Automaton Rover for Extreme Environments

Artist's conception of AREE on the surface of Venus, showing the wind turbine inside the rover's frame.

Automaton Rover for Extreme Environments (AREE) is a project to create a rover that uses Venus' harsh conditions to its advantage, controlled by a wind-powered mechanical computer. Venus' atmosphere is about 90 times denser than Earth's and heats to about 462 °C (864 °F), conditions which would prevent a standard electronic computer from operating for any significant period of time. While AREE was designed for operation on Venus, the rover's design could be re-purposed for use on Mercury, which has a comparably high surface temperature, on Jovian moons Europa or Io, where high radiation makes use of traditional electronics difficult, or on lava flows or highly radioactive areas on Earth.

The project was first proposed in 2015. NASA's Jet Propulsion Laboratory began seriously studying how AREE would operate in 2017.

Target

AREE's proposed target is near Sekmet Mons. This target was chosen because it is outside the parabolas of impact debris from any of Venus' impact craters, thus allowing the rover to directly study Venus' volcanic geology. AREE would travel northwest from its landing zone, crossing (and sampling) several lava flows. The proposed landing site is also located near a Tessera region, raising the possibility that the rover's mission could end with it exploring the Tessera.

Rover design

Though NASA initially planned to design an entirely mechanical rover, this was soon deemed to be impractical compared to a hybrid mechanical-electric design. AREE is to be powered primarily by a Savonius wind turbine. The turbine would directly drive the wheels and also store energy in a composite spring. The rover would also carry solar panels as a backup and for powering the onboard scientific instruments. AREE's most unique feature is its use of a mechanical analog computer instead of the more fragile electronic digital computers used in other robotic spacecraft. Instead of using a single general-purpose mechanical computer, like Babbage's analytical engine, the rover would rely on a suite of simpler, single-purpose devices distributed throughout the vehicle, analogous to World War II shipboard fire control computers. The rover would also use purely mechanical sensors for some of its instrumentation: temperature, wind speed, barometric pressure, seismic activity, and even chemical composition of samples can be measured mechanically.

The most challenging aspect of AREE's design is its communication with Earth. Multiple communication options are being explored, including a high temperature transponder, radar retroreflectors, and inscribing data on phonograph-style records that are then delivered to a high-altitude drone via hydrogen balloon.