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For Calliban re possible new topic ...
In Void's topic, you recently introduced what I think is an interesting idea ...
A possible topic in which you could develop it further is "Un- conventional ways to LEO"
Or perhaps it deserves a topic of it's own in the Index level Interplanetary Transportation.
I'd like to point out that the concept would work anywhere, including Mars and the Moon, if you can design it for use on Earth.
What I find intriguing about the idea is the possibility that simple chemical combustion might be enlisted to provide the impulse you've described, to accelerate a fully loaded existing rocket to 500 m/s over a 2 kilometer run.
I'm definitely hoping you will decide to pursue this (to me for sure) promising idea!
Edit#1: Traditional slow burning gunpowder has been performing the service you describe for well over a 1000 (Earth) years!
Gunpowder was invented in 9th-century China as one of the Four Great Inventions, and spread throughout most parts of Eurasia by the end of the 13th century. Originally developed by the Taoists for medicinal purposes, gunpowder was first used for warfare around 904 AD.
Gunpowder - Wikipedia
en.wikipedia.org › wiki › Gunpowder
Is there a mixture of gases that could be enlisted to perform a slow burn over that 2 km course?
A related idea is to admit fuel and oxidizer to the cylinder of the piston as the piston rises. That would have the effect of providing for a gradual burn, instead of an explosive one.
I am making slow progress in learning 3D printing design. I ** might ** be able to stretch to develop a 3D model of such a machine.
Or, even better, it might be possible to enlist more skilled practitioners to take on animation of your concept, so you can add facts as necessary to refine the design.
Edit#2: It would be possible to create a simple sketch of the design. I'll wait to see if you decide to pursue it.
(th)
Last edited by tahanson43206 (2020-07-14 10:47:02)
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Tahanson, I will raise the topic under "Un-conventional ways to LEO" later today.
How do I get a JPEG or BitMap file onto this site?
Last edited by Calliban (2020-07-14 11:46:39)
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
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How do I get a JPEG or BitMap file onto this site?
Short answer: you don't. You can host an image somewhere else, and post a link to that image. Use the [ IMG ] tag (without spaces) with the web address of the image between tag and close tag: [ /IMG ]
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For Calliban ... Others here have suggested imgur.com, and I can report success in using it.
There is a bit of a learning curve, and if you happen across this message, I can save you a few moments of frustration.
An account with imgur.com is free. There are the usual offers for "premium/paid" service.
Upload your image to imgur.com, and then right click on the image in the display that appears ... that provides a menu of link choices. Chose the bbcode option for compatibility with this forum.
Then open a message here and paste the link.
Note that the address of the image should start with "i." ( eye dot )
This will be provided automatically by imgur.com if you choose the bbcode option.
(th)
Last edited by tahanson43206 (2020-07-14 14:35:32)
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For Calliban ... Others here have suggested imgur.com, and I can report success in using it.
There is a bit of a learning curve, and if you happen across this message, I can save you a few moments of frustration.
An account with imgur.com is free. There are the usual offers for "premium/paid" service.
Upload your image to imgur.com, and then right click on the image in the display that appears ... that provides a menu of link choices. Chose the bbcode option for compatibility with this forum.
Then open a message here and paste the link.
Note that the address of the image should start with "i." ( eye dot )
This will be provided automatically by imgur.com if you choose the bbcode option.
(th)
Many thanks. I have set up the imgur account and will attempt to post a first draft image of a launch cannon tomorrow.
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
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This is a note of appreciation to kbd512 for the recent post in the Technology for Mars topic.
http://newmars.com/forums/viewtopic.php … 39#p170139
The reason for ** this ** post is to avoid cluttering that topic.
The reminder of the small standing army that will be needed to support folks who have ventured out to Mars is helpful!
Similar small standing armies are supporting scientific outposts around the world, although it is possible the ratio of explorer to support team may be a bit less than 1:15.
In the case of Mars, that ratio looks about right (to me at least).
(th)
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This is a follow up to #143 ...
http://newmars.com/forums/viewtopic.php … 70#p169870
My friend with the Kohler generator received a visit from the friendly local maintenance team today. The problem turned out to be a battery failure.
I admit I have not yet absorbed more than a tiny fraction of what is knowable about lead acid batteries. Such batteries are likely to find employment on Mars, but whatever battery technology is chosen for service on Mars, I'll bet the same facts of deterioration will become problems for the maintenance teams.
The specific learning point I confronted today was a misunderstanding about voltage level as an indication of battery readiness-for-service.
I was asked to serve as a gopher, and at the local automotive parts store, the clerk showed me a fancy instrument they have (apparently) received recently. It showed that the old battery was unable to crank, despite having a voltage well in excess of the rated 12 VDC.
The replacement battery started the generator instantly.
My friend got away without what might have been a major service charge, and I got a lesson about battery deterioration. Fair exchange !!!
The battery had been in service for five years, which is one year past when I change automobile batteries, whether they need it or not.
(th)
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There is a simple tool called a battery load tester, made for lead-acid automotive batteries, that has a voltmeter with a specially-marked scale and a big resistor. It works on any larger or smaller engine-starting battery that is lead-acid.
You put the leads on the battery terminals and read the voltage. Presuming the battery is not discharged, you then use the "load" switch to short the battery into the resistor for several seconds, watching the voltage change under load.
If the voltage drops too sharply, the battery is "dying" or "dead" and must be replaced. A "good" 12 volt battery won't drop more than a volt or two. The special scale has color zones for weak or not, and for 6 volt and 12 volt batteries.
But you can use it on an 8-volt tractor battery, even though there is usually no 8 volt scale: just watch for a volt or two drop, versus 3 or more.
A good battery can test "bad" if it is discharged when you load test it, so trying charging the battery first, then load test it. But if a 12 volt reads only 10 volts after charging, you already know it is bad. Same for a 6 volt that reads 4, or an 8 volt that reads 6. That 2 volt drop is a dead cell.
These things are available in auto parts stores and hardware stores. Not very expensive, really. I use mine all the time.
GW
Last edited by GW Johnson (2020-07-20 12:34:00)
GW Johnson
McGregor, Texas
"There is nothing as expensive as a dead crew, especially one dead from a bad management decision"
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For GW Johnson re #158
Thanks for the helpful tip for maintaining a fleet of 12 Volt (or similar) batteries!
I'll start looking for a load test instrument as you've described it.
I keep a set of 12 volt batteries in a state of (intended) readiness, based only on voltage showing before and after charge.
The new instrument you've described would be well worth having in the collection here!
Thanks!
Edit#1: I took one of my "stock" (retired automobile) batteries to the job site this morning, and was dismayed to see that it did not have enough cranking power to start the generator. It did better than the dead battery in the machine, but not a lot better. The instrument you've described would have enabled me to skip the labor of carting that old battery around. It might still be good for emergency lighting, but it's no longer suitable for emergency equipment use.
(th)
Last edited by tahanson43206 (2020-07-20 13:13:29)
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The open loop value of the batteries voltage is not a good indicator and that is why you need to put a load on it. The charging voltage is also another indicator as that will be 13.8 but not more than 14.5 when connected to the unit. Most likely the cells oxides with sulfur or other contaminant such that when you charge them you are trying to wake the cell back up. The lead acid batteries like to be in continual working operation and not idle. Other battery material types require other needs so as to not break down....
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For SpaceNut re #160 ... thanks for adding to GW Johnson's advice on care (and testing) of lead acid batteries.
As a follow up to the earlier report of maintenance on a generator ... it occurs to me that the generator itself is providing a pretty good load test. It cranked right up to the day it stopped cranking. It is quite possible the sound of the cranking operation changes. A recording of the cranking operation could be programmed to start just before the scheduled weekly test.
I'll look for the kind of test instrument GW Johnson suggested.
The instrument at the local automobile parts store looked (to me at least) like a professional multi-hundred dollar unit.
It was similar to one I've seen in use at Batteries+ stores.
(th)
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Sorry I am off line for the night as power just went out this was posted from a tablet., will drop baçk in tomorrow. Have a good night all.
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For SpaceNut re #162
The New Hampshire power outage report showed only 7 customers without power at midnight.
Hoping your family was not one of them.
For the Mars settlement, loss of central power should result in immediate activation of backup systems.
Planning ahead for multiple levels of backup for any locations where human lives will be at risk would seem advisable.
This forum has the luxury of theoretical discussions ... Settlers (or even just explorers) will be in need of actual solutions to multiple levels of problems.
The time to set those solutions in place is while planners have the luxury of theory to toss around.
NewMars forums are as good a place as any for those discussions.
(th)
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Here is another excerpt from a tech newsletter ...
I'm posting in Housekeeping because it is closely associated with management of plant and equipment in an installation on Mars (or anywhere).
For SpaceNut ... this kind of expertise might exist as a specialty in My Hacienda, or it might be diffused over all enterprises. In the case of Earth, the company behind this test is (apparently) earning income by offering consulting services. That model might work on Mars as well, although the custodians of one plot may decide to offer multiple kinds of expertise.
Life cycle asset management is key to increased plant efficiency
Poor maintenance and asset upkeep causes unintended downtime and financial consequences.
Download this white paper to learn the implications of poor asset management and how [company] can assist in preventing asset and production downtime.
(th)
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This is for Void who has reported issues with computer access to the NewMars site on multiple occasions ...
It is very rare for NewMars to run slow, from my observation, although it does happen if there are lots of visitors.
What is far more likely is that there is congestion in a part of the network a lot closer to me.
To be precise, my next door neighbor has a number of computers and all are connected to a wireless router.
I have a similar configuration, and every now and then (it seems) the two networks get into a push/shoving match.
There is a useful Internet performance tool called Speedtest.net.
It allows you to determine the conditions of your service, and I run it periodically.
However, the tool I have found most useful is a simple Ping ...
Normally, when I ping a services such as www.yahoo.com, the Ping program reports back promptly and shows no packet loss.
However, when my router is confused by (something) it will show packet losses ranging from 25% to 80% or more.
The solution is to power down the router, let it wait for a moment, and then power back up.
It may be necessary to recycle power a couple of times.
You are an experienced computer user so you will know this already, but for a reader who might not be as familiar with operating system utilities, the Ping command can be transmitted from a Command window.
(there are other ways, for the purist)
To start the Command window in a Windows PC, enter Command in the "Start" icon.
Then, enter ping (your favorite web site)
If you are able to determine your upstream server, it is helpful to ping that, because congestion between you and that machine will be caused by problems in your neighborhood.
(th)
Last edited by tahanson43206 (2020-07-21 12:43:08)
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Thanks (th), did it, just now it looks and acts fine.
Will be ready next time it happens.
I am starting to ask seriously "Why do I do this?"
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What I have found with the pc I currently am using is that internet explorer can beacon, which is caused by websites making writes and reads to the hard drives rather than to memory and stopping. These tend to be java script coding errors that do not end loop iterations.
Closing out the browser and clearing the extra or double tasks being performed in the task manager seems to settle it out.
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For SpaceNut .... Thank you for you comment about Internet Explorer in Post #167
Just FYI, ... Microsoft has eliminated all traces of Internet Explorer in their current Edge browser ... it is a clone of Chrome.
Depending on the OS you are using, you may be able to update to Edge, or at least the current level of Chrome.
Windows XP is locked at an early version of Chrome (50 something), so not everything I try works there, but most online activities seem to work.
***
While searching for thermodynamics in the archive, I found a post that needs fixing, if you get time ...
http://newmars.com/forums/viewtopic.php?pid=5164#p5164
(th)
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tahanson43206,
You're still using Windows XP?
And here I thought I was keeping an old machine alive well past its expiration date with my 10 year old MacBook Pro.
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For kbd512 re #169
<< Grin >> .... Windows XP did everything I needed 10 years ago, and it still does. However, that is a stand alone system, with the Internet connection permanently disabled. Newer OS are running here as well as older ones, although I never ventured down the Apple path.
Congratulations on keeping your MacBook Pro running, although I am not surprised, because those were well designed and well made machines. I have a relative who has a collection of systems. He was in education, and just stayed with Apple. Some older systems have software he prefers, so he just keeps them running and off the Internet.
I brought up Internet Explorer because SpaceNut mentioned it in his post ... If his OS is newer than XP, then (I'm pretty sure) the option to upgrade the browser to Edge should be available, or at ** least ** to Chrome, which seems to run at the current version level on Windows 7.
Edit#1 ... Since you are an Apple user, you might not be aware that anyone still using Internet Explorer should try to upgrade as soon as possible.
(th)
Last edited by tahanson43206 (2020-07-22 10:26:38)
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tahanson43206,
I've used plenty of Windows machines at work over the years. Microsoft software is pretty standard stuff in most business environments I've worked in. When it works correctly, it's fabulous. When it doesn't, well, not so good. Security was never particularly good, relative to LINUX / UNIX operating systems, but it's improved greatly over the years. Edge has some new features I require for writing custom applications and I've been fairly pleased with it overall. Although it wouldn't be good from a security standpoint, I would love to have a sort of universal browser that has all the best features of the myriad of browsers available. I know that'll never happen, but that would certainly make life easier for a lot of software developers. If anything, the explosion of variation in software platforms has made development slower and more cumbersome and incredibly specialized, rather than faster and easier to do. I guess the specialization is good from the standpoint of not being able to be treated like a commodity, though.
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The best browser that was wrapped tightly to the OS was the argument that others had and why we are where we are now....
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For SpaceNut ... While searching for something else, I came across this NASA collection of space related terms. Apparently it started out as a paper document at NASA Lewis, and it was converted to an online format now published at NASA Glenn.
https://er.jsc.nasa.gov/seh/menu.html
If NewMars forum has a library topic, this would be a useful resource to post there.
(th)
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For GW Johnson re #158
This is a follow up ...
Thanks for the helpful tip for maintaining a fleet of 12 Volt (or similar) batteries!
I'll start looking for a load test instrument as you've described it.
I finally remembered to start looking for an instrument along the lines you described, and was taken aback by the number of offerings.
I'm going to ask a question, but the set up is that for all the years I've been working with technology of various kinds, I've not run across a book or other guide that covers care and maintenance of lead acid batteries.
It occurs to me (as I think about it now) that the US military ** must ** have training manuals on the subject, but my MOS never brought me into contact with one.
So the question is: Are you aware of a resource (along the lines of a training manual) that covers this subject.
I am mildly annoyed there are so many test devices. I have no idea of the relative merits of the various offerings.
(th)
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tahanson43206,
Review the following document:
THE U.S. ARMY BATTERY MAINTENANCE MANAGEMENT PROGRAM
It's not a complete technical manual, but it does outline the types of testing this corporation does to support the US Army's Lead-acid vehicle batteries and reduce battery consumption. It contains the NSN numbers of the products used and references to maintenance articles related to best practices. To understand what you're doing and why you're doing it, you really have to understand the battery design in question.
MIL-PRF-32565 spells out performance specifications for 6T form factor 24V / 28V Lithium-ion batteries, for example. When you understand how they're being tested and the purpose of the tests, you can generally understand what types of use cases the tests were intended to cover.
NFPA's report on Lithium-ion battery hazards is a good read for understanding failure modes and why Lithium-ion batteries require the storage and use protocols that government or industry mandate (also includes relevant Underwriters Laboratories Testing Standards):
Lithium-Ion Batteries Hazard and Use Assessment
Battery University has some good basic info on battery testing, which includes both Lead-acid and Lithium-ion batteries:
BU-901: Fundamentals in Battery Testing
Anyway, hope this helps a little.
Edit:
A very helpful link from the US Department of Defense that puts applicable battery regulations into a single document signed by the relevant authorities from each service branch:
UNIFIED FACILITIES CRITERIA (UFC) - STATIONARY AND MISSION BATTERIES
Edit #2:
A link to a company here in Texas that specializes in testing electric vehicle and aviation batteries:
Arbin Instruments - High Precision Battery Test Equipment
Arbin has done work with Ford Motor Company and ARPE-E to improve battery testing methodology and equipment. They do testing of both batteries and super capacitors, as well as selling the related test equipment to OEMs.
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