Google's Lunar X-PRIZE has wet your appetite for robotic space exploration but you haven't got enough Delta-V or are cash-strapped? Enter stratospheric balloons.

A group of Canadian amateurs has flown the SABLE-3 balloon (via Backreaction) up to a height of about 35 km and got some pretty cool images of the Earth. Worth a look -- and a thought.


Paolo Amoroso

...Whoa!!! That is major cool!!!

Good thing they did it in Alberta, though; the FAA would throw 'em in jail in SoCal!

Actually there are quite a few groups that do this in the USA - google 'Near Space'
I think if the payload is less than 1 or 2 kg the FAA regulations are pretty unconstraining
(i.e. if the balloon is less massive than your average big bird, the exercise is not
meaningfully adding to aviation hazards) I guess in SoCal and the DC area (or perhaps
in general near major airports) maybe there are more restrictions.

But there is a community out there taking data with simple sensors as well as
camera images. If we ever get a Titan balloon going, these guys will get excited - a
lot of interesting issues to confront such as how could an on-board computer select
the best out of the thousands of images to send back - you can see on these guys'
images that some are more interesting than others..

Ralph

I like it : simple, low pound and lovely results.

I like it, I LOVE it and I want to do it myself...
It reminded me the glorious days of Cynthia I, how could I have abandoned that project?!

Seriously, how can a guy manage to recover the camera? Yes, I can track it but imagine that I launch a balloon like that where I live and it is dragged to the seaside?...

EDITED: This...this is crazy...

Anyone have an idea of what size the balloon expanded to before it burst?

Wow. I want to do that too.

So do I - but JP Aerospace wont return my emails

Doug

Surprising. Hell, this would be a much less expensive alternative to a Virgin Galactic flight. A sharp entrepeneur could probably charge US $50K per flight, and make a terrific profit...

On the other hand, I can just see a Bob Newhart phone routine coming out of this:

"...and, um... let me get this straight. You're going to hook me up to a balloon? OK. And, and, and... the balloon will take me up above the atmosphere? All right. And, what happens then? The... you say, the balloon breaks? And then... then I fall all the way back to the ground?! Oh, a parachute, OK, I see..."



-the other Doug

The tracking device comes in a kit and is inexpensive:
http://www.byonics.com/microtrak/mt300.php

Balloons:
http://www.scientificsales.com/SearchResults.asp

The chute looks simple and is probably home made.

Looks like you can put the whole thing together for a couple hundred dollars - not including a camera. Now Doug you and I both have the same camera, let's use yours since it has probably been tested for a longer period than mine has.

How about one of the cheap 300D's you can find on Ebay and a DIY timer circuit using the cable release socket. Probably <$500 all up.

Otherwise we'll HAVE to use yours - it has fewer cycle's used on it's lifespan

Doug

35.8 km is pretty good. I don't think any rockets ever got to that altitude until the 1940s -- I don't know what the history of balloon altitude records looks like, but I believe it was a record when the Explorer 2 reached 22 km (that may have been only a manned record, though).

A DSLR is possibly overkill but it might be justified if you could get a cheap wide angle lens to go with it - even so I reckon you would be trashing the best part of a grands worth of kit for the privilege.

These guys just used a compact digicam that had a time lapse mode (intervalometer). You can pick up the fairly decent Canon S3-IS for around Euro320 new these days so that's got pretty much all you need. You can piggy back in DC power supply too so you can ensure that you have enough juice to take lots of pictures. The S3 is limited to 2GB SD cards AFAIK so you should get about 800 shots before you run out of space or about 6 and a half hours shooting if you take 1 shot every 30 seconds. You should be able to get all of that together for less than Euro 400 (using new kit, a lot less via e-bay and its ilk).

If you bump up to the S5-IS you get SD-HC support so you could plug in an 8GB memory card and you would get ~2500 8Megapixel images before running out of space. At 1 image every 30 seconds that would be almost 24 hours of shooting, or better yet 4 hours with a shot every 5 seconds and you'd still get it all together for less than Euro 500.

It also occurred to me (knowing squat about balloons) that if you were to include some kind of pressure release valve on the balloon you'd get more time aloft rather than the burst and plummet scenario that was used here. Using Helvick's 24hr hour camera set up you could really acquire a nice animated ride to be assembled later.

Of course the ballon could go a LONG way in 24 hours and could make recovery quite a lot more difficult. I quite like the quick up and down mission profile.

James

Hmm...How many "Bobs" do you think we get if we sent Newhart up, anyhow?...
(Interpretation for our non-US friends: The Bob Newhart Show was a popular sitcom in the 70s, and a drinking game emerged where, while watching the program, everybody had to take a swig when any of the characters said "Bob". You'd usually have quite a buzz by the end of the show...)

I agree with James; balloon station-keeping is problematic at best...unless it was tethered. However, 20 km of cable seems like a pretty significant aviation hazard.

EGD, venting gas to descend sounds reasonable. The only thing that bugs me is that high-alt balloons usually launch fairly empty-looking, isnce the gas expands so much when it reaches its target altitude...think that the venting process would have to be MOST carefully controlled to assure a safe landing (talking a control loop that would regulate the venting with respect to ambient pressure & temp, here), and even then you have the drift problem to deal with.

Actually I meant it more as a delay in the balloon bursting than a descent tool . Maybe a minimal amount of venting that allows you to hang around a bit longer prior to the burst.

Oh, okay; I'm with you now! Yeah, that would be a lot easier to do; basically, you'd just pick a target altitude & hold it by venting until you're out of gas. Could conceivably get several hours of hang-time that way.

The thing is that you want to keep this all very, very simple from a mechanical point of view. Adding control capabilities to the balloon is probably asking for too much automation. If you are going to do that then you probably could add computer control to the image acquisition at no mass cost though by resusing the altitude control hardware. In any case such a capability will require either expensive custom hardware (which could be relatively light) or some cables and a cheap second hand laptop PC or something similar (which would be relatively heavy). Now I've no what the cost of the basic balloon, helium and tracker are going to be but adding that sort of capability to it is going to significantly ramp up the financial cost and payload mass.

I think we'd be better served by making the payload as light as possible (say < 2kg total for the camera, tracker and extra power), and push for altitude at speed rather than hang time - after all it's not as if we're going to waiting for something in particular, we just want something to get up high. The Sable team's site commented that they didn't get very many "good" pictures so the real challenge here would be how to build an imaging component out of cheap digicams that significantly improved on that.

One possible pitfall is that COTS digicams aren't going to work well at 10's of km altitude and the corresponding <<0degC temperatures and low pressure environment. I suspect that some attempt will need to be made to keep the camera warm and it probably wouldn't be a bad idea to try and enclose it in a 1 bar zero humidity atmosphere while you're at it. Ah yes we have scope creep.

...and - interestingly - it's from an altitude where the pressure is virtually identical to that of the Martian surface ...Not that this is a cheap way to test equipment for Mars!

Andy

I'm seing many of us interested in this theme that I will dare to advance with a proposal...
How about a UMSF communal project? An international team working on several continents sharing its diversified skills to take us to near space, that sounds really great to me...
What's your opinion? Doug, guys?...

I just ebay'd my old Canon S2 IS for about £150 - it's intervalometer was fantastic but its batterylife had reduced to nothing - a real shame. I'm sure some stacked Li-Poly's could fix that in a payload situation. The temperature issue is a challenge though - and really you would want two - one horizon looking - on down looking - OR - do you split the FOV two ways with a mirror either shot-by-shot or splitting the instantanous FOV. The smaller Canon's have Intervalometers as well - perhaps the payload could stretch to two?

Let's keep it casual - but think it through as much as is possible - as well as possible.

I like the way you put it...

I have one of this that the dog chewed a bit...It might get sacrificed for the good of mankind...And it already made part of the Cynthia-I launch...
It also as good performance regarding an aspect that I would like to see debated, how about filming?
With the card I have I'm able to get 15minutes of good quality video.

Another crazy approach...can't we think about something that would mark the difference? Some kind of testimony?
We could fill the balloon with testimonies of the participants and when it bursts would deliver our thoughts, messages, ugly faces in the near space...

Hmm- was your dog in Milan last year? Helen had one of those - and it got stolen while on holiday in Milan It was a great camera.

I think the way to choose payload elements is to think of items that are as self contained as possible - so any small camera that has the ability to take images every X seconds built in would be suitable. The lightest (size doesn't really matter - a polystyrene housing isn't going to be very 'massive' - it's mass that's the issue I would have thought) camera with a nice wide field of view, and a self-timer facility is the thing to use.

Who knows? I'll have to ask the dog...
And it is indeed a great camera.

I agree with you Doug on keeping things simple but I would love to see it filmed...
I started building a polystyrene shell to house the camera, not difficult to do (don't know really why I abandoned the idea...).
I'll search for it, but my guess is that the lady in the house got rid of it and it is now probably orbiting some dumpyard...

Hmmm

Interesting proposition Rui. I enjoy if I can join the project you want to start .
And I have a question : about the balloon, which element you want see to use into it? Helium, warm air? I had listenning about some black plastic balloon who inflate themselves with sun illumination, and air temperatures at the interior rise more and more. At the end, the balloon lift-off and can transport payload (mass in relationship to size of the balloon...).

So, I'm very interest into making/design of this project .

Gotta be helium to reach the kind of altitudes desired. Here's a pretty good project summary of one such effort:

http://moo.pl/~tygrys/balloon/

This is a highly achievable goal in terms of the engineering and cost, compared to, say, a stratospheric amateur rocket.

Playing with Excel, it really boils down to minimising envelope mass. Of course, the envelope mass is not helped by having to be big enough to contain the expanding lifting gas at high altitudes - the volume of the gas increases 70 times at 30km, 130 times at 34km. Obviously the excess envelope required at altitude is just deadweight at pressures nearer the surface.

However, using standard (and cheap) thin poly materials I calculate:

A 13.5 kg envelope (with an inflated size of 13m in diameter) could loft 2kg of payload to an altitude of 30km using less than 3kg of Helium. A more modest 4m-diameter envelope could take 500 grammes of payload to ~22km.

Not bad!

Andy

I found this page about solar balloons : http://perso.orange.fr/ballonsolaire/en-index.htm
I will try it myself

Speaking about solar balloons, these guys are supposed to launch one tomorrow.
http://www.arcaspace.ro/en/home.htm

Click to view attachment

!

...but that descent chute BETTER work!!!!

Don't worry guys. I have heard rumors that we're going to trade that old craft in for a restored classic model. So no loss if we lose it.

Well, do tell! Like every other California resident, I live for previews of concept vehicles...hell, in a way, I am a concept vehicle...

I've got a Davis VantagePro weather base station that I'd be willing throw into any effort. Couple it with a flash memory datalogger (which would probably survive a hard impact) and you could get temp, pressure, rel humidity weather data all the way up and back.

The whole package weighs in at 830 g.

The batteries might work better if they were thermally isolated. I have no idea how the system would work at very low temperatures and pressures. But that would be easy to check in a laboratory.

-Mike

Some more adding and we will be fighting for the Google X prize...

This is a fun idea to contemplate! I know that there are balloons that can target an altitude, and therefore have some control over where they drift. For example, Space Data uses balloons to create low-budge com "satellites" that drift over target areas. I do not know how much more expensive those balloons are, but it is fun to contemplate a long drift time to accomplish something more interesting than just reaching a high altitude.

Since we have interested members in both North Carolina and California, we could consider longer flight paths? We could organize with amateur radio clubs to help track, and if we need to crash land somewhere remote, there's an active community of "geocachers" who'd love to hunt for something so unique and recover it.

I suppose power supplies would be a problem for such a long flight. Are there light weight solar panels that can power the 8-watt APRS transmitter and TBD science payload? Are there cameras with really long (5+ hour) battery life?

Check out this thread:
http://www.unmannedspaceflight.com/index.p...ic=4635&hl=