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For SpaceNut ...
Thanks for endorsement of the proposal suggestion to Josh in the ion topic. This would mean extra work for Josh of course, but I am gambling that there is a reservoir of talent with visibility into this forum, beyond the high level I have already seen. Non-posters with visibility into the forum are likely to know of individuals whose studies or interests lead in the direction Josh is pointing.
Thanks too, for pointing out the search instructions. I am embarrassed to admit they were right there on the search page, but I overlooked them.
Thanks (finally) for explaining that this forum is not set up to support projects. I am not surprised. I have never encountered a forum that was designed specifically to facilitate co-working. On the other hand, there certainly are co-working web sites, and I've even used what is now UpWork with good results.
Back on the first hand ... this appears to be a gathering place for people who are interested (broadly) in Mars Society goals, and that would not be the case at a commercial co-working site.
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You said:
The search function
To search by keyword, enter a term or terms to search for.
Separate terms with spaces. Use AND, OR and NOT to refine your search.
The topics are meant to be focused discusion within the first post as moderated by the topic poster but it sometimes wanders quite a bit.
As for project "projects" we really are not structured to do these as an open forum. Thou if the topics stay true to the opening its as close as we can come.
Is there something you are looking for?
For SpaceNut ... Using #86 as an anchor ... Can you suggest a search term for any projects which members of the forum may have undertaken to achieve an I objective in support of going to Mars? I tried the word "project" and the system came back with 56 pages of citations. That's too many (for me at least). Thanks !
I am aware of Mars Society initiatives, but (I suspect) those are independent of the forum.
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For Josh ... It seems to me your idea of using ions stripped of electrons as an energy storage method for space propulsion is worth pursuing. Could you possibly work that up as a proposal for directed research? Your opening message contained arguments in support of the idea which might be expanded.
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Continuing greenhouse thread from 2016:
Meet the farmers of the future: Robots
Michael Liedtke
Associated Press
https://www.dailyherald.com/article/201 … /310039961
or
https://www.detroitnews.com/story/busin … /38066887/
Begin Quotation:
During the next few years, Iron Ox wants to open robot farms near metropolitan areas across the U.S. to serve up fresher produce to restaurants and supermarkets. Most of the vegetables and fruit consumed in the U.S. is grown in California, Arizona, Mexico and other nations. That means many people in U.S. cities are eating lettuce that’s nearly a week old by the time it’s delivered.
End Quotation.
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This topic dates back to 2007 .... The Space Show of 05 Oct 2018 featured Dr. Jay Melosh ... According to Dr. Livingston's write-up, the "gravity tractor" was discussed as one of several impact mitigation methods. I have not yet heard the broadcast, but the write-up reminded me of something that might increase the effectiveness of the gravity tractor technique for changing the path of an asteroid ... The mass of the tractor will necessarily be small compared to the mass of the asteroid, but there would seem to be no reason why the tractor could not increase its mass over time by selecting material from the asteroid. This would have the benefit of increasing the mass of the tractor and decreasing the mass of the asteroid.
Speaking only for myself, I appreciate the contributions to this discussion by kbd512 and SpaceNut ... I had to give up on my ambitions for a career in physics, but I retain a layman's interest in the field. I'd like to inquire if a version of a Bose-Einstein condensate might permit iron ions (as just one example) to be stored for use in Josh's (hypothetical) high energy thrust device. In that case, ions would be created through high energy processes, and then cooled until they can be packed to the density needed for a flight. This process would take a long time (no doubt) but if the compact storage can hold the accumulation of positive ions, then it wouldn't matter how long the accumulation took.
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Regarding capture of fairings ...
For SpaceNut #49 ... The helicopter capture method could certainly work if this were a government operation, with helicopters based on carriers. The fairings appear to be slowed down for re-entry by airfoils, so the helicopters could snag the airfoils. However, there is a new technology that might be worth considering. Drones are now being constructed large enough to transport people, so if Elon were so inclined, he could deploy a couple drones to guide the shrouds to Mr. Steven. It is even possible the SpaceX team is working on guidance for the airfoils, which can be controlled by judicious tugs on the lines.
Well! It turns out SpaceX is considering using speedboats to pull the fairings over to Mr. Steven's net:
https://www.youtube.com/watch?v=mUWmSpTwdes
For Void in #50: The YouTube above seems to match up with some aspects of your idea.
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For Void in #47 ...
Could your idea be adapted for Elon Musk and his attempts to catch fairings with Mr. Steven ... I understand the attempts have been unsuccessful so far.
Musk is using a boat for the catch attempts, and as I understand your idea, it would be capable of faster movement.
As I understand the situation, there is considerable economic advantage to catching the fairings before they hit the water.
https://www.space.com/41614-spacex-mr-s … close.html
Begin Quotation:
In the past, fairings have been severely damaged when they've slammed into the water or been exposed to the briny water. During a pre-launch call (ahead of May’s Bangabhandu launch), Musk stressed the corrosive nature of salt water, explaining that the company wants to reduce costs by cutting down on the refurbishments that each fairing half goes through after landing in the ocean.
End Quotation.
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For Louis #42:
Your observation about the advantage of inflating in space (compared to on land) leads me to ask if it might make sense to inflate habitats in space?
But that leads to a question of how the inflated habitats could be delivered safely to the surface.
Setting that aside for the moment, if the habitats are inflated in space, then that could be done in Earth orbit, and the habitats could then be used for occupancy by crew headed to Mars.
And ** that ** possibility leads to an option of spinning up a wheel of habitats to Mars gravity for the flight to Mars.
The habitats could be held close during acceleration, and then deployed on tethers.
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For Josh:
Thanks for taking a look at the ion "rotating wall" storage paper.
Your observation that ion density is low, compared to the requirements for the propulsion system you've proposed, could be read as encouragement to see if the storage system can be improved. I reread Post #1 of this topic, and noted the advantage of using iron as the working "fluid".
By coincidence, while searching for articles about GCR's, I found that iron is one of many elements which are stripped of electrons and launched into the cosmos by natural processes. I note that a propulsion system that generated 1% of light speed iron packets would (presumably) show up as a GCR generator if a detector is downstream.
I was surprised to learn how much work is being done in study of GCR's and similar high energy moving particles.
Here is one system which uses detection of Cherenkov radiation to "observe" GCR (and other radiation) activity.
https://www.hawc-observatory.org/observatory/tanks.php
Elsewhere in the forum there has been discussion of use of water to protect space travelers from radiation. It would seem from the HAWC example, that a pool of water would sparkle with Cherenkov radiation. I recall reading that astronauts have reported observing flashes of light as radiation passes through the eyeball.
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For Josh and SpaceNut ...
It turned out I had a binder with notes on the "rotating wall" ion storage system.
The article is by Hollmann, Anderegg and C. F. Driscoll
UC San Diego
The copy I have is from Physics of Plasmas Vol 7, Number 7, July 2000
However, a direct link to the American Institue of Physics citations web site appears to be showing the same paper:
https://aip.scitation.org/doi/abs/10.1063/1.874128
The first correction I have to make to my recollection from 2010, is that the storage method uses electric fields, not magnetic ones.
However, I gather that magnetic forces are present because charges are moving.
The density achieved for the experiments cited appears to be low, but it may be sufficient to demonstrate the feasibility of what I understand to be your idea.
The paper discusses electrons and ions in a section entitled: Torque from Driven Plasma modes
Extrapolating from what I understand of your idea, I can imagine a vehicle with pods to right and left of a central fuselage, dedicated to positively charged ions on one side, and electrons or perhaps negatively charged ions on the other side, with a propulsion device in the center.
Google listed multiple citations for E.M. Hollmann and for C.F. Driscol in 2010.
Amazons shows two books by Driscoll:
Pure Electron Plasmas Near Thermal Equilibrium1996
by C. F. Driscoll
Paperback
$105.00(1 used & new offers)
Transport in Nonneutral Plasmas
Transport in Nonneutral Plasmas1996
by C. F. Driscoll
Paperback
$105.00(1 used & new offers)
No books showed up for E.M. Hollmann
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This is my first post in NewMars, so if it works, I'd like to thank Mr. Burk and Daniel for solving a pesky problem with the registration process.
Josh, some time ago I ran across a paper that might be pertinent to your topic ... I was trying to learn about fusion experiments, and found a paper on a cylindrical ion storage device. I'll try to find my notes later today, but in the mean time, if anyone else is inspired to look, my recollection is that the work resulted in a patent application, and possibly a patent. The design employed rotation of the trapped ions in a magnetic field, which took advantage of the squeezing effect as charges move in the field. The design (I think) evolved from study of large ion storage rings used for high energy physics experiments.
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