Into the hot zoneThe few brave robots that have pierced Venus’s thick clouds to reach the surface did not last long in the scorching tem-peratures (460°C) and overwhelming pressures (90 bars). Researchers at NASA’s Glenn Research Center in Cleveland, Ohio, and the Jet Propulsion Laboratory in Pasadena, California, are developing concepts for landers and rovers that could last months rather than hours. They would depend on silicon carbide circuitry that can handle the extremeenvironment. AutomatonRover forExtremeEnvironments(AREE)The AREE strives tobe mechanical rather than electrical. With no memory or centralized digital brain, the AREE could rove for months, using preprogrammed behaviors to avoid obstacles.Duration: >120 daysStatus: Prototype tested under venusian conditions by 2019. ForerunnersBetween 1970 and 1985, 10 Soviet Venera and Vega space-craft survived landing on Venus. They provided the first reportsfrom the surface of another planet.Duration: <2 hoursStatus: Russia is considering Venera-D for launch in the late 2020s. Dragplate 2 m Pressurizedcontainer Landingring 1.5 m 0.6 m 1. Sample collection tool: Collects and deposits rock samples for chemical analysis. 2. Radar reflectors: Rotating shutters reveal reflectors to an orbiter. The semaphores could transmit 1000 bits a day. 3. Turbine: A double-cupped turbine gathers wind energy and stores it in a spiral-shaped clockspring. 4. Tank tread: Inspired by World War I tanks, the caterpillar track provides a ramp for surmounting obstacles. Long-Life In-Situ Solar System Explorer (LLISSE)By surviving at least 60 days, the LLISSE could gather data across at least one night-day transition of Venus’s 117-Earth-day-long day.Duration: >60 daysStatus: Prototype tested under venusian conditions by 2021. Chip shotResearchers have turned to silicon carbide, an unreactive semiconductor increasingly used in modern power converter circuits. Silicon loses its semiconductor behavior above 300°C, whereas silicon carbide maintains it above 900°C. 1. Drag plates: Like feathers on a shuttlecock, plates help keep the lander oriented during descent through the thick atmosphere. 2. Turbine: Dual turbine contains inner cups and outer blades to maximize energy collection from slow surface winds. 3. Electronics: High-temperature circuits eliminate the need for a heavy, pressurized container. 4. Radio antenna: Planar antenna transmits data at tens of bits per second. Ceramic 175 transistors Transistorgate Metallayers Insulator Siliconcarbide Currentflow Built to lastChips are fixed within stable ceramics instead of polymers. Glenn research-ers baked chips inside a chamber that mimics venusian conditions. Outdoing ApolloModern chips contain billions oftransistors. But this silicon carbidecircuit has 175 transistors—more than the chips on the Apollo spacecraft. Etched for successCrisscrossed metal layers increasecircuit density. Silicon carbidejunction gates are used instead ofmodern chips’ metal oxide gates.
CREDITS: (GRAPHIC) C. BICKEL/SCIENCE; (DATA) NIAC NASA/JPL/CALTECH

Download this graphic