The next decade in space exploration is almost exclusively focused on Mars, a planet with atmospheric and surface conditions most conducive to human habitation in the solar system apart from Earth itself. Despite the fact that a trip to and from Venus would likely be 30 to 50-percent shorter in duration than a round trip to the Red Planet, the former has largely remained an inaccessible mystery to astronomers.
This might not come as a surprise, considering that Venus has the reputation of being the most hostile planet in the entire solar system. Definitely the hottest of the eight planets, it is blessed with a highly-corrosive and dense atmosphere that makes exploration of any kind almost impossible. The longest a space probe has managed to survive on this toxic inferno is 2 hours and 7 minutes, ending with its circuits getting badly scorched.
The probe in question is the 1982 Soviet Venera 13. Since then, astronomers have mostly avoided Earth’s sister planet, until now that is. Scientists at NASA’s Glenn Research Center claim to have developed the technology that could take us back to Venus. According to the team, the new and advanced circuitry is designed to withstand the planet’s harsh conditions up to 100 times longer than the previous record. Speaking about the project, Philip Neudeck, an electronics engineer at the space agency, said:
If you look at Mars missions, there’ve been rovers on the surface getting all sorts of scientific data. That dataset is totally missing from Venus, and that’s because the electronics don’t function on Venus.
Coming to why such robust electronics are needed in the first place, Venus has an average surface temperature of around 462 degrees Celsius (or 863 degrees Fahrenheit). In addition to being the densest of the four terrestrial planets in our solar system, it is surrounded by turbulent sulfuric acid skies and a carbon dioxide-rich atmosphere. These in turn result in extremely high atmospheric pressure nearly 92 times that of Earth.
Regular electronics will inevitably stop functioning under such severe conditions, which is why the Soviet missions made use of special thermal as well as pressure-resistant vessels with airtight chambers for the rover’s circuitry. The NASA engineers, however, have come up with something even sturdier: semiconductor integrated electronics built using silicon carbide. As explained by the team, silicon carbide has a much higher durability than normal silicon chips.
For instance, conventional silicon chips can withstand temperatures of up to 250 degrees Celsius (approx. 482 degrees Fahrenheit). Beyond this, the electrons in the circuits start behaving erratically because of the excess of energy in the system. For the purpose of testing, the researchers placed the newly-developed silicon carbide chips in the Glenn Extreme Environments Rig (or GEER), which is an 800-liter contraption that recreates the atmospheric and surface conditions prevailing on Venus.
The new technology, the scientists revealed, managed to last over 521 hours inside the GEER chamber, which is an enormous improvement from the previous record. During a similar experiment in the past, the silicon carbide integrated circuits were able to withstand an impressive 1,000 hours at temperatures of around 500 degrees Celsius (about 932 degrees Fahrenheit) and pressure equivalent to the Earth’s atmospheric pressure. Neudeck added:
We demonstrated vastly longer electrical operation with chips directly exposed – no cooling and no protective chip packaging – to a high-fidelity physical and chemical reproduction of Venus’ surface atmosphere. And both integrated circuits still worked after the end of the test… No one has ever made circuits run in this environment at this temperature for this long. It really opens up a whole new way of doing Venus missions.
The findings of the research were recently published in the AIP Advances journal.