The new VX-200 (VASIMR Experimental, 200 kW) lab prototype we are working on has the capability of applying 200 kW of total RF power. ~30 kW to the first stage (Helicon plasma source), and ~ 170 kW to the second stage (Ion Cyclotron Heating, ICH, stage). The VX-200 will also have superconducting magnets (to be delivered in several weeks). The peak magnetic field inside the VX-200 will be on the order of two tesla, similar to the field strength in a strong MRI machine. At our old lab in NASA-JSC, we actually had a pacemaker safety line that limited people from getting too close to the intense magnetic field. Please see http://www.adastrarocket.com/vx200.html for a few more details.
The VASIMR engine that will be placed on the International Space Station (ISS) will likely be the VF-200 (VASIMR Flight, 200 kW). However, the flight version will actually have two 100 kW plasma cores. The two cores will have antiparallel magnetic fields, which sets up a quadrupole magnetic field configuration for the device as a whole. This quadrupole design is used so that the magnetic field dies off faster (1/r^4, instead of 1/r^3 as with a solenoidal magnetic field). In addition to being safer for the ISS, this faster die-off facilitates faster plasma detachment from the magnetic field lines of the nozzle. The ISS does not have 200 kW of power available for experiments, so a 200 kW battery pack would be charged up over a long period of time (hours to days) and used fire the VF-200 for a shorter period of time (seconds to minutes). Imagine looking up at the ISS flying by at night and seeing a bright blue and magenta kilometer-long plasma rocket plume.
Both the VX-200 and the VF-200 use argon gas as the propellant because of argon's mass and ionization potential. Previous VASIMR prototypes and experiments used hydrogen, deuterium, and neon. Argon is used for the current VASIMR prototypes because it will give an Isp of ~5000s (50,000 m/s). It turns out that this is an optimal Isp for the given LEO orbit, the cost of launching, and the power and weight of VASIMR and related components. A mars mission would likely use a lighter propellant like hydrogen because of the higher Isp obtained with lighter gases.
The reason that VASIMR 'wins' over other ion thrusters, ion engines, and Hall thrusters is that VASIMR can process a huge amount of power and couple that power into a neutral (equal number of ions and electrons) flowing plasma. In this way, VASIMR provides the exhaust velocity and fuel performance of an ion thruster, but produces 10 to 1000 times the thrust typically associated with these thrusters. VASIMR also has the ability to vary the power going to the first or second stage, thus changing from a high-thrust low-velocity exhaust to a lower-thrust higher-velocity exhaust, similar to shifting gears in a car while accelerating. The VX-200 is designed to produce upwards of 5 N of thrust.
The VASIMR program was moved out of the NASA-JSC Advanced Space Propulsion Laboratory in late 2007 and into the private lab of the Ad Astra Rocket Company in Webster TX (http://www.youtube.com/watch?v=ZXofYP_VfUg&feature=user
Slashdot Mirror
Dear Slashdot readers, Here are a few videos of VASIMR that we have taken in the Ad Astra lab:
http://www.youtube.com/watch?v=E_FGqb0cr1k
http://www.youtube.com/watch?v=KVsgSjm_vXg
http://www.youtube.com/watch?v=ZXofYP_VfUg
http://www.youtube.com/watch?v=yvg-Dsh9s2I
Kind Regards, Ben
Dear Slashdot readers, Here are a few videos of VASIMR that we have taken in the Ad Astra lab: Kind Regards, Ben
The new VX-200 (VASIMR Experimental, 200 kW) lab prototype we are working on has the capability of applying 200 kW of total RF power. ~30 kW to the first stage (Helicon plasma source), and ~ 170 kW to the second stage (Ion Cyclotron Heating, ICH, stage). The VX-200 will also have superconducting magnets (to be delivered in several weeks). The peak magnetic field inside the VX-200 will be on the order of two tesla, similar to the field strength in a strong MRI machine. At our old lab in NASA-JSC, we actually had a pacemaker safety line that limited people from getting too close to the intense magnetic field. Please see http://www.adastrarocket.com/vx200.html for a few more details.
The VASIMR engine that will be placed on the International Space Station (ISS) will likely be the VF-200 (VASIMR Flight, 200 kW). However, the flight version will actually have two 100 kW plasma cores. The two cores will have antiparallel magnetic fields, which sets up a quadrupole magnetic field configuration for the device as a whole. This quadrupole design is used so that the magnetic field dies off faster (1/r^4, instead of 1/r^3 as with a solenoidal magnetic field). In addition to being safer for the ISS, this faster die-off facilitates faster plasma detachment from the magnetic field lines of the nozzle. The ISS does not have 200 kW of power available for experiments, so a 200 kW battery pack would be charged up over a long period of time (hours to days) and used fire the VF-200 for a shorter period of time (seconds to minutes). Imagine looking up at the ISS flying by at night and seeing a bright blue and magenta kilometer-long plasma rocket plume.
Both the VX-200 and the VF-200 use argon gas as the propellant because of argon's mass and ionization potential. Previous VASIMR prototypes and experiments used hydrogen, deuterium, and neon. Argon is used for the current VASIMR prototypes because it will give an Isp of ~5000s (50,000 m/s). It turns out that this is an optimal Isp for the given LEO orbit, the cost of launching, and the power and weight of VASIMR and related components. A mars mission would likely use a lighter propellant like hydrogen because of the higher Isp obtained with lighter gases.
The reason that VASIMR 'wins' over other ion thrusters, ion engines, and Hall thrusters is that VASIMR can process a huge amount of power and couple that power into a neutral (equal number of ions and electrons) flowing plasma. In this way, VASIMR provides the exhaust velocity and fuel performance of an ion thruster, but produces 10 to 1000 times the thrust typically associated with these thrusters. VASIMR also has the ability to vary the power going to the first or second stage, thus changing from a high-thrust low-velocity exhaust to a lower-thrust higher-velocity exhaust, similar to shifting gears in a car while accelerating. The VX-200 is designed to produce upwards of 5 N of thrust.
The VASIMR program was moved out of the NASA-JSC Advanced Space Propulsion Laboratory in late 2007 and into the private lab of the Ad Astra Rocket Company in Webster TX (http://www.youtube.com/watch?v=ZXofYP_VfUg&feature=user
* A video from the NASA Advanced Space Propulsion Laboratory, the firing of the VX-100.
http://www.youtube.com/watch?v=KVsgSjm_vXg
* A video of the new VX-200 vacuum chamber arriving in Houston and being installed in the Ad Astra lab.
http://www.youtube.com/watch?v=yvg-Dsh9s2I&feature=user
* A video of a conceptual human Mars mission using 3 Megawatt-class VASIMR engines.
http://www.youtube.com/watch?v=Zj53rVWK5z0&feature=related
* Mike griffin makes a statement about placing VASIMR on ISS.
http://www.thespacereview.com/article/1182/1