Satellites
Earth Mars Communication
LONDON : The
sun can block direct communication
between Earth and Mars for
weeks at a time, cutting
off any potential mission
to the red planet. The solution
– satellites on special
orbits around Mars.

Earth
Mars Communication
The European
Space Agency (ESA) is working
on how to ensure reliable
radio communication when
Mars and Earth line up at
opposite sides of the sun,
blocking any signal between
mission controllers on Earth
and astronauts on Mars.
The natural
alignment, known as a conjunction,
happens approximately every
780 days, and would seriously
degrade and even block transmission
of voice, data and video
signals. Researchers have
proposed an innovative solution
by placing a pair of communication
relay satellites into a
very special type of orbit
near Mars: a so-called ‘B-orbit’
(against an ‘A-orbit’,
based on natural orbital
laws).
However, to
counter the effects of gravity
and remain in place, they
would have to be equipped
with cutting-edge electric
ion propulsion. Such ion
thrusters, powered by solar
power and using tiny amounts
of xenon gas as propellant,
would hold the satellites
in a B-orbit in full view
of both Mars and Earth.
The satellites
could then relay radio signals
throughout the Mars-Earth
conjunction season, ensuring
that astronauts at Mars
were never out of sync with
Earth, says an ESA release.
These findings were released
this week at the 60th International
Astronautical Congress (IAC),
the world’s biggest
space event, in Daejeon,
South Korea.