NASA’s New High-Temperature Components Could Enable Missions to VenusFebruary 21, 2017 by Robin Mitchell
NASA scientists work to make ICs more durable to survive the harsh conditions of the surface of Venus.
NASA engineers are creating ICs that can withstand extreme temperatures and pressures not found on Earth. Venus's harsh environment puts electronics to their toughest test yet.
Evolving electronic components are allowing us to explore to some of the most inhospitable places, from the edge of space to the deepest oceans. However, the surface of Venus seems to be one of the most difficult places to survive and only a handful of pictures of this harsh environment exist. To change this, NASA has developed ICs that can survive just a bit longer–in planetary exploration, every second counts!
Boldly Go Where No Chip Has Gone Before
Space, the final frontier. These are the voyages of the IC 8086, but its bold mission to Venus would not last more than five minutes thanks to the unforgiving environment there. Imagine a place that is always on fire. The air is crushingly thick with poisonous gases and the ground, itself, is sharp. It's a vivid description of hell, but it's also a decent interpretation of Venus.
Despite being further away from the sun than Mercury, Venus is the hottest planet with a daytime temperature of 462 degrees Celsius. The atmosphere is thick with carbon dioxide and sulphuric acid while having an atmospheric pressure of 92 bar at the surface (92 times that of the earth). In fact, the air pressure is so massive that it is the equivalent of being at a depth of 1km in the ocean (which would instantly crush a human if exposed).
The surface of Venus. Lovely for a death trap. Image courtesy of NASA/JPL
With this hellish thought, how do modern components cope in such a place? The short answer is that they don't.
Modern components simply cannot survive on the surface of Venus. Commercial parts are typically rated between 0°C and 70°C while industrial temperature ranges are typically -40°C to 125°C. See the issue? The surface of Venus typically sits above 400°C and has even been known to reach as high as 500°C, which would destroy any circuit in a very short amount of time.
So how can we expect to send probes to the surface of Venus and have them survive long enough to send information?
Believe it or not, a team from the Soviet Union did just this during the Cold War with their Verena mission which included the landing of several probes on the surface of Venus. The probes, themselves, did not survive for more than an hour after landing but were able to send back images of the surface revealing lava patties and rocks.
One of the few surface photos of Venus. Image in the public domain, accessed via the UCL Mathematics and Physical Sciences Flickr
NASA Says “Shoot To Chill”
To overcome the challenges that Venus presents, NASA has created semiconductor ICs that can survive Venus's temperatures for up to 500 hours.
NASA's Glenn Research Centre-based team tested two of these long-duration ICs in temperatures of 480°C (which were originally designed for jet engines) for 521 hours without failure. The test was devised after the same research group created 4h-SiC JFET integrated circuits with ceramic packaging that remained functional for over 41.7 days at 500 °C. However, this first test was conducted in Earth-atmosphere testing; therefore requiring the creation of a chamber that simulated the atmosphere of Venus (PDF). Using the same designed semiconductors as in the first test in this chamber, the time of functionality decreased by around half; however, this timespan remains a very productive window.
“With further technology maturation, such SiC IC electronics could drastically improve Venus lander designs and mission concepts, fundamentally enabling long-duration enhanced missions to the surface of Venus.” – Phil Neudeck, NASA
As a bonus, such ICs in missions to Venus not only have the benefit of surviving for longer periods but also reducing the overall weight of the probe (which, in turn, reduces the cost of sending a probe). So how is the weight reduced? Remember how the team from the Soviet Union landed probes on the surface of Venus? This was only possible because the probe had many pressure containment cases and plenty of cooling systems just to keep the electronics working for as long as possible, thus increasing the weight of the whole contraption significantly. A probe that is less affected by the heat will not need such temperature management (or at least not as much as the Venere probes).
The Venus landers had many bulky parts and cooling systems just to survive for an hour. Image via NASA
This reduced weight is a game-changer, especially when every moment of data captured on Venus is valuable. Even a probe that only survives a matter of days could be pivotal in changing our understanding of our neighbor planet. Advances in hardware are key to extending probe life. According to the researchers, "further-developed SiC JFET ICs will play a mission-enabling role in the first landers to return weeks of important science data from the surface of Venus."
Integrated circuits that can withstand harsher environments allows for us to constantly push the barriers of exploration and human understanding. It may not be long before we can start to explore deeper in our own planet's core or even in the atmosphere of the sun, which still holds many mysteries.