Venus In-Situ Surface Imager

Recent advances in wide-bandgap electronics has resulted in development of electronic circuits capable of operation in the high-temperature, corrosive environment of the Venus surface, leading to possibility of a future mission operating at the ambient temperature of Venus. However, the scientific instrumentation that would fly on such a mission still needs further development. In particular, it is highly desirable that any mission to the surface of Venus would include a camera, but designs for cameras that operate at temperatures of 450°C do not currently exist. We propose to develop an integrated imaging array capable of operating for long periods of time (months) in the ambient Venus surface environment (740K, 92 bars). All conventional approaches to operating a camera on the surface of Venus have required a sealed vessel to thermally isolate a camera from the environment, most specifically from the external temperature. This requires a protected, insulated, and windowed vessel, and the heat leak from the Venus thermal environment necessarily results in an operational lifetime of at most a few hours before the system undergoes thermal failure. Such systems also incur the significant penalties of increased spacecraft mass (and power, if active cooling is used.) In contrast, our proposed approach is intended to provide an imager with an extended operating lifetime at Venus ambient temperature, consistent with other long-lived lander technologies currently under active development. The combination of high-temperature integrated circuits (consisting of amplifiers, logic gates, and analog-to-digital converters) with small, wavelength-appropriate photovoltaic diodes allows for the construction of a low-mass, low-power imaging photodetector array that is able to function continuously for timescales comparable to a Venus solar day (117 Earth days). Following the example of the Viking Mars lander cameras, this effort will start with the demonstration of a low-bandwidth, linear array scanning platform capable of gradually building up a high resolution, visible light panorama of a landing site through a simple actuation mechanism. We will leverage significant high-temperature, harsh environment expertise in designing and manufacturing electronic circuits, optical detectors and components, and actuators to enable a mission-enabling advance in imaging for Venus exploration and science. There is driving science need for such a capability. Of twenty-five missions to land on Venus, only four have resulted in images from the surface, where the most recent images were collected in 1982. Visual imagery at a microscopic and macroscopic scale have been transformational for Mars science, which demonstrates that contextual images of rock and regolith texture at the millimeter scale, and landing site geology/geomorphology at the kilometer scale, are critical tools for interrogating and understanding the history and current state of a planetary surface. The high temperature, pressure, and reactivity of Venus' near-surface atmosphere make it unfeasible to repurpose and adapt instruments with significant flight heritage for use outside a thermally and chemically protected shell, so this development effort under the PICASSO program is both appropriate and needed. The imaging system produced by this effort would be suitable for deployment on future Venus landers and rovers, with a lifetime long enough to observe transient surface phenomena and over time obtain a suite of microscopic context images that would facilitate small sample analysis of rock grains and minerals. Demonstration of such a proof-of-concept system with photodetectors, electronics, and basic actuation mechanisms will provide the basis for a revolutionary new avenue of Venus exploration. More »