Quote from: Raj2014 on 12/21/2014 10:35 pmThey have done a lot of work on the VASIMR.No doubt. What they haven't done is produce a rocket engine.
They have done a lot of work on the VASIMR.
it is my understanding that the VF 200 is fully built and ground tested. what does it take other than that to "produce a rocket engine?"
Quote from: Stormbringer on 12/21/2014 10:52 pmit is my understanding that the VF 200 is fully built and ground tested. what does it take other than that to "produce a rocket engine?"We've been through this. They haven't demonstrated exhaust separation. It doesn't produce thrust. After 37 years, that's pretty impressive!
So NASA agreed to send a engine to space that produces no thrust? I don't think so. That does not sound likely.
I don't recall being through this. Please elaborate why you say VASIMR doesn't produce thrust and site your sources.
The described particle simulations in VASIMR demonstrate plasma detachment from the magneticnozzle. Reasonable agreement between MHD andparticle simulation is observed in plasma betadetachment analysis. The codes developed so far arebeing validated in the VX-10 laboratory experimentand assisting researchers in the design of a VASIMRflight demonstration experiment.
One of the remaining untested issues was potential vs actual thrust; that is, whether the hot plasma actually detached from the rocket.
Quote from: RonM on 12/21/2014 11:20 pmI don't recall being through this. Please elaborate why you say VASIMR doesn't produce thrust and site your sources.http://forum.nasaspaceflight.com/index.php?topic=18382.msg487159#msg487159If you want a source, how about this unfunded grant application for demonstrating plasma detachment: http://www.uh.edu/research/spg/uhdiagnostics.htmlOr Ad Astra's computer simulation paper: http://www.adastrarocket.com/AndrewASS02.PDFQuoteThe described particle simulations in VASIMR demonstrate plasma detachment from the magneticnozzle. Reasonable agreement between MHD andparticle simulation is observed in plasma betadetachment analysis. The codes developed so far arebeing validated in the VX-10 laboratory experimentand assisting researchers in the design of a VASIMRflight demonstration experiment.There's no dispute, Ad Astra have yet to demonstrate that VASIMR produces thrust. They expect to demonstrate that on a flight mission, which hasn't been funded and for which no launch has been allocated.
Quote from: QuantumG on 12/21/2014 10:58 pmQuote from: Stormbringer on 12/21/2014 10:52 pmit is my understanding that the VF 200 is fully built and ground tested. what does it take other than that to "produce a rocket engine?"We've been through this. They haven't demonstrated exhaust separation. It doesn't produce thrust. After 37 years, that's pretty impressive!Here is a video showing a engine producing thrust.
As far as I'm aware, Ad Astra have never claimed they could demonstrate detachment of the plasma from the nozzle on the ground and have no plans to do so.
I think anything that poops anything out one end (even if it's just blue glowy stuff) produces thrust.
Quote from: Raj2014 on 12/23/2014 11:20 pmQuote from: QuantumG on 12/21/2014 10:58 pmQuote from: Stormbringer on 12/21/2014 10:52 pmit is my understanding that the VF 200 is fully built and ground tested. what does it take other than that to "produce a rocket engine?"We've been through this. They haven't demonstrated exhaust separation. It doesn't produce thrust. After 37 years, that's pretty impressive!Here is a video showing a engine producing thrust.No it isn't.Go to your kitchen sink, fill it with water and swirl your hand around to create a vortex. Now stick a large flat spoon into the flow. You will feel a force, that's momentum response. To claim that your setup is producing net force would be silly, but to do it you'd need to make an argument about the detachment of the medium from the vessel. That is, you need to pull out the plug. As far as I'm aware, Ad Astra have never claimed they could demonstrate detachment of the plasma from the nozzle on the ground and have no plans to do so.
Quote from: QuantumG on 12/23/2014 11:54 pmQuote from: Raj2014 on 12/23/2014 11:20 pmQuote from: QuantumG on 12/21/2014 10:58 pmQuote from: Stormbringer on 12/21/2014 10:52 pmit is my understanding that the VF 200 is fully built and ground tested. what does it take other than that to "produce a rocket engine?"We've been through this. They haven't demonstrated exhaust separation. It doesn't produce thrust. After 37 years, that's pretty impressive!Here is a video showing a engine producing thrust.No it isn't.Go to your kitchen sink, fill it with water and swirl your hand around to create a vortex. Now stick a large flat spoon into the flow. You will feel a force, that's momentum response. To claim that your setup is producing net force would be silly, but to do it you'd need to make an argument about the detachment of the medium from the vessel. That is, you need to pull out the plug. As far as I'm aware, Ad Astra have never claimed they could demonstrate detachment of the plasma from the nozzle on the ground and have no plans to do so.You say the VASIMR does not produce thrust, yet in the video I posted, we can see the VASIMR move the Momentum/Impulse response target.
You say the VASIMR does not produce thrust, yet in the video I posted, we can see the VASIMR move the Momentum/Impulse response target.