Making contact with the International Space Station
requires a lot of equipment! We also rely heavily
on computers to locate the ISS and tune our transceivers
to adjust for doppler effects.
We use Amateur Radio equipment to talk to the
astronauts. Amateur Radio is a range of radio
frequencies that are used for experimental work
by qualified operators all over the world (and
The Space Station is traveling at 27 000 kmh,
and takes around 10 minutes to cross our sky.
We have to point our antenna's (called Yagi's)
at the station for the best signal. We use a machine
called a rotator to do this. Our computer gets
the position of the space station from the internet,
and controls where the antennas are pointing.
We also have to change our frequency because
of a phenomenon called Doppler shift. It's like
when a car approaches you from a distance - the
noise from the car increases in frequency as it
approaches, then reduces in frequency as it moves
away from you. The same thing happens with radio
waves! The same computer that controls the antenna
adjusts the radio frequency to compensate for
So what if a computer or radio fails?
The backup station is ready to go! We even have backup batteries and generators ready just in case!
What else are we doing?
Well, people all over the world will be able
to hear the St Thomas’ students talk to the Astronauts,
via a program called 'Echo Link'. Echo Link connects
to our backup transceiver and puts the sound from
the transceiver onto the internet. Other amateur
operators will re broadcast the signal to cities
all over the world by connecting to our Echolink
server! So we are not only talking to an Astronaut,
we are talking to the entire planet!