Dynaverse.net
Off Topic => Ten Forward => Topic started by: Stormbringer on December 05, 2003, 12:40:56 am
-
standard ion engines are efficient but they take too much time to build velocity due to low thrust output. This is proof that will not always be so:
November 20
Prometheus Nuclear Program Achieves Milestone
NASA's Project Prometheus received a gentle nudge toward reality, courtesy of the first successful test of a High Power Electric Propulsion (HiPEP) ion engine. The event marked the first in a series of performance tests to demonstrate new high-velocity and high-power thrust needed for use in nuclear electric propulsion (NEP) spacecraft.
NASA announced the test success in a November 20 statement.
HiPEP is one of several candidate propulsion technologies under study by Project Prometheus for possible use on the first proposed flight mission, the Jupiter Icy Moons Orbiter (JIMO). The mission is not proposed for launch before the year 2011.
The HiPEP experiment involved the largest microwave ion thruster ever built. The use of microwaves for ionization would enable very long-life thrusters for spacecraft applications. The test was carried out at NASA's Glenn Research Center in Cleveland, Ohio.
JIMO's ion thrusters are to be powered by a nuclear fission reactor and a system for converting the reactor's heat to electricity. This could give the craft more than 100 times as much power as a non-fission system of comparable weight.
A heavy lift expendable launch vehicle would place JIMO into high Earth orbit. The ion-propulsion thrusters would spiral the spacecraft away from Earth and then on its way to Jupiter.
JIMO would orbit three different moons of Jupiter where earlier spacecraft discovered evidence for vast saltwater oceans hidden beneath icy surface layers: Europa, Ganymede and Callisto. The proposed flagship mission is also being pursued to raise NASA's capability for space exploration to a new level by demonstrating safe and reliable use of electric propulsion powered by a nuclear fission reactor.
-- Leonard David
-
Interesting. Just one point though, isn't ion thruster technology very ineffective in atmospheres?
-
There is no reason one with a more powerful output would be so disadvantaged. Currently the thrust output is so small that they just don't work there. But thier thrust is currently measured in fractions of a gram. Eventually thier specific impulse would be comparable to chemical rockets. In that event the atmosphere will not interfere either by resistance or electrically. Does the atmosphere prevent lightning bolts?
-
i dont like the idea of using a nuclear reactor.....
-
Firstly it's not the first time nuclear rockets have been proposed or even tested. Those were even more primative and dangerous as they outputted irradiated steam as the propulsion agent. Secondly a bnuch of enviromentalists protested the Galileo and older probes predicting disaster becuase they were powered by plutonium RTG powerplants. Some even went so far as trying to break into the launch site to sabotage the rocket. In those cases they were far more dangerous than the missions they were protesting and the missions return incalculable value in knowledge gained. Thirdly why does this have to be a discussion about political subjects at all? Why can't it be about the technical problems such an undertaking would entail? Political discussions here gain nothing. As evidence look at the latest second ammendment argument and tell me how it is different from the last one? Or the One about the mutineers in the Israeli army, or the one about church and state separation, or the core of the Gay marriage thread. They are all saying the same things back and forth like a bunch of trained parrots. Who wins a debate between two parrots? neither parrot changes thier repetoire one iota. All it does is piss people off. I've posted a topic that bypasses all that and yet either it gets turned to politics or people ignore it altogether.
I Should have posted this particular vent in another thread, sorry. It's late.
-
Ok. There is one problem with your lightning analogy and that is lightning isn't trying to propel any substantial mass. I hope that this project is a stunning success though.
-
The main reasons ion drive doesn't work in an atmosphere is the low thrust not overcoming air resistance and gravity. If you've ever seen a down high tension power line jumping around you'd not doubt the power of ions or EMF in high power outputs. And lightning has a lot of force provided it is not conducted away. As with all engines it is a question of thrust verses mass, inertia, entropy and so on. The output overcomes those and the engine moves. Enough excess output and the engine can carry something other than it's own wieght.
-
standard ion engines are efficient but they take too much time to build velocity due to low thrust output. This is proof that will not always be so:
November 20
Prometheus Nuclear Program Achieves Milestone
NASA's Project Prometheus received a gentle nudge toward reality, courtesy of the first successful test of a High Power Electric Propulsion (HiPEP) ion engine. The event marked the first in a series of performance tests to demonstrate new high-velocity and high-power thrust needed for use in nuclear electric propulsion (NEP) spacecraft.
NASA announced the test success in a November 20 statement.
HiPEP is one of several candidate propulsion technologies under study by Project Prometheus for possible use on the first proposed flight mission, the Jupiter Icy Moons Orbiter (JIMO). The mission is not proposed for launch before the year 2011.
The HiPEP experiment involved the largest microwave ion thruster ever built. The use of microwaves for ionization would enable very long-life thrusters for spacecraft applications. The test was carried out at NASA's Glenn Research Center in Cleveland, Ohio.
JIMO's ion thrusters are to be powered by a nuclear fission reactor and a system for converting the reactor's heat to electricity. This could give the craft more than 100 times as much power as a non-fission system of comparable weight.
A heavy lift expendable launch vehicle would place JIMO into high Earth orbit. The ion-propulsion thrusters would spiral the spacecraft away from Earth and then on its way to Jupiter.
JIMO would orbit three different moons of Jupiter where earlier spacecraft discovered evidence for vast saltwater oceans hidden beneath icy surface layers: Europa, Ganymede and Callisto. The proposed flagship mission is also being pursued to raise NASA's capability for space exploration to a new level by demonstrating safe and reliable use of electric propulsion powered by a nuclear fission reactor.
-- Leonard David
-
Interesting. Just one point though, isn't ion thruster technology very ineffective in atmospheres?
-
There is no reason one with a more powerful output would be so disadvantaged. Currently the thrust output is so small that they just don't work there. But thier thrust is currently measured in fractions of a gram. Eventually thier specific impulse would be comparable to chemical rockets. In that event the atmosphere will not interfere either by resistance or electrically. Does the atmosphere prevent lightning bolts?
-
i dont like the idea of using a nuclear reactor.....
-
Firstly it's not the first time nuclear rockets have been proposed or even tested. Those were even more primative and dangerous as they outputted irradiated steam as the propulsion agent. Secondly a bnuch of enviromentalists protested the Galileo and older probes predicting disaster becuase they were powered by plutonium RTG powerplants. Some even went so far as trying to break into the launch site to sabotage the rocket. In those cases they were far more dangerous than the missions they were protesting and the missions return incalculable value in knowledge gained. Thirdly why does this have to be a discussion about political subjects at all? Why can't it be about the technical problems such an undertaking would entail? Political discussions here gain nothing. As evidence look at the latest second ammendment argument and tell me how it is different from the last one? Or the One about the mutineers in the Israeli army, or the one about church and state separation, or the core of the Gay marriage thread. They are all saying the same things back and forth like a bunch of trained parrots. Who wins a debate between two parrots? neither parrot changes thier repetoire one iota. All it does is piss people off. I've posted a topic that bypasses all that and yet either it gets turned to politics or people ignore it altogether.
I Should have posted this particular vent in another thread, sorry. It's late.
-
Ok. There is one problem with your lightning analogy and that is lightning isn't trying to propel any substantial mass. I hope that this project is a stunning success though.
-
The main reasons ion drive doesn't work in an atmosphere is the low thrust not overcoming air resistance and gravity. If you've ever seen a down high tension power line jumping around you'd not doubt the power of ions or EMF in high power outputs. And lightning has a lot of force provided it is not conducted away. As with all engines it is a question of thrust verses mass, inertia, entropy and so on. The output overcomes those and the engine moves. Enough excess output and the engine can carry something other than it's own wieght.
-
standard ion engines are efficient but they take too much time to build velocity due to low thrust output. This is proof that will not always be so:
November 20
Prometheus Nuclear Program Achieves Milestone
NASA's Project Prometheus received a gentle nudge toward reality, courtesy of the first successful test of a High Power Electric Propulsion (HiPEP) ion engine. The event marked the first in a series of performance tests to demonstrate new high-velocity and high-power thrust needed for use in nuclear electric propulsion (NEP) spacecraft.
NASA announced the test success in a November 20 statement.
HiPEP is one of several candidate propulsion technologies under study by Project Prometheus for possible use on the first proposed flight mission, the Jupiter Icy Moons Orbiter (JIMO). The mission is not proposed for launch before the year 2011.
The HiPEP experiment involved the largest microwave ion thruster ever built. The use of microwaves for ionization would enable very long-life thrusters for spacecraft applications. The test was carried out at NASA's Glenn Research Center in Cleveland, Ohio.
JIMO's ion thrusters are to be powered by a nuclear fission reactor and a system for converting the reactor's heat to electricity. This could give the craft more than 100 times as much power as a non-fission system of comparable weight.
A heavy lift expendable launch vehicle would place JIMO into high Earth orbit. The ion-propulsion thrusters would spiral the spacecraft away from Earth and then on its way to Jupiter.
JIMO would orbit three different moons of Jupiter where earlier spacecraft discovered evidence for vast saltwater oceans hidden beneath icy surface layers: Europa, Ganymede and Callisto. The proposed flagship mission is also being pursued to raise NASA's capability for space exploration to a new level by demonstrating safe and reliable use of electric propulsion powered by a nuclear fission reactor.
-- Leonard David
-
Interesting. Just one point though, isn't ion thruster technology very ineffective in atmospheres?
-
There is no reason one with a more powerful output would be so disadvantaged. Currently the thrust output is so small that they just don't work there. But thier thrust is currently measured in fractions of a gram. Eventually thier specific impulse would be comparable to chemical rockets. In that event the atmosphere will not interfere either by resistance or electrically. Does the atmosphere prevent lightning bolts?
-
i dont like the idea of using a nuclear reactor.....
-
Firstly it's not the first time nuclear rockets have been proposed or even tested. Those were even more primative and dangerous as they outputted irradiated steam as the propulsion agent. Secondly a bnuch of enviromentalists protested the Galileo and older probes predicting disaster becuase they were powered by plutonium RTG powerplants. Some even went so far as trying to break into the launch site to sabotage the rocket. In those cases they were far more dangerous than the missions they were protesting and the missions return incalculable value in knowledge gained. Thirdly why does this have to be a discussion about political subjects at all? Why can't it be about the technical problems such an undertaking would entail? Political discussions here gain nothing. As evidence look at the latest second ammendment argument and tell me how it is different from the last one? Or the One about the mutineers in the Israeli army, or the one about church and state separation, or the core of the Gay marriage thread. They are all saying the same things back and forth like a bunch of trained parrots. Who wins a debate between two parrots? neither parrot changes thier repetoire one iota. All it does is piss people off. I've posted a topic that bypasses all that and yet either it gets turned to politics or people ignore it altogether.
I Should have posted this particular vent in another thread, sorry. It's late.
-
Ok. There is one problem with your lightning analogy and that is lightning isn't trying to propel any substantial mass. I hope that this project is a stunning success though.
-
The main reasons ion drive doesn't work in an atmosphere is the low thrust not overcoming air resistance and gravity. If you've ever seen a down high tension power line jumping around you'd not doubt the power of ions or EMF in high power outputs. And lightning has a lot of force provided it is not conducted away. As with all engines it is a question of thrust verses mass, inertia, entropy and so on. The output overcomes those and the engine moves. Enough excess output and the engine can carry something other than it's own wieght.