Original Subject Line was: Regarding the slanderous accusations leveled at balloon track prognosticators in episode 665
And the note was ...
Ok, not as serious as all that but ...
Molly, Jason and Thomas ...
It's Rick, the "balloon scientist" and amateur radio operator from Colorado. :-) Hey everyone as to be the xyz occupation from somewhere right?
Allow me to drop a "well actually" or two on you folks. And in no way would I expect you to know any of this stuff without doing a fair amount of research so this isn't a rag on you guys just a friendly "well actually".
Balloons. Hmmm, at last something I know something about. This just goes to show, your audience can probably address just about any issue under the sun with some level of expertise, assuming they are sufficiently interested to respond. And, this time out apparently I was motivated to do so.
This email is in response to the very brief mention you made in episode 665 where at the end you discuss Google's possible acquisition of Space Data's balloon borne Cell system technology. Your discussion of this issue is probably dwarfed by my wordy response. But, I'm sure you say things like smurf and get 100 page diatribes all the time. It's the nature of a large audience right? Some of us have no common sense or word governors.
I tend to write voluminous tomes about inconsequential stuff so, here is the short version:
---------------------short---------------------
I know what I'm talking about (more or less).
$50 bucks for a balloon to fly these airborne cell towers ... NO WAY! The balloon has to be around at a minimum $100 and the helium to fly it around the same.
Tom's idea that we should bomb the countryside with high velocity projectiles from the sky, well ... possible but not a good idea and not necessary. The parachute will solve this problem.
Molly's worry about balloons going off on their own and disobeying the laws of atmospheric physics, I don't think so. But again, it is possible under some circumstances that generally won't crop up except infrequently.
Molly's concern about the polluting nature of balloon debris all over the place. Well again, as is true of much in life, yes and no. Yes, in the short term it can be a problem for wildlife. No, in the long term latex balloons degrade to nothing and actually are eaten by the bacteria in soil. So, we're helping the little guys and should be applauded for our supporting the underdogs.
Jason's brief thoughts about tethering balloons, no way! But, Jason pretty much gave up on that idea almost before he finished the sentence he suggested it in. Never the less, I address it below.
Now, on to the ridiculously long version. I'm a lot less snotty and there are some good links that show neat photos, videos, and interesting information so if you have a few minutes ...
---------------------long---------------------
I belong to Edge of Space Sciences, Inc. (EOSS) (www.eoss.org), a group with the sole purpose of flying high altitude helium balloons. We fly them as a hobby for ourselves as amateur radio operators and as a volunteer (non-profit 501 (c3) NPO) service for students at all levels of education. In fact our group's "motto" is:
"Promoting Science and Education through High Altitude Balloons and Amateur Radio"
We incorporated back in the early 90s and have been flying ever since and have a total of 125 flights under our belts. We have recovered 100% of our payloads launched. Perhaps this speaks to Molly's worry about recovery operations of the Space Data flights. We have a reputation for that in our little niche of high altitude balloon flight community. But we also live in absolutely ideal territory for this so it is almost cheating. Eastern Colorado is pretty flat and there are practically no trees to speak of to grab payloads from the sky and hide from our Tracking and Recovery teams.
In recent years we have been pretty focused on college level students. Their courses are usually created in conjunction/cooperation with an entity known as the NASA Space Grant Consortium (SGC). SGC's goal is to encourage scientific and engineering tracks in college curricula. SGC helps out with the funding and we as a group are compensated for the balloons, and helium. All our time is donated to the effort. Many of our members by the way are "rocket scientists" and work at one or another of the aerospace firms that are situated in the Denver area. A lot of us are significantly worried about the state of science education in our country to want to do this in hopes of making some minimal but real impact on the problem.
I'm also the author of Balloon Track for Windows, a program used to predict where a balloon will fly and where its payloads will return to earth under a parachute after the balloon has burst.
This program's original incarnation written by Bill Brown (credited in the about screen of my version) was used to help "Amateur Radio High Altitude Balloon" (ARHAB) groups to recover their fairly expensive payload systems. It was a GWBASIC program and was extremely cumbersome to use, so I asked for permission from the author to use his core code and build a more user friendly interface around it. Initially back in the mid-90s I wrote a QuickBasic shell around it. However, I soon moved on to learn Visual Basic and decided to "port" the program over to that environment. My version of the program can download actual RAOB upper level winds aloft data or NOAA predicted upper level wind data for a date in the future (up to 384 hours into the future). It then uses this data to model the flight of one of our balloons. BTW, no one actually trusts much more than an 84 hour prediction. From there to flight time the predicted winds aloft are usually fairly accurate and only waver a modest amount unless a front is expected to cross over the area during a flight.
All that to drop my "CV" in this area.
Ok, so things mentioned in BOL:
50 bucks for balloon - NO WAY. First, the helium for a modest balloon probably will cost more than that:
http://marketplace.publicradio.org/display/web/2007/11/05/helium/I think we are currently paying around $80 dollars for a cylinder of helium that would launch a small 1200 gram balloon. And as described in the link above that is only going to get more expensive in the near term.
Balloons come is sizes measured by their weight in grams. 1200 gram balloons can lift around 12 pounds of stuff. I use the technical term stuff because payload can become confusing. Stuff would include everything tied under the balloon including even the weight of the support lines. Payload might indicate JUST the box that is the airborne cell "tower". That balloon would run around $110:
https://secure.scientificsales.com/weather/Details.cfm?ProdID=129&category=18The group I "work" with regularly flies 25 to 30 pounds of "stuff" on a flight. We need to use a 3000 gram balloon. Just to drive the point home, this thing weighs in at 6.6 lbs of balloon if you aren't metrically adjusted yet. It's made of essentially the same stuff as a party balloon. But it is WAY, WAY bigger. That balloon will list for $400 and the helium to fill that guy is significantly more expensive than the small 1200 gram balloon.
So, cost = $50 is a no go.
Tom referred to a shockproof payload to survive the fall. I'm not going to "well actually" that as it probably would be possible to design a payload that could survive the fall. In fact, a few payloads built by students and improperly attached to the lift line have departed early and did not benefit from a controlled descent. They managed to survive Ok. They were all tied together and so offered a rather large cross section against of low mass objects which the atmosphere could drag against and thus reduce their descent velocity. But, I will say that for a few bucks you can sew a parachute or for a fairly modest investment ($15 to $130) buy a chute:
http://spherachutes.com/items/parachutes/spherachutes/list.htmOur large payloads require a 10 foot diameter $130 chute. Smaller (lighter) payloads can get away with smaller (diameter) parachutes. I should also throw in here that the NWS/NOAA which launches 184 weather balloons per day uses chutes to retard the descent speed of their payload systems.
http://www.ua.nws.noaa.gov/The point here is... we in the ARHAB community fly a bunch of pretty expensive custom designed and built payloads that probably would cost more than a couple of thousand dollars and many many volunteer hours of labor to build. It's the time we hate the most. We want to fly our systems and get them back intact so they can be reused again and again after minor refurbishment. A parachute will return the full payload train (our systems and the experimental modules we fly for the SGC) with no appreciable damage. The worst that usually happens is a few scratches to external cases as they are dragged over a rough field. I'm sure Space Data wants to recover its "cell towers" intact and they would have parachutes too. Also, without a parachute you're going to have a pretty fast terminal velocity. You could probably do some damage. Our payloads land at around 10 mph under the chute. You could probably get hit on the head with our most dense payload and not be bothered by it at all. I bet the Space Data cell boxes are denser and might cause some problems banging you on the head. But with a hard hat, or a glancing blow, you'd probably be fine. I've ventured outside of my area of expertise with the impact statements. The speed of descent at landing is pretty much were my expertise ends.
Molly mentioned the fact that balloons might be blown off track. Really this isn't an issue unless you launch at the same time a significant weather front moves into, across and through an area. Winds aloft on one side of the front move in one direction, and in a different direction on the other side of the front. If there are no fronts moving through the area then it is quite possible to predict generally were a balloon will go. I have personally predicted over 100 flights and I've come as close as 0.18 miles difference between the preflight predicted landing site and the actual touchdown of a balloon that flew for over 90 miles from the launch site. That is awesomely impressive and ... a tribute to blind luck. But it does show that you can on rare occasions predict with phenomenal accuracy. In reality, I pretty much guarantee my tracking and recovery teams that the balloon will land within 10 miles of the predicted touchdown point if everything goes as expected. That is the average of all our our flights at EOSS. BTW if for some unknown reason you are interested in this stuff, there is bunches of data on our fairly poorly organized web site. I'm the webmaster there so I can say that. Specifically you can go to:
http://www.eoss.org/ansrecap/overview/all_flights/flight_history_1_to_113.htmTo see a cumulative review of our flights through the end of 2006. Which reminds me to update that page with last year's results. But, it will convey in a numerical sense what we experience. If you want to see the prediction vs. actual data you need to download the spreadsheet linked to that page. I didn't want to post that data as a table on the web as it just gets a bit to cumbersome to look at. If your really interested you're going to want the spreadsheet so you can design some of your own calculations. Oh, and if you do download the spreadsheet, much of the data in that sheet is calculated in VBS so you will probably get a script alert when you load it into excel.
The point is, if you launch a balloon you are going to have an excellent chance of knowing generally where it will land ... within a circle with a radius of 10 miles. So, recovery isn't too big an issue. Our flights are straight up and straight down so I can use the winds encountered during ascent to plot a new prediction once the balloon has burst or the payloads have been cut away. This post burst prediction usually is accurate within a mile or two. During the ascent phase of one of our flights we can compare where the balloon was predicted to go, where it is actually going (GPS downlinked via radio), determine if folks should move to get into a more propitious location for recovery and once the burst occurs they are probably quite close to the touchdown location. Running the post burst prediction, I can give them a point where they can get very close. We now often get folks on scene of a touchdown making video recordings of a landing. Look through this recap page link to videos:
http://www.eoss.org/ansrecap/ar_100/recap79.htmThe video of this landing (above) is fun as the area is totally fogged in. My prediction in conjunction with live GPS from the balloon enabled this tracker to actually record the landing in the fog, he was that close at touchdown and had no visual help until the payload train was almost on the ground.
The Space Data balloons will be (are) different in flight profile from what we do. They send a balloon up and have it float at high altitude for a day or two. Their prediction method would be significantly different from what I do, but the important thing here is that the part of the atmosphere which is most volatile is the troposphere where we live and were all the weather is located. They will be flying above that in the stratosphere. Winds up there are much slower to change over time. So, predicting where a balloon will be once it's reached float altitude would be the first step, next you'd expect the balloon to float with the winds up at 80K to 100K feet and those winds would be fairly constant over 24 to 48 hours. Then you'd have to get the tropospheric winds again at cut down time and use them to plot the track the balloon would follow during descent to landing.
An EXCELLENT way to visualize a flight track is to load a Google Earth KML file of a flight. Check out:
http://www.eoss.org/ansrecap/ar_130/recap124_125.htmYou can see a screen capture of Google Earth showing both the preflight prediction and the actual flight. At the bottom of that page are links to the KML files that include the data for both the prediction and the actual flight. Load 'em up and play in GE to see how they look from various angles. Position your viewpoint a hundred miles away and see how much of the flight appears above your horizon. If you don't see the track in the sky, GE is applying atmospherics to obscure it. Go into the preferences of GE and turn off the Sky effects and you will see what looks like a night time sky and the track of the balloon on the horizon. Writing that export routine for Balloon Track was a bit of a chore but well worth it now that I can generate these kinds of views with the click of a mouse.
In fact, looking at the recap pointed to above is an excellent way to get a sense of our group's activities. We flew two balloons on that day, a bunch of experiments for Colorado University students, the audio recordings of the flight as heard through the radio station (amateur radio repeater) that carried all the recovery operations can be listened to, lots of photos lots of data
Molly raged against the pollution. This is a real concern and I definitely won't "well actually" it. But, the balloons generally shred upon explosion. They are made of latex and should degrade into nothing eventually. Here is a link that discusses the degradation of latex balloons.
http://www.ukrivers.net/balloon_fact.htmlIt does point out that even thought the balloons do degrade gracefully into the environment the can pose a hazard to wildlife while decomposition is taking place. Shredded balloons will have an impact for a period of perhaps up to 12 months but after that they have sufficiently degraded to the point that they should pose no problems for wildlife. In another 12 months they are effectively gone.
Here are a few photos showing such an "explosion" and shredding of a high altitude balloon.
http://www.eoss.org/ansrecap/ar_030/recap30c.htmAnd a video is here:
http://www.eoss.org/ansrecap/ar_100/recap86.htmThe burst is around 1:20 into the video ... that's minutes and seconds, don't panic.
I don't think this is currently a serious or significant problem as there are only a few hundred flights per day over the entire US, but if these "cell towers" started going up all over the place, who knows. I'm guessing that the party balloon releases discussed in the link above actually contribute more latex to the environment than all large WX type balloons.
There is a different type of balloon used for large payloads, it is made of plastic and does NOT explode. The plastic is not elastic! So the balloon is filled with helium and the plastic envelope is huge. At launch you see this little bubble of helium at the top of a long "strip" of plastic. As the balloon rises into te atmosphere the helium expands in the constantly falling external pressure until the helium completely fills the balloon. Rising a little higher the pressure inside becomes great enough to force a purposefully weakened seam designed into the balloon to tear open. The helium is vented, the whole shebang descends to earth. Everyone I know who flies this type of balloon envelope recovers the balloon as well as the payloads. There is absolutely NO DOUBT that this type of balloon will pose a problem to wildlife, domesticated animals (primarily cattle who seem to eat anything that is on the ground) and is anathema to the ecology. Thus, we all pick up these balloons post flight and there is no trash left over from this type of flight at all. These balloons are 10 times more expensive and very delicate (think dry cleaning bags but not stretchy). If the envelope is forced to the ground by a gust of wind, dried out lawn grass will often perforate the envelope making the balloon leak helium and not attain the expected max altitude. This makes them less than ideal for anything but flights that require really large lift capabilities. Here is a link to a recap of a flight using such a balloon.
http://www.eoss.org/ansrecap/ar_100/recap90.htmThere is a single photo of the balloon system just before launch and if you scroll down to the video section you can click on a link and download a video of the launch which very nicely shows how really large the balloon envelope is for one of these plastic balloons. This is the type of balloon used for really large 1000+ lbs payloads NASA flies out of the Columbia Balloon Facility in Palestine TX. The balloon we used on EOSS-090 was around 54,000 cu ft. The big balloons nasa files are millions of cubic feet in volume. WOW and double WOW. Watching one of those launch is impressive to the extreme.
Wondering what kind of cell coverage a balloon borne cell system might provide? Look at the printout for this weekend's flight of EOSS-126.
http://www.eoss.org/flight/prediction.htmSpecifically check out the column marked "Dist to LOS" (Loss of Signal). You can see that up at 95,000 feet you can see (work radios) out to 404 miles. Our payload systems can pretty easily reach out that far too. VHF and above (50 MHz and up) radio can generally be heard at great distances with very little power. The primary consideration is line of site. If you can see someone, you can often work them (talk to them via radio) with very little power. I once talked to the astronauts aboard the Space Shuttle using a handheld radio transmitting 5 watts (with a gain yagi antenna). Granted I was very lucky to get through but that wasn't because I was using only 5 watts of power it was because in those days (early 90s) this was a very popular activity among amateur radio operators and I was competing with others who were transmitting hundreds of watts into gain antennas. My luck was that there was a moment when they all stopped transmitting and my puny 5 watt signal made it through. Anyway, if I were designing a balloon borne cell system I'd probably decrease my power from my "cell tower" so that I couldn't reach further away than 200 miles or so. That way I wouldn't be interfering with the balloon that was launched much more recently back to the west of me. Oops, balloons can actually fly in almost any direction so referring to back there to the west is probably an opportunity for someone else to "well actually" me. Generally the troposphere's winds are out of the west almost all the time. However, winds in the stratosphere actually change directions seasonally. In the summer they come from the east thus pushing balloons back to the west, in the winter they come from the west thus elongating a flight to absurd (occasionally) distances to the east.
http://www.eoss.org/onlinepubs/turnaround/turn_around_winds.htmJason mentioned tethered balloons. Well actually :-), that probably won't work. Tie a long very light weight string (thread) onto a helium party balloon. Go out side and reel out 100 feet of thread. Ok, you have a tethered balloon. Question, how high up is that balloon. If the surface winds are absolutely calm then the balloon is directly above your head and 100 feet up there. Add light breeze and the balloon will be blown in the direction the winds are heading. Since it is on a limited length tether it will constantly "fly" lower and lower until the force of lift and the effect of the wind's drag equalize. Tethers work up to around 200 feet. They are actually legally restricted to fly no higher than 500 feet:
http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr&sid=ea968eea871ed9ab2380f6d979eaa7a6&rgn=div5&view=text&node=14:2.0.1.3.15&idno=14were they are actually limited by the FAA. Sorry about the long URL.
Referring to that flight prediction above you can see the LOS for a balloon's VHF and above frequencies for various heights above the local terrain. So you can see to be effective the "Cell Tower" needs to be up at around 40,000 plus feet to effectively cover a large area. Imagine 40,000 feet of line. Many problems. First, weight. the lightest tether would be quite heavy and the balloon would have to lift all of that weight in addition to the balloon borne "cell tower". Second, wind. If you had any wind and you always do aloft, how strong is it and how far down would it "push" the balloon as it forced it further and further away from the tether site? And, third, how about a balloon just sitting there at 40K with all that "string" below it. what would be the chances an aircraft might hit it? The damage would probably be negligible to unnoticeable if you hit the string. But still, the FAA isn't going to want that ad they've fixed that fact in stone in the regulations (linked above). So, this is a no-no and I think Jason himself pretty much dismissed his own idea within a few seconds. I just thought I'd toss some nails toward the coffin of that idea.
I believe it is now time to state the mandatory, "Love Buzz out Loud". I don't mind complying as I do love the show.
BOL listener for several years, Veronica was already piping up when I joined in the ranks of listeners.
Rick
Parker, Colorado
