There is now Wi-Fi on the moon. Scientists at MIT and NASA said last week they discovered how to transmit data to space by lasers – technology that could be used by future missions to Mars and other planets.
If future generations live or work on the moon, scientists say, a broadband connection would allow them to keep in touch with family and friends back on Earth.
Four separate telescopes based in New Mexico were used to send an uplink signal to a receiver mounted on a satellite orbiting the moon. Each telescope, about 6 inches in diameter, transmits information to the lunar satellite as coded pulses of infrared light, Discovery News reported.
The MIT and NASA scientists behind the project will present their findings at CLEO laser technology conference in California on June 9.
The team succeeded in transmitting data across the 238,999-mile distance between Earth and its moon at a rate of 19.44 megabits per second, comparable to a slower broadband connection speed, according to Discovery News.
Once transmitted to the lunar satellite, they were able to download data at a rate of 622 mbps, which is over 4,000 times faster than radio transmission speeds currently used to send information between Earth and the Moon, according to Wired. Such speeds would allow large data transfers and high definition video streaming.
But sending information as light through Earth's atmosphere isn't without challenges, researchers said.
"Communicating at high data rates from Earth to the moon with laser beams is challenging because of the 400,000-kilometer distance spreading out the light beam," Mark Stevens, of MIT Lincoln Laboratory, told Wired. "It's doubly difficult going through the atmosphere, because turbulence can bend light – causing rapid fading or dropouts of the signal at the receiver."
The atmosphere bends the laser beams, the scientists said, and each beam experiences the bending differently. That’s why four telescopes are used to beam lasers through different columns of air – to increase the probability that at least one will hit the receiver on the lunar satellite, Wired reported.
The lunar satellite has its own telescope, which collects the laser beam sent from Earth and focuses it into an optical fiber. A photodetector is used to translate the pulses of light into electrical pulses and then they are converted to data, according to Wired.
Even though the lunar satellite typically receives less than a billionth of a watt from the 40-watt signal, that is ten times more than necessary for reliable communications, Stevens said, adding that the team hopes the technology will be eventually be used on deep-space missions to Mars and other planets.