[ music ]
>> Hello, my name
Sultan Aineyadi,
and I'm an astronaut
from the United Arab Emirates,
currently living
and working onboard
the International Space Station.
Reliable communication
between the crew up here
and our support team on Earth
is critical.
We rely on
space-to-ground communication
for many of our activities,
from official calls
during spacewalks
and while conducting experiments
to making personal calls
with our friends on Earth.
Let me show you how
we make phone calls
up here on the station
using an IP
or Internet protocol phone
through our computer.
The phone connection
is really clear.
You would never know
we are calling from space.
I'll call a good friend of mine,
NASA astronaut Megan McArthur.
[ phone ringing ]
>> Oh, I think it's
Space Station calling.
Hey, this is Megan.
How's it going up there?
>> Good.
We are just hanging around.
>> I'm with a student right now,
Mikayla, and we're talking
about the crew on station
and how you communicate
with Earth, so we have
some questions for you.
But first, Mikayla,
check out this area code.
>> Oh, cool.
That's the Houston area code.
>> That's right.
>> Calls from the Space Station
show up with
281 Houston area code
because our calls are routed
through Johnson Space Center
in Houston, Texas.
>> This is pretty cool.
Are you hearing us
all the way from
the Space Station right now?
>> Yes, I hear you
loud and clear.
>> But I thought
sound doesn't travel in space.
>> You're right, Mikayla.
Sound waves are
mechanical waves
and can't travel
through the vacuum of space.
They need a medium
like air, water,
or other material
to be transmitted through.
For example, imagine
a spacewalking astronaut
working on the outside
of Space Station.
We hear the noise
from inside the ISS,
because the motion outside
creates a vibration
that transmitted
through the whole
of the Space Station.
We hear this as
the sound inside the ISS,
because the spacecraft
is a material medium.
>> Unlike sound waves,
electromagnet waves
can travel through space.
Think about the waves
of the ocean.
All the water does
not move into the beach,
but the energy moves
through the water
in a repeated
up and down motion.
The wave transports the energy
rather than the material
from one point to another.
>> Oh, take a look.
A group of teachers
at Space Center Houston
demonstrated a wave for us.
[ cheering ]
What a terrific wave.
Even though the teachers
didn't change seats,
the motion was moved
from one person to another
and continued
throughout the auditorium.
Like ocean waves,
electromagnetic waves
move energy,
in this case,
from an electric charge
from one point to another.
>> Oh, that makes sense.
How is the sound of my voice
reaching you in space right now?
>> Great question.
>> The sound of your voice
is encoded into a series
of electromagnetic waves
and sent to a satellite
that will then relay the signal
back to the station.
Next, the wave is decoded
into sound that the receiver
can hear and understand.
>> It seems pretty fast.
How long does it take
for all that to happen?
>> Well, the signal reaches
the Space Station
in about a quarter of a second.
The time from transmission
to reception
depends on the location
of the transmitter
and the receiver.
Since the Space Station
orbits the Earth
at about 250 miles above,
it's close enough
to make the communication
nearly instantaneous.
>> So it takes a few hours
for astronauts to get to the ISS
and three days
to get to the moon.
How long does it take
for the communication
to get to the moon
during the Artemis mission?
>> The moon is
a bit farther away
from the ISS.
Waves traveling at
the speed of light from the moon
would reach Earth
in about 1.25 seconds,
so the small delay would
hardly be noticeable.
Houston, Moon Base.
What's for lunch today?
>> Moon Base, Houston.
Looks like space burgers.
[ cheering ]
>> The trip to Mars would
take about seven months, right?
>> Do I even want to know
how long it'll take to have
a conversation from Mars?
>> [ laughing ]
That's a great point, Mikayla.
When we travel to Mars,
the signal will have to travel
much farther
because of the great distance.
Even at the speed of light
it can take
from 3 to 22 minutes,
depending on where the planets
are in their orbit.
>> Are you able to use
the Internet,
send text messages
or use social media
in the Space Station?
>> Yes and no.
We can't send text messages
or use smartphones here,
because we have
no cell reception
on the station.
Yet, we can use our computers
to connect to the Internet
and send pictures directly
to our friends and family
through email.
We also use our computers
to post on social media
and share about life on Station.
>> Station, Houston
on space-to-ground 2
for Sultan.
>> I'm getting a call
from Mission control.
I have to run.
Continue to think
about the ways
communication connects us
in space and on Earth.
>> How fun was that, Mikayla,
to get a call from
the International Space Station?
>> That was so fun.
I'm glad I got a chance
to talk to them.
>> Me, too.
To learn more about
space communication,
check out the corresponding
classroom connection found
at NASA.gov/STEMonstration.
If you'd like to have a chance
to talk to an astronaut
on station,
have your school apply
to host a downlink.
Thanks for exploring space
with us today.