In the future, we'll want to expand the internet across the galaxy, and NASA has just demonstrated a key piece of technology that could help, transmitting messages via lasers some 10 million miles from Earth.
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This is about 40 times farther than the Moon, and is the first time optical communications have been sent over such a distance.
Traditionally, we use radio waves to communicate with distant spacecraft – but higher frequencies of light, such as near-infrared, offer increased bandwidth and therefore, a huge leap in data speed.
If we want to be able to send high-definition video messages to and from Mars without significant delay, then this is the technology we need.
The test is part of NASA's Deep Space Optical Communications (DSOC) experiment, and the successful establishment of the communication link is referred to as "first light."
For high-speed communications on Earth's surface, we all rely on similar technologies embedded in optical fibers. However, here it has been adapted for use in space, in order to improve existing methods of transmitting information to Earth.
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As infrared light, engineers can easily transmit its waves in the form of a laser. This doesn't speed up the light's movement, but it does straighten and confine its beam into a narrow channel. This requires much less energy than radio waves and is harder to track.
That's not to say it's a simple task. The data is encoded in the photons emitted by the laser, which requires a series of sophisticated tools—including an array of high-performance superconducting detectors—to prepare the information for transmission and translate it at the other end.
Another challenging factor is adjusting the system's positioning layout in real time. In this latest test, the laser photons took about 50 seconds to travel from the spacecraft to the telescope, both of which are moving at high speed through space during this process.
The laser transceiver that made the connection is onboard the Psyche spacecraft, which is on a two-year technology demonstration mission headed to the asteroid belt between Mars and Jupiter. It contacted the Hale Telescope at Palomar University in California.
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Testing will continue to optimize this innovative near-infrared laser communication method, and ensure that it is as fast and reliable as required.
Source: science alert
