Thursday, May 28, 2009
Idea 1 of 3:
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
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.
Tuesday, May 26, 2009
Friday, May 8, 2009
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.
Thursday, May 7, 2009
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.
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.
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?...
I started off with the purely functional -
Well, how about adding an EAU?
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.
Again, something nice to test!
A useful away perhaps to fly more than 6Ib in one go (about 2.7kg Metric)
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?
Saturday, May 2, 2009
Back up parachute in case canopy bursts
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?
Partial pressure Oxygen
Wind speed and direction
Solar irradiance - might be too expensive to fly a suitable spectrophotometer early, they cost $1000 - so just UVC?
Any other suggestions?
I've exhausted my Blackberry for the night, it's giving me "low battery"! Until tomorrow!
After a bit of googling, here is a likely looking cyclo-olefin with good transmission at UVC germicidal wavelengths (260nm):
Friday, May 1, 2009
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?
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!)
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.
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! :-(
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 1µm). Or panspermia.
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.