Way back in 1880, Alexander Graham Bell communicated wirelessly over a distance of more than 200 yards using sunlight with an invention called the photophone. Bell was so excited about his invention that he almost named his daughter after it. However, light-based wireless communication never really took off, and even today’s wireless systems use radio signals instead of light. Now, advances in modern electronics have made light-based communication more practical, and researchers around the world are bringing it back to light, so to speak. These days, the wireless method for using lights for high-speed communication similar to Wi-Fi is known as Li-Fi or visible light communication (VLC). NASA’s Kennedy Space Center just announced a five year partnership with Light Visually Transceiving (LVX) System Corp. to develop wireless communication using LEDs.
“The technology simply provides a wireless network using light instead of radio signals and copper wires to transmit data,” explains NASA researcher Dr. Eirik Holbert. Li-Fi has two main advantages over Wi-Fi: it offers better security and virtually limitless data capacity, because the visible light spectrum is 10,000 times larger than radio-frequency bandwidths.
NASA and LVX are studying the technology to explore its potential applications, as well as improving the performance and adding features such as GPS navigation. By the end of the contract, engineers are expected to provide a final prototype consisting of a camera, microphone and speaker technologies. The light-based technology could be used everywhere we currently use Wi-Fi—in offices, coffee shops, and homes—but NASA also sees its potential for communication on the International Space Station or deeper in outer space. “A future manned spacecraft making a trip to Mars could be a candidate for this kind of communications system,” Holbert says. He also suggests that Li-Fi could be used in a Deep Space Habitat—a NASA concept for allowing astronauts to live and work on missions beyond low-Earth orbit, such as on the surface of Mars.
Despite its speed, security, and capacity, Li-Fi is far from perfect. Unlike Wi-Fi, it can only be used where lighting is available, and it can’t penetrate walls the way radio waves can. “Li-Fi will likely never completely replace Wi-Fi,” Holbert says. “But it does have potential. If we can make it worthwhile, it could become a very valuable technology down the road for space travel.”
