NASA is Working on Ultrafast Laser Machining for Multiple Spaceflight Applications

NASA is Working on Ultrafast Laser Machining for Multiple Spaceflight Applications

Scientists might be able to join dissimilar materials without epoxies following the latest development at the Goddard Space Flight Center of NASA.

The anagram ‘LASER’ stands for Light Amplification by Stimulated Emission of Radiation. The combined study of light and optics enabled man to artificially create lasers. Unlike natural light or conventional bulbs that emit multiple wavelengths of light, lasers produce a narrow beam of light in which all the light waves have near identical wavelengths. The waves of a laser’s light travel together in phase, thus their beams are extremely narrow, bright, and focused. Consequently, laser beams can travel very long distances and concentrate a lot of energy in a minute area.

Lasers are used in precision tools, can cut through diamonds or thick metal, help in delicate surgeries, and recording and retrieving information. One of their most common scientific uses is in spectrometers that help scientist’s ascertain what things are made of.

NASA continues to use lasers frequently in space and at home. The Curiosity rover’s laser spectrometer helped in the chemical analysis of Martian rocks. Other missions have used lasers to study the gases in Earth’s atmosphere, used them in instruments that map the surfaces of planets, moons, and asteroids. However, new innovations in laser technology are pushing the envelope to modify and find new uses for lasers. Recently, a team of optical physicists at NASA’s Goddard Space Flight Center were experimenting with a femtosecond laser that has shown that it can effectively weld glass to copper, glass to glass, and drill hair-sized pinholes in various materials.

Physicist Robert Lafon leads the team which is expanding its research to exotic glass (sapphire and Zerodur) and metals (Titanium, Invar, Kovar, and Aluminium). Frankie Micalizzi and Steve Li are also there in this researching team. All these materials are found in spaceflight instruments. Their primary goal is to demonstrate the merits of laser technology in welding larger pieces of these materials and to each other and other applications.

The Center Innovation Fund program of the Space Technology Mission Directorate enables the group to explore this technology’s use in fabricating and packaging photonic integrated circuits. This could benefit everything from communications and data centers to optical sensors. Though similar to electronic integrated circuits, photonic integrated circuits are fabricated on a mixture of materials, including silica and silicon, and use visible or infrared light, instead of electrons, to transfer information. Lafon mentioned that they are experimenting with different materials and techniques that could benefit spaceflight applications. He said,

“This started as pure research, but now we hope to start applying what we have learned to the fabrication of instruments here at Goddard. We already see what the applications could be. In this case, research for research’s sake is in our best interests,”

He explained that in order to move forward with these applications, the ultra-fast laser by virtue of its short pulses, measured at one quadrillionth of a second, is Central. Ultrafast lasers interact with materials uniquely. The laser energy doesn’t melt the target material instead it vaporizes it without heating the surrounding matter. Thus, technicians can precisely target the laser and bond dissimilar materials that otherwise couldn’t be attached without epoxies. He referred to that by saying,

“It’s not possible to bond glass to metal directly, you have to use epoxy, which outgases and deposits contaminants on mirrors and other sensitive instrument components. This could be a serious application. We want to get rid of epoxies. We have already begun reaching out to other groups and missions to see how these new capabilities might benefit their projects. The ability to remove small volumes of material without damaging the surrounding matter allows us to machine microscopic features.”

Microscopic features include everything from drilling hair-sized pinholes in metals — an application the team already demonstrated — to etching microscopic channels or waveguides through which light could travel in photonic integrated circuits and laser transmitters. The same waveguides may allow liquids to flow through microfluidic devices and chips needed for chemical analyses and instrument cooling. Lafon talked about the importance of this discovery in the following words:

“Once we are able to demonstrate this capability reliably, we will attempt to apply it to existing challenges here at Goddard. Our initial research is showing that this technology could be applied to a large number of projects across NASA.”

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