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In article ,
(William) writes: (Len Over 21) wrote in message ... In article , (William) writes: They need a way to burst the balloon on command (i.e., nichrome wire wrapped around the balloon plug, a receiver, and a battery), metallized RADAR reflectors on the instrument chain, and FAA clearance to launch. The "command burst" receiver better have some secure coding to it or some jughead will burst-command it beforehand. Make that "CBer." There are no jugheads in the amateur service. 8^0 Riiiiighhhht...especially the morsemen who would never Ever do any wrongness! :-) A corner-cube reflector can be done with aluminum foil on a balsa wood frame...just three mutually-perpendicular planes in that corner cube, less than a foot in any dimension and still good for skin tracking. Maybe Kelly could diagram one on the back of an envelope for us? I've made them. They weigh about a half ounce or so for 1-foot sides (good for reflections down to transponder frequencies of 1.1 GHz and up to X band. Little ones for X-band (and some C band) search/weather radar can be a few inches on the side. Balsa wood strips for the edges and ordinary kitchen aluminum foil for the reflector. Corner cubes are extensively used in optics/laser benches. Those are just three planes of reflectors, each perpendicular to the others. No matter the azimuth or elevation of the source, a reflection goes back on the same direction vector. Ideal for a positive radar return in any azimuth or elevation. According to Mike, the FAA is "accommodating." :-) They've lost all sense of jumor since 9/11 The air controllers weren't too happy about the comms outage (including the backup system) at the Los Angeles Center, either! Back in the 60s the weather folks used to loft a quarter million or so weather balloons per year...with little transmitters in them and telemetry done with extremely low-cost electronics. Good example of doing things simply and for low cost per launch. They still do. It is called a rawindsonde and the rawin observations are transmitted over the weather networks and shared worldwide. These ballons often reach 10MB, but the payload is much smaller than most EOS amateur projects. I had one cluttering up the workshop since the 60s. Military type by the markings. One-shot battery, a simple aneroid bellows driving a printed-circuit rotary switch to kick in temp and moisture and light sensors, all of them variable resistive types that changed the rep. rate of a simple pulse modulator for the combination RCA pencil triode and cavity oscillator assembly and inverted ground-plane antenna. That must be why the ground operator had headphones and counted clicks. It's a lot different today. Not quite. The USAF launched this one I had in the mid-1950s. Guess where? :-) They used a tracking radar receiver on the ground and recorded the telemetry frequencies (of the rep rate) for altitude, temp, and humidity. Azimuthal accuracy was as good as the boresight of the tracking antenna (with some corroboration of altitude by tracker's elevation at close ranges). All of that went in the dumpster long ago except the translucent plastic sleeve on the Xmter assembly went two weeks ago (found it in a box of junk after sorting out the workshop). Best place for all that stuff. Perhaps. :-) RCA's tube works had a steady producion of pencil triodes with crimped-on cavities formed by thin sheet metal. They made millions of units over a couple decades. Was a fairly cheap combination tube & cavity. Those same pencil triodes were later used in a small boat radar unit made by Bonzer. Flattened disk kind of radome, had a planar array of helix antennas inside. A few miles range, good for very small boats. The experiments can be just about anything you can think of that can be done at that altitude. Most launches are multi-mission, with both science and Ham fun stuff on board. And of course the Ham fun can be scientific too. Hams have had fun ballooning for quite a while, but the advent of inexpensive GPS has changed things dramatically. We now fully expect to get our payloads back! That wasn't the case not too many years ago. The balloon is usually one of the latex weather balloon variety. Zero pressure balloons can be used too, but since they are designed to go up and stay up for a long time, that would be a more complex proposition. You need to do some math on that before envisioning such a "low- cost" approach to get to 100 Kilofeet. Those 8-foot (typical) "weather balloons" aren't going to get up that high, not even a mass of them. You need to consult some (free for the asking) density values of the atmosphere and some back-of-the-envelope figuring first. Note that you have to allow for the lifting gas expansion with altitude. It is far from the same at 100 kilofeet versus sea level. Lots of expansion. Tsk. Mike hasn't consulted a Standard Atmosphere table set yet. 100 kilofeet he will NEVER make with some surplus latex weather balloons. Get sponsor, buy new. Mike is still NOT going to make 100 kilofeet altitude with "latex weather balloons." [that was his original statement and, by Rules of Engagement in this newsgrope, he MUST follow that EXACTLY or be termed a "failure" or "defunct"] The payload uses Amateur radio for command and control. At the heart of the system is a GPS unit in conjunction with a packet radio. The telemetry data is sent back to earth and kept track of with a computer. The computer lets us know where the payload is, where it is going and how fast, and predicts the landing site. Oh, and it's freeware. That's going to be a minor cost item. As you will find out, the balloon structure, its support infrastructure, and lifting gas will cost more than you think.. It all adds up. Might be good idea to get a sponsor. Tsk. He gots the "recycling" spirit. Maybe he has a new way to "mine" helium out of the air or ground? [collectors around some heliarc welders might work? :-) ] I was a forecaster for a "round-the-world" balloon venture. They lost their helium due to a fabric tear. Couldn't find enough replacement helium in Argentina. Most helium still comes from Texas. :-) In addition, the packet radio can send back other info as the mission may desire. The mission is often controlled by a microprocessor. To date, a lot of balloonatics use basic stamp controllers. Often a repeater is put on board. A small one has a lot of coverage at 100,000 feet! There is usually a VHF beacon, and occasionally a 10 meter beacon also, although that is not as prevalent as it was before GPS. Two words: Payload weight. You can't get up in the blue sky with lack-of-detail blue sky ideas. If it were that easy, lots and lots of folks would have done so a half century ago. And all of those gps, beacons, packets, thermistors, pressure transducers, and video cameras and ATV transmitters operate off of heavy batteries. Luckily the ascent and descent won't be that long, and the batteries can be scaled back from what is normally required with one caveat. You'll want the beacon to be operable for several days, if possible. Mere details. It is "doing science!" It is "inexpensive!" One-shot batteries are one source, but they ARE truly one-shot and can't be recycled afterwards. I'm sure our multi-disciplinarian engineer who's "been there and back" could do it. Absolutell! :-) The experiments vary. One of the favorite devices for the grade and middle school kids is something called a pongsat. This is an experiment that can be anything that will fit inside a ping-pong ball. Sounds weird, but there are plenty of small scale experiments that fit the bill... er, ping-pong ball. The balloon lifts the payload to the predetermined altitude, and bursts. The payload drops, and the Ham comms can continue during descent, although the first few moments after burst can be pretty weird as the payload often does some pretty strange gyrations until the parachute can grab some atmosphere. Drops like the proverbial rock. All this time, the GPS is keeping track of the whereabouts of the payload. Commercial grade GPS recievers are designed to not work above 60,000 feet. Crazy precaution against strapping one to a missile and using it as a guidance system. No sweaty-dah. Seal the GPS unit in more balloon material, it stays in a local pressure regardless of the vehicle altitude. More or less. The ascent and descent shouldn't be more than 4 - 5 hours. Descent much faster. :-) That weather balloon will probably go POP before 50 kilofeet. [someone finally noticed that those balloon things filled at near sea level DO get rather BIG at high altitude...like, no kidding?] Then at landing, it turns into a foxhunt as the hams use the beacon transmissions to find the payload. With the advent of us getting used to the software and the precision with which the GPS can determine the location, it is not too uncommon for the recovery team to witness the landing. Launch of one of these things does not take as much bureaucratic red tape as most people think. You've done that? You are going to the edge of the stratosphere and think you can do so freely? Ain't quite that easy. And it can be done for surprisingly little money. "Surprisingly little" is a highly subjective term. Real projects have quite objective, finite budgets. The people that are needed are of course Hams, and people with some programming experience. People with experience building things, and a meteorologist can't hurt! People that don't mind a drive on a weekend day to serve on the recovery team. Plenty of subteams, such as payload, publicity, science, visualization, integration, education liaison. Even people that might just want to feed all the other reprobates. Sounds like you've already filled the "executive" position. :-) This is real stuff. This might spark the interest in science in some youngster. And that is not only a career choice, but a service to the country. American scientists are becoming pretty rare. "Becoming pretty rare?" Not quite as any visit to academia will show but feel free to get opinionated. Its great publicity for Amateur radio. It will get ham radio noticed, but what is written up by journalists may not be what you expect. Free ballooning has been going in the USA since 9 January 1793, the first American flight by Frenchman Jean-Pierre Blanchard, lifting off from the Walnut Street Prison in colonial Philadelphia. That was witnessed by none other than President Washington. [from "Lighter Than Air Flight" by Lt. Col. C. V. Glines, USAF, Franklin Watts Inc., NYC, 1965, data from pp 29-35] That's over two centuries of time... And we can innovate and experiment. Radio is a pretty mature science now. It's doubtful that any of us are going to invent a grand new communication scheme, or an antenna that does DC to daylight, or even one that is a whole lot better than what we have now. So What we need to do is to integrate what we have now, and do some innovation with it. We also need (or at least should) prove our worth to the community. That we can do it while having fun is a real bonus. You can have all your innovative fun doing many, many things. Until you find out what helium costs to lift the total balloon (the balloon itself, its payload, its carrying structure, its all going to be a pipe dream having no more basis than enthusiasm. Check out the prices for helium with a gas supplier, plus what it takes to haul to HEAVY gas cylinders to a launch area, plus the metering system plus the filling system plus whatever else. All that after you've investigated what the actual lifting capacity will be in terms of ounces per cubic feet of balloon. [I said ounces, not pounds...lighter than air does not mean negative weight] You could get "efficiency" by going for hydrogen gas...which is offset by very direct DANGER from many and varied sources. Yikes! If they use the nichrome wire on the balloon plug trick... Hydrogen is a very efficient lifting gas. It CAN be generated by amateurs...chemistry amateurs. Getting into the balloon is going to be tricky. Friend of mine had a hydrogen generator for launching balloons on Antarctica. I guess it was cheaper/less weight than hauling in helium. Surplus catalogs used to sell the little generators but haven't seen them in years. It's high school chemistry time. Electrolysis...separate oxy and hydrogen from water via electrickery. Takes a while for any sort of H volume but that can be automated. Water cheap, electricity relatively cheap. [some hams extremely cheap...[ Still going for 100,000 foot altitude? Start thinking in terms of the balloon exapanding to something on the order of EIGHT times in size at altitude maximum. That's visible on some of the high altitude research balloon flights of the 1960s using lots and lots of plastic sheet for balloon material. Your project may need a virgin...such as Richard Branson...to help start it off. Now, if you are REALLY thinking about this whole thing, look into "Project STAR" and a little thing like a model airplane that crossed the Atlantic (from Newfoundland to the Irish coast) during the 38 hours in August 9, 10, and 11, 2003. Laugh all you want but a few guys from around DC managed to do that through GPS guidance on board as an autopilot. You can read about it at http://tam.plannet21.com/index.htm Pictures and stuff to guide you even if you are not into model flying. 38 hours (approx) of powered flight using only 5.5 pounds of fuel, flight path of 1882 miles. Radio control only for take off and climb- out, then landing in Ireland...the rest entirely on "autopilot." It had some means of reporting its position to earth via satellites. That alone would be of interest to anything else involving GPS location or guidance. Search around on the huge NASA website for atmospheric info, especially for density versus height. You could do an approximate curve of payload + balloon weight versus cost of helium in hundreds of cubic feet to whatever altitude limit. That will give you some realistic viewing into feasibility of it all. Sounds like fun. Dense air operations in the eastern states may pose a big problem. Not to worry. Air carriers are on the "Victor" ways above the max. balloon altitude. General Av types will be in the denser altitudes and props will chop it up nicely. :-) I wouldn't count on it. Maybe CAPman can fly by with a skyhook and snatch the descending package before it becomes FOD for the General Av types? A large budget bump there...CAP is unlikely to pay for the snatch aircraft fuel, maintenance costs, etc. Anyway, this entire thing is highly doable as it's already been done by amateur radio operators for at least a decade. Well, YES, it has. Thing was that Mike was making out like it was something "new" in going to "near space!" NOT with surplus latex weather balloons he aint. A mylar or other polymer film gasbag, yes, but the ground support for anything sizeable is going to be MUCH larger than realized for that "near space" altitude. Then there are all of the high-power amateur rocket types who regularly get FAA approval, have telemetry, and a good set of binocs. I participated once with another amateur and they were thrilled with our ability to communicate from the launch area to the pick-up area. Today, FRS and cell phones can probably fill that niche. Ooops! Darn it! Brian! You said some naughty words! You will now be lectured interminably by the S. :-) |
Len Over 21 wrote:
Dreaming about something is fine. DOING it is quite another. Getting outraged at not being psychologically sugar-boosted happens all the time in here, realized by most but never by the proposer. :-) Tsk. This reads like the story of your entry into amateur radio, Leonard. Dreaming about getting that ticket is one thing. DOING it is quite another. Mike will likely see "Leonard" at 100k feet before you obtain an amateur radio license. Happy psychological sugar-boosting and message knuckling to you. Dave K8MN |
In article , Dave Heil
writes: If you break 100,000 MSL we'll ship Leonard off to Sean O'Keefe at NASA so that O'Keefe can pin astronaut wings on Leonard. HOWL! Now that's funny! Yes, it was incredibly funny, yet there are those who think that there is a lack of humor in r.r.a.p. I like W3RV's idea. I thought it might be more appropriate to consider naming the vehicle itself "Leonard" but I was advised that there is already a gas bag with that name. Remember, too, that the balloons Mike is considering obtain their lift from helium (a noble gas) rather than hot air. 73 de Jim, N2EY |
In article , Mike Coslo
writes: Leo wrote: On Mon, 15 Nov 2004 21:24:23 -0500, Mike Coslo wrote: Leo wrote: On Mon, 15 Nov 2004 19:50:46 -0500, Mike Coslo wrote: Len Over 21 wrote: It's times like this that can bring people together. You and Brian Kelly have something in common. Realism? Perhaps you could tell me, Leo? I've shown that it can and does happen and that a lot of people are doing exactly what I speak of on a regular basis. Believe or don't believe. It is your choice. Mike, my point was that you have two folks with a fair amount of knowledge and experience taking the time to give you feedback. Who are they, Leo? Who on this newsgroup has even attempted to launch a radio-carrying ballon to 100,000 feet? Or even to half that? They aren't saying that you're nuts to be considering doing what you intend to do, but they are offering you the benefit of their understanding of engineering and physics as it pertains to your project. Perhaps we've been reading different posts... If they are missing something (and me too, perhaps - this sure ain't my area of expertise either!), then by all means show them where they're wrong - but they are both pretty intelligent, educated and knowledgeable guys, with years of real-world experience in their fields - maybe worth at least a rational discussion? Or you could throw a bunch of web references in their faces and get angry.... Your call. Leo, There is a world of difference between someone like Jim, who questions and looks at my answers, and one member that says what I am considering is impossible, and yet another that calls me incompetent. At least two out the three are willing to look at the websites. And there is a lot of difference between me illustrating my points wit web references, and finally getting annoyed after I am called incompetent. Considering that to Len, this is an impossible task, and that Brian Kelly has thinks I'm an idiot that is only suited for cheerleading, I would have to say that they probably don't have anything to offer me in my doomed project with which I am going to hurt someone. My call. The websites offer a lot of evidence that it can be done, has been done and even how to do it. 73 de Jim, N2EY |
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William wrote:
Mike Coslo wrote in message ... I still might. - Mike KB3EIA - Mike, be nice. I think you have a good project, and cannot understand why all these "movers and shakers" of RRAP keep poo-pooing the idea. Maybe they are paper tigers, code-tape Extra's, or just plain old windbags themselves. Anyway, you have several of them in your backyard and I haven't seen a single one throw in with you yet (but then I haven't read all of the blabbering). Speaks volumes. :(( My best advice is to associate the project with a Scouting Troop/Venture Crew, or H.S. honors science class, etc, find a handful of sponsors (easier when you have the scouting affiliation), and find some motivated no-code Techs who aren't afraid of a challenge, or maybe don't know enough to get out of the way. A good idea, Brian. I've made a few presentations on other subjects with the scouts, and it has been a lot of fun. FWIW, the military has standing orders to assist the Scouts wherever they can. That I did not know. They might be helpful in many ways, from lodging to launch location to weather support. You could make a request to the Air Force Weather Agency to have a Support Assistance Request (SAR) in place to run the trajectory model and predict the final resting place of your package (you supply launch time and ascent/descent rates), preposition your recovery team in that vicinity, then adjust as real-world conditions dictate. This is a gold mine of a post, Brian. Thanks much! - Mike KB3EIA - |
Subject: Near Space Science - was They just don't get it!
From: Mike Coslo Date: 11/18/2004 7:42 AM Central Standard Time Message-id: William wrote: Mike Coslo wrote in message ... I still might. - Mike KB3EIA - Mike, be nice. I think you have a good project, and cannot understand why all these "movers and shakers" of RRAP keep poo-pooing the idea. Maybe they are paper tigers, code-tape Extra's, or just plain old windbags themselves. Anyway, you have several of them in your backyard and I haven't seen a single one throw in with you yet (but then I haven't read all of the blabbering). Speaks volumes. What speaks volumes is that you, Brain, in one breath make an accusatory statement, then immediately excuse yourself with ..."(but then I haven't read all of the blabbering)". My best advice is to associate the project with a Scouting Troop/Venture Crew, or H.S. honors science class, etc, find a handful of sponsors (easier when you have the scouting affiliation), and find some motivated no-code Techs who aren't afraid of a challenge, or maybe don't know enough to get out of the way. A good idea, Brian. I've made a few presentations on other subjects with the scouts, and it has been a lot of fun. Started off strong, reasonable suggestions, followed up with sleights and insults. FWIW, the military has standing orders to assist the Scouts wherever they can. That I did not know. As they do for Civil Air Patrol, JROTC, ROTC, and a handful of other civic minded programs. They might be helpful in many ways, from lodging to launch location to weather support. You could make a request to the Air Force Weather Agency to have a Support Assistance Request (SAR) in place to run the trajectory model and predict the final resting place of your package (you supply launch time and ascent/descent rates), preposition your recovery team in that vicinity, then adjust as real-world conditions dictate. This is a gold mine of a post, Brian. Thanks much! It would have been had he been able to start it off without being insulting and demonstrating his arrogance. He cudda been a contender. He had to be condescending, instead. 73 Steve, K4YZ |
Mike Coslo wrote in message ...
N2EY wrote: In article , Mike Coslo writes: Brian Kelly wrote: Mike Coslo wrote in message ... 1500ºC is 2732ºF, over a thousand degrees hotter than the melting point of steel! "That's hot!" . . WTF . . ?! The atmosphere does indeed heat up in the area known as the Thermosphere Does other odd things too. Bouncy, bouncy! Space, or near space is a very strange place... If you don't believe me, here is some info from NASA. They give even higher values as a maximum. "That's hot!" http://liftoff.msfc.nasa.gov/academy...tmosphere.html and http://en.wikipedia.org/wiki/Thermosphere gives a nice explanation of the Thermosphere, and there is a bit of info there as to why Amateurs should be interested in it. A good question is "Why doesn't everything that passes through the thermosphere burn up?" Because they don't. In fact, despite these high temps, things passing through this region would "feel" cold. Would you rather stick your hand into water heated to 200 degrees F or air heated to 400 degrees? Why should Hams know about the Thermosphere? 'Cause it's hot? ;-) If it wasn't hot, we wouldn't have the ionization that allows us to communicate all over the world on HF. You *don't* understand some *very* basic things about the atmosphere, things that you should know as a Ham. This whole thread got me thinking about how balloons work and how much helium costs and such. One thing I found out is that 1000 cu ft of helium can be had for about $200. A bit of $$ for an individual launch but not much if split up amongst a group. And of course you don't need that much per typical launch. I'd seriously consider using hydrogen instead of helium. Hydrogen would be a terrible choice for use in party balloons but in a controlled situation like this outdoors and handled properly hydrogen can be used quite safely. Hydrogen is used in large volumes throuhgout the industrial sector and it's being used in experimental hybrid vehicles. If the pros in the auto biz don't have a show-stopping problem with hydrogen being used as fuel for the interstate kamikazis neither do I. Propane is nasty stuff too but propane-powered vehicles have been out there for 40-50 years. I believe it's much cheaper than helium. With hydrogen you wouldn't have to inflate the balloon as much to get it airborne which in turn means that the balloon would be able to fly higher before it pops. "Higher stretch ratio", etc. Another thing was the lifting power at high altitudes and low pressures, and the concept and behavior of a balloon open at the bottom that's not filled all the way with gas. Fascinating. Those balloons get BIG before bursting. I've seen some video of it. I haven't seen what happens to the form of the zero-pressure balloons, though. Certainly the zero-pressure balloons are a fascinating example of a self regulating system. - Mike KB3EIA - w3rv |
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