The experiment shows the potential that lasers have in deep space communication. Laser transmissions allow a higher data transfer rate.
The Mercury Messenger spacecraft making its way to the planet Mercury has transmitted a laser signal to Earth from a distance of 24 million kilometers. The spacecraft exchanged laser signals with the ground station in the USA.
MESSENGER was launched in 2004 on a mission to map the surface of the planet closest to the Sun. After arriving at the planet Hema in 2011, the spacecraft will circle the planet for about a year and monitor the atmosphere, as well as the composition and structure of the planet Mercury.
NASA equipped the spacecraft with a laser altimeter that mapped the topography of Mercury by measuring the times at which the laser pulses returned to the planet from its surface. The instrument and the ground station in Maryland transmitted laser signals to and from the spacecraft to examine the equipment.
David Smith of the Goddard Space Flight Center in Greenbelt, Maryland and his colleagues reported on the experiment in the latest issue of the journal Science.
"The experiment demonstrated the ability to time laser pulses in sub-nanoseconds, and the success of creating bidirectional laser contact at interplanetary distances." They said. "In addition to bidirectionality, the highest speed in the transmission and reception of laser signals was also achieved." added According to the scientists, the experiment shows the potential that lasers have in deep space communication. Most spacecraft today use microwave transmitters, but laser transmissions allow a higher data transfer rate.
The only experiment done so far with laser transmission into space was done in 1992, when two ground laser transmissions were picked up by the cameras of the Galileo spacecraft which was then making its way to Jupiter, from a distance of about 6 million km.
