work. You’re on a luxury liner, sailing on the Aegean Sea, and you’d
like to call someone in Istanbul.
As you place your call, your phone
connects to the ship’s on-board,
‘transmitter’, which then beams it
up to a ‘receiver’ up on a satellite in
an ‘uplink’. The satellite’s transmitter, in turn, sends it back down in
a ‘downlink’ to another receiver on
the Turkish coast, from where it’s
then routed to the recipient. The
entire process takes place within a
flash. But while it works wonderfully for a standard, voice-only phone
call, it may not if you were trying
to tweet from the deck or download
‘War and Peace’ on your e-reader
from inside your cabin.
To an observer, looking out the
window, therefore, they’d appear to
be stationary, hovering at the same
position night after night. They’re
so placed such that ground-based
antennas, which ‘talk’ to them, don’t
have to keep rotating to keep track
of them. They serve as enormous
mirrors in space, capable of bouncing off telephone calls, television
and radio broadcasts, and internet
content, from one sector of the
world to another. This is how they
Presently, satellites are slowpokes
when it comes to providing entry to
the Internet. Signals from Earth—
in the form of radio waves, which
travel at the same speed as light—
take 0.25 seconds to make one
round-trip. While that may sound
like an infinitesimal time frame,
it’s not small enough to support a
real-time video call, mad RF