Looking for the fastest broadband connection around? Then look up, say U.S. scientists who are reporting their successful attempt to set up a broadband connection between the Earth and the moon using lasers.
In October of last year and again early this year, researchers at the Massachusetts Institute of Technology and NASA cooperated in tests of the Lunar Laser Communication Demonstration, using potent laser beams to transmit information from the Earth to the moon at exceptionally fast speeds.
In the tests, the findings of which are being presented publicly this week at the Conference on Lasers and Electro-Optics in California, the LLCD broke a number of records, downloading data over the 238,999 miles between the moon and the Earth at 622 megabits per second. That is about 5 times the current rate from lunar distances, NASA says.
Upload speeds were a bit slower, around 19.44 Mbps, but still fast enough to send a high-definition video to our moon to allow high-definition video conferencing via Skype.
Those data rates far exceed anything NASA is seeing with any of its current radio frequency communications devices, and the download speed in particular is thought to be faster than that of any commercial broadband or Wi-Fi service available in North America, which has typical download speeds of between 15 and 25 Mbps.
The ability to use lasers in space to send and receive information will be a boost to future missions, the researchers said.
"It is generally agreed that present-day science and exploration missions to deep space are constrained by the amount of data they can get back to Earth," explained Don Boroson, who headed the MIT research team developing the communication system. "It has been known for years that laser communications have the potential to deliver much higher data rates and use smaller space terminals than radio-based systems."
Wi-Fi signals, converted to laser pulses, were transmitted between four telescopes in White Sands, New Mexico, and a NASA satellite, LADEE, in orbit around the moon.
The researchers said the success of the MIT LLCD tests was a big step on the way to an even more sophisticated system to be known as the Laser Communications Relay Demonstration (LCRD), set to begin testing in 2017.
"The on-orbit performance [of the LLCD] was excellent and close to what we'd predicted, giving us confidence that we have a good understanding of the underlying physics," said team member Mark Stevens of MIT's Lincoln Laboratory.
