A tiny spacecraft made from a single silicon chip may initiate a sweeping revolution in interstellar exploration. The Korea Advanced Institute of Science and Technology (KAIST) collaborated with NASA in developing the sensational technology.
NASA’s Dong-Il Moon shared the details of this innovation during a talk at the IEEE International Electron Devices Meeting
in San Francisco. According to the speaker, this technology may let spacecrafts survive the expected powerful radiation during the journey.
Self-Healing Transistors for Chip-Scale Starships (c) IEEE Spectrum
The research suggests, if the silicon chips will be used to form the heart of a spacecraft, the craft could accelerate to one-fifth the speed of light. This speed would allow the ships to reach the nearest stars in just 20 years, compared to the thousands of years it would take in a conventional spacecraft.
However, 20 years in space is still too long for an ordinary silicon chip. The spacecrafts' materials would probably be bombarded by more high-energy radiation than what it encounters on Earth.
“You are above most of the magnetic fields that block a lot of radiation, and above most of the atmosphere, which also does a good job of blocking radiation,” Brett Streetman, who leads efforts in chip-scale spacecraft at the Charles Stark Draper Laboratory, in Cambridge, Mass told the IEE Spectrum.
I think I know now where the idea came from
To address the issue of chip damage, Moon suggested an approach. That would be letting the devices suffer damage during the flight, but design them in a way they can heal themselves with heat.
“On-chip healing has been around for many, many years,” says Jin-Woo Han, a member of the NASA team in a statement
. Han says, the critical addition made now is the most comprehensive analysis of radiation damage so far.
The researchers plan to use KAIST’s experimental “gate-all-around” nanowire transistor, which uses nanoscale wires as the transistor channel instead of today’s fin-shaped channels.
According to KAIST, nanowire transistors are ideal for space as they are highly immune to cosmic rays; also because they are small, with dimensions in the tens of nanometers.
“The typical size for [transistor dimensions on] chips devoted to spacecraft applications is about 500 nanometers,” says Choi. “If you can replace 500-nm feature sizes with 20-nm feature sizes, the chip size and weight can be reduced.” Costs fall too.
With the use of a microprocessor, a DRAM memory for supporting this, and a flash memory, repairs to radiation-induced damage can be made many times.
During the experiments, the flash memory can be recovered up to around 10,000 times and DRAM returned to its pristine state 1012 times. This means longer interstellar space travelling could take place, with the chip powered down every few years, heated internally to recover its performance, and then brought back to life.