A new breakthrough, announced Wednesday during the International Electron Devices Meeting in San Francisco, could bring NASA one step closer towards their goal of developing spacecraft made from a single silicon chip – a breakthrough that could significantly cut space travel time.
Based on the US space agency’s calculations, chip-sized spacecraft could travel at a velocity of up to one-fifth the speed of light and reach Alpha Centauri (the star closest to Earth) in just 20 years, NASA scientist Dong-Il Moon explained in his conference presentation.
Of course, as IEEE Spectrum noted, in order to make the journey, a silicon chip would need to survive exposure to intense radiation. Fortunately, NASA and its partners at the Korea Institute of Science and Technology (KAIST) have come up with a solution – technology which would enable such spacecraft to heal itself after suffering radiation damage.
Radiation exposure isn’t the only obstacle preventing the use of chip-sized spacecraft, but it is arguably the most significant, and if scientists can overcome this and the other issues facing such technology, it could ultimately lead to space travel 100 times faster than currently possible.
Transistors would repair radiation damage using heat
In order to make these minuscule spacecraft a reality, the NASA and KAIST researchers have to first come up with silicon chips capable of spending two decades in space, meaning that it would not only have to survive temperature swings, but also the negative effects of radiation.
As IEEE Spectrum explained, radiation exposure would result in the accumulation of positively charged defects in the silicon dioxide layer of the chip, leading to performance degradation. One such issue would result in an increase in the current that leaks through a transistor when it is off, the researchers noted. Another is a change in voltage when the transistor is turned on.
So how do the developers hope to overcome this problem? According to Inverse, they are hoping to create chips that contain an extra gate, which would allow any damage that the chips sustained during its journey to be repaired through heating. Prior experiments have demonstrated that flash memory damaged by radiation can be recovered as many as 10,000 times, the website noted, and while this would raise production costs, it could make interstellar travel possible.
“On-chip healing has been around for many, many years,” NASA researcher Jin-Woo Han told IEEE Spectrum. The difference in this case is that the team is using an experimental new type of nanowire transistor developed by KAIST that uses nanoscale wires as transistor channels instead of the fin-shaped channels used by most current chips. Adding an extra contact to this gate allows current to pass through it, surrounding the nanowire with heat and repairing it.
“A chip that could heal itself after radiation damage could revolutionize how we explore space in the future,” said Inverse. “No longer would we need to just create tank-like probes to investigate the far reaches of interstellar space. It’s just a matter of time before we start throwing off chip-sized spacecraft into every direction and waiting to see what we find.”
Alpha Centauri A and Alpha Centauri B create the closest star system to our own. (Image credit: ESA/NASA)