WHY THIS MATTERS IN BRIEF
Traditional RF communications in space are slow, and can be blocked by the Earth’s atmosphere during re-entry, X-Ray communications have no such problems.
Recently NASA tested the world’s first interplanetary space internet by sending a selfie from the Arctic to the International Space Station (ISS), but asides from that not much has changed in the way we communicate with objects in space for decades. But that might all about to change. While radio waves are still the main way to communicate with spacecraft, it now looks like that age old technology could soon be getting a massive upgrade that will allow significantly faster data transfers to and from space thanks to a new NASA experiment that’s going to test out a first of a kind X-ray communication system on the International Space Station (ISS).
The project, known as XCOM, will initially re-purpose equipment that’s already on the space station such as the Neutron-star Interior Composition Explorer (NICER) which is currently perched on the outside of the station, where today it’s merrily scanning the cosmos for X-ray emissions from distant neutron stars. But NICER, fortunately, is no one-trick pony.
In 2017, NASA engineers demonstrated how the instrument could use data from millisecond pulsars as a kind of space-GPS, precisely calculating the position of the ISS to within 3 miles (4.8 km), and NASA believes that it’s this potential to pick up X-ray signals that makes it an ideal candidate to become a receiver their new X-ray communication system.
To test the idea, at the other end, NASA is going to be using a specially-designed device called the Modulated X-ray Source (MXS) that produces X-rays by first shining UV light onto a photocathode material like magnesium. That produces electrons, which are then accelerated into another material that in turn produces X-rays. Importantly, the MXS can be quickly switched on and off, encoding binary messages into X-rays that can be beamed to, and deciphered by, a receiver.
For the upcoming test NASA installed the MXS on the outside of the ISS. There, it will beam X-ray messages over a distance of 165 ft (50 m) to NICER, which will then attempt to decode them. The message itself will be kept simple at first, the team says, to ensure that the device can pick up exactly what was sent, and f that works, a more complicated message will be transmitted later this year. If all goes to plan, X-ray communication could then eventually be used to beam data to and from a range of spacecraft, they say.
X-rays have much shorter wavelengths than radio waves or even laser communication systems, which are also in development. That means they should be able to pack more data into tighter beams, effectively allowing faster data transfer rates. And considering the long delay that can come from communicating with distant craft like New Horizons, anything that hurries the process along can only be a good thing.
Another potential advantage is that X-rays can penetrate the hot plasma sheath that normally cuts off radio communications when spacecraft, like the recent SpaceX Crew Dragon craft that completed its first test mission to transfer astronauts to the ISS, are blasting through the Earth’s atmosphere. X-rays could keep the crew in touch with ground control during this critical and intense period.
The XCOM tests are due to take place on the ISS in the next few months.