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Topic: Thruster


  
  Electric Thruster Test and Evaluation
Electric thrusters have an exhaust velocity normally 2 to 10 times higher than chemical thrusters, which means their efficiency with respect to propellant usage is greater.
In a Hall-effect thruster, neutral atoms from a heavy gas such as xenon are ionized by collision with high-energy electrons whose movement is confined by a radial magnetic field.
Thruster performance, life-limiting characteristics, and interactions between spacecraft and exhaust plumes are best understood through a combination of measurements and modeling.
www.aero.org /publications/crosslink/fall2005/05.html   (3721 words)

  
 American Antigravity - Vortex Thruster Aircraft Technology
Physically, the difference between conventional jet propulsion and the vortex thruster is that in the former, the net force generated and the power requirements are determined by the same axial velocity component.
In the vortex thruster, a large net force is generated primarily by the tangential velocity component, but only a relatifvely small axial flow rate, and hence, relatively small power is required.
Preliminary experiments using a simple device to model a thruster have verified that thrust is in fact generated in the same direction as the exit flow.
www.americanantigravity.com /vortexthruster.html   (732 words)

  
 helicon thruster
A device that works in a similar way to a pulsed-plasma thruster but with one important difference: a traveling electromagnetic wave interacts with a current sheet to maintain a strong force on a plasma moving along an axis.
The principle of this helicon double layer thruster is similar to that behind a natural phenomenon in space.
Despite the challenges to be overcome, in principle the potential for helicon-type thrusters operating at high power levels to produce a high continuous thrust and high, variable specific impulse (compared to some other types of electric propulsion) make them an attractive choice for propelling large spacecraft requiring high delta-V and acceptable transfer times.
www.daviddarling.info /encyclopedia/H/helicon_thruster.html   (723 words)

  
 Micro pulsed plasma thruster and method of operating same - Patent 6216445
The thruster of claim 1 wherein said heat producing means are MEMS micro heaters capable of independently producing sufficient quantities of heat to cause said solids to sublime at times and locations to reduce ignition voltages and increase the PPT efficiency at desired values of propellant velocity.
The thruster of claim 1 wherein said power source is configured to control the shape and magnitude of said ignition signal in three segments corresponding to an open circuit to a constant voltage segment, a constant voltage segment, and a constant current segment.
The method of operating a pulsed plasma thruster according to claim 32 wherein the step of directing the high pressure vapor in the direction of said thrust discharge chamber is performed in a manner that creates pressure between the two electrode plates of the thrust discharge chamber.
www.freepatentsonline.com /6216445.html   (5331 words)

  
 Bledsoe Products: Thruster OA Knee Brace
Thruster RLF LA - This device is indicated for Lateral Unicompartmental Gonarthrosis, to help relieve pain and inflammation, to aid in delaying osteotomy or total joint procedures, to increase daily walking time while increasing activities, and to aid in slowing the progression of the condition.
Thruster RLF MA - This device is indicated for Medial Unicompartmental Gonarthrosis, to help relieve pain and inflammation, to aid in delaying osteotomy or total joint procedures, to increase daily walking time while increasing activities, and to aid in slowing the progression of the condition.
Thruster RLF MA - This device is contraindicated for Lateral Unicompartmental Gonarthrosis tri- or bi-compartmental osteoarthritis for knees with injury or chronic stretch of the medial collateral ligaments or other medial or antero-medial structures of the knee.
www.bledsoebrace.com /products/thruster.asp   (578 words)

  
 Avoidable Thruster Damage Paper
Water and dirt in thruster gear oil systems is a serious problem costing offshore vessel owners thousands of dollars every year due to loss of position, down time, thruster repairs, oil changes and unplanned docking.
Water ingress in thrusters - usually through the main propeller shaft seal - can be caused by several factors such as pumping effect, entangled fishing lines, wear and vibrations, and even though the seal manufactures has improved the designs, water ingress still cannot be totally avoided.
Normally a gear oil system on a thruster is only equipped with an in-line filter with a nominal filtration degree of between 10 and 25 micron, which is not capable of removing water.
www.ccjensen.com /Avoidable_Thruster_Damage_Paper.htm   (1037 words)

  
 Bledsoe Products: Thruster 3 OA Knee Brace
Thruster 3 Medial (MA) - This device is indicated for Medial Unicompartmental Gonarthrosis, to help relieve pain and inflammation, to aid in delaying osteotomy or total joint procedures, to increase daily walking time while increasing activities, and to aid in slowing the progression of the condition.
Thruster 3 Lateral (LA) - This device is indicated for Lateral Unicompartmental Gonarthrosis, to help relieve pain and inflammation, to aid in delaying osteotomy or total joint procedures, to increase daily walking time while increasing activities, and to aid in slowing the progression of the condition.
Thruster 3 Medial (MA) - This device is contraindicated for Lateral Unicompartmental Gonarthrosis tri- or bi-compartmental osteoarthritis for knees with injury or chronic stretch of the medial collateral ligaments or other medial or antero-medial structures of the knee.
www.bledsoebrace.com /products/thruster3.asp   (544 words)

  
 DST - Precision Thrusters
State of the art ion thruster technology, such as the DS1 thruster, is relatively large, and scaled for main propulsion applications, i.e.
For formation flying applications, however, ion thrusters would be used in a unique attitude control mode, accurately maintaining the relative position of several spacecraft, or the rate at which they are moving with respect to each other.
This represents a major advance in the long history of ion thruster development, since small thrusters due to a higher surface-to-volume ratio have a greater tendency to loose ions to the thruster walls in recombination reactions, decreasing thruster efficiency.
dst.jpl.nasa.gov /thrusters/index.htm   (924 words)

  
 Ion thruster Summary
Ion thrusters are therefore able to achieve high specific impulse, reducing the amount of reaction mass required, but increasing the amount of power required compared to chemical rockets.
The first ion thrusters, known as Kaufman-type ion thrusters, were developed by Harold R. Kaufman, working for NASA in the 1960s, and were based on the Duoplasmatron.
The Hall effect thruster is a type of ion thruster that has been used for decades for station keeping by the Soviet-Union and is now also applied in the West: the European Space Agency's satellite Smart 1 uses it.
www.bookrags.com /Ion_thruster   (1719 words)

  
 - Solar Thruster Sailor (STS) - a huge solar sail with ion-thruster-ring-skeleton
The Solar Thruster Sailor as a mother carrier ship provides cheap transportation through the possibility to hold a huge free photonic thrust producing sail (and therefor saving fuel mass and costs) with the ability to carry a lot of payload combined with the secure docking ability for also highly steerable Thruster-Ring daughter units.
using Mini-STS Solar Thruster Sailors (solar sails which are compounding solar sail with ion thruster propulsion) to retrieve samples of asteroid regolith to land on one or several asteroids, drill asteroidal sample cores and bringing them back to earth or to the ISS for analysation.
Since the lower weight of the thrusters would be substantial this solar sails could be even smaller than the Mini STS or they could move faster.
solar-thruster-sailor.info /sts/sts.htm   (4406 words)

  
 Mini Microwave Thruster Has The Power
He says electric propulsion thrusters currently used to position and maneuver satellites in space operate inefficiently or not at all in the 100-Watt range.
The new mini microwave thruster has the potential not only to reduce on-board power requirements but also to extend a satellite's productive life since it requires only one third the amount of propellant used by other systems.
The thruster concept is based on the fact that microwaves can be used to create and maintain a free-floating plasma or superheated, electrically charged gas within a cavity, Micci says.
www.spacedaily.com /news/thruster-99b.html   (652 words)

  
 Menu Exercise
A stern thruster becomes helpful in very tight slips where you have to position the stern in close quarters or when you want to “parallel” park, literally walking the boat sideways into the slip.
Considering that a normal thruster burst is between 5 to 10 seconds, limited continuous duty should not be a concern.
Run the thruster at least once a week, even when not using the boat, to blow the tunnel clear and dislodge marine growth from the blades.
www.great-water.com /pages/product_pages/qlthrusterfaq.htm   (754 words)

  
 Thruster Performance   (Site not responding. Last check: 2007-10-03)
A single thruster was mounted on a floating support on the surface of the tank at the NBRF as shown in Figure 2-4.
This sequence was repeated at intervals of 65 RPM until the maximum angular velocity attainable by the thrusters at 18V was reached.
After this sequence was completed, the thruster was rotated 180 degrees, and the entire test was repeated in the reverse direction.
www.ssl.umd.edu /Projects/RangerNBV/thesis/2-3-1-2.htm   (867 words)

  
 The E-field thruster project   (Site not responding. Last check: 2007-10-03)
When the layer of the dielectric cover at the thruster’s bottom was thinner, a small negative thrust was detected (from the bigger electrode towards the smaller).
The primary aim of the research is to obtain knowledge about the magnitude of all the partial forces present in the thruster, and their dependency upon the parameters of the system.
To clear this issue a cylindrical thruster element with two different parallel dielectrics should be constructed and the thrust measured for different voltages.
www.gyogyitokezek.hu /fe/thrusterproject.htm   (1203 words)

  
 PEPL Electric Propulsion Thrusters
This thruster has a discharge chamber outer diameter of 173 mm and was designed to emulate the characteristics of commercial Hall thrusters.
The Linear Gridless Ion Thruster (LGIT) is a two-stage device that is designed to incorporate the efficient ionization process found in gridded ion thrusters with the high thrust density and crossed-field acceleration mechanism of Hall thrusters.
It is convenient to think of this thruster as the ionization stage of an ion thruster combined with the acceleration stage of a Hall thruster.
www.engin.umich.edu /dept/aero/spacelab/thrusters/thrusters.html   (819 words)

  
 Florida Bow Thrusters
In order to ensure the best performance under all sorts of weather and water conditions, the bow thruster should be able to provide a thrust force which is suitable, or rather: sufficient, for the boat in which it has been installed.
The bow thruster is required to apply a countering thrust force, which is at least equal to the thrust force applied by the wind.
The required thrust force of the bow thruster may now be calculated by dividing the torque by the distance (B) between the center of the bow thruster and the pivot point of the boat.
www.floridabowthrusters.com /information.htm   (1601 words)

  
 Bow Thrusters, Tunnel Thruster, Stern Thrusters, Dynamic Positioning
Because the Harbormaster Tunnel Thruster is relatively small in its awthwartship dimension, it can be installed in a ship with fine entrance lines and can be located in the optimum position for maximum turning moment.
The Harbormaster Bow Thruster / Tunnel Thruster consists of a cylindrical weldment, supporting near its center a right angle gear box with input shaft, coupling, and propeller shaft, and a Kaplan type propeller with blades working in close proximity to a corrosion and abrasion resistant wear ring.
Bow Thrusters / Tunnel Thrusters are normally operated only for limited periods during docking and maneuvering, however we build them for rugged service by using many of the same components as our continuous-duty Harbormaster Outboard Drive Units.
www.harbormastermarine.com /Tunnel_Bow_Thrusters.htm   (570 words)

  
 Universe Today - Researchers Create a New Plasma Thruster
The thruster is called the Helicon Double Layer Thruster (HDLT), and it works by passing hydrogen atoms through a magnetic field to create a beam of plasma.
While the plasma thruster has a fraction of the power of the rockets that launch the space shuttle, it uses far less fuel and gets more thrust as a ratio of the fuel it burns, making it ideal for interplanetary missions.
While the technology of plasma thrusters is not new, its popularity has only taken off in recent years, with it being used to help satellites maintain their positions in orbit.
www.universetoday.com /am/publish/plasma_thruster_created.html?2912004   (468 words)

  
 Electric Thruster   (Site not responding. Last check: 2007-10-03)
The spec for this unit is approximately 36 amp maximum draw at 12 volts, which yields 42 pounds of static thrust.
The heavy fiberglass thruster support shaft is indexed into a retractable steering motor, which allows our software to control the thrust angle.
The real smarts behind this is the adaptive thruster control system, which both steers the motor and delivers a continually fine-tuned power level that exactly utilizes left-over solar power after the battery and other system loads are satasfied.
microship.com /microship/techinfo/microshipnet/thruster.html   (183 words)

  
 High-Power Magnetoplasmadynamic Thruster Being Developed
In the self-field version of the thruster, an azimuthal magnetic field generated by the current returning through the cathode interacts with the radial discharge current flowing through the plasma to produce an axial electromagnetic body force, providing thrust.
The MPD thruster is fitted inside a magnetic field coil, which in turn is mounted on a thrust stand supported by thin metal flexures.
This short period of time is sufficient to establish thruster performance similar to steady-state operation, and it allows a number of thruster designs to be quickly and economically evaluated.
www.lerc.nasa.gov /WWW/RT2000/5000/5430lapointe.html   (539 words)

  
 DC Thrusters
However, use of DC Thrusters on larger yachts has been restricted by limitations in their power and thrust.
The DC Thruster market is filled with product where lower prices are achieved at the expense of performance and quality.
One of the most important components of a DC thruster is the motor.
www.thrusters.com /thrusters/dcthrusters.html   (385 words)

  
 NASA - NASA's New Hall Thruster Passes Performance Testing
The HiVHAC thruster was designed and fabricated over the last year by a team from Glenn and Aerojet, Redmond, Wash., to operate efficiently over a wide range of input power levels.
The thruster was shown to operate successfully with input powers between 200 and 2900 watts at specific impulses (a measure of propellant fuel economy) between 1,000 and 2,800 seconds.
The next step for this technology will be to design and demonstrate the thruster's ability to achieve the long life necessary to reach outer destinations.
www.nasa.gov /centers/glenn/news/pressrel/2005/05-033_Thruster.html   (583 words)

  
 ACT Advanced Concept Team   (Site not responding. Last check: 2007-10-03)
The need to demonstrate the predicted performance breakthroughs of the dual-stage gridded ion thruster concept led to the initiation of a proof-of-concept experimental thruster research, development and test programme in June 2005.
A picture and 3D CAD model of the thruster are shown in Figs 1 and 2.
The plasma source tube (white cylinder in the picture) is 5 cm inner diameter, the beam diameter is 2.3 cm and the clamp plates are 20 cm in diameter.
www.esa.int /gsp/ACT/propulsion/safe_thruster.htm   (566 words)

  
 American AntiGravity - Stainless Steel Vortex Thruster
This is because the exhaust from the thruster would exist over the top of the wing and create lift similar to the manner that forward movement would.
This is because a tornado uses a rotating airflow to generate high-speed wind-shear, which separates low pressure air on the inside from the high-pressure air outside.
The idea behind the Vortex Thruster is to generate a high-speed rotating flow, and then use that flow to create a low-pressure area over a doughnut-shaped airfoil.
www.americanantigravity.com /vtcss.html   (811 words)

  
 JPL Work on Russian Thrusters - JPL Universe (16-Dec-94)
Loral is interested in using the thrusters on its commercial communications satellites and the stated goals of the BMDO- sponsored test are sufficient, Brophy said, to demonstrate 15 years of on-orbit satellite operations.
The company wanted to further demonstrate the thruster's reliability to its potential commercial spacecraft customers by demonstrating that the thruster could operate for 150 percent of the required mission duration with using only one of the thruster's two cathodes.
The test substantially exceeded the Russian experience with this thruster, and a representative of Fakel Design Bureau, the Russian manufacturer of the thruster, came to JPL in November to inspect the device.
www.islandone.org /Propulsion/RussianThrusters.html   (886 words)

  
 [No title]
The Hall thruster is an electric rocket engine, which accelerats ions in crossed electric and magnetic fields in a quasineutral plasma.
The thruster was designed to work at 1 kW power range by a linear scaling of its geometry relative to a subkilowatt Soreq Hall thruster.
The use of emissive spectroscopy for measurements of plasma properties inside and outside the thruster and for indirect characterization of the beam divergence inside the thruster channel.
w3.pppl.gov /~fisch/proj_hallthruster.html   (495 words)

  
 Stern and Bow Thrusters from STI Thrusters
Although damaging a Stern Thruster would be very difficult to do because they are so protected, your boat doesn't have to be hauled and you can easily continue on with your cruise or work.
The end result is like mounting a large outboard sideways on the stern of your boat and running it in forward or reverse thus pushing the boat to port or starboard with just a flick of a switch.
Our Bow Thrusters are great, but our Stern Thrusters are so easy to install, 85% of our sales are installed by the boats owner.
www.dockhooker.com /sternthrusters/questions.html   (511 words)

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