http://www.unmannedspaceflight.com/index.p...20&start=20

We began talkin about a UMSF balloon - and who know what might happen if enough people think about something hard enough, thoroughly enough and long enough.

How's about this as a starting point.
http://vpizza.org/~jmeehan/balloon/ with http://www.chem.hawaii.edu/uham/part101.html as an important regulatory start point (I'm going to look up the UK regs for this as well)

http://www.srcf.ucam.org/~cuspaceflight/nova1launch.html is also very impressive - all done in the UK

This http://www.makezine.com/blog/archive/2007/...video_podc.html is particularly impressive - I like the multiple-cameras slant.

Anyway - thought I'd get a thread going - this is an idea I like too much to let it gather dust in a corner - the one thing that I think would be nice to achieve is self-portraiture of some sort - think Beagle 2's WAM etc....perhaps in a corner of the FOV of one of/the imaging system. What sort of limit's should we set ourselves? 1kg 10x10x20cm? (sort of 2U Cubesat-on-a-diet budget)

Doug

I'm definitely on board for this but I'm in the middle of some chaos as I'm moving so my input may be patchy over the next couple of weeks. Putting up shelving, rewiring lights, fitting out kitchens etc is sort of top of my list at the moment.

I think it's a very good idea to put a stake in the ground for mass budget - 1kg sounds about right but obviously it would need to be confirmed against the carrying capacity of the balloon(s). I'm not 100% sure that there is a real need to set strict constraints on physical dimensions but I think going with the 2U cubesat framework is a good starting point and thermal insulation will almost certainly mean the payload will be a very compact box.

I'd love to see a shot of a UMSF logo against a deep black background with the curve of the upper atmosphere just below it - that's definitely got my vote for #1 mission success criterion.

A mirror might be useful for this.


Paolo Amoroso

That's what WAM means - Wide Angle Mirror - you can see it above one of the two cameras here -
http://www.beagle2.com/download/number9-mid.jpg

and folded to one side here
http://www.beagle2.com/download/number7-mid.jpg


Doug

Thanks. MTA: Mind The Acronym.


Paolo Amoroso

A starter for 10:

Powershot A570IS (IS would be a good thing on a rough ride to near-space)
89.5 x 64.3 x 42.8mm - 175g's.

It takes two AA's. NiMH's are typically 230g's a pair - and produce a total of 1.2v x 2500mAh - 3 whrs. - the same as the optional NB-3AH cells. In terms of Whrs/kg - LiPoly gives double the performance of a good pair of NiMH's - perhaps enough to accomodate TWO similar cameras. I would like to see something near 4 hours at 4 shots per minute - 1000 photographs. That would require somewhere around 9 whrs of power.





Doug

That sounds like a good definition. Just remember, though, that in NASA-ese, you always capitalize Mission Success Criteria -- so that, if you don't meet those critera, everyone will know that You Have Failed...

-the other Doug

Things to bear in mind.

Not all digital cameras have a time lapse \ "intervalometer" mode. Whatever models are considered have to have that capability either built in or available cheaply (in terms of mass and money) as an add on.

A reasonably wide angle lens would be nice - most Compact Digicams have a wide end that's equivalent to ~ 35mm focal length on a classic 35mmm SLR providing approximately 55x37deg FOV but some have a more useful 28mm wide end giving a ~65x46deg FOV that covers about 50% more solid angle.

Storage capacity depends very much on how new the camera is - storage above 2GB may not be possible on older SD only devices for example. 1000 7Megapixel jpg shots stored in fine mode would be just about 2GB I reckon so that would be OK (just).

I think that a 2 camera approach is a very good idea. I'm torn between having them pointed in such a way that stitched panoramas are possible versus having them pointed so that we optimize the probability of getting a wider range of individual shots.
As far as power is concerned something like the Tekkeon MyPower MP3300 would give us 40whrs for 320grammes which is probably way more than we need for just the cameras but we still have to build in some sort of tracker\GPS unit and a transmitter which will both need juice too. Taht 40whrs is probably optimistic, no doubt there are losses in the voltage conversion circuitry and we'll probably have temperature related power issues so the margin with that might not actually be all that high.

Anybody got any information on a tracker\transmitter so we can find the thing once it comes crashing back to mother earth?

Well, here's something for that; not cheap, though (US$700). It calls a cell phone with position, and can be set for time-based or event based (jars, impact) reporting. 2.5 m accuracy isn't bad, but may be overstated for straight civilian GPS; would love to find a DGPS for more precision. Battery-powered, so no additional load on the vehicle bus.

I'll look around some more.

This is an absolutely excellent idea.

I'll volunteer whatever feeble skills I've got. And I'll definitely kick in bucks when we start passing the hat.

[I've set my Davis Vantage Pro station (with WeatherLink datalogger) aside with a post-it note saying "Save for UMSF high-altitude balloon flight."]

-Mike


"Up, up, and awaaaayayyy...."

I tracked down the Sable-3 equipment. I'd say some of that would be a fine starting point due to it's proven abilities

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

Here are some balloons
http://www.scientificsales.com/SearchResults.asp

I saw 'kit' and thought 'great- I've done loads of soldering..' but if it's $10 to get it built and tested...screw it

Doug

The MicroTrak looks like an ideal solution and as Dan says it has the significant advantage of being proven for the purpose and the whole thing is cheap (~$100) and weighs less than a couple of ounces. Receivers for a tracking team (or teams) seem to be dirt cheap - this site has the RF part for less than 20 euros and it looks as if linking this into a PC\laptop is also cheap and straightforward if we wanted to do that.

If we were happy to use a cellular phone type device for tracking then I can build a solution using any Windows Mobile\Pocket PC Phone Edition device with an internal GPS ( I have one of these that's got a broken power connection that I'm happy to donate to the cause if I can fix it ) that is certainly good for <5m accuracy which is more than good enough. It will probably need additional power to keep its GPS and cellular radios running for the sort of time we're talking about. I don't think it would be able to give anything like live telemetry at any serious altitude (a couple of thousand m) but it's no problem to get it to log to an SD card and send what it can over GPRS when its available so it might not be a bad approach. Total mass without the battery is about 190g. It's even got a very lousy cell phone camera that we could use to get some additional pictures as a backup.

The smartphone is a genius idea - it would make an excellent secondary system that's virtually stand alone. GPRS'ing lat/long - ESPECIALLY once it's landed again would be GENIUS because a VHF transmitter from ground level is unlikely to get very far. We can call it the Independant Backup System. IBS

Just because I like getting my hands dirty - I'm going to look at foam insulation at lunch time and make a gondola. Not to fly - just to make something cool.

Doug

Here's a more-or-less self-explanatory table of altitudes with some notes. The only odd column here is the one called deg - this is the dip from the local horizontal at the listed altitude to the Earth's horizon. Higher the dip, the better the curve!

There's a few potential Mission Success Criteria here that would be good to see: personally, I think that the old tropopause feels almost too achievable with off-the-shelf weather balloons. I'd be, well, tempted to aim just a little higher...not too much, but still...


km deg tempC Pa kg/m3 notes
53 7.4 +27.3 60 0.7
52 7.3 +24.3 67 0.8 51.82km - highest unmanned balloon flight
51 7.2 +21.3 76 0.9
50 7.2 +18.3 85 1.0 800km to horizon
49 7.1 +15.3 96 1.2
48 7.0 +12.3 108 1.3
47 6.9 +09.3 121 1.5
46 6.9 +06.3 137 1.7 Shuttle SRB burnout
45 6.8 +03.3 155 2.0 SpaceShipOne engine cutoff
44 6.7 +00.3 175 2.2 750km horizon
43 6.6 -02.6 198 2.6
42 6.6 -05.6 225 2.9
41 6.5 -08.6 256 3.4
40 6.4 -11.6 291 3.9 40.00 km - QinetiQ (failed) manned record attempt
39 6.3 -14.6 332 4.5
38 6.2 -17.6 379 5.2
37 6.2 -20.6 434 6.0
36 6.1 -23.6 497 6.9
35 6.0 -26.6 570 8.1 34.67km - Highest manned balloon flight
34 5.9 -29.6 654 9.4 1% reduction in gravity
33 5.8 -32.5 753 10.9
32 5.7 -35.5 869 12.7 Mars surface pressure
31 5.6 -38.5 1003 14.9 Above 99% of the atmosphere
30 5.6 -41.5 1161 17.5
29 5.5 -44.5 1346 20.5
28 5.4 -47.5 1564 24.2
27 5.3 -50.5 1821 28.5
26 5.2 -53.5 2124 33.7
25 5.1 -56.5 2523 40.6
24 5.0 -56.5 2952 47.5
23 4.9 -56.5 3453 55.6 FAI definition for the lower edge of near space
22 4.8 -56.5 4040 65.0
21 4.7 -56.5 4727 76.1 Above 95% of the atmosphere
20 4.5 -56.5 5531 89.0 500km to horizon
19 4.4 -56.5 6471 104.1
18 4.3 -56.5 7571 121.8
17 4.2 -56.5 8857 142.5
16 4.1 -56.5 10363 166.7 Above 90% of the atmosphere
15 3.9 -56.5 12125 195.1 SpaceShipOne release altitude
14 3.8 -56.5 14185 228.2
13 3.7 -56.5 16597 267.0
12 3.5 -56.5 19418 312.4
11 3.4 -56.4 22707 365.2 Approximate height of Tropopause
10 3.2 -49.9 26516 414.0 Commercial Airliners
09 3.0 -43.4 30827 467.7
08 2.9 -36.9 35688 526.6
07 2.7 -30.4 41152 591.0
06 2.5 -23.9 47274 661.2
05 2.3 -17.4 54114 737.7 250km to horizon
04 2.0 -10.9 61734 820.7
03 1.8 -04.4 70201 910.7
02 1.4 +02.1 79584 1008.1
01 1.0 +08.6 89958 1113.3 ~900m - Montgolfier Brothers, 1783
00 0.0 +15.0 101401 1226.6

Great info AndyG.

Looking at some of the other folk who have done stuff like this, 30 - 35km seems to be reasonable.

Surely we've got to be aiming for the 32km 'Mars surface pressure' mark.

J

At that level it's a little bit about luck - but I'd say the 30km, 100kft, 10% air pressure, mars air pressure type level is a sensible ultimate goal. Maybe not first time around - but eventually.

Doug

Hey Doug...what do you think of this first approach to a possible name anf badge for the project?...

On following opportunities we could follow this policy and use our beloved ones names...I'm sure each launch would have a distinct personality...

Click to view attachment

Hopefully even with just one camera some nice panoramas will be possible.

Some quick tests:

Nova - images taken 15 seconds apart - altitude change 300ft - altitude 100,000ft
Click to view attachment

Even at low altitudes and with large time intervals this can still be done.
SABLE-3 - images taken 1 minute apart - altitude change 800ft - altitude (above ground) 10,000ft
Click to view attachment

If we had two cameras I'd vote for one pointing horizontally and one pointed down at 45 degrees and turned 90 degrees 'portrait', which should give maximum coverage.

It may take a while to sort through the images but with a couple of cameras like this firing quite frequently some pretty spectacular stuff should be possible.

James

Nice logo, ustrax!

Just a general engineering note based on AndyG's terrific table: need to determine an optimum rate of climb (ideally, maximized) in order to minimize thermal effects on the electronics, unless the payload will be environmentally controlled. Major trade-off in all areas is, of course, that more payload weight equals less achievable altitude...

Payload wouldn't be thermally 'controlled' per.se - but something like a foam (there's 3cm thick foil covered foam available at my DIY store) cube which would thermally insulate it from the cold - and then the electronics inside would hopefully keep it fairly warm simply by using up the Whr's.

I knew someone would start thinking of logo's and names before we got too far

Doug

One more stitching test using the SABLE-3 images. These images are fully 6 minutes and 6,400ft apart and still stitch nicely. With two cameras taking pictures 15 seconds apart and we could have 50 images within this time frame, nice.

Click to view attachment

James

EDIT: just came across this page of records for this sort of thing - http://showcase.netins.net/web/wallio/ARHABrecords.htm

You know how this guys are Doug...

Seing those images I can't avoid to think about something I already made reference here, I would L-O-V-E to see some video footage with sound...what are the major constraints for something of that nature?...

Storage, Volume, Mass, Power, Money If you can find a small digital camera that can take movies of approx 2 hours onto SD card etc, and last that long on the battery, that's small enough (10 x 10 x 3 cm sort of size) and light enough (<300g) - then maybe. While movies are cool - I think I'd rather have mega-pixel stills than a lower res movie ( although both would be cool.)


Real time video transmission is possible but typically not further than 5km with the transmisison power allowed by the radio spectrum laws.

Yeah, that'd help. Main concern here is electrical connectors. Probably a good idea to seal them with ScotchGard or RTV, which in addition to adding another insulation layer to minimize thermal contraction/expansion would also prevent moisture intrusion/condensation.

Hi - this link has a nice high altitude photo from the Edge Of Space Sciences balloon group:

http://www.eoss.org/ansrecap/ar_030/recap13.htm

One possibility might be to put all the batteries in a custom battery harness which is itself inside a small thermos. That should keep them from getting too cold during the trip up. The downside will be making sure that all the connections are nice and tight.

Yet another possibility would be to put a small "box" of solar panels around any package. At least one of the panels would be pointed towards the sun and delivering power. But then you gotta deal with transformers, etc.

-Mike

[...]

Actually - the altitude will be limited by the envelope which seem to always burst at 80-110kft

Doug

Good point, Doug. However, ascent velocity is still contrained by payload weight, so it's still a significant consideration. For recovery purposes, seems like you want to get up & down as rapidly as possible in order to limit your touchdown CEP.

Have y'all thought about where you'd want to fly this thing? Most of the U.S. has severe restrictions on flying any non-commercial, non-military vehicle above about 2,000 feet, and there are a lot of places where the restriction is lower than that, or where you can't fly anything. Most of this is due to airlanes, landing patterns, etc., but some has to do with laws against unlicensed surveillance.

I can't imagine Europe is a lot more open about this kind of thing -- if anything, Europe has more crowded skies than does the U.S.

And to add another inconvenient point -- even if you could launch from, say, the U.K., won't the camera pod come down several hundred miles from the launch point? There are a lot of things several hundred miles away from Britain that aren't very welcoming places for recovery of a pod -- the North Sea and the Alps are a couple that come to mind.

Just asking the obvious question I haven't seen raised yet...

-the other Doug

Here's an idea for a future mission: re-enact the Huygens probe.

You'd need three cameras (or two if one had a big enough FOV), arranged so as to cover the angles covered by Huygens' cameras. Once you'd recovered the payload, you'd release a subset of the pictures, downgraded to Huygens quantity and quality. The challenge then is to stitch them together as people did with Huygens, making mosaics of the landscape and identifying the landing spot in it if possible.

It'd be an interesting game - and it'd help one imagine what the Huygens imagery really means.

Actually - the FAA ( and I'm looking up the UK version, the CAA ) are fairly liberal with these things up to a certain mass. Many of these balloons have ( and indeed one is going up today ) been launched from the UK - in a typical 2hr up 30 min down flight - you'll cover something like 30-100 miles. Launching from the western UK ( Wales ) would put you back down in central UK.

I think the flight reg analogy is that if you're not going to launch something heavier than a duck, then what's the problem as no law's going to ground all the ducks and swans at 12000 ft \

I got bored - I went out to Maplin ( local electronics store ) and thought that I might need some soldering practice, as whatever we make I'm sure some soldering - even if just for power leads - will be required. They've got LOADS of cheap little kits - so I found the only one that seemed to make any sense for a payload...a small super bright white LED strobe kit. I figure I can rewire the LED's to be external to the WEB on cables running out the box, and perhaps on strut I thought we could mount a WAM for self portraits and in the case that we're still looking for the payload at night...it might help find it. Three little transistors, two capacitors, half a dozen resistors, a variable resistor and a brace of switches - cute little setup really (and suprisingly bright)

Sorry - crap pics - using my cell phone's camera.

And I've found a supplier for a suitably sized parachute for a 2kg payload ( 36 inch diam ) - it's on its way.



Doug

Just a bit of fun using Google Sketchup. Never used it until about an hour ago, it's amazing!

The GMC is somethign I already have. It's a £20 digital camera that takes 1280 x 1024 images at pre-determined intervals. It runs from a single AAA. The Convex Mirror would be the sort you can get to stick on your car side mirror to see blind spots. Having the GMC as a stand alone component is a good move for redundency. I want to see if I can make the GMCSA from what was 'cat cam' - some foam, a mirror ,and then put it in the freezer to see how long it can last.

I got some foam insulation yesterday - and it's too thick really - 50mm thick which is a bit crazy. The thermal properties are amazing, just leaning up againt it you feel hot after 5 seconds because it's not letting heat get away, it's bizarre.

Anyway - if anyone wants the GSU file - let me know

I'm still aiming for something like 10 x 10 x 15-20 internal space - and then if the foam is a few cm thick, you can always carve into it a little.

Weather permitting, I'll be going to Cambridge next Sunday to see a launch by James - http://www.pegasushabproject.org.uk/ -

Never heard of it before. Thanks for the idea. Any idea what all "pro" does.

I think it just lets you interface with other formats more easily (import and export 3DS etc ), and do pretty plans. As it is - GSU (£free) is making me hate 3ds max (£thousands) for lacking the annotation tool.

I really hope you guys pull this off. Unfortunately I've got nothing technical to contribute, just a greedy suggestion:

Fly two of the things in tandem, set to separate at some altitude. You could get beautiful stereo cloud imagery. I can imagine something like this being done on Titan one day to study the morphology of storms there. Earth's atmosphere seems the perfect place to try it out.

Cool project! How much would a weather balloon set one back these days?

I think for the stereo idea you'd want the two cameras on the same platform (a bit like the SIM mission) since the balloons will drift apart quite quickly and randomly I would think,.

By the way, did this link get mentioned?

http://www.ukhas.org.uk/

Seems like this might be useful in this case.

Yet the baseline you can feasibly pull off in such a way would be useless for producing stereo of clouds tens of kilometers below. I think stereo is a no-go here.

The twin balloon idea is pretty good. Launching two simultaneously from slightly different locations will give some really cool information:

If they stay together, you could pull off a stereo image. (Launcing them a few kilometers apart should give a stereo good baseline at altitude.)

If they drift apart, your tracking data gives great information on weather patterns.

With two balloons, you'll also get an idea of the consistency of ascent rate under nearly identitical conditions. And all the telemetry data will be doubled, so you get double information on performance that you can use to cross-check.

Two attempst also increase the chances of mission success, should one fail (or land on someone's roof).

Plus you'll have the fun of two recovery teams chasing around the countryside....

If they're cheap, send two! (which is pretty much my sentiment regarding all missions)

-Mike

Even if they stay together, there's no guarantee they'd be pointed in the same direction at any given time. You'd probably only get a couple of lucky shots, I'm not sure if it's worth launching 2 balloons just for that.

Plus -two of everything to buy (and in this case, there are not any savings) - double the ground-station equipment to acquire - double the number of people.

Lovely idea - but think of this more of Ranger rather than Mariner ( consecutive, not simultaneous )

Doug

Just as well, given that there was only one successful launch of a Mariner pair (6 & 7)...

Well... considering the fact that Voyagers 1 and 2 were originally to be Mariners (though I have no idea if they would have been Mariners 11 and 12 or not), we *almost* got a second successful pair-launch out of the program!

-the other Doug

Hmmm... maybe not the best choice in concepts, there, karma-wise, Doug...

-the other Doug

I'm wondering... had they been indeed called Mariners, would they have both launched successfully or would Vgr 1's Titan booster for example decide to underperform some more?

Is there an issue with expanded polystyrene at very low pressures? Or is the plastic part of the matrix mechanically strong enough to withstand the expansion of the embedded gas?

Andy, also looking at envelope materials for high altitude balloons - not the rubberised standard Met ones.

Tens of thousands of met balloons have gone to 100k+ without any trouble of that nature - as well as probably dozens of amateur projects. They all use polystyrene or similar materials.
oug

Status update :

Proposal :
<2kg payload - on the order of 20 x 20 x 30 cm external + extras.
VHF APRS GPS for realtime tracking
Multiple internal cameras for mosaicing Horizon-to-Nadir view
External camera on independant power supply using WAM or Fisheye lens for self portraiture
Standalone system for tracking via SMS / GPRS

On order:
36 inch chute ( suitable for up to 2kg )
Microtrack 300, GPS and VHF antenna.
10 x (cheap lot off Ebay) 31x21x24cm external, 26x16x17cm internal polystyrene boxes
Wide angle mirrors ( circular and rectangular )
Literature study so I can pass the Fundamental radio licence course to allow broadcast by the Microtrack.

On offer:
Independance Backup System from Helvick in form of Smartphone with camera and GPS

Investigating:
Balloon
Gas (both kind of important)
Power supply
Groundstation
Gondola cameras - powershots with intervalometer, or other cameras with a shutter-release via a timing circuit. Will multiple cameras carry keep their intervalometers in sync if set off together - or will a timing circuit be needed - and if so, is it worth tying that into the GMC (even though I said I wanted that to be independent)


Future options for later flights:
Data logging of GPS Lat/Long/Alt, Pres, Temp, Accel ( nice science to tie in to Huygens with accel data) other params.