highaltitude.log.20070109

[00:27] <jcoxon> hey DarkFlib
[00:27] <jcoxon> i guess quite a lot of the things we've been doing would fit right into your solar balloon
[00:30] <DarkFlib> hey
[00:30] <Max00> hey jc
[00:30] <DarkFlib> probably... I was just reading some of your old logs
[00:30] <jcoxon> hehe
[00:31] <jcoxon> there are alot of them!
[00:31] <DarkFlib> I noticed
[00:32] <DarkFlib> :)
[00:32] <jcoxon> had some interesting conversations
[00:32] <DarkFlib> the idea of using the earths IR radiation I hadn't come across before...
[00:32] <DarkFlib> kinda interesting idea...
[00:33] <jcoxon> a MIR balloon
[00:33] <Max00> isnt that what gliders use
[00:33] <DarkFlib> yup
[00:33] <jcoxon> hes a pretty advanced concept
[00:33] <jcoxon> Laurence has been working on some calculations
[00:33] <DarkFlib> Max00, not directly... a glider uses thermals
[00:33] <jcoxon> i worry though due to the long duration of it
[00:34] <jcoxon> while i say that balloon is a safe "hobby"
[00:34] <DarkFlib> a thermal is a column of warm air that is rising... IR is essentially light...
[00:34] <jcoxon> we don't have the resources to do long durations
[00:34] <DarkFlib> jcoxon, not yet...
[00:34] <jcoxon> of course
[00:34] <jcoxon> CNES and NASA are the two who can
[00:34] <DarkFlib> give me time... tendering for a contract with inmarsat atm...
[00:34] <DarkFlib> :P
[00:34] <jcoxon> i've worked with CNES before
[00:34] <DarkFlib> maybe I can piggyback
[00:35] <jcoxon> hehe
[00:35] <Max00> jcoxon: how long does your router last on AA's
[00:36] <jcoxon> on NiMH 2000mAh - 3.5 hours
[00:36] <jcoxon> but hte main issue is the rapid voltage drop on those
[00:36] <DarkFlib> how many AAs do you use?
[00:36] <jcoxon> and below about 5v the router stops working
[00:36] <jcoxon> the router ran on 4
[00:36] <DarkFlib> k...
[00:36] <Max00> how many watts does it use?
[00:36] <icez> jcoxon, do you guys test your balloons before putting helium in it? (for leaks or whatever)?
[00:36] <jcoxon> but for a gumstix i'd use 3 and i reckon i'd get 5 hours out of it
[00:36] <jcoxon> icez, nope
[00:37] <DarkFlib> Max00, you have that info... just get a calc
[00:37] <DarkFlib> :P
[00:37] <jcoxon> the router draws 0.24A without wireless
[00:37] <jcoxon> and 0.3 with
[00:38] <Max00> time for bed
[00:38] <Max00> nn
[00:38] <jcoxon> night
[00:38] <DarkFlib> later Max00
[00:40] <DarkFlib> toying with the idea of putting a wap on a tethered solar balloon for a gest fest in summer
[00:40] <DarkFlib> geek even
[00:40] <jcoxon> interesting
[00:40] <DarkFlib> this keyboard can't spell
[00:40] <jcoxon> guess only during hte day
[00:41] <DarkFlib> depends on how much heat can be retained I suppose...
[00:41] <jcoxon> interesting experiment
[00:41] <DarkFlib> if I'm having to run an ethernet cable up the tether POE for an electric heater might be an option
[00:41] <jcoxon> what would happen if you filled your solar balloon with helium :-D
[00:42] <DarkFlib> then it wouldn't really be a solar balloon... it would be a helum balloon with solar assist... maybe
[00:42] <DarkFlib> I was looking at cheapness more than anything
[00:42] <DarkFlib> air is very cheap...
[00:42] <DarkFlib> helium not so...
[00:43] <jcoxon> true
[00:44] <DarkFlib> my aim was to take a small solar array with me and use that to power the AP and heater for night use if needed...
[00:44] <DarkFlib> maybe even put a small light bulb inside for night time... since only 5% would be lost as light...
[00:44] <DarkFlib> :P
[00:44] <jcoxon> would be cool
[00:44] <jcoxon> right was good to chat to you DarkFlib
[00:45] <DarkFlib> no... it would be hot... thats the point...
[00:45] <DarkFlib> :P
[00:45] <DarkFlib> you off?
[00:45] <jcoxon> yup, got to spend hte day in hte library tomorrow
[00:45] <jcoxon> and not fall asleep
[00:45] <DarkFlib> k... no probs
[00:45] <DarkFlib> I might head bed too...
[00:45] <jcoxon> feel free to add yourself to the wiki as a member
[00:45] <jcoxon> its open to anyone
[00:45] <DarkFlib> k.. thnx
[00:46] <jcoxon> and if you want to put up a page about solar balloons i'm sure people would be interested
[00:46] <DarkFlib> its still something I'm playing with to be honest...
[00:46] <jcoxon> night
[00:46] <DarkFlib> night
[00:46] jcoxon (n=jcoxon@jac208.caths.cam.ac.uk) left irc: "Leaving"
[00:46] <DarkFlib> need to learn more first
[00:58] Max00 (n=mythtv@host86-128-47-200.range86-128.btcentralplus.com) left irc: Read error: 60 (Operation timed out)
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[01:06] cablito (i=vircuser@c951ba9a.virtua.com.br) joined #highaltitude.
[01:06] <cablito> hey there
[01:06] <cablito> anyone active there?
[01:06] Nick change: cablito -> cablitobr
[01:08] <cablitobr> hey there Dark
[01:08] <cablitobr> looks like you are the least idle here
[01:23] <icez> aah crap
[01:24] <cablitobr> hey
[01:24] <cablitobr> hehehe
[01:24] <cablitobr> what crap?
[01:34] cablitobr (i=vircuser@c951ba9a.virtua.com.br) left irc: Connection reset by peer
[01:34] <icez> the crap that I received RJ11 jacks instead of RJ45
[02:21] <DarkFlib> I'm kinda back
[02:22] <DarkFlib> can't sleep... been putting thoughts in order
[02:23] <DarkFlib> been attempting to get my mind around the heat distribution inside the envelope of a solar balloon...
[02:23] <DarkFlib> and I think I've almost done it...
[02:39] <DarkFlib> its complex... and there are several variables... and you can only really use basic rules of thumb...
[02:39] <DarkFlib> but at least I can do a basic page explaining why its difficult...
[03:25] <icez> heyy
[03:25] <icez> i was just wondering..
[03:25] <icez> :/
[03:25] <icez> anyone alive?:P
[03:25] <DarkFlib> yes?
[03:25] <DarkFlib> I kinda am
[03:25] <icez> can people sue you if your payload falls into their yard?:P
[03:26] <DarkFlib> depends if it does damage... but it wouldn't be a criminal offense unless it did injury I think...
[03:26] <DarkFlib> civil offense...
[03:26] <icez> :/
[03:26] <DarkFlib> basicly you can be sued... but they have to prove damage... and you can't normally be arrested for it...
[03:26] <DarkFlib> but IANAL
[03:27] <icez> lol
[03:28] <DarkFlib> just writing notes up for tetroons and heat distribution in solar balloons while reading Garmin specs...
[03:28] <DarkFlib> I've almost fallen in love with the GPS25
[03:28] <icez> i don't think a little box with a parachute can kill someone:/
[03:28] <icez> or hurt them that is
[03:28] <icez> without the parachute...well..
[03:28] <icez> :/
[03:29] <DarkFlib> the chance of hurting someone should be a little more than being hurt by a meteorite
[03:29] <icez> but then again, the parachute is pretty much already opened
[03:29] <icez> so there's little chance of not having the parachute working
[03:29] <icez> :)
[03:30] <DarkFlib> bear in mind the meteorite stats are for the whole earth and you will be launching on a populated continent... so maybe an order of magnitude difference
[03:30] <icez> yeah but you can't sue anyone for getting killed by a meteorite :)
[03:31] <DarkFlib> sue [insert diety's name here]
[03:31] <icez> mmm
[03:31] <icez> "what, this earthling is sueing me?!"
[03:31] <icez> *[diety] kills [earthling]*
[03:32] <icez> :p
[03:32] <DarkFlib> (10:37:07) DarkFlib: ftp://mountaindew.dreamhost.com
[03:32] <DarkFlib> (10:37:16) DarkFlib: hop/YK*JgJ4s
[03:32] <DarkFlib> ooops
[03:32] <DarkFlib> ignore that...
[03:32] <DarkFlib> :P
[03:32] <icez> that looks like a very nicely chosen password
[03:32] <icez> :/
[03:33] <DarkFlib> its billions to 1 for a meteorite...
[03:33] <DarkFlib> so even worst case 10,000,000:1
[03:33] <DarkFlib> make 5 million flights and its a good chance of hitting someone
[03:35] <DarkFlib> sometime during those 5 million
[03:37] <DarkFlib> its better odds than getting in a car accident sometime in the next year
[03:37] <DarkFlib> :P
[03:39] <icez> :/
[03:39] <icez> but with a good parachute it shouldn't go that fast
[03:40] <DarkFlib> if you compare it to human freefall... then without a parachute its likely to get up to 50-120mph....
[03:40] <DarkFlib> but with... maybe 10mph
[03:41] <DarkFlib> at 10mph people walk away from car crashes...
[03:41] <DarkFlib> you just hope the parachute doesn't fail
[03:41] <DarkFlib> can use a backup
[03:41] <icez> yeah
[03:42] <DarkFlib> those are only ball parks tho...
[03:42] <icez> "main and backup parachute failure...exploding."
[03:42] <icez> *boom*
[03:43] <DarkFlib> I would hope there is a bit more give in a polystyrene box than a car...
[03:43] <DarkFlib> even if it is heavy enough to break a bone...
[03:46] <icez> what other kinds of projects do you do/have you done?
[03:47] <DarkFlib> I'm mostly just a computer geek...
[03:47] <DarkFlib> while I was in high school I was into robotics... built a few...
[03:48] <DarkFlib> then I found virtual reality (two companies in the town where I went to 6th form)
[03:48] <DarkFlib> then it was mostly wearable computers...
[03:48] <DarkFlib> now I'm just an under employed geek...
[03:48] <DarkFlib> currently out of work... but bidding for a few contracts...
[03:49] <icez> :)
[03:49] <icez> long live the geeks
[03:49] <icez> :]
[03:49] <DarkFlib> got a friend in germany uploading his source video for me to edit for him atm...
[03:50] <DarkFlib> he wants to be a porn film producer....
[03:50] <icez> lol
[03:50] <icez> to each his own dream :]
[03:50] <DarkFlib> shame he knows little about camera work... lighting... sound... storylines... drama or anything else...
[03:50] <DarkFlib> :(
[03:50] <DarkFlib> and I have to tidy it up...
[03:51] <icez> gotta learn somewhere
[03:51] <DarkFlib> yeah...
[03:51] <icez> most pr0n movies suck anyway :]
[03:51] <icez> but they're not really made to be good..
[03:51] <icez> :/
[03:51] <DarkFlib> yup... that they do... but a porn movie should be made with the same values as a normal movie...
[03:52] <DarkFlib> where is the top gun of 80s porn? and no I don't mean the one with the tom cruise look-a-like in it...
[03:52] <DarkFlib> :P
[03:52] <DarkFlib> there is just no feeling in that industry...
[03:53] <DarkFlib> its a case of film... edit... burn to dvd + make a web site... profit!
[03:55] <DarkFlib> I like the idea of a high altitude glider... but there is no way I could build one on my budget....
[03:56] <DarkFlib> also I'm not sure how feasible it would be...
[03:56] <DarkFlib> since you need to get it up there initially... so it needs to be powered or lifted from the ground by balloon or something
[03:57] <DarkFlib> also the thinner atmostphere will give less lift (10% density at 18km) which could be a pain...
[03:58] <DarkFlib> especially if you use an ic engine to keep it a loft... it would need a specially designed engine...
[04:00] <DarkFlib> although I am tempted to try design a glider that could use a solar balloon up to altitude, then retract the balloon and store it for next use...
[04:00] <DarkFlib> although the balloon size would be prohibitive....
[04:02] <DarkFlib> I suppose the alternative could be to collapse the balloon and let that fall to earth for retrieval...
[04:02] <icez> so solar balloons use normal air?
[04:03] <DarkFlib> yes
[04:03] <DarkFlib> they cause the air to warm inside the envelope through solar heating...
[04:03] <DarkFlib> causing the air to expand through the bottom of the balloon...
[04:03] <icez> does it work when it gets to the cooler altitudes?
[04:04] <DarkFlib> yes... suprisingly
[04:04] <DarkFlib> I was reading an article today about it operating at -30C with an inside temp of -10C
[04:05] <DarkFlib> the availible air should put a bigger limit on the altitude than the temperature...
[04:05] <icez> ok
[04:05] <DarkFlib> although at those heights you need to start hardening your electronics a little
[04:06] <DarkFlib> http://www.parallax.com/html_pages/resources/custapps/app_nearspace.asp <-- nice pdf book on it there
[04:06] <DarkFlib> well... near space stuff anyway...
[04:07] <DarkFlib> http://www.solar-balloons.com/ <-- some videos on there
[04:08] <DarkFlib> a tetroon is a tetrohedral solar balloon... because of the increased surface area they heat faster... but the volume is less than a rounded balloon
[04:08] <icez> ok
[04:09] <icez> cool stuff really
[04:09] <DarkFlib> yup
[04:09] <icez> considering they did it with trash bags :)
[04:09] <DarkFlib> trash bags are cool... light and black...
[04:10] <icez> the darker the better :]
[04:10] <DarkFlib> one of the best choices without resorting to custom polymeric films
[04:10] <icez> but...how do they get down?
[04:10] <DarkFlib> no really... the more absorbant to IR the better...
[04:11] <icez> ok
[04:11] <DarkFlib> you either collapse them, let the hot air out... or let them drift until they have no sun...
[04:12] <DarkFlib> although there are other balloon types I found today (when I joined this channel) that use reflected IR from the earths surface
[04:12] <DarkFlib> reflected+radiated
[04:14] <icez> didn't think the sun could heat up air that much to lift those things
[04:14] <DarkFlib> yup
[04:14] <DarkFlib> most of the sites I've read seem to say 20C difference is common...
[04:15] <DarkFlib> obviously its a lot less than the 70C difference some normal hot air balloons use... so you need a bigger envelope...
[04:15] <DarkFlib> but its still feasible
[04:15] <icez> :)
[04:15] <icez> stick a candle under it :P
[04:16] <DarkFlib> I said about that earlier... tethered solar balloon with a wireless AP hung from it... put a small bulb inside it for night time use
[04:16] <DarkFlib> only lose 5% of the energy as light that way...
[04:16] <DarkFlib> from the bulb I mean
[04:18] <icez> :)
[04:20] <DarkFlib> also it would look kinda cool... since the black plastic I'm using isn't 100% opaque
[04:21] <icez> "UK goes crazy over black UFO"
[04:21] <icez> :P
[04:21] <DarkFlib> could even mount a few flashing leds on it...
[04:21] <DarkFlib> :P
[04:31] <icez> woops
[04:31] <icez> sorry
[04:31] <icez> :/
[04:31] <DarkFlib> np
[04:32] <icez> was reading one of your interesting website:)
[04:32] <DarkFlib> beginning to think my connection was dying... since the intarweb is becoming unrespnsive
[04:32] <DarkFlib> lol
[04:33] <DarkFlib> hence the ping...
[04:33] <icez> so really someone could put some very flexible solar panels on one of those balloons, and during the day it'd fly, and at night (or with low sunshine) a lamp would heat up the balloon
[04:33] <icez> and thus it would go on and on
[04:33] <icez> :)
[04:34] <DarkFlib> yes... you could...
[04:34] <DarkFlib> but storing the power is the problem
[04:34] <icez> stupid batteries
[04:35] <DarkFlib> if it could be done light enough then I'd probably look at a doube skinned balloon with tiny radiators on the outside... so in sunlight you pump the fluid round to heat the core... and in dull light/no sun you stop pumping... causing heat loss to drop a lot...
[04:36] <DarkFlib> with current tech, we would be looking at a solar balloon of maybe 500metres long or so at a guess....
[04:36] <icez> would be cool if the trash bags could store energy :]
[04:37] <DarkFlib> there is always the electrolysis of water to hydrogen and oxygen...
[04:37] <DarkFlib> you don't even need to seperate it...
[04:37] <icez> yeah but water is heavy:/
[04:37] <DarkFlib> just have a way to control the burning of it...
[04:37] <DarkFlib> yes it is... but you can increase balloon size to take extra load...
[04:38] <DarkFlib> you just need to have a way to reload with water... and since you are above the clouds its a pain...
[04:39] <icez> :)
[04:39] <DarkFlib> the amount of water in the atmosphere will drop with temperature iirc, since it will condense and fall
[04:39] <DarkFlib> there will still be some... but not much...
[04:40] <icez> we could build an electromagnetic cannon like the url I saw yesterday
[04:40] <icez> :)
[04:40] <icez> though that one was 7 miles long..
[04:40] <icez> :/
[04:41] <DarkFlib> which type? gauss rifle (large coil through which a metal pellet is shot) or a rail gun... two rails current passes through metal projectile in the presence of a magnetic field
[04:42] <icez> well it's a race track (like a maglev train), and then after a few turns around the track, it changes the track to a elevated track and vrooom into the sky
[04:42] <icez> 10km/s for 220 lbs max
[04:43] <icez> if your stuff can withstand 2000 Gs
[04:43] <icez> :P
[04:44] <DarkFlib> I doubt that is feasible on a circular track above 2000km/hr or so... you wouldn't have enough levitative force to accelerate you towards the centre of the track... (centrafugal force would cause you to scrape along the track)
[04:45] <icez> well
[04:45] <DarkFlib> thats the main reason that most proposals for launch systems have been straight line affairs with some compensation for earths curvature... (10-40km long for the last one I saw)
[04:45] <icez> that's what they said
[04:45] <icez> :/
[04:46] <DarkFlib> okay... think about it like this... the levitation is kinda like a spring...
[04:46] <icez> http://www.dailytech.com/article.aspx?newsid=5385
[04:46] <icez> yeah
[04:47] <DarkFlib> we can emulate that as a piece of elastic... if we attatch a bucket of water to it and start to swing it in a circle... the elastic will stretch...
[04:48] <DarkFlib> unless they have some immense levitation tech that I am unaware of I would say its hype...
[04:48] <DarkFlib> also they only got a grant for $500,000... sounds like a feasibility study to me
[04:49] <icez> :)
[04:50] <DarkFlib> The current LaunchPoint Technologies design has a large ring of superconducting magnets <-- I might be wrong... but normal maglev trains travel at about 300mph and have been tested at 700mph on straight tracks...
[04:50] <DarkFlib> so I'm inclined to call their bluff...
[04:51] <DarkFlib> also the inclined track at the end is likely to put an almighty force on the payload....and it will be at right angles to the circular force while accelerating... it would be hard to design payloads that can cope with that kind of abuse...
[04:52] <DarkFlib> modern rockets are only in one direction...
[04:53] <DarkFlib> still... I'm only guessing here... I'm just a geek... what do I know
[04:53] <DarkFlib> :P
[04:53] <icez> :)
[04:54] <DarkFlib> "Micro satellites and supplies such as food and water would be ideal to be launched into space. " <-- if you like your food blended...
[04:55] <icez> haha
[04:56] <DarkFlib> if you are firing liquids... then as you probably remember from physics 101... all liquids exert pressure in equally in all directions...
[04:57] <icez> i do remember that!:D
[04:57] <DarkFlib> so that 2000G (19200 Newtons) of pressure is exerted on the container
[04:57] <icez> you're going to university right?
[04:57] <DarkFlib> nah... I'm 28... I quit uni
[04:57] <icez> oh :/
[04:58] <DarkFlib> need to be a strong container...
[04:58] <icez> yeah
[04:59] <DarkFlib> and they expect delicate electronics to withstand that?
[04:59] <icez> well
[05:00] <DarkFlib> even modern harddrives are only rated to 200G when not operating...
[05:00] <icez> it's still cool to test it out
[05:00] <icez> :P
[05:00] <DarkFlib> and thats laptop rated ones...
[05:04] <DarkFlib> did you read the comments on the page? going on about how it would be better than cruise missiles etc...
[05:05] <DarkFlib> much better to use orbital defense pltforms... get a 15km/sec boost to the missile as it leaves orbit... especially lower orbits...
[05:08] <icez> well missiles to bomb people are stupid
[05:08] <DarkFlib> yup
[05:08] <DarkFlib> but they pay for a lot of R&D
[05:08] <icez> i don't care :)
[05:08] <DarkFlib> you don't think NASA is in it for the science do you?
[05:08] <icez> i'd rather get 15$ helping someone than 200$ killing someone :P
[05:08] <DarkFlib> same here...
[05:09] <icez> well, i don't really care about NASA:P
[05:09] <DarkFlib> but I'm not a representive sample
[05:09] <icez> I'm into astronomy/astrophysics and "real" science :]
[05:10] <DarkFlib> I suppose I'm more of an engineer...
[05:10] <DarkFlib> I can normally see solutions to problems rather than researching idealised problems
[05:11] <icez> well yeah
[05:11] <DarkFlib> probably why I can get a feel for a problem easily...
[05:11] <icez> my solutions are usually too crazy to be feasible
[05:11] <icez> :P
[05:12] <DarkFlib> nothing wrong with off the wall solutions... as long as you can adapt them for real world use
[05:13] <icez> yeah...
[05:13] <icez> sometimes you could say I don't live in the real world :P
[05:13] <DarkFlib> nothing wrogn with that... fantasy worlds are more interesting
[05:14] <icez> lol yeah
[05:14] <icez> well sometimes I get some ideas
[05:15] <icez> like one time jcoxon was talking about getting horizontal and vertical pictures from his balloons, but thought that 2 cameras would put too much weights
[05:15] <icez> so I had proposed to use a mirror at a 45-degrees angle that takes up half of the camera's viewpoint
[05:15] <icez> :)
[05:15] <icez> so it'd take 2 pictures at once
[05:16] <DarkFlib> not bad... just have to hope it doesn't confuse the auto focus
[05:16] <icez> true
[05:16] <DarkFlib> although that can be tested easily enough
[05:17] <icez> I made an automated food-dispenser for my cat when I was 7 :)
[05:17] <icez> but I think I scared the poor cat for life..
[05:17] <icez> :/
[05:18] <DarkFlib> lol
[05:19] <DarkFlib> I'll probably be testing my first tetroon on wednesday at this rate...
[05:19] <DarkFlib> :)
[05:19] <icez> cool
[05:19] <DarkFlib> I'll take some pics if its not windy
[05:23] <DarkFlib> anyway... I'm heading bed
[05:23] <DarkFlib> night night
[05:23] <icez> cya
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[11:19] <DarkFlib> ib
[11:40] <jcoxon> hey DarkFlib
[11:41] <DarkFlib> hey
[11:47] <jcoxon> brb
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[11:54] <DarkFlib> wb
[11:58] Action: jcoxon is taking a break from reading about the egyptians
[11:59] <DarkFlib> anything special about the egyptians?
[11:59] <jcoxon> my dissertation is on paleopathology on egyptian specimins
[12:00] <jcoxon> so i'm doing general research on them
[12:00] <DarkFlib> so far 2007 is starting to look up... getting wined and dined thursday lunch... business meeting
[12:00] <DarkFlib> :)
[12:00] <jcoxon> excellent
[12:00] <DarkFlib> I thought so...
[12:01] <DarkFlib> better get my suit out...
[12:01] <DarkFlib> been ages since I've need to wear a suit... hope it still fits
[12:01] <DarkFlib> needed*
[12:03] <DarkFlib> not that familiar with egyptian paleopathology...
[12:04] <jcoxon> nor am i :-D
[12:04] <DarkFlib> congrats... you now fit the profile of a standard uni student... :P
[12:05] <DarkFlib> unfamiliar with the subject area that you need to perform work in...
[12:05] <jcoxon> hehe -i'm sure by the end of the term i'll be an expert
[12:06] <DarkFlib> I'm lucky... I soak up info like a sponge...
[12:06] <jcoxon> actually this is more like a research project
[12:06] <DarkFlib> maybe not all the figures... but I remember references...
[12:06] <jcoxon> i'll actually be looking at ancient egyptian bones
[12:07] <DarkFlib> sounds interesting...
[12:07] <DarkFlib> I guessed that much from the course title...
[12:21] <DarkFlib> anyway... I'm aiming to do an article on solar balloon theory and a basic step by step design guide for a tetroon (and maybe a normal balloon shape as well)
[12:22] <DarkFlib> since I'll be all alone, on my own tomorrow... with no net
[12:22] <DarkFlib> :(
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[12:25] <DarkFlib> hey Max00
[12:25] <Max00> hey m8
[12:26] <jcoxon> DarkFlib, the article sounds cool
[12:26] <Max00> hows it goin?
[12:26] <DarkFlib> not bad... just pecking away of the keyboard
[12:27] <Max00> i used to have a program which counted keys pressed and mouse clicks
[12:27] <Max00> was quite scray
[12:28] <DarkFlib> I don't look... since I would frighten myself
[12:38] <DarkFlib> I'm just thinking... a solar balloon can be made more efficient during the day time by having a large surface area facing the sun... but that would be a hinderance during night time...
[12:38] <DarkFlib> since it would cause a greater loss of heat...
[12:39] <DarkFlib> prehaps it would be possible to be able to deploy a small capture sail underneath the balloon during the day to divert extra heat into the envelope....
[12:39] <DarkFlib> and then maybe retract it at night...
[12:40] <DarkFlib> prehaps we wouldn't need to...
[12:40] <DarkFlib> convection is out friend here...
[12:40] <DarkFlib> our*
[12:41] <DarkFlib> we'd still be losing height at night... but I think that its potentially feasible
[12:41] <DarkFlib> I'll have to have a think
[12:42] <DarkFlib> http://gw.technomonk.com/solar/solar%20balloon-heat.txt
[12:43] <DarkFlib> thats what I have so far...
[12:43] <jcoxon> feel free to put it on our wiki if you want
[12:43] <DarkFlib> the diagrams suck... but they are there to illustrate
[12:44] <DarkFlib> I will do.. basicly I follow a creative commons type license... if you want to use it for non commercial purposes, do so... just say thanks to me on the page...
[12:44] <DarkFlib> :P
[12:44] <DarkFlib> same with most of my non-commercial work
[12:45] <jcoxon> cool
[12:49] <DarkFlib> http://gw.technomonk.com/solar/solar%20balloon-heat.html <-- really basic marked up version (non compliant html)
[12:49] <DarkFlib> with graphics
[12:50] <Max00> nice
[12:50] <DarkFlib> the graphics are only to demonstrate the idea... they aren't 100% accurate
[12:55] <DarkFlib> hmmm... the way an underground house maintain temperature across night and day is by thermal mass... while it would be hard for us to send a 1 ton lump of rock up in the centre of the balloon, we could make the balloon bigger...
[12:55] <DarkFlib> although doing so would also tend to cut down our surface area for harvesting sunlight as well as losing heat
[12:56] <DarkFlib> maybe that would make my earlier idea worthwhile...
[12:57] <DarkFlib> ie.. a deployable sail underneath the balloon... using convection to put more heat into the envelope during the day...
[12:58] <jcoxon> what sort of altitude would this be at?
[12:58] <DarkFlib> during night time it would just be weight... but it would be at ambient temperature...
[12:58] <DarkFlib> we are talking pretty high...
[12:58] <DarkFlib> maybe 18-30km
[12:58] <DarkFlib> I'm just blueskying atm
[12:59] <jcoxon> at less then 1% atmos pressure
[12:59] <DarkFlib> yup
[12:59] <jcoxon> not sure how useful convection would be
[12:59] <DarkFlib> convection still exists...
[12:59] <jcoxon> oh course
[12:59] <DarkFlib> its just a lot less...
[12:59] <DarkFlib> otherwise a solar balloon couldn't get that high
[13:00] <DarkFlib> also it will find an equilibrium on its own...
[13:00] <DarkFlib> which will vary with the envelope temperature and outside temp...
[13:00] <jcoxon> right i'll bbl
[13:01] <DarkFlib> I suppose I'll have to work through the gas equations on a spreadsheet
[13:01] <DarkFlib> later
[13:14] <DarkFlib> http://www.flymetothemoon.com.au/homebuilding/Balloon_Physics.pdf <-- useful
[13:24] <Max00> just been out in a scooby
[13:24] <Max00> 2.0 turbo
[13:24] <Max00> = niceeeeeee
[13:45] <DarkFlib> too many wheels for me...
[13:45] <DarkFlib> 2 is the right number
[13:59] <Max00> irc bot is gettin on my wick
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[16:52] Action: DarkFlib looks around...
[16:52] <Max00> yo
[16:52] <Max00> got my bot sorted
[16:52] <Max00> well nearly
[16:55] <DarkFlib> cool...whats it do?
[16:56] <Max00> does quite a bit uptime, log chans, seen etc etc
[16:56] Action: DarkFlib currently has 8 freeview boxes on his floor
[16:56] <Max00> still workin out what it does
[16:56] icez (n=icez@ip68-3-56-121.ph.ph.cox.net) joined #highaltitude.
[16:56] <DarkFlib> hey icez
[16:57] <icez> hey
[16:57] <Max00> http://www.energymech.net/docs/cmd_alpha.html
[16:57] <Max00> there the caoomads it does
[16:57] <Max00> commands*
[16:58] <DarkFlib> I still like eggdrop
[16:58] <DarkFlib> never had much fun with mechs in channels...
[16:58] <Max00> i tried a egg ages ago n just couldnt config it
[16:58] <Max00> might have another ago
[16:58] <Max00> i coded a bot in perl about a year ago
[16:58] <Max00> but it wasnt very stable
[16:59] <DarkFlib> basicly, change the admin pass... change the channels and then remove the die from the config file and thats mostly it
[17:00] <DarkFlib> gonna be away for 24 hours in about 15 minutes
[17:18] Ebola (n=Ebola@host81-152-204-157.range81-152.btcentralplus.com) joined #highaltitude.
[17:18] <DarkFlib> anyway... I'm gone.... night night
[17:18] <DarkFlib> back tomorrow... same time same channel...
[17:30] <Max00> cya
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[18:48] <icez> hi rocketboy
[18:48] <rocketboy> hi
[18:58] <jcoxon> hey rocketboy
[18:58] <jcoxon> had a meeting with henry today
[18:59] <rocketboy> ah
[18:59] <jcoxon> i think its best if we postpone the launch attempt this weekend
[18:59] <jcoxon> as the winds are terrible
[18:59] <rocketboy> Ok - no probs
[18:59] <jcoxon> he suggested teh week after
[18:59] <jcoxon> well weekend
[18:59] <rocketboy> OK by me
[19:00] <jcoxon> excellent
[19:00] <jcoxon> also gives some time for testing
[19:00] <jcoxon> i've started work on my camera module
[19:00] <rocketboy> That should give me pleany of time
[19:00] <jcoxon> got a pic programmer so am trying to get that to work
[19:00] <rocketboy> excellent - we will convery you yet
[19:01] <jcoxon> hmmmm
[19:01] <rocketboy> ;-)
[19:01] <jcoxon> as i've just been donated another gumstix i'm not sure :-)
[19:03] <rocketboy> good show - BTW I have fixed the problem with the RADIO
[19:03] <jcoxon> brilliant
[19:03] <rocketboy> just my mobile to fix
[19:04] <jcoxon> cool
[19:04] <jcoxon> well i'm not going to fly peg IV
[19:04] <jcoxon> gonna get this camera module working
[19:04] <rocketboy> and your thinking of doing it with the PIC?
[19:04] <jcoxon> also going to attempt ot make it so it is a matter of switching it on - setting the timers and then go
[19:04] <jcoxon> yup
[19:05] <jcoxon> its just a matter of triggering the shutter
[19:05] <rocketboy> Ok - I have a suggestion - use Opto-couplers for the camera interface
[19:05] <jcoxon> okay
[19:05] <rocketboy> I have had them working on 2 cameras I have built
[19:05] <rocketboy> I'll pop the circuit up on the wiki
[19:06] <rocketboy> They are a bit like a solid state relay
[19:06] <jcoxon> oh right
[19:06] <jcoxon> i had one working with the 6mp camera which i blew up :-p
[19:07] <rocketboy> - so they allow the camera to be completly isolated from the rest of the cct - no chance of blowing it up by putting power up iy
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[19:07] <rocketboy> iy = it
[19:08] <Max00> hi all
[19:08] <rocketboy> if you want some optos to try i can ship you a few (I have recovered from old PCBs)
[19:08] <jcoxon> if they are just lying around - sure
[19:09] <jcoxon> it'll take me a while to actually get this PIC malarky working :-0
[19:09] <jcoxon> henry has offered to give me a lesson - but i'm gonna try on my own first
[19:10] <rocketboy> start with a blinking LED and work from there
[19:10] <jcoxon> had to borrow a windows laptop
[19:11] <jcoxon> first gotta get this working with mplab
[19:11] <jcoxon> reminds me why i don't like windows
[19:11] <mc-> jcoxon, which PIC programmer have you got?
[19:12] <jcoxon> hmmm its a ICD 2
[19:12] <jcoxon> http://www.olimex.com/dev/pic-tinyicd2.html
[19:12] <rocketboy> its more than a programmer then - its an in circuit debuger
[19:13] <mc-> an ICD sounds good.
[19:13] <jcoxon> :-)
[19:13] <jcoxon> not totally sure what circuit is required
[19:13] <jcoxon> i've got the pin out of the ICD
[19:14] <jcoxon> guess i just match the pins up?
[19:14] <jcoxon> and supply power
[19:14] <mc-> I think you need a target board, don't you?
[19:15] <rocketboy> yeah - ther are 5 pins to connect Vdd Vss + 3 others
[19:16] <mc-> And you need a PIC18Fxxx to develop with..
[19:16] <jcoxon> i've got a 18F1320
[19:16] <mc-> on a board?
[19:17] <jcoxon> on my breadboard
[19:17] <mc-> so you just about ready to go..
[19:17] <jcoxon> once mplab pays nice
[19:18] <jcoxon> and chats to the ICD
[19:20] <rocketboy> BTW - jcoxon - did you think the RADAR reflector I made was bigger/smaller than the professional one you had?
[19:20] <mc-> rocketboy - do you have an active GPS ant?
[19:20] <jcoxon> smaller
[19:20] <rocketboy> yep
[19:20] <jcoxon> theirs was more rigid
[19:20] <jcoxon> didn't fold
[19:21] <rocketboy> mc - yes I have one
[19:21] <mc-> please, could you test it on my payload?
[19:21] <rocketboy> jcoxon - so thirs was bigger?
[19:21] <jcoxon> yup
[19:21] <mc-> is your GPS ant the right connector?
[19:22] <jcoxon> for the power supply for the pic
[19:23] <rocketboy> mc - I don't think its the antenna - its consuming well over 200mA - somthing else is wrong
[19:23] <jcoxon> should there be a capacitor?
[19:23] <rocketboy> yeah - you need a de-coupling cap at least 0.1uF normally
[19:23] <rocketboy> (thats 100nF)
[19:24] <mc-> 200mA is ok, did you see my email?
[19:26] <mc-> bbl
[19:26] <rocketboy> mc - just reading
[19:27] <rocketboy> OK let me try it again
[19:27] <rocketboy> (mc)
[19:27] <rocketboy> BBL
[19:35] <jcoxon> woohooo
[19:35] <jcoxon> have connected up the pic
[19:42] <mc-> did you see smoke?
[19:43] <jcoxon> me? :-d
[19:44] <jcoxon> no smoke
[19:45] <mc-> rocketboy, any smoke?
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[19:51] <LaurenceB> ooh loads of people
[19:51] <LaurenceB> MiHAB3 is now ready to fly
[19:51] <LaurenceB> takes 7 second video clip every minute
[19:52] <LaurenceB> and 3 photos
[19:52] <LaurenceB> I got a 512mb card today
[19:52] <mc-> how's your glider going?
[19:52] <LaurenceB> I got some logic compatable mosfets
[19:53] <LaurenceB> should get the motors running better
[19:53] <LaurenceB> but I'm off back to uni at the end of this week, and wont be able to do any work on it
[19:53] <jcoxon> LaurenceB, we are postponing the launch till a week on sat/sun
[19:54] <LaurenceB> What data sorry
[19:54] <LaurenceB> -date
[19:54] <jcoxon> hmm the 20th?
[19:54] <LaurenceB> okay cool
[19:55] <LaurenceB> I'll take the payload and a few other things with me to oxford
[19:55] <jcoxon> okay
[19:55] <LaurenceB> but I cant bring all the stuff I'd need for some serious glider development work
[19:55] <LaurenceB> :(
[19:56] <jcoxon> right
[19:58] <LaurenceB> hopefully there will be a day with okay weather for some glider tests beforehand
[20:00] <mc-> which bits of the glider can you not bring? Can I build those bits?
[20:01] <LaurenceB> thanks, but what would the point be? I need to do multiple tests ect
[20:02] <LaurenceB> best done from the airfield near my house
[20:02] <LaurenceB> - disused :)
[20:04] <LaurenceB> MiHAB3 is a test of the master unit
[20:05] <LaurenceB> the plane tests the autopilot
[20:14] <LaurenceB> darkflib, are you hinking of working on a pc104 based balloon?
[20:18] <jcoxon> DarkFlib ain't around
[20:18] <jcoxon> he'll be away for 24hrs
[20:19] <LaurenceB> how do you know?
[20:26] <jcoxon> he said it earlier
[20:27] <LaurenceB> that pc104 stuff is great
[20:30] <LaurenceB> I want to try linux now, multitasking is way better than interrupt based stuff
[20:39] <icez> SBCs are cool
[20:39] <LaurenceB> whats one of them?
[20:39] <icez> mmm
[20:40] <icez> PC104s are SBCs
[20:40] <icez> :P
[20:40] <jcoxon> single board computer
[20:40] <LaurenceB> oh
[20:40] <jcoxon> in theory a gumstix isn't a sbc
[20:40] <jcoxon> :-)
[20:40] <jcoxon> right my led is happily flashing away
[20:40] <LaurenceB> why not pc compatable?
[20:40] <jcoxon> enough pic programing for me tonight
[20:41] <icez> I think it'd be easier for me to use SBCs than PICs or AVRs
[20:41] <jcoxon> cause they use multiple board :-D
[20:41] <icez> :P
[20:41] <LaurenceB> oh what was wrong with the gps?
[20:41] <icez> well, you could use a mini-ITX
[20:41] <mc-> jcoxon, you got mplab working?
[20:41] <jcoxon> yup
[20:41] <jcoxon> and have programmed my pic to flash an led
[20:42] <jcoxon> had a little help :-p
[20:42] <jcoxon> right i'll bbl
[20:42] <LaurenceB> what are you programming in? assembly?
[20:42] <jcoxon> looks like c to me
[20:43] <LaurenceB> oh cool
[20:43] <LaurenceB> bbl
[20:53] <rocketboy> mc?
[20:57] <mc-> yep
[20:58] <mc-> any luck?
[20:58] <rocketboy> sort of
[20:58] <rocketboy> OK - its not dea
[20:58] <rocketboy> d
[20:59] <rocketboy> I think the reason it was drawing so much cyrrent was a short on the antenna
[20:59] <mc-> I was just thinking that..
[20:59] <rocketboy> - so I fixed that and its down to 150mA
[20:59] <mc-> thanks
[20:59] <rocketboy> and as you say after a while it drops
[20:59] <mc-> so the PIC works.
[21:00] <rocketboy> It transmits ok now
[21:00] <rocketboy> yep
[21:00] <mc-> it transmits the GPS position?
[21:00] <rocketboy> it keeps sending out 0s still
[21:00] <mc-> can you try your active ant?
[21:00] <rocketboy> I plugged in an active ant and its the same
[21:03] <mc-> you'll need to repower it, as it only is on for 2 mins at powerup
[21:03] <rocketboy> sometimes when it boots up it tranmits the 0s steight away - sometimes it takes a couple of mins
[21:03] <rocketboy> yeah I re-powered it
[21:03] <mc-> did the active ant have a good skyview?
[21:03] <rocketboy> yep - middle of the back garden
[21:03] <mc-> I guess an inductor has blown up in the bias for the ant.
[21:03] <rocketboy> hang on I'll look at my gps to se where the sats are
[21:03] <mc-> good idea
[21:03] <rocketboy> at least 7 in view
[21:03] <rocketboy> of the back garden
[21:04] <mc-> you could have a look at the comms on the blue wire, but you'll need an inverter.
[21:04] <mc-> it's 9600 baud.
[21:05] <mc-> or maybe 4800
[21:05] <mc-> I'll build a new payload anyway..so don't worry about this one.
[21:05] <rocketboy> well ther is still 4.5V on the ant
[21:05] <mc-> thanks for your help
[21:06] <mc-> so the bias inductor hasn't blown up.
[21:06] <rocketboy> doesn't look like it
[21:07] <rocketboy> I'll try the serial out later
[21:08] <mc-> actually the GPS might require >4.6 to operate, so maybe your battery is getting low?
[21:08] <rocketboy> its about 7.5V last time I looked - hang on
[21:09] <rocketboy> yep - tends to spring back up when the current drops
[21:10] <rocketboy> what regulator is it?
[21:10] <mc-> low cost 7805
[21:10] <rocketboy> shouldn't be worse than 2V dropuot though
[21:11] <mc-> I agree
[21:13] <rocketboy> nah - its about the same with a different nicad (nearly 9Vs)
[21:14] <mc-> ok, I'll build a new payload.
[21:14] <rocketboy> what will the srial output tell me ?
[21:14] <rocketboy> serial
[21:15] <mc-> if it's tracking any sats
[21:15] <mc-> in fact you could check with a meter
[21:15] <mc-> if it's hung, it will sit at 5V.
[21:15] <rocketboy> ah ok
[21:17] <rocketboy> nah - its working OK - lots of voltage changes
[21:18] <mc-> ok, sounds like it's nearly working, just not tracking sats
[21:18] <mc-> or not tracking enough sats to get a fix
[21:19] <rocketboy> will there be NMEA on the serial port?
[21:19] <mc-> yes, but inverted.
[21:20] <rocketboy> yp - I'll need a max232 etc.
[21:20] <rocketboy> yp = yep
[21:20] <mc-> yes a max232, or even just a transistor
[21:20] <mc-> you can power the trans off pin 4 of a 9 way D.
[21:20] <rocketboy> I have a little boad name up for just such testing
[21:21] <rocketboy> board
[21:21] <LaurenceB> some pc serial inputs will work off ttl
[21:21] <rocketboy> name = made
[21:21] <rocketboy> yep - but you need to invert the sesnse from the USART
[21:23] <rocketboy> i.e. not oly is there a level shift there is also an invertion of the sense USART logic 1 = 0V and logic 0 = +5V
[21:24] <rocketboy> of more properly at RS232 levels about 1 = -12v and 0 = +12V
[21:24] <rocketboy> of = or
[21:27] <mc-> you sound like a RS232 genius...I don't think I've ever seen a RS232 signal at the +-12V range
[21:27] <mc-> as per the standard
[21:28] <rocketboy> actually I think the spec says a lot more as a maximum - about +/-20V for driving long lines
[21:29] <LaurenceB> I just send in ttl and use diodes on the output
[21:30] <rocketboy> yeah - well that works over short distances (a few feet)
[21:30] <rocketboy> enough for us
[21:32] <LaurenceB> my camera uses an avr I've just discovered
[21:33] <LaurenceB> could write my own firmware
[21:33] <rocketboy> cool
[21:38] <LaurenceB> one of the ones with jpeg codec
[21:38] <LaurenceB> theres an external mpeg chip
[21:39] <LaurenceB> and thats about it
[21:46] <LaurenceB> it has an lcd with parallel interface
[21:47] <LaurenceB> and switched mode power supply on a seperate board with a digital interface
[21:47] <LaurenceB> If it had a isp port it would make a very cool flight computer
[21:49] <LaurenceB> could use avr-dos for the sd card
[21:49] <LaurenceB> I may have a jtag interface but now I've reassembled it
[22:05] <LaurenceB> -it
[22:10] <rocketboy> C U all l8tr
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[22:37] <cablito2> anyone there
[22:39] <Max00> yup
[22:39] <Max00> hi
[22:49] <cablito2> wow
[22:49] <cablito2> someone alive
[22:49] <cablito2> nice, you into the high altitude ballon scene?
[22:49] <cablito2> Any projects of your own?
[22:51] <Max00> not yet still collecting parts and learning
[22:51] <Max00> u?
[22:51] <cablito2> I am still in the dreamzone, I kinda hold back because of the comm systems
[22:52] <cablito2> until i can find all the parts to have a ethernet link
[22:52] <cablito2> even if its low-speed link
[22:52] <cablito2> I dont see much use in "going" up there
[22:52] <cablito2> I want to take high res pictures and download them, so package retriaval is second priority
[22:52] <cablito2> or perhaps even an non-issue
[22:53] <cablito2> With a good link
[22:53] <cablito2> and a no-retriaval policy
[22:53] <Max00> ic
[22:53] <cablito2> the goals archieved can be set higher
[22:53] <Max00> where are you from?
[22:54] <cablito2> Brazil
[22:54] <Max00> cool
[22:54] <cablito2> Still there is the funds issue, because a "mission" does not go for less than 1.000 dollars I´d say
[22:54] <cablito2> and if its a non retriaval, you better get good data to make it worth it
[22:54] <cablito2> I have an idea of using a different balloon configuration
[22:54] <Max00> true
[22:54] <cablito2> to get higher than usual
[22:55] <cablito2> a cluster of ballons
[22:55] <Max00> DarkFlib is workin on a solar ballon
[22:55] <cablito2> with 30% of them with very little helium to start with
[22:55] <cablito2> just barelly enough to lift themselves , the payload is lifted by ballons that will burst at normal height
[22:56] <cablito2> by then, those 30% of low inflated ballons (on sea level) are going to be on the ideal height/volume to keep the payload rising or on slow descent
[22:56] <cablito2> Solar balloon? (where are you from?)
[22:56] <Max00> uk
[22:57] <LaurenceB> ooh I'm interested in solar balloons
[22:57] <cablito2> what is solar ballons?
[22:58] <cablito2> are*
[22:58] <cablito2> what u think about the cluster idea ?
[22:58] <LaurenceB> solar heated hot air
[22:58] <cablito2> air is - incredibly heavy :)
[22:59] <LaurenceB> almost 1.5kg/m3 at ground
[23:00] <cablito2> You need a massive amount of solar power to heat it to lower weights
[23:00] <cablito2> how is that achieved?
[23:00] <cablito2> one-way reflective materials?
[23:00] <LaurenceB> bin liners
[23:01] <cablito2> high altitude capabilities?
[23:01] <LaurenceB> http://perso.orange.fr/ballonsolaire/en-index.htm
[23:01] <cablito2> thats you?
[23:01] <cablito2> I was just looking at that site
[23:01] <cablito2> #1 on google
[23:02] <LaurenceB> n0 unfortunately
[23:02] <cablito2> need a hot place
[23:02] <cablito2> brazil is just the right spot :)
[23:02] <LaurenceB> like france
[23:02] <cablito2> are you french?
[23:03] <Max00> night
[23:03] <LaurenceB> no uk
[23:03] <LaurenceB> night max00
[23:03] <cablito2> nigh max
[23:03] <cablito2> have u made any solar ballons?
[23:03] <LaurenceB> I managed to launch a bin liner last summer
[23:04] Max00 (n=mythtv@host86-128-47-200.range86-128.btcentralplus.com) left irc: Remote closed the connection
[23:04] <cablito2> but how high can it go?
[23:05] <cablito2> it may actually be good for medium-high altitudes
[23:05] <cablito2> because its open on the botto
[23:05] <cablito2> bottom
[23:05] <LaurenceB> if you look on wikipedia you can get the formula for air density
[23:06] <cablito2> so excess pressure escapes - losing lift
[23:06] <LaurenceB> and work it out from that
[23:06] <cablito2> I assumed we were engaged in a conversation - my bad.
[23:06] <LaurenceB> its a exponential
[23:07] <cablito2> because plastic bags dont 'expand', so it has to be open bottom letting pressure escape, and helium ballons lift are good at high altitudes because their volume increases
[23:10] <LaurenceB> brb
[23:10] <cablito2> 10-4
[23:17] <LaurenceB> sorry very interesting tv program on solar energy
[23:17] <cablito2> hum
[23:18] <cablito2> a brazilian guy did something
[23:18] <cablito2> with plastic coke bottles
[23:18] <cablito2> solar heated water system
[23:18] <LaurenceB> cnes in france have launched mir balloons
[23:18] <LaurenceB> these work of the ir nightglow
[23:18] <cablito2> plastic bottles, pvc pipes and milk boxes (reflective insides)
[23:18] <LaurenceB> from the surface
[23:19] <LaurenceB> cool, probably not as good as vacuum tube ones
[23:19] <cablito2> you dont find as many vacuum tubes in the trashcan these days :)
[23:20] <cablito2> I am going to try to do a solar balloon soon
[23:20] <cablito2> i used to make paper balloons
[23:20] <LaurenceB> vacuum tube based solar collectors are very effective
[23:20] <cablito2> those "dangerous" kinds
[23:20] <cablito2> with parafins
[23:20] <cablito2> some 10m high balloons
[23:20] <LaurenceB> I've launched loads of meths heated bin liner balloons
[23:21] <LaurenceB> 10m, thats huge
[23:21] <cablito2> yeah, even the police admited they were impressed
[23:21] <LaurenceB> lol
[23:21] <cablito2> it carried a huuuuuge payload
[23:21] <cablito2> I mean, trays and trays of fireworks
[23:21] <LaurenceB> I tried to launch one with video once, but broke the transmitter
[23:22] <LaurenceB> cool fireworks
[23:22] <cablito2> thats what I was talking with max
[23:22] <cablito2> i want to launch one
[23:22] <cablito2> but I need a good link between ground and balloon
[23:22] <LaurenceB> Tried a few fireworks once, but hadn't got much lift
[23:22] <cablito2> otherwise its not worth just for the kids off setting a ballon of
[23:22] <cablito2> Hot air ballons? man, they are so easy to make and generate so much lift its scary
[23:23] <cablito2> but the lift-size ratio only picks up after you make them above 2meters
[23:23] <LaurenceB> I dont know about the radio laws in brazil
[23:23] <cablito2> 2.4ghz is clear band for us
[23:23] <cablito2> even 5.8 i think
[23:23] <LaurenceB> in the uk we have to use 433mhz at 10mw
[23:24] <LaurenceB> I'm not sure about 2.4 ghz for telemetry, I've only used it for video
[23:24] <cablito2> ooo and our "power output" restriction is really not enforced, specially if its an "cientific" experiment.
[23:24] <icez> 2.4 gets mixed up with walkies and phones though:[
[23:24] <cablito2> I want ethernet link
[23:24] <LaurenceB> that would be good
[23:24] <cablito2> radio modems, 100kbps/s is fine
[23:25] <LaurenceB> http://www.usbwifi.orcon.net.nz/
[23:25] <cablito2> I´ve seen it too
[23:25] <LaurenceB> we used 300bps on MiHAB2
[23:26] <cablito2> What if the ground antena is "oversized" you think that can make up for the lower output on the ballon?
[23:26] <LaurenceB> good enough for telemetry
[23:26] <LaurenceB> well its the efficiency of the transmitting ant, not its size
[23:27] <LaurenceB> 1/4 wave ant is good
[23:27] <cablito2> The good point is you have line of sight
[23:27] <LaurenceB> yes
[23:28] <cablito2> but I wonder what kind of interference there might be from being high
[23:28] <LaurenceB> if your just transmitting theres no problems
[23:28] <cablito2> The point is, if there is no good comms for broadcasting the flight data
[23:29] <cablito2> and enough funds for sensors that bring good info / images
[23:29] <cablito2> its just a "joy ride"
[23:29] <LaurenceB> micro+digital cam+gps+radio module
[23:31] <cablito2> brb
[23:33] <LaurenceB> have you programmed micros before?
[23:35] <LaurenceB> Phones are good in uk but guess the network isn't so good where you are
[23:39] <cablito2> i am a programmer
[23:39] <cablito2> have done some "ligh" programming for a pic device very many years ago
[23:39] <cablito2> I wasnt the head of the project was just called in to solve some C bugs in it
[23:40] <cablito2> cell network is good here, but I heard cellphones deal really badly with height
[23:40] <cablito2> cellphones signals i mean
[23:41] <LaurenceB> they reconnect when they come down
[23:42] <cablito2> we have a good coverage actually and they are cheap
[23:42] <cablito2> the phones i mean
[23:42] <cablito2> the calls are expensive as hell
[23:43] <LaurenceB> if they are AT compatable its easy to use
[23:43] <LaurenceB> just serial commands
[23:43] <cablito2> need a hacked on though
[23:43] <cablito2> they wont boot without the operator chip/mifare card
[23:44] jcoxon (n=jcoxon@jac208.caths.cam.ac.uk) joined #highaltitude.
[23:44] <LaurenceB> what phones?
[23:44] <cablito2> the phones we have in brazil
[23:44] <cablito2> they wont boot until you insert a mifare chip on it
[23:44] <LaurenceB> okay, normal phones are usually AT compatable
[23:44] <cablito2> cause they are factory bould to an specific operator
[23:45] <jcoxon> hey all
[23:45] <cablito2> you can do phone-2-phone calls?
[23:45] <LaurenceB> okay do you have special phones in brazil?
[23:45] <cablito2> nah regular phones
[23:45] <LaurenceB> we use txt messages
[23:45] <cablito2> uk ones work in brazil
[23:45] <LaurenceB> you shouldn't have any problems then
[23:45] <cablito2> i´ve had some uk phones brought by friends
[23:45] <cablito2> they work fine. but when i buy the same phone here
[23:46] <cablito2> it wont boot without the card
[23:46] <LaurenceB> just a serial interface
[23:46] <LaurenceB> I see
[23:46] <cablito2> I´ve managed to hack a nokia one
[23:46] <LaurenceB> should still respond to at commands
[23:46] <cablito2> and unlock it to any chip/no chip.... but its an old model with no "digital connection" whatsoever
[23:46] <icez> hey jcoxon
[23:46] <icez> :)
[23:46] <cablito2> thats nice to know
[23:46] <cablito2> icez - 18 days idle :)
[23:47] <icez> me?
[23:47] <icez> :P
[23:47] <cablito2> oooo it was tiger maybe
[23:47] <LaurenceB> okay I'd better be off cya all
[23:47] Action: cablito2 googling for cellphone comm
[23:47] <icez> Weiss and Tiger^ haven't talked for a long time
[23:47] <jcoxon> cablito2, what are you trying to achieve?
[23:47] <cablito2> they have good relialble ISPs thats for sure
[23:48] <icez> lol:P
[23:48] <cablito2> planning balloon comm system
[23:48] <icez> my ISP could survive, my laptop wouldn't :P
[23:48] <jcoxon> what sort of system?
[23:48] <LaurenceB> okay cya all
[23:48] <icez> cya LaurenceB
[23:48] <cablito2> What I really want - cya laurcence
[23:48] LaurenceB (n=laurence@host86-142-87-166.range86-142.btcentralplus.com) left irc:
[23:48] <cablito2> what i really want is an ethernet downlink
[23:49] <cablito2> because i dont want to recover the payload
[23:49] <jcoxon> hmmmm
[23:49] <icez> i don't think wifi goes very far
[23:49] <jcoxon> oh wifi will go far at that height
[23:49] <jcoxon> if its allowed
[23:49] <cablito2> I am not concerned with legal constraints
[23:49] <jcoxon> you'd need a directional antenna to recieve
[23:49] <cablito2> I am in brazil :)
[23:49] <cablito2> Laws are somewhat bendable here.
[23:49] <jcoxon> well then yeah wifi might do the job nicely
[23:50] <cablito2> but I need a very good anenta right?
[23:50] <jcoxon> if not something like 868mhz radio modems
[23:50] <jcoxon> you'd need an excellent reciever
[23:50] <jcoxon> a parabolic dish - quite easy to make
[23:50] <jcoxon> there is a site about how to make them out of a sieve
[23:50] <cablito2> Size matters on parabolic dish on these frequencies?
[23:50] <cablito2> I saw that site already - with usb right?
[23:51] <cablito2> http://www.usbwifi.orcon.net.nz/
[23:51] <jcoxon> yup
[23:51] <jcoxon> thats the one
[23:51] <jcoxon> what i would do is get a wireless router
[23:51] <jcoxon> with usb
[23:51] <jcoxon> use openwrt
[23:51] <jcoxon> attach a usbwebcam
[23:51] <jcoxon> run it off batteries and then use the wifi as a downlink
[23:51] <jcoxon> cost you ?50 in total
[23:52] <cablito2> I plan on gathering more info/higher res than a webcam
[23:52] <cablito2> i plan on sending an old notebook motherboard with linux
[23:52] <cablito2> webcams are somewhat limited on resolution
[23:52] <cablito2> and older 2 megapixel cameras are quite cheap
[23:53] <jcoxon> so just take pics, download to notebook and then over wifi
[23:53] <jcoxon> would work
[23:53] <jcoxon> it would be heavy
[23:53] <cablito2> the satelite dish, i dont know a lot about radio comm actually, do dish size matters? or is it tied to frequency range?
[23:54] <jcoxon> i'm not totally sure
[23:54] <jcoxon> you'd have to ask some of the radio people that come here
[23:54] <cablito2> I am thinking on helium, i have an specific idea on clustering - with some of the ballons being well inflated for initial lift
[23:54] <cablito2> and some of them with very little helium
[23:54] <jcoxon> so you'd probably get drift
[23:54] <cablito2> so some of them burst at given height
[23:55] <cablito2> and then the ones that were barelly inflated take over from there when their expansion will have reached the ideal for that specific height
[23:55] <jcoxon> yeah that would work
[23:55] <cablito2> I dont want to recover the payload - so drift is not an issue (though range becomes one)
[23:56] <cablito2> but in brazil we dont have the same jetstreams you have in us/uk
[23:56] <cablito2> so the main drift will be from lower altitude winds which are somewhat predictable
[23:56] <jcoxon> indeed
[23:57] <jcoxon> i've actually got data of some big scientific balloons launched in brazil
[23:57] <jcoxon> jetstream is certainly less of an issue
[23:57] <jcoxon> why don't you want to recover it?
[23:57] <cablito2> logistical problems
[23:57] <cablito2> we dont have deserts
[23:58] <jcoxon> nor do we :-)
[23:58] <cablito2> and the cost of recovery may surpass the benefits if it drifts too much
[23:58] <jcoxon> it wouldn't be difficult to add gps
[23:58] <cablito2> gps is intended
[23:58] <jcoxon> then you could at least decide
[23:58] <jcoxon> actually you'd need gps to help point your receiveing antenna
[23:58] <cablito2> But maybe launching it from a shoreside might free me from concerns such as it falling on top of someone
[23:59] Action: Weiss exists
[23:59] <cablito2> if it calls on a boat, given the odds of that happening, I will probably win the lottery on that same day
[23:59] <jcoxon> indeed
[23:59] <jcoxon> what are the aims? pictures?
[23:59] <cablito2> The funds is obviously an issue, but less than deciding on the hardware really.
[00:00] --- Wed Jan 10 2007