Robert McTaggart By analyzing how circuits behave in the upper atmosphere, McTaggart will be able to understand why similar electronics in satellites or spacecraft fail.
Not All Hot Air Electronic circuits, fungus and ethanol feedstock were launched 77,000 feet into the air to see how they were affected by high-altitude temperature and radiation.
3:03 PM rmctaggart08: I am on-line.
First welcome to the IM Interview. Could you tell me where you are writing from?
3:08 PM rmctaggart08: I'm writing from Brookings, South Dakota at South Dakota State University, which is about an hour due north of Sioux Falls.
me: And what is your area of research? rmctaggart08: Primarily my area of research is in particle physics, but applications of radiation would also be included in what I do. me:
Okay. And so we're having this little chat because I read something you
and your team launching a balloon for purposes of research. Could you
elaborate on that?
3:11 PM rmctaggart08:
Yes. We've been working with Aerostar in Sioux Falls on a high altitude
balloon launch. We put in several small experiments to expose different
items to the conditions of the upper atmosphere. me: So when you say "high altitude" how high does it go? Is it like weather balloon? rmctaggart08:
I think it was bigger than a weather balloon. Originally we had thought
about 100,000 feet, but the recent flight on Sept. 18 went up to about
77,000 feet.
3:14 PM me: And you say that your experiments were meant to expose different items to conditions in the upper atmosphere. What "items?" rmctaggart08:
For example, we put in a type of transistor that is used in non-linear
circuits to see if the temperature change would impact the non-linear
behavior. We also put in a type of fungus that is hardy to extreme
conditions. me: So what does a transistor, some fungus and a high altitude balloon have to do with particle physics -- your area of expertise?
3:18 PM rmctaggart08:
Initially we had considered making some of these balloon flights out of
the Stratobowl near Rapid City, which is close to the site of the
proposed Deep Underground Science and Engineering Laboratory. So we had
considered using balloons to test different particle detector
materials. That may still happen later.
3:21 PM me: Hmmm. What is the Deep Underground Science and Engineering Laboratory? rmctaggart08:
The NSF has selected the Homestake Mine in Lead, SD (where all the
"Black Hills Gold" came from) as its preferred site. Several
experiments for dark matter and neutrinos require shielding from cosmic
rays. Preparations are on-going in its development. It would complement
the Large Hadron Collider at CERN.
3:24 PM me:
Ok....so you said that you "had considered using balloons to test
different particle detector materials. That may still happen later." So
what HAS happened with the balloon?
3:27 PM rmctaggart08:
We launched the balloon early Sept. 18. The materials that were
included within the balloon (circuits, fungus, ethanol feedstock,
digital imaging and atmospheric data) are all undergoing analysis at
the present time. I think over the 3 hour flight the change in
temperature will have had the most impact, not radiation.
3:29 PM me:
So you put these items in the balloon, launched it, let it fly for 3
hours, and now are measuring the effects of temp and radiation on these
things. Is that right?
3:31 PM rmctaggart08:
That is correct. We could control when the payload could detach from
the balloon if necessary. The balloon was designed to burst a certain
altitude and then it parachuted down to earth. A good samaritan called
it in after picking it up on the highway. me: Did the balloon have your contact info on it?
3:36 PM rmctaggart08:
Yes. There were actually two payloads: One for flight instrumentation,
and one for the actual experiments. Both had the information attached.
Aerostar tracked the entire flight (GPS, etc.).me:
I'm getting a little off track here, but South Dakota isn't the most
populated state in the nation. Were you counting on someone finding the
balloon? What if no one found it? Did you have a way to track it?
3:39 PM rmctaggart08:
That is what makes South Dakota great for ballooning, so they won't run
into cities. We had a chase vehicle that was in constant communication
with the balloon. The balloon will actually detach if communication is
lost for a couple of minutes. me: I see.
So
I read that this kind of research can help examine how life developed
in the early history of the earth when there wasn’t an atmosphere to
offer protection from ultraviolet and other types of radiation. Is that
true? is that why you were doing these experiments?
3:43 PM rmctaggart08:
There is interest here at South Dakota State and elsewhere in the
viability of certain microbes to withstand extreme conditions (the
so-called extremophiles). As you may know, it is not well understood
how life originated here, or possibly elsewhere for that matter.
Survivability and adaptation of currently known microbial life to
different stresses may help fill in some of the blanks. me:
so can you give me an example of how the effect of an extreme condition
on current organisms, living now, can shed light on how life developed?
3:47 PM rmctaggart08:
I'll go back underground at the Homestake Mine. They have found several
species that thrive in an environment without any photosynthesis
possible. It may be the case that life first developed without an
ultraviolet shield, so that underground conditions in high temperatures
would have to be tolerated. Those organisms may tell us something about
how radiation repair mechanisms developed. me: Do you mean repair mechanisms inside DNA?
3:50 PM rmctaggart08:
Yes. DNA may actually be the endpoint of a "survival of the fittest"
between different mechanisms that life developed over a couple billion
years. We always talk about DNA and RNA, but there may have been
something else too. However, they have not found anything else yet. We
may not have gone deep enough.
3:52 PM me: And what about the electronic devices you sent up? Why did you send them? What questions where you hoping to answer?
3:55 PM rmctaggart08:
Space and near-space applications are becoming ever more so important
in our hi-tech world. How these circuits behave in the upper atmosphere
will be critical in determining when they fail, and when you need
another communication satellite, etc.. Their reaction to low doses of
radiation is different than at high doses (say in an accelerator).
Upper atmosphere communication in general will only grow in importance. I
will say also that balloon flights for testing these devices will be
cheaper than launching them in a rocket or in the space shuttle.
3:57 PM me: I was wondering about that. And what about the ethanol you sent up? Why did you send that up?
For when we drive in space? rmctaggart08:
Ha! George Jetson asked me about that. I have a pet project to
irradiate ethanol feedstocks, specifically those that are not derived
from corn, to see how it breaks up the lignocellulose. The balloon
flight will allow me to compare those results with what a wide range of
temperatures will do in breaking structures down.
4:01 PM me:
So you mention that launching these items in a balloon is way cheaper
than launching them up into space via a rocket. Does that encourage you
to consider testing other things at high altitudes? Do you have a wish
list?
4:04 PM rmctaggart08:
As they say around here, "You betcha!" I would like to collect
particulate and aerosol samples in the upper atmosphere, which might be
interesting after a volcanic event, but also may say something about
transport mechanisms of dust and other microbes. I'd also like to
engage other partners in the testing of photovoltaics and other
communications devices. me: Sounds important. What about unimportant, random tests? Like did you ever want to sent up a Twinkie?
4:07 PM rmctaggart08:
Why not? I think as things develop we will want to include ideas from
students interested in making science fair projects. So for instance,
seeing how seeds grow with or without high altitude exposure, or just
something out of the box. I don't think we'd want to put a coke can up
there however... me: Ha! Well, now that you've said it....
So when is the next balloon launching?
4:10 PM rmctaggart08:
That's a good question. The date of the launch was selected so that the
winds in the upper atmosphere would not be too large. There are a
couple of times during the year when balloon launches are best done
(called "turn-around" when the winds shift and the wind speed
decreases), so it may be in the spring sometime. Otherwise, we won't be
able to keep up with it ( > 100 mph sometimes) to track it. me: Whoa. Talk about a chase team! Okay, just a couple more questions.
4:12 PM I'm
wondering what sorts of things you're guessing you might find after
sending these things into the high altitude. Let's take electronics for
example. How do you think they may be affected?
4:14 PM rmctaggart08:
Those are solid state devices, whose properties depend on boundary
conditions at different interfaces, as well as any defects. I would
think that any expansion and contraction that occurred will change the
behavior of the circuit (it's electrical resistance for example).
me: is "change behavior" a nice way of staying "totally ruin?"
4:17 PM rmctaggart08:
Maybe a certain sequence of temperature changes will modify the
properties in a beneficial manner, but I'm not counting on it. Launch
vehicles can go up and down several times, so perhaps there are ways to
ameliorate this kind of failure that need to be tested. me: I see. Well, I've taken up a lot of your time. So I guess I should let you go. Thanks a bunch for answering the questions.
4:19 PM rmctaggart08: Thank you for inviting me to do this interview. It was my pleasure.
me:
Could you do me a favor and send me a couple of jpegs of the balloon
and also of yourself? Horizontally cropped images are very much
preferred. rmctaggart08: Yes, I have a couple of those that I can send you. I'll send you the horizontal version.
me: great. all the best!
4:21 PM rmctaggart08: OK: Let me know if you have any other questions over e-mail.
me: okay.
rmctaggart08: Signing off. |
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