X-Rays: Next-Gen Way to Travel and Talk in Space?

NASA scientists say they have figured out a way to use X-rays to both communicate with long-distance spacecraft, as well as navigate as they sail past the outer limits of the solar system.

They say that using X-rays is faster than existing radio wave communications, can carry more information and won’t be blocked when spacecraft enter a planet’s thick atmosphere.

“While we are using X-ray navigation to guide us to Pluto, we might also use X-ray communication to talk back to Earth,” said Keith Gendreau, principal investigator at NASA’s Goddard Space Flight Center in Greenbelt, Md.

The concept of X-ray navigation will be tested during a NASA mission called NICER/SEXTANT that is set to launch in August 2016. The spacecraft will study the insides of neutron stars, which produce X-rays, and test equipment that could be used for x-ray navigation.

Gendreau and other scientists have been thinking for several decades about using pulsars, which also emit beams of X-rays, as outer space lighthouses to help spacecraft tell where they are. Instead of just using a single radio source from Earth to tell their position and location, a future mission would tap into a hypothetical map of pulsars, each of which sends out its own identifiable frequency.

Existing “star charts will tell your spacecraft orientation, but it won’t tell you in three dimensions,” Gendreau said. “With radio waves, you get precise range information between your spacecraft and the Earth, but that’s only one direction in the sky. Pulsars are distributed all over the galaxy. They are more or less uniform in the sky.”

Other engineering teams have also been working on pulsar navigation using X-rays, but so far haven’t convinced NASA or other space agencies to fully implement the idea yet. Werner Becker, an astrophysicist at the Max Planck Institute in Germany, has been simulating pulsar navigation in his laboratory and published a study last year about using pulsar navigation to allow spacecraft to navigate autonomously.

“This technology of pulsar navigation is so simple,” Becker said. “You just need a demonstrator mission.”

Becker thinks pulsar navigation could also be used for missions closer to Earth. Perhaps setting up a super-accurate, pulsar-linked satellite in Earth orbit as a reference point and thereby eliminating the need to synchronize the existing Global Position System (GPS) satellites every three days to maintain the entire system’s accuracy.

Becker is so excited about pulsar navigation that he’s putting on a conference in Germany next year to further explore the idea.

Other experts say that X-ray navigation, or XNAV, just needs a little push to get it going, according to Dan Jablonski, communications engineer at Johns Hopkins University’s Applied Physics Laboratory.

“Things are constantly being adapted from one mission to another and they find their way to the communications market pretty quickly,” Jablonski said. “Everybody watches everybody else’s projects with great interest. When it works they take it and run with it.”

NASA’s Gendreau also believes he can communicate and send scientific data back to Earth in almost real-time using X-rays. In a crowded second floor lab in Goddard’s Building 34, Gendreau has set up a small experiment that uses a small X-ray source to transmit digital music from his iPhone across a workbench to a nearby speaker.

“We’ve developed the core technology, we just now just need to refining existing encoding techniques and maybe going beyond,” Gendreau said.

Read more at Discovery News