Thursday, May 28, 2009

Some interesting things to do with H.A.B after reading the most recent Nature

Here are some ideas I had after reading that issue of Nature:

Idea 1 of 3:
Planetary Protection
Nature 459 21 may 2009 308-309

Possibly an angle for the cyclo-olefin encapsulation/UVC sterilisation idea (CO/UVC) I pitched earlier for balloon canopies.
The article describes the concerns of Plan Protect people (Catharine Conley is interviewed) as to how existing spacecraft (eg Mars landers) are inadequately sterilised.
NASA is thinking of adopting hydrogen peroxide sterilisation because, for instance, autoclaving is too difficult for entire spaceprobes.
I think my CO/UVC is more practical since it allows by steady sterilisation over a period of time, so it is much less harsh than any chemical treatment.
Spacecraft could be sterilised in cruise flight by fixed UVC sources covering every nook and cranny.
A CO shroud, illuminated from within, also could be useful since it allows encapsulation of extra clean components (eg arms, scoops etc)

Could we use HAB as a near-space demonstrator of this?
Is there money to be had from people like Caroline?

Idea 2 of 3:
Public funded small scale science
Nature 459 21 may 09 p305
www.sciflies.org
Allows you to fund small projects from public donations - you pitch your project on the website.
Might be useful for some small scale funding (I.e a particular HAB flight perhaps)

Idea 3 of 3:
Nature 459 21 may 09 316-319
Mike Russell origin of life article
Not so much an idea - interested to know what you think of Mike's ideas. I heard a lecture by him some years back and was transfixed.

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Tuesday, May 26, 2009

Ballooning spiders

I was catching up on my viewing of the BBC's latest offering - South Pacific - last night and they talked of colonization of remote islands. One of the ways was by being caught up in typhoons, small animals and seeds, but they also mentioned the use of ballooning by small spiders. A little wander through the internet has demonstrated that this is true and that the spiders need to endure very low temperatures to do it, also that they need to be less than 1mg in weight and use enormously long silks as their lifting devices. But could they get into the stratosphere? I don't know - reports suggest 7000m and aircraft height, though the latter can be highly variable. If they did, would they survive and could they carry microbes with them?

Friday, May 8, 2009

Moving the LEDs around inside the canopy: reefing in the canopy to deflate the balloon

I had previously suggested moving the LEDs around inside the canopy on something like an automatic extending car aerial. Now we'd be talking about moving the radar reflector with LEDs.

How would we do something like this?
You could for instance have a pulley and rope made of cyclo-olefin and turned by an electric motor. But then it occurred to me that the canopy will expand during flight so it will be hard to keep the pulley tight - or not too tight. The pulley would presumably have to be attached to the roof of the canopy.

Maybe we are still looking at the extendable car aerial idea then. Heavier but simpler. A similar system could be used to deploy a sampler (perhaps surrounded by a VRS stream?) Perhaps.

(One quick thought... If the LEDs are attached to an aluminised radar reflector, then presumably this could be a common earth for the LEDs?)

Where we COULD attach something to the canopy would be for deflating it, assuming we try to reuse it and don't just burst it. Remember, this could be a custom C-O canopy.
By opening a valve and then taughtening a line attached to the inside of the canopy, which can slowly reef in the canopy like a concertina and squeeze out the Helium, triggering a controlled descent.

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Thursday, May 7, 2009

Making the radar reflector

I would envisage making this by 3D printing too and then again aluminising it or coating with mylar.

I have previously suggested mounting this inside the canopy. Perhaps this could have UVC LEDs in each of its interstices - e.g 8 LEDs - and then the entire reflector is moved around inside the canopy to achieve sterilisation.

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Your humble smartphone for balloon communications? With a parabolic dish?

If Ham radios are out, could we use a mobile phone instead?
Or are all forms of unmanned balloon radios banned? Must check!

With a smartphone that has GPS, such as a Blackberry, we could broadcast the balloon's position straight onto Googlemaps (e.g. http://www.google.co.uk/latitude ) which surely would be a publicity coup and moreover useful for Air Traffic purposes.

The only problem is, 'phones are short range transmitters - only needing to communicate with the nearest cell base station a few miles away. We will reach altitudes as high as 20 miles.

Maybe a quick way around this would be to have a parabolic dish on the balloon gondola, pointing straight down. It doesn't need to be steered.

I have already checked with Paul and we can design and 3D print parabolas OK. We could spray it with aluminised paint or line it with mylar. We could even print it as a mesh to save weight, allowing for the wavelength of the 'phone signals.

This gives our 'phone a tighter focussed beam facing straight down from altitude. This would presumably cover one or more base stations at a higher signal strength (instead of the signal going off in all directions as it would usually)
Would this be enough??
Again, something to test!

The 'phone could be mounted directly at the prime focus of the dish. Perhaps it could even be hung there by ropes. That way it will be more likely to withstand the landing, especially if we cocoon it somehow.


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Balloon safety - tethered? Where to fly!

Some more on practical considerations for flying balloons.

In the U.S at least, they need to weigh less than 6Ib, have a parachute built in, use rope of a certain strength, have a redundant means of bursting the balloon on command (say by radio and a timer), carry a radar reflector, not be flown at night, and have their position reported to Air Traffic Control by 'phone regularly (usually by the balloon radioing back its GPS coordinates to you).

If you don't know where the balloon is or can no longer control it, then it is declared "derelict", which is a very bad reputation to get!

This is all pretty stringent enough but in the U.K it would be worse.

It is fine for a 6 Ib gondola to plummet out of the sky over the Kansas prairie or whatever but I think your chances of this landing on a house or a road or suchlike in the U.K, with its much higher population density, are depressingly higher.
Also, I remember reading somewhere that you're not allowed Ham radios etc on the balloon in the U.K.

Still, it has been done - any of you remember the "Space Teddies" flown by the Cambridge Uni student space club?
(We should try and get in touch with them). I think they flew from a military range - but that must have taken some sorting!

So - we fly over water (and prepare to get wet recovering it - anybody got a boat or likes sailing?) or fly in the U.S with our friends at NASA, which was always the plan.
But it would be so nice to test some of this in the U.K...

Could we test it on a tether?
The weight of tether would quickly drag it down, but perhaps we could offset this with balloonets (multiple balloons supporting a structure, in this case the tether). How far up could we go?...


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The COCTEAU Twins? 6 Ib limit, Bluetooth

There comes an important moment in every project... when you have to give it a witty acronym.

I started off with the purely functional -
Cyclo-
Olefin
Canopy
Test,
COCT.

Well, how about adding an EAU?

Cyclo-
Olefin
Canopy
Test
Experiment for
Absorbance in
Ultraviolet

Sorted! Although I was always a more Teardrop Explodes man myself.

But then I thought... Cocteau Twins... Why not actually fly TWO balloons for the gag?

And then I realised that this was actually extremely useful from a practical point of view!

In the U.S at least, the weight limit for weather balloons is 6 Ib. Heavier than this and you need all sorts of special permission.

But... Why not launch multiple balloons at the same time??
One could do our biology experiment...
One could provide the radio communications... And so on!
"All" you'd need is some form of cross-balloon coms - Bluetooth or Wifi perhaps.
This would be imperilled if the balloons drifted too far apart, but if they weighed the same and were launched side by side simultaneously, they should stick fairly close together.
...Shouldn't they?
Again, something nice to test!

A useful away perhaps to fly more than 6Ib in one go (about 2.7kg Metric)
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Wankel engines

Robin's Facebook post reminded me to finish this post... Have been busy with other things recently, apols!

I have mentioned these contraptions a few times so some more explanation is due. A Wankel engine is an internal combustion engine which basically has a triangle-shaped rotating piston inside a cavity instead of the up-and-down cylinder pistons you might be used to. A Wankel engine has less moving parts and inherently rotational motion, so no need for a crankshaft, vs its upright cylinder cousins. Mazda is keen on them for instance but they haven't caught on that much elsewhere.
Why my interest? I think there is no way we will have enough power for everything using batteries or solar cells, although perhaps I will be pleasantly surprised.
So, I was wondering: There is still some air at the altitude we have in mind; about 0.01bar to be precise. So can we still use an internal combustion engine, Wankel or otherwise? These have a much higher power density per unit weight than a battery.
I happened to have a Wankel in mind since there is a Wankel popular model aircraft engine, putting out a horsepower or so - I.e about 750W.
Let's imagine we rig something like this to work with ambient air. Now it can only burn about 1% as much fuel as usual (since there's only 1% as much oxygen), so let's say about 7.5W. Still pretty good though.
Any holes in this reasoning?

Obviously you'd need fuel injection, not a carburettor, since you'd need to constantly match the available air and fuel (propane, say?) stoichiometrically (sic?).

At some point the mechanical friction in the moving parts would be more than the pressure the exploding gases could generate. Who knows? Would it work?

Can you in fact compress the air to get a higher power density from the engine and still come out on top? (I.e more power out than used in the compression)

Better to take your own oxygen?

Better to use something exotic like a fuel cell?

Comments welcome!!!
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Saturday, May 2, 2009

Things that would go inside the canopy:

UVC LEDs and any necessary supports
Back up parachute in case canopy bursts
Radar reflector
Pressure sensor (in case of leaks)

But all the above sterilised by UVC from outside before flight! (That way, leaks don't jeopardise sterility - only flight time)

Ahhh - here's something interesting, a bit like the Travelling Salesman Problem:
You have one LED in the middle of a big spherical balloon
You have one LED travelling up and down a cylinder balloon
At what given combination of radius and power does one sterilise quicker than the other?

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Things to measure at altitude

Air pressure
Partial pressure Oxygen
Temperature
Wind speed and direction
Solar irradiance - might be too expensive to fly a suitable spectrophotometer early, they cost $1000 - so just UVC?
GPS coordinates
Camera

Any other suggestions?

I've exhausted my Blackberry for the night, it's giving me "low battery"! Until tomorrow!
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Fly at night for sterility

UVC exposure at night is a wise move for sterilisation since it denies microorganisms the diurnal respite that they'd normally receive from solar UV damage. That's if we can fly at night however...
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Buckminster-Fuller?

You could have a spherical balloon instead of a cylindrical one, but only if you had some framework inside it, like a Buckminster-Fuller geodetic sphere, to hold the UVC LEDs. This would likely be too bulky and fragile for the weight limit. So we're back to the cylinder?

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Test one UVC LED on its own if need be

If we don't have enough money/power/weight to fly all the UVC LEDs we need, maybe just fly one illuminating a test spot on the canopy, and if that comes back significantly cleaner in microbial terms than the rest.
Ol


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I'll never hear another bad word against Gmail

Just one more:
Look what my Googlemail gave me as a directed advert!:
Not bad eh?
I'll give them a ring too (but not optimistic about price!)

The mystical beast, cyclo-olefin, finally sited! Well, Googled.


After a bit of googling, here is a likely looking cyclo-olefin with good transmission at UVC germicidal wavelengths (260nm):
And the graph above is for a 3mm thickness! How much thinner can we go I wonder for our balloon?
It's actually pretty hard to find out what weather balloons are actually made of. Anybody know? You just buy one - for $45! This is an amazing and fun hobby I think, as long as you are not near a major air traffic corridor.

I am aware I seem to becoming obsessed with UVC illuminated balloons. But maybe this is no bad thing! This is where the biology has led us. There is no point, IMHO, building a high altitude bioprospector unless you are stone cold certain it is itself sterile.

Come the new week I think I will ring Zeonex's European office and see how game they are!
Questions I will ask:
How much does this stuff cost?
What is the sheet size?
How does one stick it together? (A thermal crimp etc?)
Can they make the entire structure for us - at a cost?

If it is cheap to make then we can burst our balloon at altitude like most normal balloon flights. If it is expensive then we find some way of reusing the balloon, for instance by letting the helium out gradually through a valve. Presumably the valve would sit in an invagination in the cyclo-olefin to allow it to be UVC-illuminated.

Bed now I think! :-)
 

Beware the dead zone! Also how to make a sterile wind vane

Let us assume we can create a really sterile canopy, most likely through UVC. What we are really saying is that we have sterilised the balloon canopy  as well as a volume of air around outside it, which has likewise been exposed to the UVC. So, streaming off downwind of the balloon is a plume of sterile air. We must make sure we DON'T sample this by accident!
We need to sample upwind, or make sure the UVC LEDs are turned off for a good period before sampling so that the plume dissipates. And how long would that be? Again, we really need some way to simulate plumes, eddies etc.  We need to monitor air currents and direction at altitude, perhaps using a tell-tale. But how to sterilise it? Oh dear... perhaps something cool like a segmented area of canopy and you mention the pressure in each segment, so you can see which segment is being distorted by the wind blowing against it?

Another thing we could do is to fire a probe out of the gondola, for instance on a small rocket, trailing a sample line well clear of the gondola and any possible plume. Since this would have been stored inside the gondola it could have been pretty easily sterilised on the ground. Does a model rocket engine withstand autoclaving? Gamma irradiation? Ethylene dioxide? An interesting experiment to find out :-)
As a simple experiment, we could imagine drawing the sample line (made of what? Coated with what?) back into the gondola and then over the different culture mediums that my colleague was discussing, so inoculating them.

UVC LEDs modulated for coms?

Here's an idea: We could modulate the UVC LEDs with rapid pulses and see if this could be detected from the ground (UVC is blocked by the atmosphere but there must presumably be residual radiation at other wavelengths from the LEDs). This could be used as a high rate, non-radio data downlink.

The inverse square law and long thin sausage balloons with internal skeletons

Our balloon could end up quite an interesting shape. If we are going to sterilise it with UVC LEDs then we want to make it as long and thin as possible. Why? Well, the intensity of UVC light at the balloon's surface from an LED in the centre of the balloon falls off with the square of the radius of the balloon - so if we can half the diameter of the balloon we boost our intensity fourfold. A normal balloon is essentially spherical at altitude, presumably to minimise the surface area, and hence the weight, of the canopy. But sterility is our overwhelming priority. Can we make a long thin balloon that can still lift its own weight to high altitude? Either way it will start looking rather like a Zeppelin - or a Skylon. The Skylon would be a better analogy, pointing straight up as our balloon will.
How do we work out the buoyancy of our balloon at a given altitude anyway? Any buoyancy experts out there?
One difference from a zeppelin though is that our balloon can have internal structures but no hoops, plates etc on the skin. We need all the parts of the skin to be illuminated, without any dead zones, by the UVC.

Something else to save weight perhaps - don't have lots of LEDs, have a few, and move them around. Imagine a central pole within the canopy which is extendable (maybe an adapted telescoping car aerial? Do they still do those??), or has a pulley mounted on it perhaps. This allows a UVC LED to be moved back and forth along the entire inside length of the balloon, illuminating its entire surface with a germicidal dose of UVC - eventually...

Friday, May 1, 2009

Nice things to make balloons out of

A chemist friend of mine thought of some very interesting things to make balloons out of. I'm still waiting to hear from him for some more details, but here are the highlights:
1) A superhydrophobic material, so that microbes can't stick to it
2) A superhydrophilic material, so that they are stuck fast and broken up
3) A photocatalytic material, which would catalyse anything on it to break down, ultimately into CO2 and water

I think (2) is out because the canopy would pick up too much moisture in the troposphere and would presumably be weighed down, reducing the height reached.

1 and 3 might well work, and 3 seems most elegant since it is an active process of sterilisation. Having said that, the same colleague still thought UVC might be best.

Our ultimate task is to kill spores - if we can kill spores then we can kill anything! Hence a massive UVC dose from LEDs etc might be necessary - if we can carry that many LEDs and enough power...

As always in "balloon material fantasies", it comes down to if we can find a suitable compound, if it is gastight for helium, robust enough for flight (without tearing etc), if someone will make balloons out of it for us, and for how much!
Cyclo-olefins is at least a name we can bandy around for the chosen property of UVC transparency... Any ideas who to order that from and any ideas about the other sorts of compounds?

If we can't fly a full size balloon made of our dream compound, then perhaps we can fall back on a small scale model, and then fly other hardware on a "dirty" normal balloon for a high altitude proof of concept?
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RTPCR as well as cultures?

We could also look for 16S RNAs by RT-PCR, which would tell us if something biological was present even if we couldn't culture it.
I saw an intriguingly small qPCR unit today in "Biotechniques", but still expensive ($10,000). I'll look into it further. With something like this we could at least detect a 16S signature in flight - and then sequence the amplicon back on the ground? (Sequencing in flight I think if for the deluxe version!)
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Culture mediums and flight durations

I would suggest we go for all the different culture mediums described! The only question then is: Are trying to culture in flight? If so, then we should be aiming for a flight of many days or weeks. We could assume that metabolic turnover will be very low at such low temperatures and Oxygen concentrations. Balloon flights are typically less than a day - longer than a day and you need radio and light beacons and so on.
But we don't need to do everything on the NESTA grant in one go - it could be enough for instance to say we have tested the unit for one day but would ideally fly for many more.
We could also, for instance, fly on a "dirty" balloon if we can't find a way to make a clean one. This would at least show that everything works at altitude.
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People with hypobaric chambers

One place with hypobaric chambers is the RAF. I had explosive decompression training about 13 years ago. Without going into too much detail this was also for a space-related experiment, in this case a zero gravity airplane flight. You had to have full safety training.
Unfortunately the flight never happened but the explosive decompression experience was, in my opinion, the best fun you can have with your clothes on. A tale for another time perhaps!
The RAF did this for me for free at the time since some of the older medical officers were sympathetic to spaceflight. They have since retired. I know this since a colleague in the RAF checked a few years later and was given a curt no for the same request. You have to pay for it now! :-(
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Atmosphere structure




To educate myself a little I have borrowed this image from Rashid's blog, we live down in the tiny troposphere and that the tropopause is a barrier to things getting above into the stratosphere. Ideas out there for getting things up there include volcanoes, blue lightning strikes, concurrent thunderstorms and forest fires, and lastly gravito-photopheresis (through this it would take 50years for a piece of soot to get to 20-80km up but it has to be less than 1┬Ám). Or panspermia.

Thoughts on bacteria

I have been trying to find out a bit about what kinds of bacteria have already been found in the atmosphere, so that we can take some educated guesses in trying to culture them in situ. All of the articles I have read thus far have captured some air and tried to culture things from it - and this started back in 1878 by Mr Dowdeswell! But more contemporary accounts ranging from 2m off the ground to 41km up find remarkabley similar types of species. The vast majority are Gram positive from two main groups of G+ve bacteria - Firmiculates and Actinobacteria. There are also reports for the species Pseudomonas from the Proteobacteria but these are G-ve, though very hardy, and are very good at nucleation in clouds. The G+ve are a mix of rods and cocci in shape. And as far as I can tell they're all spore formers - which is a good way of getting through a tough spot. As for the two fungi that have been reported - Engyodontium and Penicillium - they also form spores. Lots more information can be gleaned from the Microbewiki.

So what could we grow them on - they're likely to be anaerobic, and hopefully cold adapted if we're going to grow them, if we start looking at interesting agars may be we'd need something with a low redox potential (like Schaedler's) or something with inorganic nitrogen ( eg Czapek-Dox or Simmon's) or may be try and mimic other extreme environments (Marine) or just go for bog standard stuff (nutrient) in an anaerobic environment. All suggestions welcome, and I'll go and seek advice from some of the micro people here in Brum. I'm going to do some ground level (sea level and ~1000m ie up Snowdon) experiments and comparisons.