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Hi I'm Kristin and this is NASA Now for November 30, 2011.
It looks fun to float around effortlessly in space,
but over a long period of time, your bones
and muscles would start to weaken from lack of resistance.
So what do astronauts do to stay healthy
and strong during the long visits
to the International Space Station?
We'll find out in a minute,
first here's what's happening at NASA Now.
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After almost six months aboard the International Space Station,
Expedition 29 returns to Earth on the Soyuz TMA-21 spacecraft.
Russian recovery teams were on hand
to help the crew exit the Soyuz vehicle and adjust to gravity
after their long stay in space.
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Now let's take a look at the past.
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June 1965, the Gemini 4 crew performed the first
in-flight exercise.
The device consisted of two rubber bungee cords attached
to a nylon handle at one end
and to a nylon foot strap at the other.
During the 4-day mission,
each astronaut used the device several times a day
for 15 to 30 minutes.
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Physical fitness is just as important in space as it is
on Earth, but exercising in space can be difficult.
What good are weights, if weights don't have any weight?
NASA engineers have come up with a few countermeasures
to help keep the astronauts healthy.
Biomedical Engineer Aaron Weaver will help explain.
Hi, I'm Aaron Weaver, and this is the Exercise Counter
Measures Lab.
At the Exercise Counter Measures Laboratory,
we have a treadmill that's not mounted like your treadmill
at home or in the gym.
We put our treadmill vertically
and have a runner running on his back.
The purpose of this is to try to mimic the treadmill
that we have on the space station.
Lets take a look at how he got into this position.
The first thing we do is put these cuffs
and the cuffs will go on both the arms and the legs.
And what these do is allow us to attach bungee cords
to those cuffs because gravity is still here even though we are
trying to mimic what is going on at the space station.
But now gravity is going to want
to pull your arms and legs behind you.
So now that most of the cuffs are on the subject,
we put the harness on him.
He is now going to climb up onto the table.
Then, we are going to hook him up to a bunch
of different bungee cords and cables that are on the ceiling
because we are trying to mimic weightlessness at this point.
So we want him to be as natural as possible.
Now, what we are going to do is lift him up off the gurney
or the bed that he is on and this is actually now going
to put him suspended in air.
And now he is ready to start running.
Everyone should be getting as much exercise as possible,
but the reasonable amount that is suggested is an hour a day.
The astronauts are allotted two and a half hours a day,
which sounds like a lot of time, but when you take out the fact
that time includes getting dressed,
setting the equipment up, cleaning up, showering.
So they are allotted extra time for that.
On Earth, we can do things like play sports and other things
that are active, for exercise,
that they can't do on the Space Station.
It's a little difficult to have a football game
on the Space Station.
So, we have them doing things like treadmill exercise,
which basically, so they can run.
We have stationary bicycles.
We have resistive exercises, which mimic lifting weights.
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One of the things that we're currently working on here
at NASA Glenn is a redesign of the harness
that the astronauts use to exercise
on the treadmill on the Space Station.
In microgravity, they need, you need to be held
down to the treadmill, because you can imagine as soon
as you took the first step,
you'd fly up and hit the ceiling.
So to do that, they currently wear a harness similar to this
over here, which, we've been using for and its fine,
but it's not necessarily that comfortable.
So, what we're doing is redesigning the harness
to be more like you'd see in a backpack.
The primary objective of the exercises that we have them do,
it's not, I mean, it's to keep them in general shape,
but it is to try to keep them from losing bone and muscle
and other types of properties in the body.
Typical, average for a longer term mission,
astronaut might lose 1% to 2% of their bone, per month,
which is a lot, if you're in space for a couple of months.
To compare to what happens here on Earth, women, as they age,
typically, can have osteoporosis.
And, so, those people on Earth might lose .1%,
which is 10 times less bone than you're losing in space.
So, an astronaut does regain their muscle
and bone mass once they return to Earth.
Basically, over the course of a year or two,
they're in a program that helps them gain that back.
We are working on things
that would be more suitable to go to Mars.
One of the challenges we have, when you go longer term
in travel, is exercise becomes more important,
because I said you lose 1% to 2% of your bone per month, so,
on the Space Station, we're up there for six months,
so that means you might lose 6% to 10% of your bone.
If you're gone for three years, that goes up to, say,
30% of your bones, so you're losing a lot.
One of the challenges we have is how to develop equipment
and instruments that are smaller, so that we don't take
up all the room in the capsule trying to do exercise
and medical stuff, when, obviously, if we're going to go
to Mars, we'd like to do a lot more science type missions,
when we get there.
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Did you know that the vertical treadmill can simulate three
different gravity environments?
The microgravity conditions on the ISS, the 1/6 gravity
of the moon and the 3/8 gravity found on Mars.
Now you know.
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There are many negative effects to living in space
and the only way scientists learn how
to counteract these challenges is through testing and research.
You and your students can explore these challenges
through five different activities
in the lesson plan titled Space Adaptations: The Body.
Look for them on the NASA Explorer Schools Virtual Campus.
Well that's it for NASA Now, be sure to join us on Facebook
and let us know your thoughts, Until next time -
we'll see you then on NASA Now.
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NASA Now comes to you from the Virtual Campus
at NASA Explorer Schools.