Remnants of the shot-down spy balloon can be seen here
News of a Chinese spy balloon being shot down by the US military at the beginning of February has captured the attention of many. The balloon was seen flying over the coast of South Carolina and was tracked for a while as it flew at an altitude of around 18,000 metres. More balloons have been spotted since, imaging the ground below. The US military claims that China was attempting to spy on American military bases, while Chinese officials say that balloons from scientific research simply ventured off-track. Spy balloons are relatively rare, as spy satellites are less of a target than a
low-flying
gas-filled
balloon.
An
advantage
to
using
balloons
is
that
they
fly
much
closer
to
Earth,
giving
cameras
a
clearer
view
of
what’s
going
on
below.
These
balloons
are
usually
very
difficult
to
control
and
have
to
travel
with
the
wind.
The
spy
balloon
that
made
headlines
had
propellers,
helping
control
navigation.
This
type
can
operate
for
weeks,
but
is
sensitive
to
pressure
changes
and
can
burst
as
its
altitude
changes.