[AMIKO KAUDERER] So that question comes to us today from Astro_Joe5,
"What was your favorite experiment on the ISS?"
[MIKE FOSSUM] My favorite experiment on the ISS was one that was called SHERE,
and I'm sorry I don't remember what the acronym stood for.
But it was a fluid physics experiment that took place in the glovebox,
the microgravity science glovebox, and I enjoyed that one because it was kind
of a hands-on activity where we got to set the equipment up, it required a careful setup
and calibration, and then we got to actually open, open up,
get in an open up this fluid sample which was a small little dollop inside there,
about the size of a peanut chocolate coated candy.
And then it was like a lathe where it rotated, and there was,
it was a fluid with polymer strands inside, which were microscopic.
You couldn't see those, but that affected the physics of the fluid.
And so they spun half of it.
So you were putting, you're basically putting a twirl on that dollop of material
and then stretching it, and they could actually measure the tension in the in the fluid
that came from the microscopic strands of polymer plastics
that were tangling together and that..
The reason was interesting was first of all and we got
to really observe the science taking place, even though we weren't measuring.
It was automatically measuring the properties of fluid.
It also has direct application for the petrochemical,
plastic industries as part of their process.
This is something that they're trying
to understand exactly how this affects these polymer fluids in the industrial processes
and so there's a direct application, and it was science they wanted for the industrial use.
So it was fun to do something like that.
[KAUDERER] That sounds like a fun experiment.
Thanks for sharing.
So again, we've been talking about some of the science experiments, it all sounds great.
I have another question coming from the public on Twitter, and it's a science question.
We're going to go with this one.
Their question, first of all it's the greeting from Poland.
"Hi! I want to ask about HydroTropi.
How much have you learned about growing plants in space since June 2011."
This person's been following you.
"Greets from Poland" [FOSSUM] I guess so.
Well, we have several different plant growth experiments and they're quite interesting.
One of them, we're growing plants in a centrifuge,
and so we're comparing them side-by-side on board with a 0G and then a centrifuge spinning
so that the plant seeds for the germination and all are growing at 1G
and you can see the difference in the just the structure
of the plant itself as a very young plant.
You could see 0G they're weaker, and that appears to be
because the gravity actually helps toughen things up because the plant has
to work against the gravity itself.
It needs more structure and so it grows thicker stems.
The roots will grow down quicker.
At least this is just a quick look.
I'm not the investigator here, but when you get a chance to look at the samples
when you're coming out of the growth chamber.
There's another one that uses, that has a plant growth medium, and then they grow them...
They're looking, and of course it's a little confusing to talk about it
because I'm not a biologist in the sense.
They're looking at the details of makes roots grow the way they grow.
And this is kind of a fundamental experiment on the surface,
but what we're really doing is getting down to the real enzymes and proteins,
and the way the plant sends the signal to the root system to tell it what to do.
And one of the things they're looking at is trying to figure out the amount of impact
that light has on telling the plant which way to grow.
And so we plant these seeds in a growth medium, and then some of them are grown
in a dark chamber and some are grown in a light, in a chamber that has a lot of light
over the top of it, and of course that affects the way the upper part of the plant grows
but also it affects the way that the roots grow, and so, you know,
it looks like there may be a signal that goes to the roots that says, "Okay, light is that way.
Therefore down and more nutrients must be the other direction."
And so it sounds a biochemical signal...
[KAUDERER] In a place where there is no down [FOSSUM] In a place where there is no down.
The play says "Okay, gravity's not helping us.
But light tells us which way down must be, and so we'll grow in that direction."
[KAUDERER] Great!
That is fascinating.
That question comes to us from UrtheCast.
The question is, "What time zone do you keep in space?"
[FOSSUM] Okay, well that is a good question.
And because you go around the Earth in 90 min., you have a sunrise and a sunset every hour
and half, we had to pick a time, and we ended up just choosing GMT
or Universal Time to use as the standard clock.
And then you can still kind of arbitrarily set, you know, at what time you choose to wake up,
and we set 6 a.m., which is kind of a normal wake up time here on the ground.
Of course it's the middle of the night in Houston.
You know, to begin that, and that was just so we could all have a time that we all agree on,
that we all could communicate in, this standard GMT time.
And on orbit, that's what you're always thinking in, is GMT time.
At the same time, part of your brain is trying to keep track of what time it is back home,
because you might want call home to the family, or you know, call some friends or something
like that, so you're trying to, you want
to remember what time it is back home so you don't....
[KAUDERER] Wake 'em up in the middle of the night?
Although I am sure they would welcome that phone call.
[FOSSUM] Oh yeah.
The first time, not the second time.
[KAUDERER] So that leads me to another Twitter question we have here.
This one comes from Rhythmreactor.
"Are there any day and night shifts?
Do you rotate duties?
Is there a weekend off?
I wonder about that."
[FOSSUM] You bet.
Normally we..
we're all working the same shift.
We don't, we don't need to have a night watch on the station.
We do have a night watch, but that's mission control.
They have, they're watching the systems and taking care of everything...
[KAUDERER] So that's these folks that we're seeing in this view.
[FOSSUM] That's exactly right.
They are there 24 hours a day, seven days a week.
They are always on duty in Mission Control Houston, Mission Control Moscow, Huntsville,
Tsukuba in Japan, Huntsville, Alabama.
So they're there in mission control centers around the world and they're keeping an eye
on the vehicle so we don't have to .
So we work a single shift.
Everybody gets up at six in the morning.
And the official bed time is 9:30 in the evening.
I would say we pretty very rare that we're actually in bed at 9:30 in the evening.
That's time to kind of finish catching up and have little bit of free time.
But usually we're trying to get to bed by 10, 10:30.
[KAUDERER] Great.
Thank you.