dr. Franklin R. Chang Díaz serves as company President and CEO. Dr. Chang Díaz invented the VASIMR concept and has been working on its development since 1979, starting at The Charles Stark Draper Laboratory in Cambridge Massachusetts and continuing at the MIT Plasma Fusion Center before moving the project to the Johnson Space Center in 1994."

The company has produced a 50 kW engine which it has retired and a 100 kW engine which it is now using for materials testing for its future 200 kW engines.

==New Mars Discussions==
==News Articles==
[[http://www.space.com/businesstechnology/technology/vasimr_rocket_020807-1.html Space.com]]
==External Links==
[[http://www.nasatech.com/Briefs/Sep01/MSC23041.html Lyndon B. Johnson Space Center, Texas]]<br>
[[http://www.nasa.gov/vision/space/travelinginspace/future_propulsion.html NASA]] Propulsion Systems of the Future<br>
[[http://www.daviddarling.info/encyclopedia/V/VASIMR.html The Encyclopedia of Astrobiology]] VASIMR (Variable Specific Impulse Magnetoplasma Rocket)<br>
[http://www.astronautix.com Encyclopedia Astronautica]
==Papers==
[[http://peaches.ph.utexas.edu/ifs/ifsreports/977_Arefiev.pdf Theoretical components
of the VASIMR plasma propulsion concept]] Alexey V. Arefiev and Boris N. Breizman
Institute for Fusion Studies, The University of Texas, Austin, Texas 78712

--[[User:Mweiss|Mweiss]] 17:30, 3 March 2009 (UTC)

Pulsed Inductive Thruster

2009-03-03T17:26:20Z

Mweiss: Undo revision 717 by Mweiss (Talk)

#redirect [[Pulsed Inductive Thruster (PIT)]]

Pulsed Inductive Thruster

2009-03-03T17:23:28Z

Mweiss: Removing all content from page

PIT

2009-03-03T17:22:38Z

Mweiss: Redirecting to Pulsed Inductive Thruster

#REDIRECT [[Pulsed Inductive Thruster]]

PIT

2009-03-03T17:22:19Z

Mweiss: New page: #REDIRECT Pulsed Inductive Thruster

#REDIRECT Pulsed Inductive Thruster

Magnetoplasmadynamic Thruster

2009-03-03T17:15:34Z

Mweiss: MPD thruster moved to Magnetoplasmadynamic Thruster: comply with naming rules

The magnetoplasmadynamic (MPD) thruster (also called an MPD arc-jet) is a form of electric rocket which produces thrust through the interaction between a current flowing through a plasma and a magnetic field acting on the same plasma. Generally speaking, devices of this type are called electromagnetic thrusters.

== Description of electromagnetic thrusters ==

The force in operation in electromagnetic thrusters is called a Lorenz force and the direction of thrust is perpendicular to both the current and the magnetic field. In physics, this is known a cross product, in this case J X B (read j-cross-b). Therefore electromagnetic thrusters are sometimes categorized as JxB thrusters or Lorenz force thrusters. Electromagnetic thrusters are generally considered to be the highest power electric thrusters, suitable only to situations in which larger nuclear power sources are providing the electricity. (100s of kilowatts to tens of megawatts, with economies of scale at increasing power levels.)

== The categorization of MPD thrusters ==

MPD thrusters are considered to be the classic electromagnetic thrusters. They are the first thrusters to have demonstrated megawatt level outputs. The first ones operated by oblating a teflon rod at the cathode (the electrode forming the center of the thruster engine) and heating the teflon to a plasma, which then gets ejected by the Lorenz force mentioned above. Since then variations of that concept have been used with different materials. What remains the same is that the device works by running a current between a central cathode and an anode forming the wall of the thurst chamber.

The forces at work in an MPD thruster are both the Lorenz force mentioned above and also (parasitically) an arcjet mode, which is more prevalent at lower powers (kilowatts). An arcjet is an electrothermal engine in which the force is produced solely by the electric heating of a gas and ejection through gas expansion. At lower powers, then, where the arcjet thrust is much more present than the Lorenz force, the MPD thruster is classed as an electrothermal device. However, at the higher powers for which it is being designed, the electothermal force dissappears and the Lorenz force dominates. At these power levels the device is an electromagnetic thruster.

== Variations ==

MPD thrusters are refered to as being either self-field or applied field depending on whether the presence of the magnetic field is self induced by the creation of the plasma or applied externally.

== Limitations ==

The MPD thruster is subject to high corrosion because of the presence of electrodes in megawatt level electric-plasma discharges. For this reason, similar electrodeless Lorenz devices have taken a lead over MPD thrusters in more recent research. The two prime examples are the [[Pulsed Inductive Thruster (PIT)]] and the Variable Specific Impulse MPD Rocket ([[VASIMR]]).

== Sources ==
(More to be added later)
http://www.nasa.gov/centers/glenn/about/fs22grc.html

--[[User:Mweiss|Mweiss]] 16:57, 3 March 2009 (UTC)

MPD thruster

2009-03-03T17:15:34Z

Mweiss: MPD thruster moved to Magnetoplasmadynamic Thruster: comply with naming rules

#REDIRECT [[Magnetoplasmadynamic Thruster]]

MPD Thruster

2009-03-03T17:12:28Z

Mweiss: Redirecting to Magnetoplasmadynamic Thruster

#REDIRECT [[Magnetoplasmadynamic Thruster]]

MPD Thruster

2009-03-03T17:12:06Z

Mweiss:

#REDIRECT Magnetoplasmadynamic Thruster

MPD Thruster

2009-03-03T17:11:45Z

Mweiss: Mpd moved to MPD Thruster

Mpd

2009-03-03T17:11:45Z

Mweiss: Mpd moved to MPD Thruster

#REDIRECT [[MPD Thruster]]

MPD Thruster

2009-03-03T17:09:18Z

Mweiss: Removing all content from page

MPD Thruster

2009-03-03T17:05:59Z

Mweiss: New page: #REDIRECT Magnetoplasmadynamic Thruster

#REDIRECT Magnetoplasmadynamic Thruster

User:Mweiss

2009-03-03T16:59:13Z

Mweiss: New page: Moishe Weiss Phoenix, Arizona, United States

Moishe Weiss
Phoenix, Arizona, United States

Magnetoplasmadynamic Thruster

2009-03-03T16:57:34Z

Mweiss:

Magnetoplasmadynamic Thruster

2009-03-03T16:56:44Z

Mweiss: /* Limitations */

Magnetoplasmadynamic Thruster

2009-03-03T16:55:49Z

Mweiss: /* Limitations */

The magnetoplasmadynamic (MPD) thruster (also called an MPD arc-jet) is a form of electric rocket which produces thrust through the interaction between a current flowing through a plasma and a magnetic field acting on the same plasma. Generally speaking, devices of this type are called electromagnetic thrusters.

== Description of electromagnetic thrusters ==

The force in operation in electromagnetic thrusters is called a Lorenz force and the direction of thrust is perpendicular to both the current and the magnetic field. In physics, this is known a cross product, in this case J X B (read j-cross-b). Therefore electromagnetic thrusters are sometimes categorized as JxB thrusters or Lorenz force thrusters. Electromagnetic thrusters are generally considered to be the highest power electric thrusters, suitable only to situations in which larger nuclear power sources are providing the electricity. (100s of kilowatts to tens of megawatts, with economies of scale at increasing power levels.)

== The categorization of MPD thrusters ==

MPD thrusters are considered to be the classic electromagnetic thrusters. They are the first thrusters to have demonstrated megawatt level outputs. The first ones operated by oblating a teflon rod at the cathode (the electrode forming the center of the thruster engine) and heating the teflon to a plasma, which then gets ejected by the Lorenz force mentioned above. Since then variations of that concept have been used with different materials. What remains the same is that the device works by running a current between a central cathode and an anode forming the wall of the thurst chamber.

The forces at work in an MPD thruster are both the Lorenz force mentioned above and also (parasitically) an arcjet mode, which is more prevalent at lower powers (kilowatts). An arcjet is an electrothermal engine in which the force is produced solely by the electric heating of a gas and ejection through gas expansion. At lower powers, then, where the arcjet thrust is much more present than the Lorenz force, the MPD thruster is classed as an electrothermal device. However, at the higher powers for which it is being designed, the electothermal force dissappears and the Lorenz force dominates. At these power levels the device is an electromagnetic thruster.

== Variations ==

MPD thrusters are refered to as being either self-field or applied field depending on whether the presence of the magnetic field is self induced by the creation of the plasma or applied externally.

== Limitations ==

The MPD thruster is subject to high corrosion because of the presence of electrodes in megawatt level electric-plasma discharges. For this reason, similar electrodeless Lorenz devices have taken a lead over MPD thrusters in more recent research. The two prime examples are the [[Pulsed Inductive Thruster (PIT)]] and the Variable Specific Impulse MPD Rocket [[(VASIMR)]].

== Sources ==
(More to be added later)
http://www.nasa.gov/centers/glenn/about/fs22grc.html

Magnetoplasmadynamic Thruster

2009-03-03T16:55:36Z

Mweiss: /* Limitations */

The magnetoplasmadynamic (MPD) thruster (also called an MPD arc-jet) is a form of electric rocket which produces thrust through the interaction between a current flowing through a plasma and a magnetic field acting on the same plasma. Generally speaking, devices of this type are called electromagnetic thrusters.

== Description of electromagnetic thrusters ==

The force in operation in electromagnetic thrusters is called a Lorenz force and the direction of thrust is perpendicular to both the current and the magnetic field. In physics, this is known a cross product, in this case J X B (read j-cross-b). Therefore electromagnetic thrusters are sometimes categorized as JxB thrusters or Lorenz force thrusters. Electromagnetic thrusters are generally considered to be the highest power electric thrusters, suitable only to situations in which larger nuclear power sources are providing the electricity. (100s of kilowatts to tens of megawatts, with economies of scale at increasing power levels.)

== The categorization of MPD thrusters ==

MPD thrusters are considered to be the classic electromagnetic thrusters. They are the first thrusters to have demonstrated megawatt level outputs. The first ones operated by oblating a teflon rod at the cathode (the electrode forming the center of the thruster engine) and heating the teflon to a plasma, which then gets ejected by the Lorenz force mentioned above. Since then variations of that concept have been used with different materials. What remains the same is that the device works by running a current between a central cathode and an anode forming the wall of the thurst chamber.

The forces at work in an MPD thruster are both the Lorenz force mentioned above and also (parasitically) an arcjet mode, which is more prevalent at lower powers (kilowatts). An arcjet is an electrothermal engine in which the force is produced solely by the electric heating of a gas and ejection through gas expansion. At lower powers, then, where the arcjet thrust is much more present than the Lorenz force, the MPD thruster is classed as an electrothermal device. However, at the higher powers for which it is being designed, the electothermal force dissappears and the Lorenz force dominates. At these power levels the device is an electromagnetic thruster.

== Variations ==

MPD thrusters are refered to as being either self-field or applied field depending on whether the presence of the magnetic field is self induced by the creation of the plasma or applied externally.

== Limitations ==

The MPD thruster is subject to high corrosion because of the presence of electrodes in megawatt level electric-plasma discharges. For this reason, similar electrodeless Lorenz devices have taken a lead over MPD thrusters in more recent research. The two prime examples are the [[Pulsed Inductive Thruster (PIT)]] and the [Variable Specific Impulse MPD Rocket [(VASIMR)]].

== Sources ==
(More to be added later)
http://www.nasa.gov/centers/glenn/about/fs22grc.html

Magnetoplasmadynamic Thruster

2009-03-03T16:54:34Z

Mweiss:

The magnetoplasmadynamic (MPD) thruster (also called an MPD arc-jet) is a form of electric rocket which produces thrust through the interaction between a current flowing through a plasma and a magnetic field acting on the same plasma. Generally speaking, devices of this type are called electromagnetic thrusters.

== Description of electromagnetic thrusters ==

The force in operation in electromagnetic thrusters is called a Lorenz force and the direction of thrust is perpendicular to both the current and the magnetic field. In physics, this is known a cross product, in this case J X B (read j-cross-b). Therefore electromagnetic thrusters are sometimes categorized as JxB thrusters or Lorenz force thrusters. Electromagnetic thrusters are generally considered to be the highest power electric thrusters, suitable only to situations in which larger nuclear power sources are providing the electricity. (100s of kilowatts to tens of megawatts, with economies of scale at increasing power levels.)

== The categorization of MPD thrusters ==

MPD thrusters are considered to be the classic electromagnetic thrusters. They are the first thrusters to have demonstrated megawatt level outputs. The first ones operated by oblating a teflon rod at the cathode (the electrode forming the center of the thruster engine) and heating the teflon to a plasma, which then gets ejected by the Lorenz force mentioned above. Since then variations of that concept have been used with different materials. What remains the same is that the device works by running a current between a central cathode and an anode forming the wall of the thurst chamber.

The forces at work in an MPD thruster are both the Lorenz force mentioned above and also (parasitically) an arcjet mode, which is more prevalent at lower powers (kilowatts). An arcjet is an electrothermal engine in which the force is produced solely by the electric heating of a gas and ejection through gas expansion. At lower powers, then, where the arcjet thrust is much more present than the Lorenz force, the MPD thruster is classed as an electrothermal device. However, at the higher powers for which it is being designed, the electothermal force dissappears and the Lorenz force dominates. At these power levels the device is an electromagnetic thruster.

== Variations ==

MPD thrusters are refered to as being either self-field or applied field depending on whether the presence of the magnetic field is self induced by the creation of the plasma or applied externally.

== Limitations ==

The MPD thruster is subject to high corrosion because of the presence of electrodes in megawatt level electric-plasma discharges. For this reason, similar electrodeless Lorenz devices have taken a lead over MPD thrusters in more recent research. The two prime examples are the [[Pulsed Inductive Thruster (PIT)]] and the [[Variable Specific Impulse MPD Rocket (VASIMR)]].

== Sources ==
(More to be added later)
http://www.nasa.gov/centers/glenn/about/fs22grc.html

Magnetoplasmadynamic Thruster

2009-03-03T16:47:16Z

Mweiss: MPD Thrusters

The magnetoplasmadynamic (MPD) thruster (also called an MPD arc-jet) is a form of electric rocket which produces thrust through the interaction between a current flowing through a plasma and a magnetic field acting on the same plasma. Generally speaking, devices of this type are called electromagnetic thrusters.

Description of electromagnetic thrusters
The force in operation in electromagnetic thrusters is called a Lorenz force and the direction of thrust is perpendicular to both the current and the magnetic field. In physics, this is known a cross product, in this case J X B (read j-cross-b). Therefore electromagnetic thrusters are sometimes categorized as JxB thrusters or Lorenz force thrusters. Electromagnetic thrusters are generally considered to be the highest power electric thrusters, suitable only to situations in which larger nuclear power sources are providing the electricity. (100s of kilowatts to tens of megawatts, with economies of scale at increasing power levels.)

== The categorization of MPD thrusters ==

MPD thrusters are considered to be the classic electromagnetic thrusters. They are the first thrusters to have demonstrated megawatt level outputs. The first ones operated by oblating a teflon rod at the cathode (the electrode forming the center of the thruster engine) and heating the teflon to a plasma, which then gets ejected by the Lorenz force mentioned above. Since then variations of that concept have been used with different materials. What remains the same is that the device works by running a current between a central cathode and an anode forming the wall of the thurst chamber.

The forces at work in an MPD thruster are both the Lorenz force mentioned above and also (parasitically) an arcjet mode, which is more prevalent at lower powers (kilowatss). An arcjet is an electrothermal engine in which the force is produced solely by the electric heating of a gas and ejection through gas expansion. At lower powers, then, where the arcjet thrust is much more present than the Lorenz force, the MPD thruster is classed as an electrothermal device. However, at the higher powers for which it is being designed, the electothermal force dissappears and the Lorenz force dominates. At these power levels the device is an electromagnetic thruster.

== Variations ==

MPD thrusters are refered to as being either self-field or applied field depending on whether the presence of the magnetic field is self induced by the creation of the plasma or applied externally.

== Limitations ==

The MPD thruster is subject to high corrosion because of the presence of electrodes in megawatt level electric-plasma discharges. For this reason, similar electrodeless Lorenz devices have taken a lead over MPD thrusters in more recent research. The two prime examples are the Pulsed Inductive Thruster (PIT) and the Variable Specific Impulse MPD Rocket (VASIMR).

== Sources ==
(More to be added later)
http://www.nasa.gov/centers/glenn/about/fs22grc.html