highaltitude.log.20060716

[00:18] icez_ (n=icez@ip68-3-56-121.ph.ph.cox.net) joined #highaltitude.
[00:24] EvilGuru (n=evilguru@margaret2708.plus.com) left irc: "This computer has gone to sleep"
[00:32] icez (n=icez@ip68-3-56-121.ph.ph.cox.net) left irc: Read error: 110 (Connection timed out)
[08:28] icez_ (n=icez@ip68-3-56-121.ph.ph.cox.net) left irc: "Lost terminal"
[12:15] rocketboy (n=steve@217.47.75.147) joined #highaltitude.
[12:22] rocketboy (n=steve@217.47.75.147) left irc:
[12:23] rocketboy (n=steve@217.47.75.147) joined #highaltitude.
[13:26] malgar (n=malgar@adsl-ull-10-247.47-151.net24.it) joined #highaltitude.
[14:15] rocketboy (n=steve@217.47.75.147) left irc:
[15:47] jcoxon (n=jcoxon@81-178-226-201.dsl.pipex.com) joined #highaltitude.
[15:50] <phatmonkey> hi james!
[15:51] <malgar> jcoxon, my compliments for pegasus III
[15:51] <jcoxon> thanks malgar
[15:51] <jcoxon> hey phatmonkey (bored already! so i'm about to write up peg III)
[15:52] <malgar> i didn't know that you lanuched yesterday :) I should read more here
[15:52] <malgar> :)
[15:52] <phatmonkey> ah, ok!
[15:52] <phatmonkey> what you going to do for IV?
[15:52] <phatmonkey> oh yes, the africa camera
[15:53] <phatmonkey> i expect we'll have a working glider by the start of next month
[15:53] <phatmonkey> will give us a good month and a half of tweaking and testing before i go back to school
[15:55] <jcoxon> malgar, :-D well we kept the launch quite quiet just cause we weren't sure when we were launching
[15:55] <jcoxon> phatmonkey, yeah africa - i'm thinking of getting a better camera
[15:55] <phatmonkey> would be nice
[15:55] <jcoxon> as i'll definitly get it back
[15:55] <phatmonkey> just remember that megapixels aren't everything!
[15:56] <malgar> yeah! a good lens
[15:56] <jcoxon> true
[15:56] <phatmonkey> yhay! our gpsd reader works
[15:56] <malgar> set
[15:56] <jcoxon> phatmonkey, i'm glad things are working now
[15:56] <phatmonkey> yeah, phew
[15:56] <jcoxon> phatmonkey, have you explored the legal issues yet?
[15:57] <phatmonkey> not really
[15:57] <phatmonkey> i can't see how it's any different from yours, especially as it's far safer
[15:57] <phatmonkey> it will descend and release a parachute
[15:57] <phatmonkey> it just happens to be in the shape of a wing!
[15:57] <jcoxon> perhaps but it is a UAV
[15:57] <phatmonkey> i'm wondering if UAVs have to be powered
[15:57] <jcoxon> good point
[15:58] <jcoxon> i'm just playing the devils advocate so that you cover all the bases
[15:58] <jcoxon> i'm keen to see it work!
[15:58] <phatmonkey> it's making an uncontrolled descent far safer, common sense would say that it's fine!
[15:58] <phatmonkey> hehe, yeah
[15:58] <phatmonkey> radio is a big issue actually
[15:58] <jcoxon> 10mw 434
[15:59] <phatmonkey> do you have the ground equipment and things?
[15:59] <jcoxon> i saw it work yesterday
[15:59] <HenryHallam> morning gang
[15:59] <phatmonkey> i could buy the stuff for the glider, then we can see if it works nicely
[15:59] <HenryHallam> yeah 434 is the way to go
[15:59] <jcoxon> no Steve brought his along
[15:59] <phatmonkey> if it works, i can buy all my gear
[15:59] <phatmonkey> morning!
[15:59] <jcoxon> HenryHallam, you guys have some don't you
[15:59] <phatmonkey> i'll have to chat to him about it then
[15:59] <phatmonkey> it sounds like it worked fantastically
[15:59] <jcoxon> oh phatmonkey can i be added to ukhas :-D
[16:00] <jcoxon> and MiHAB
[16:00] <phatmonkey> what sort of data rates do you expect we can get?
[16:00] <HenryHallam> We have a traxa that transmits on 434, we don't actually have the groudn equipment but we know someone we can borrow it from on a day's notice
[16:00] <phatmonkey> added where? you're a user!
[16:00] <jcoxon> no the launches!
[16:00] <HenryHallam> data rates... 300 baud maybe
[16:00] <phatmonkey> http://www.ukhas.org.uk/launches/10/pegasus-iii
[16:00] <phatmonkey> !
[16:00] <phatmonkey> ah, that's masses
[16:01] <jcoxon> you only just added the ;-p
[16:01] <HenryHallam> Steve said 300 should be doable
[16:01] <jcoxon> there was MiHAB as well
[16:01] <phatmonkey> much enough for transmit position, attitude, status, waypoints and all that
[16:01] <phatmonkey> oh yes
[16:02] <phatmonkey> MiHAB stats?
[16:02] <jcoxon> ummmm
[16:02] <jcoxon> HenryHallam?
[16:02] <phatmonkey> link too?
[16:03] <HenryHallam> hang on let me look in the logfile
[16:03] <jcoxon> well the pics are on henry's webspace (http://www.srcf.ucam.org/~hmh33/flight_mihab/)
[16:03] <HenryHallam> 10800ft
[16:03] <phatmonkey> MiHAB I?
[16:03] <HenryHallam> about 15 mins ascent and 10 mins descent
[16:03] <jcoxon> phatmonkey, i guess so
[16:04] <jcoxon> HenryHallam, wasn't it climbing at about 1400ft per min?
[16:05] <phatmonkey> http://www.ukhas.org.uk/launches/11/mihab-i
[16:05] <phatmonkey> that sort of thing?
[16:06] <HenryHallam> something like that initially, the ascent rate decreased a bit after ~2 minutes
[16:06] <HenryHallam> the only log data recorded is in http://www.srcf.ucam.org/~hmh33/flight_mihab/flight%20log.txt
[16:06] <phatmonkey> jcoxon, what sort of release permits do you have?
[16:06] <HenryHallam> lat,lon,alt
[16:06] <phatmonkey> you've got one for a few months don't you?
[16:06] <jcoxon> phatmonkey, perhaps not the bit with Peg III
[16:07] <phatmonkey> hokay
[16:07] <jcoxon> just the day instead
[16:07] <jcoxon> phatmonkey, ummm basically henry, carl, robert and myself can launch balloons and then have them descend by parachute
[16:07] <jcoxon> if we launch from cam and inform air traffic control
[16:08] <phatmonkey> any chance of tagging on the glider?
[16:08] <HenryHallam> I would think that would be fine.. james?
[16:08] <jcoxon> ummm is there a parachute involved?
[16:09] <phatmonkey> yes
[16:09] <jcoxon> well then i don't see an issue
[16:09] <phatmonkey> the glider will descend by parachute once it is back to the laynch point
[16:09] <HenryHallam> we have the permission until 16 September, but I think we will apply for an extension when we get near that date
[16:10] <phatmonkey> wonderful, that's when i go back to school
[16:10] <phatmonkey> probably no need for me to apply for one i guess
[16:10] <phatmonkey> well, i might once it's working
[16:11] <HenryHallam> I'm keen on building a 100km balloon-launched staged solid rocket
[16:12] <phatmonkey> that would be amazing
[16:12] <jcoxon> HenryHallam, steve has had some plans for this
[16:12] <phatmonkey> with wings so it can fly back again? :D
[16:12] <HenryHallam> no :P
[16:12] <jcoxon> he reckons you'd need a 10kg rocket
[16:12] <jcoxon> to reach sub-orbital space
[16:13] <HenryHallam> I was hoping for something closer to 2kg
[16:13] <jcoxon> i'd been keen to help though i'm not sure i could blag permission in the UK :-p
[16:13] <jcoxon> HenryHallam, 2kg would still get a higher altitude
[16:13] <HenryHallam> weeeelll there's nothing in that CAA letter forbidding rockets
[16:13] <HenryHallam> am I right in thinking homemade solid rockets can have an Isp up to ~180 seconds?
[16:14] <jcoxon> no idea
[16:14] <jcoxon> HenryHallam, but i reckon we could blag a sea launch :-D
[16:14] <HenryHallam> totally
[16:14] <jcoxon> get round all that permission malarky
[16:15] <HenryHallam> would be more of a hassle though
[16:15] <HenryHallam> you'd need to go quite far out to sea
[16:15] <HenryHallam> and probably Atlantic rather than North Sea
[16:15] <HenryHallam> anyway I'm going to the skunkworks now, see you guys later
[16:15] <jcoxon> cya
[16:15] Nick change: HenryHallam -> HH|away
[16:15] <phatmonkey> see ya
[16:16] <phatmonkey> wow
[16:16] <phatmonkey> just need to fix up a servo controller library (just copying and pasting from dave's code), make the thermopile circuit, add code to read from the thermopiles
[16:16] <phatmonkey> ... and it's done
[16:16] <jcoxon> excellent
[16:17] <jcoxon> just uploaded peg III log files
[16:17] <phatmonkey> i'm waiting on a company in america who are making a "servo multiplexer", they say it'll be out before the end of the month
[16:17] <phatmonkey> nice
[16:17] <phatmonkey> basically it switches between two servo inputs by a servo input
[16:17] <phatmonkey> so we can use standard radio control gear to switch between my control and the autopilot
[16:18] <phatmonkey> so i can launch it, get it some height, then switch over to the autopilot. if something goes wrong, i can quickly switch it back
[16:18] <phatmonkey> if we finish everything before that comes, we can run around fields holding the plane above our heads to test it :D
[16:19] <phatmonkey> hokay, thought is needed on releasing the parachute though
[16:20] <phatmonkey> we probably need to release it out of the back, and it needs to be held inside the glider somehow
[16:20] <phatmonkey> i'm thinking a little hatch that can be blown open, maybe with a servo or one of your explosive widgets
[16:20] <phatmonkey> hmm, maybe not the explosive thing, it'll destroy the glider won't it
[16:21] <jcoxon> ummm i don't know
[16:21] <phatmonkey> well, damage it anywho
[16:21] <jcoxon> will let you know when i blow one up this week to see what went wrong
[16:21] <phatmonkey> ok
[16:21] <phatmonkey> i could use a servo that holds the hatch in, but also doubles at pushing it out with another arm
[16:22] <phatmonkey> once it's been pushed out a bit, it'll catch the wind
[16:22] <phatmonkey> the parachute can be attached to the hatch so it acts as a drogue
[16:22] <jcoxon> electro magent
[16:22] <phatmonkey> will that be secure enough?
[16:22] <jcoxon> could be
[16:22] <phatmonkey> that would be quite neat
[16:22] <phatmonkey> it could push the hatch off too
[16:26] defy (n=defy@60-234-234-98.bitstream.orcon.net.nz) left irc: Read error: 110 (Connection timed out)
[16:30] <phatmonkey> i'll have a think about servos, since we already have a servo controll
[16:30] <phatmonkey> er
[16:30] <phatmonkey> and they'll have a much stronger hold too
[16:33] <jcoxon> probably best
[16:35] <phatmonkey> everything is drawing about 500ma at the moment, i wonder what batteries would be best
[16:36] <phatmonkey> above 5Ah would be a good idea i suppose
[16:36] <phatmonkey> hmm, i might have to find some lithium ion cells, not polymer
[16:36] <phatmonkey> i don't really want to go the unrechargable route
[16:40] <jcoxon> hmmmm
[16:41] <jcoxon> i'd start with non rechargeables
[16:41] <jcoxon> then once everything is working nicely find a rechargable source
[16:42] <phatmonkey> i suppose
[16:43] <phatmonkey> I guess we can start testing far earlier now live communication is possible
[16:43] <phatmonkey> it doesn't really matter if it screws up
[16:59] rocketboy (n=steve@217.47.75.147) joined #highaltitude.
[17:09] malgar (n=malgar@adsl-ull-10-247.47-151.net24.it) left irc: "*** E' solo l'urto con un iceberg, che vuoi che sia, questa è una nave inaffondabile. *** 75$/barile"
[17:31] icez (n=icez@ip68-3-56-121.ph.ph.cox.net) joined #highaltitude.
[17:47] <phatmonkey> hi rocketboy
[17:51] <rocketboy> hi
[17:51] <rocketboy> sorry I didn't have the sound on
[17:51] <phatmonkey> what radio gear were you using on PIII?
[17:52] <phatmonkey> on the ground especially
[17:52] <phatmonkey> i must learn more about it, i know little about radio
[17:52] <rocketboy> I used a 434MHz 10mW narrow band licence exempt transmitter
[17:52] <rocketboy> into a 1/4 wave vertical antenna under PIII
[17:53] <rocketboy> the receive end was a 7 element yagi and an old ham radio rig
[17:53] <rocketboy> very good signals for almost the entire flight
[17:54] <rocketboy> I'm very confident that a data downlink could be added
[17:54] <phatmonkey> ok
[17:55] <rocketboy> this was more of a test flight - just to check signal strength
[17:55] <phatmonkey> yes
[17:55] <rocketboy> I'm doing some work to
[17:55] <rocketboy> add low speed data
[17:56] <rocketboy> hope to have another version ready in a couple of weeks
[17:56] <phatmonkey> brilliant, ok
[17:56] <phatmonkey> i definately want to use something like this on my glider
[17:57] <rocketboy> yes - I'm confident it will work over 100Km path - as long as its in the air
[17:58] <phatmonkey> what is the vertical antenna like?
[17:58] <rocketboy> the trick is using a narrow bandwidth
[17:59] <rocketboy> I'm just writing up somthing for the wiki - it will have a pic of the setup
[17:59] <phatmonkey> ok, nice
[18:00] <rocketboy> give me 20mins and I'll put it up
[18:35] <rocketboy> tis up - start » licenced » licence_exempt » basics » communication » piii_experiance
[18:35] <jcoxon> cool
[18:35] <jcoxon> i'm just writng my peg III report
[18:38] <icez> :D
[18:39] <phatmonkey> very nice
[18:39] Nick change: HH|away -> henryhallam
[18:40] <jcoxon> oooo can some on choose a picture to go at the top of the peg 3 page (like peg I)
[18:40] <jcoxon> can't decide
[18:40] <henryhallam> hmm
[18:40] <henryhallam> there were a couple I liked
[18:40] <phatmonkey> ooh, there are some nice ones there
[18:40] <henryhallam> substation for humour value :P
[18:41] <phatmonkey> http://www.srcf.ucam.org/~jac208/pegasus/pictures/pegasus3/flight/DSCI0118.JPG - that's quite a nice one
[18:41] <jcoxon> 135 is nice as well
[18:41] <phatmonkey> or the one with the ufo!
[18:41] <phatmonkey> http://www.srcf.ucam.org/~jac208/pegasus/pictures/pegasus3/flight/DSCI0129.JPG
[18:41] <icez> oh and jcoxon
[18:41] <henryhallam> 112 is nice
[18:41] <jcoxon> the moon would be cool though
[18:41] <phatmonkey> vivid colour
[18:41] <icez> you have a 404 on your peg3 page
[18:42] <icez> Launch Photos <this-link> and <here>
[18:42] <jcoxon> oh yes
[18:42] <phatmonkey> i love #129
[18:42] <jcoxon> sorry i haven't upload that bit yet
[18:42] <jcoxon> still got lots to do :-D
[18:42] <icez> ok:p
[18:42] <jcoxon> like a launch description
[18:42] <jcoxon> only onto the software section now
[18:42] <henryhallam> which one is the ufo? the squashed moon?
[18:45] <phatmonkey> not sure, there's one with a weird shape on the horizon somewhere
[18:45] <phatmonkey> #186 - pretty clouds! wow
[18:46] <icez> you guys have weird clouds in the UK
[18:46] <icez> :P
[18:46] <phatmonkey> :D
[18:46] <icez> or i'm not used to see them from above
[18:48] <phatmonkey> rocketboy, do you want me to change the page name from experiance to experience? hehe
[18:48] <icez> this one looks like it was done with the painting plugin on GIMP/photoshop: http://www.srcf.ucam.org/~hmh33/flight_mihab/flight100.jpg
[18:48] <phatmonkey> very interesting stuff though
[18:48] <phatmonkey> quite artistic really :P
[18:48] <icez> yeah
[18:49] <rocketboy> Have you got somthing that gives the time of balloon track - so we can relate the picture to the position
[18:50] <rocketboy> also I'd be interested in checking where the balloon was when I took varios signal strength readings
[18:50] <rocketboy> various
[18:51] <phatmonkey> http://www.srcf.ucam.org/~jac208/pegasus/pictures/pegasus3/logs/
[18:51] <rocketboy> ah
[18:53] malgar (n=malgar@adsl-ull-139-221.47-151.net24.it) joined #highaltitude.
[19:02] <phatmonkey> jcoxon, can't the gumstix use an ext filesystem?
[19:36] <jcoxon> it probably could
[19:36] <jcoxon> but jffs2 is much better suited
[19:36] <jcoxon> apart from this one issue
[19:37] <jcoxon> as its designed for embeded use
[19:37] <phatmonkey> ok
[19:37] <phatmonkey> i guess i'll just have to split up log files
[19:38] <jcoxon> its probably a good idea anyway to split log files
[20:03] <phatmonkey> true
[20:16] <henryhallam> james, do you recall the details about your 1.2kg balloon? (where it came from, cost, burst diameter)
[20:27] malgar2 (n=malgar@adsl-ull-170-240.47-151.net24.it) joined #highaltitude.
[20:45] malgar (n=malgar@adsl-ull-139-221.47-151.net24.it) left irc: Read error: 113 (No route to host)
[20:51] <henryhallam> man gravity losses are a bitch aren't they
[20:52] <henryhallam> hmm if this gps says it's rated for 4g acceleration I wonder how much it can actually take
[20:54] <rocketboy> I remember a discussion on this - not a lot more - I think its to do with crystal stress causing frequency shift
[20:56] <henryhallam> aw
[20:56] <henryhallam> ok I'll go with 5g max then
[20:56] <henryhallam> well
[20:56] <henryhallam> actually
[20:57] <henryhallam> maybe operationally it can't take very much more but I can't use the gps during motor firing anyway, because of those stupid COCOM restrictions
[20:57] <henryhallam> so perhaps I can exceed the g limit with it turned off, then switch it back on again some time close to apogee
[21:03] <rocketboy> If you using it in a rocket then expect it to loose lock during the assent - should get it bak at apogee
[21:05] <rocketboy> I don't think the software restrictions 2 out of 3 of velocity, acceleration, altitude are that acheivable by amateurs
[21:08] <henryhallam> well I've been running the numbers for a two stage solid fueled rocket launched from a balloon at 35km, rocket total mass about 4kg
[21:08] <henryhallam> trying to see how possible it would be to get to 100km
[21:09] <henryhallam> I think it might be doable
[21:09] <henryhallam> the big composite motors have Isp about 150s, right?
[21:09] <rocketboy> yes I run the numbers some time ago - I think a single stage M class motor would do it
[21:10] <rocketboy> You tried using rocksim or wRASP - thse will give you accuarte simulations with NASA atmospheric model
[21:12] <henryhallam> ah no I've just been doing it with excel and the equations, will give those a try, thanks
[21:12] <rocketboy> the biggest problem is stability - you need some form of active stabilization system (gas jets/motors/javitar)
[21:12] <henryhallam> yes indeed
[21:12] <henryhallam> was thinking a couple of servos to move the avionics/camera/parachute relative to the motor
[21:12] <henryhallam> the motor is heavier so you aren't really tilting the motor :P
[21:12] <rocketboy> change the centre of gravity?
[21:13] <henryhallam> but it should still move the c of g relative to the thrust axis
[21:13] <henryhallam> yes
[21:14] <henryhallam> hopefully rate gyros should be stable enough over the ~50 seconds burn time
[21:14] <rocketboy> humm - don't know of any commercial system that does it that way - I suspect its becuse most of the mass is immovable (motor/airframe) - and the rest isn't enoght to make a difference
[21:15] <henryhallam> what is javitar?
[21:15] <rocketboy> yes the right sort of gyro
[21:15] <phatmonkey> you could experiment with IR horizon detection for stabalising rockets, but i dunno how well it would work
[21:16] <rocketboy> its a device to vector the motor thrust - like a graphite ring around the motor jet
[21:16] <henryhallam> sounds clever
[21:16] <rocketboy> nah I'd use a gyro
[21:17] <rocketboy> don't know any commercial rockets using horizon detection
[21:17] <henryhallam> I wasn't going to bother with much of an airframe since the air is so thin
[21:18] <rocketboy> humm -maybe ther is somthing in that
[21:29] Nick change: henryhallam -> hh|brb
[21:56] defy (n=defy@60-234-234-98.bitstream.orcon.net.nz) joined #highaltitude.
[21:58] <jcoxon> oooo interesting discussions happening here :-D
[22:00] <jcoxon> borism, defy hh|brb malgar2 rocketboy Tygrys Weiss - just to say to you all that you are all welcome to put yourselves in the members section of the ukhas wiki (we count you all as members!)
[22:00] <malgar2> ok :)
[22:00] <defy> sweet :)
[22:00] <jcoxon> tis lonely with only 4 people hehe
[22:02] <defy> I'm trying my hand at serial port programming to get this little camera working....
[22:02] <defy> its not fun
[22:03] <jcoxon> defy, what is required?
[22:03] <defy> just talking to it 8 bits at a time I guess, I was trying to be lazy and do it with perl, but I think im going to have to move this one over to C
[22:04] <jcoxon> hehe
[22:04] <jcoxon> C would probably be better in the long run
[22:04] <defy> yeah
[22:04] <defy> Do you know how hard it is to get c++ code compiled and running on the gumstix?
[22:04] <defy> I already have some sample code for it, but its c++
[22:05] <defy> I want to avoid reflashing =/
[22:05] <jcoxon> ummm i seem to remember its just a little change in the build root
[22:05] <defy> cool, ill search the list a bit
[22:05] <jcoxon> and if you copy across the correct libraries
[22:05] <jcoxon> i don't see an issue
[22:09] Nick change: malgar2 -> malgar
[23:22] icez (n=icez@ip68-3-56-121.ph.ph.cox.net) left irc: "Lost terminal"
[23:30] <hh|brb> James, are you sure you have the times right for Peg 3? I thought it was airborne for nearly 3 hours, not 2
[23:34] <jcoxon> hh|brb, oops
[23:34] <jcoxon> forgot to convert one of the numbers from gmt to bst
[23:35] <rocketboy> night all
[23:35] rocketboy (n=steve@217.47.75.147) left irc:
[23:36] Nick change: hh|brb -> henryhallam
[23:36] <henryhallam> can I link it from a pilot forum?
[23:37] <jcoxon> of course
[23:38] <henryhallam> cheers
[23:40] <jcoxon> i'm prepared to receive safety complaints :-p
[23:41] <henryhallam> haha
[23:45] <henryhallam> I've ordered a 3MP camera and one of the radio transmitter chips like Steve used for your 434 Morse sender, for Nova 2
[23:45] <henryhallam> we should be able to get it off this w/e
[23:45] <jcoxon> excellent
[23:46] <jcoxon> whats to forecast like?
[23:46] <henryhallam> no idea, I'll check later in the week
[23:47] <jcoxon> hmm wunderground seems to be down
[23:49] <phatmonkey> ah, almost finished the thermopile amplification circuit
[23:49] icez (n=icez@ip68-3-56-121.ph.ph.cox.net) joined #highaltitude.
[23:52] <henryhallam> how many thermopiles do you have?
[23:52] <phatmonkey> 6
[23:52] <phatmonkey> two for each axis
[23:53] <phatmonkey> each thermopile has a 100 degree view, so it gives us a full 360 degree reading with some overlap (4 * 100)
[23:55] <henryhallam> they just give a single reading right? not like a ccd
[00:00] --- Mon Jul 17 2006