3 ms·

Very interesting. I've been following this in the news for some time, hoping to learn the results of the latest research. In previous tests it seemed like the

by Pyxl101 11y ago

Very interesting. I've been following this in the news for some time, hoping to learn the results of the latest research. In previous tests it seemed like the significance of the effect was diminishing on each iteration, suggesting it might be experimental error. Anyone have a handle on how the latest results have changed? I don't get a good sense from the article.

threeseed 11y ago
The purpose was to reduce the Lorentz force interactions: 1) Built and installed a 2nd generation, closed face magnetic damper that reduced the stray magnetic fields in the vacuum chamber by at least an order of magnitude and any Lorentz force interactions it could produce. 2) Changed up the torque pendulum's grounding wire scheme and single point ground location to minimize ground loop current interactions with the remaining stray magnetic fields and unbalanced dc currents from the RF amplifier when its turned on. This reduced the Lorentz force interaction to less than 2 micro-Newton (uN) for the dummy load test. 3) Rebuilt the copper frustum test article so that it is now fully integrated with the RF VCO, PLL, 100W RF amp, dual directional coupler, 3-stub tuner and connecting coax cables, then mounted this integrated test article at the opposite end of the torque pendulum, as far away as possible from the 2nd generation magnetic damper where only the required counterbalance weights now reside. Now since they were still seeing 100uN of force that means they have 98uN of force unaccounted for. And the next iteration of the test is trying to mitigate the effect of any thermal forces.
- gambiting 11y ago
  At which point it would be actually cheaper to put this whole thing in space, turn it on and see if it produces any trust? If it does, then it definitely works. As long as it's on Earth, they will spend forever trying to account for extra variables.
  - JohnBooty 11y ago
    Yeah. The general rule of thumb is that it costs $10,000/pound to put something into orbit. The cost would increase by orders of magnitude once you include all of the other resources needed to track the experiment, but this does seem like a relatively cheap experiment to run in space. http://www.nasa.gov/centers/marshall/news/background/facts/astp.html_prt.htm http://www.nasa.gov/centers/marshall/news/background/facts/a... I think what's preventing this is: 1.) NASA can only run a certain amount of experiments at once and I'm sure there's a long waiting list. If they run this one, something else doesn't run. 2.) Space may not be the extra variable-free environment we're hoping for here: tons of intense electromagnetic activity and so forth.

by Pyxl101 11y ago

threeseed 11y ago

The purpose was to reduce the Lorentz force interactions: 1) Built and installed a 2nd generation, closed face magnetic damper that reduced the stray magnetic fields in the vacuum chamber by at least an order of magnitude and any Lorentz force interactions it could produce. 2) Changed up the torque pendulum's grounding wire scheme and single point ground location to minimize ground loop current interactions with the remaining stray magnetic fields and unbalanced dc currents from the RF amplifier when its turned on. This reduced the Lorentz force interaction to less than 2 micro-Newton (uN) for the dummy load test. 3) Rebuilt the copper frustum test article so that it is now fully integrated with the RF VCO, PLL, 100W RF amp, dual directional coupler, 3-stub tuner and connecting coax cables, then mounted this integrated test article at the opposite end of the torque pendulum, as far away as possible from the 2nd generation magnetic damper where only the required counterbalance weights now reside. Now since they were still seeing 100uN of force that means they have 98uN of force unaccounted for. And the next iteration of the test is trying to mitigate the effect of any thermal forces.

gambiting 11y ago
At which point it would be actually cheaper to put this whole thing in space, turn it on and see if it produces any trust? If it does, then it definitely works. As long as it's on Earth, they will spend forever trying to account for extra variables.
- JohnBooty 11y ago
  Yeah. The general rule of thumb is that it costs $10,000/pound to put something into orbit. The cost would increase by orders of magnitude once you include all of the other resources needed to track the experiment, but this does seem like a relatively cheap experiment to run in space. http://www.nasa.gov/centers/marshall/news/background/facts/astp.html_prt.htm http://www.nasa.gov/centers/marshall/news/background/facts/a... I think what's preventing this is: 1.) NASA can only run a certain amount of experiments at once and I'm sure there's a long waiting list. If they run this one, something else doesn't run. 2.) Space may not be the extra variable-free environment we're hoping for here: tons of intense electromagnetic activity and so forth.