highaltitude.log.20070311

[00:47] Ebola (n=Ebola@host86-143-156-147.range86-143.btcentralplus.com) left irc: "gone"
[05:02] icez__ (n=icez@ip68-3-56-121.ph.ph.cox.net) joined #highaltitude.
[05:18] icez_ (n=icez@ip68-3-56-121.ph.ph.cox.net) left irc: Read error: 110 (Connection timed out)
[06:50] icez__ (n=icez@ip68-3-56-121.ph.ph.cox.net) left irc: Remote closed the connection
[09:16] jcoxon (n=jcoxon@jac208.caths.cam.ac.uk) joined #highaltitude.
[09:49] flowolf (n=flowolf@host135-224-dynamic.1-87-r.retail.telecomitalia.it) joined #highaltitude.
[09:57] edwardmoore (n=edwardmo@pomegranate.chu.cam.ac.uk) joined #highaltitude.
[09:57] <jcoxon> good morning edwardmoore
[09:57] <edwardmoore> good morning jcoxon
[09:57] <jcoxon> am just writing up all the links on to the wiki from last night
[09:57] <edwardmoore> how's things?
[09:57] <edwardmoore> cool
[09:58] <edwardmoore> i've been thinking about designs all night
[09:59] <jcoxon> hehe
[09:59] <jcoxon> well i've found a few interesting links
[09:59] <edwardmoore> send!
[09:59] <jcoxon> http://www.eddiem.com/toys/rcplanes/myfoil/myfoil.html
[10:00] <jcoxon> basically he uses a normal parafoil kite
[10:00] <jcoxon> + a winch system like ours
[10:00] <jcoxon> nice bit about changing the rigging on the foil
[10:00] <edwardmoore> yep that's good
[10:03] <edwardmoore> they do tend to glide pretty fast
[10:03] <jcoxon> so whats the plan then?
[10:04] <_defy> heh thats pretty much exactly what i made, but a whole lot better :P
[10:05] <jcoxon> hey _defy
[10:05] <edwardmoore> well i was thinking something akin to what onyx do, which is to deploy a big sod-off main chute at very low altitude
[10:05] <edwardmoore> to drop the thing in gently
[10:05] <_defy> heya
[10:06] <jcoxon> okay
[10:06] <_defy> his seems to fly about as well as mine did too, heh..never got the whole steering thing down :P
[10:06] <jcoxon> _defy, yours was powered wasn't it
[10:06] <jcoxon> edwardmoore, so it will go:
[10:06] <jcoxon> drone -> parafoil -> big parachute
[10:07] <edwardmoore> yeah
[10:07] <edwardmoore> is drone going to be pre-deployed?
[10:07] <jcoxon> i was reading about the X-38 - they don't use the parafoil till quite low
[10:07] <jcoxon> edwardmoore, i think so
[10:07] <jcoxon> it'll help stabalise the payload after apogee chaos
[10:07] <edwardmoore> well......
[10:07] <jcoxon> and is easy to do
[10:08] <edwardmoore> i've been drawing some shapes on some pieces of paper, y'see
[10:08] <edwardmoore> and i think/know an inherently stable payload design is very doable
[10:09] <jcoxon> http://www.engr.uconn.edu/~accorsi/chutes/chutes.html
[10:09] <jcoxon> use of sliding reefers
[10:10] <jcoxon> + parafoil dynamics
[10:12] <edwardmoore> the sliding reefers are very nice
[10:13] <edwardmoore> also
[10:13] <edwardmoore> most of the systems seem to use the drogue to pull out a pack containing the main chute
[10:13] <edwardmoore> which then extends the chute lines out before the main chute unfurls
[10:14] <edwardmoore> a good example is the x-38 vid when we see a chute deploying the parafoil. go through it frame by frame http://www.dfrc.nasa.gov/gallery/Movie/X-38/Medium/EM-0038-01.mpg
[10:14] <jcoxon> yeah
[10:16] <jcoxon> right i've got to go to hockey
[10:16] <edwardmoore> ok, catch you later
[10:16] <jcoxon> but
[10:16] <jcoxon> wait there is no reason for hte but
[10:16] <jcoxon> will talk later
[10:16] jcoxon (n=jcoxon@jac208.caths.cam.ac.uk) left irc: "Leaving"
[10:16] <edwardmoore> lol, om :)
[13:15] flowolf (n=flowolf@host135-224-dynamic.1-87-r.retail.telecomitalia.it) left irc: "Leaving"
[13:18] flowolf (n=flowolf@host135-224-dynamic.1-87-r.retail.telecomitalia.it) joined #highaltitude.
[13:39] jcoxon (n=jcoxon@jac208.caths.cam.ac.uk) joined #highaltitude.
[13:44] <edwardmoore> hi jcoxon
[13:44] <jcoxon> hey edwardmoore
[13:45] <edwardmoore> good hockey?
[13:45] <jcoxon> sadly lost but i was good
[13:45] <jcoxon> it*
[13:46] <jcoxon> that originally sounded very arrogent
[13:46] <edwardmoore> :)
[13:46] <jcoxon> what you up to?
[13:46] <jcoxon> still dreaming about the X-38?
[13:46] <edwardmoore> restoring order to my room
[13:46] <edwardmoore> and yes, still am
[13:47] <edwardmoore> and thinking about giving some directionality during the drogue stage
[13:48] <jcoxon> a lifting body like the X-38 with a rudder?
[13:48] <edwardmoore> well the lifting body is designed for re-entry and supersonic stuff
[13:49] <edwardmoore> but the solution i have in mind doesn't look a million miles away from it
[13:49] <jcoxon> so for our part of the deal - next week we need to construct a r/c payload and adapt the parafoil
[13:49] <edwardmoore> a shape which naturally produces lift
[13:49] <edwardmoore> yep
[13:50] <jcoxon> do we want lift?
[13:50] <edwardmoore> trim seems crucial with these things (again) :)
[13:50] <edwardmoore> i think lift would give us the ability to go other than straight down
[13:50] <jcoxon> right okay
[13:50] <edwardmoore> i'm not talking horizontal flying or anything
[13:50] <jcoxon> so fall gracefully :-D
[13:51] <edwardmoore> but imagine if a wing falls vertically, the lift will produce a force at right angles to the vertical fall
[13:51] <edwardmoore> so you can move slightly whilst falling on drogue
[13:51] <jcoxon> okay
[13:51] <edwardmoore> i like the idea of a huge control surface on the back like the flap on the x-38
[13:52] <jcoxon> as long as it doesn't get to big and therefore become a glider and therefore have the problems that ruled that out originally
[13:52] <edwardmoore> yes i'm with you there
[13:53] <edwardmoore> more of a guiuded bomb :)
[13:53] <jcoxon> indeed
[13:53] <jcoxon> for our prototype (which we need a name for) will we use a single servo
[13:54] <jcoxon> ?
[13:54] <edwardmoore> i don't think we can
[13:54] <edwardmoore> because you kinda need independant control of the left and right sides which you tug down
[13:55] <jcoxon> how does the winch system work then?
[13:55] <edwardmoore> the design seems to be that we have a fixed harness for the parafoil, and then tug either the left of right trailing edges
[13:56] <edwardmoore> or both to brake
[13:56] <edwardmoore> if you look at the x-38 landing, it tugs hard down on the both the left and right trailing edges to loose speed
[13:56] <jcoxon> right
[13:56] <jcoxon> so 2 servos on seperate channels
[13:57] <jcoxon> the transmitter will be a little weird as one will be in the wrong direction :-)
[13:57] <edwardmoore> we can twist it round 90 degrees
[13:57] <edwardmoore> assuming it's not moulded in
[13:58] <edwardmoore> infact actually we can use a mixer
[13:58] <edwardmoore> have played that game many times with transmitters :)
[13:59] <jcoxon> okay
[13:59] <jcoxon> so basically we are going to make a payload with 2 servos, the receiver and power
[14:00] <edwardmoore> yep
[14:00] <jcoxon> could bolt the the servos end to end
[14:00] <edwardmoore> and scale weight?
[14:00] <jcoxon> yeah
[14:00] <edwardmoore> i was thinking they could be mounted it blue foam.
[14:01] <edwardmoore> kind of a t-piece again
[14:01] <edwardmoore> but vertical
[14:01] <edwardmoore> with a weight on the bottom
[14:01] <jcoxon> to give more leverage?
[14:01] <jcoxon> so pulling left will swing the weight at the bottom more?
[14:02] <edwardmoore> i think it'll give it a little more authority on the control yeah
[14:04] <jcoxon> okay
[14:04] <jcoxon> sounds pretty easy
[14:04] <edwardmoore> laurence
[14:04] <edwardmoore> has just sent an email
[14:11] <jcoxon> just pm'd you
[14:28] <jcoxon> skype?
[14:28] <edwardmoore> ok
[14:30] Ebola (n=Ebola@host86-143-156-147.range86-143.btcentralplus.com) joined #highaltitude.
[14:56] Golfgeo (n=ice@x142235.fttd-s.tudelft.nl) joined #highaltitude.
[14:56] <Golfgeo> Hi all
[14:57] <edwardmoore> hi golfgeo
[14:57] <Golfgeo> How's it going in here?
[14:58] <edwardmoore> air's a little thin
[14:58] <edwardmoore> :P
[14:58] <edwardmoore> it's good
[14:58] <edwardmoore> been talking about a guided recovery system
[14:59] <Golfgeo> Ah, that is a big maybe. Using a parashut for this sounds iffy to me....
[14:59] <edwardmoore> it's the trickiest bit, i think
[15:00] <edwardmoore> but our technical tests so far (throwing stuff off the top of the engineering department) have been heartening
[15:01] <Golfgeo> hmm, I would opted for laticework winglets to stear during decent, but if people can stear, then...
[15:02] <edwardmoore> they can be steered suprisingly well. there's a good video which i found quite convincing
[15:02] <edwardmoore> http://www.atairaerospace.com/press/onyx_video.html
[15:03] <Golfgeo> Quick time :-( But I beleave that it can be done. I just wouldn't want to depend on it...
[15:04] <edwardmoore> the steerability seems fine once it's stable. The biggest obstacle, so far as I can tell at the moment, is deploying it reliably
[15:05] <Golfgeo> Mordern Daisy cutter bombs use latice work winglets to stream onto targets and whould be possible with a teardrop design and then a late parachute deploi
[15:06] <Golfgeo> If the shute ?foulces? then your done...
[15:06] <Golfgeo> What type of shute designe are you using?
[15:06] <edwardmoore> the problem with that I think, though i haven't tested it, is that we've got to get the thing to travel potentially 60 miles over the ground
[15:07] <edwardmoore> we're using a parafoil
[15:07] <edwardmoore> which seems to have the best rigidity and wind attacking capability
[15:07] <Golfgeo> yea, should be
[15:08] <Golfgeo> Still...
[15:08] <Golfgeo> brb
[15:08] <edwardmoore> ok
[15:08] Nick change: Golfgeo -> Golfgeo|away
[15:10] Nick change: Golfgeo|away -> Golfgeo
[15:11] <Golfgeo> Edward, did you account for the low presure of near-space?
[15:11] <edwardmoore> yes
[15:12] flowolf (n=flowolf@host135-224-dynamic.1-87-r.retail.telecomitalia.it) left irc: "Leaving"
[15:12] <Golfgeo> Will the bed inflate?
[15:12] <edwardmoore> on the next balloon flight i'd quite like to send up a Pitot Tube so we can get some measurements about the dynamic pressure of the descent
[15:12] flowolf (n=flowolf@host135-224-dynamic.1-87-r.retail.telecomitalia.it) joined #highaltitude.
[15:13] <edwardmoore> but you can do a lot with the basic aerodynamic equation, and velocity is proportional to the square root of density
[15:14] <Golfgeo> Oke, just got a introduction book on fluid dynamics. But not much time atm.
[15:14] <Golfgeo> But this problem isn't on my wishlist :-)
[15:14] <edwardmoore> it's one of those fun subjects that i really don't have a hope of ever understanding :)
[15:14] <Golfgeo> :-)
[15:15] <edwardmoore> we're lectured by a nutty german fluid dynamicist, and he's very helpful.
[15:15] <edwardmoore> i might ask him a few questions
[15:15] <edwardmoore> also there's a fellow in my college who did work on shuttle re-entry aerodynamics and the x-plane programs
[15:15] <Golfgeo> I followed a webcast cource of Berkeley "Fysics For Future Presidents" And it helped understand those types of things...
[15:16] <Golfgeo> Thats a pro of higher education, I'm just following Computer Science...
[15:17] <edwardmoore> i think a few basic analytical skills without knowing any equations makes a world of difference with fluid dynamics
[15:17] <Golfgeo> I don't know, well, not yet :-)
[15:17] <edwardmoore> just being able to point your fingure at where you think areas of high and low pressure will be, or where you might get flow seperation and so on
[15:17] <Golfgeo> I have know Idear... lol
[15:18] <edwardmoore> lol, well you could learn with a bit of time applied to that book :)
[15:18] <edwardmoore> i need to go into town to do some things- cya soon!
[15:18] <Golfgeo> Yep, thats why I got it :-)
[15:18] <Golfgeo> cya :-)
[15:19] edwardmoore (n=edwardmo@pomegranate.chu.cam.ac.uk) left irc:
[16:16] icez (n=icez@ip68-3-56-121.ph.ph.cox.net) joined #highaltitude.
[16:18] Golfgeo (n=ice@x142235.fttd-s.tudelft.nl) left irc: "gtg"
[16:36] mc- (n=mfcastle@cpc2-glfd1-0-0-cust995.glfd.cable.ntl.com) joined #highaltitude.
[17:16] flowolf (n=flowolf@host135-224-dynamic.1-87-r.retail.telecomitalia.it) left irc: "Leaving"
[18:18] edwardmoore (n=edwardmo@pomegranate.chu.cam.ac.uk) joined #highaltitude.
[18:18] <edwardmoore> hi all
[18:19] <icez> hi
[18:19] <edwardmoore> all well?
[18:19] <icez> bah my server is playing tricks on me :(
[18:19] <edwardmoore> they do things like that
[18:20] <icez> what's funny is that the all-new dell server messes up all the time, and the old 50s compaq never, ever, has trouble;)
[18:30] edwardmoore (n=edwardmo@pomegranate.chu.cam.ac.uk) left irc:
[18:35] edwardmoore (n=edwardmo@chu-gw.churchillcambridge.co.uk) joined #highaltitude.
[18:49] flowolf (n=flowolf@host135-224-dynamic.1-87-r.retail.telecomitalia.it) joined #highaltitude.
[19:10] <edwardmoore> hi jcoxon
[19:11] <jcoxon> hey edwardmoore
[19:11] <jcoxon> i'm off to formal in 1 minute so can't stay
[19:11] <edwardmoore> got the email
[19:11] <edwardmoore> ok np
[19:11] <jcoxon> email me
[19:11] <edwardmoore> it stalls like hell!
[19:11] <edwardmoore> but a trim change would fix that. quite impressive yes
[19:12] <edwardmoore> will email
[20:18] edwardmoore (n=edwardmo@chu-gw.churchillcambridge.co.uk) left irc:
[20:19] flowolf (n=flowolf@host135-224-dynamic.1-87-r.retail.telecomitalia.it) left irc: "Leaving"
[20:22] edwardmoore (n=edwardmo@pomegranate.chu.cam.ac.uk) joined #highaltitude.
[20:29] mc- (n=mfcastle@cpc2-glfd1-0-0-cust995.glfd.cable.ntl.com) left irc:
[20:44] Ebola (n=Ebola@host86-143-156-147.range86-143.btcentralplus.com) left irc: Read error: 145 (Connection timed out)
[21:02] flowolf (n=flowolf@host135-224-dynamic.1-87-r.retail.telecomitalia.it) joined #highaltitude.
[22:51] flowolf (n=flowolf@host135-224-dynamic.1-87-r.retail.telecomitalia.it) left irc: "Leaving"
[23:03] rocketboy (n=steve@host86-132-47-82.range86-132.btcentralplus.com) joined #highaltitude.
[23:11] <jcoxon> hey rocketboy
[23:11] <jcoxon> just writing an email to you
[23:11] <jcoxon> though its going to be quite long so might take a bit of time :-D
[23:29] <edwardmoore> hi jcoxon
[23:29] <edwardmoore> sunday is perhaps problematic- i think i might be going home
[23:29] <edwardmoore> however i was planning to come back up monday to make a second trip to get some stuff
[23:30] <rocketboy> hiya - well actually I cvant stay I'm off to bed shortly
[23:30] <edwardmoore> me too in theory
[23:31] <edwardmoore> i'm sort of in a mind to agree with jcoxon with regards to the side-effects of limited testing time with the tether. it'd be my main concern
[23:34] <jcoxon> right well email with comments then and we'll work something out
[23:34] <jcoxon> i've got to go to bed as well so night all
[23:34] jcoxon (n=jcoxon@jac208.caths.cam.ac.uk) left irc: "Leaving"
[23:36] <rocketboy> CU guys
[23:36] rocketboy (n=steve@host86-132-47-82.range86-132.btcentralplus.com) left irc: "Leaving"
[23:36] edwardmoore (n=edwardmo@pomegranate.chu.cam.ac.uk) left irc:
[00:00] --- Mon Mar 12 2007