NASA image of electron nanotube coating

NASA is developing a sci-fi electron gun to shoot lasers at objects in space

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May 17, 2018

What if all you had to do to find out the chemical composition of a space rock (which could tell you secrets about phenomena that happened billions of years ago) was shoot a laser at it? 

NASA Goddard scientist Lucy Lim and optical engineer John Hagopian have reimagined a supercharged carbon nanotube coating for an electron probe that is right out of a sci-fi movie. When the probe shoots laser beams, they will pass through the clusters of carbon nanotube "ammunition," no wider than a human hair, to excite a geological target and unearth geological data on airless cosmic objects such as the moon and Mars. And, of course, asteroids.

This is something possibly even cooler than an enormous blaster exploding a monster asteroid into millions of pieces (which you may or may not be visualizing right now), but if anyone is going to take something like this out of people’s imaginations and make it a tangible reality, it’s NASA.

NASA image of scientists with electron emitter

NASA Goddard scientists Lucy Lim (front), John Hagopian (left) and Larry Hess. Credit: NASA

Producing these nearly invisible clusters of nanotubes involves heating up the silicon or another substrate inside a furnace, then bathing it in carbon gas until it is coated in minuscule bumps. Lim and Hagopian are using silicon wafer as a substrate to grow them on. The way they are evolving the technique is by arranging them in a grid formation, which allows the placement of silicon wires, and another grid that produces two different voltages, above and below the rows. Here’s where it really starts to blow your mind. The dual voltages create an electrical field that activates the release of electrons inside those clusters of nanotubes, and Lim conceptualizes those beams passing through electrostatic lenses to accelerate before zooming in on a space rock.


Macro and super-macro of the nanotube bumps.

Wielding X-rays in space is nothing new to NASA, but Lim’s concept could really advance how we analyze the chemical composition of moon dust or Martian regolith. Her electron shooter is not just compact, but can also be fully controlled, which is kind of a big deal since humans won’t always be the ones exploring alien surfaces even after our species leaves bootprints on them for the first time — or the first time in decades.

“We would be able to choose which bump to activate,” Lim said. “We would be able to analyze different spots on the sample individually. We want to obtain compositional maps. Without the addressable emitter, we might not discover all the minerals contained within a sample, how big they are, or their relationship to each other.”

For now, the probe, which is being funded by NASA’s Planetary Instrument Concepts for the Advancement of Solar System Observations Program (PICASSO), has proven it can fire enough electrons to excite a sample. A flight to the ISS has also shown that it can survive in space.

Can it put up with the harsh conditions outside low Earth orbit? Stay tuned.

(via NASA)