Floating LEAVES Could Characterize Venus’s Atmosphere

Venus’s atmosphere has drawn a lot of attention lately. In particular, the consistent discovery of phosphine in its clouds points to potential biological sources. That, in turn, has resulted in numerous suggested missions, including floating a balloon into the atmosphere or having a spacecraft scoop down and suck up atmospheric samples. But a team of engineers led by Jeffrey Balcerski, now an adjunct at Kent State University but then part of the Ohio Aerospace Institute, came up with a different idea years ago – use floating sensor platforms shaped like leaves to collect a wide variety of data throughout Venus’ atmosphere.

The Lofted Environmental and Atmospheric Venus Sensors (or LEAVES) project was funded by NASA’s Institute for Advanced Concepts (NIAC) program in 2018. The mission design is simple enough: design lightweight platforms with a wide surface area, attach some low-cost and weight sensors to them, release them from a mothership transiting into orbit around Venus, and let those platforms float down through the Venusian atmosphere over the course of a few hours, all the while sending back atmospheric, chemical, and temperature data to the mothership.

There are a few enabling technologies behind the idea. The first is a lightweight yet robust and deployable structure that could support a platform of sensors and not be destroyed by Venus’s notoriously hellish environment. Designing this structure required understanding expected flight times and geolocation requirements, as well as the requirement that the system must be trackable by orbital radar in order to communicate back to the mothership. The resulting design resembles the famous inverted pyramid at the Louvre.

Inside that structure, the second enabling technology sits—harsh environment sensors designed to operate in Venus’s extreme environments. Chemical, pressure, and electrical sensors have undergone extensive development work over the past few years, and some are approaching readiness for use on Venus. They are also lightweight, allowing the structure to descend slowly, which is necessary to complete its mission goals.

After receiving the NIAC Phase I grant, the team led by Dr. Balcerski got to work modeling LEAVES’ structure and mission design. They quickly realized that delivery methodology and a system’s light weight would be critical to future missions. As such, they modeled depositing a series of upwards of 100 LEAVES throughout Venus’ atmosphere, each of which would be networked back to the mothership that deposited them as part of its planned orbital maneuver. They also thought there were several planned Venus missions, such as DaVINCI, which could easily take LEAVES on as a secondary payload with no real risk to mission success or uptime, as the LEAVES would fall and be destroyed by the lower Venusian atmosphere in a matter of hours.

But those hours of data, relayed back to the mothership and then on to Earth, could provide invaluable insights into the inner workings of Venus’s atmosphere. LEAVES would be able to reach a wide altitude range—it is estimated to operate between 100 km and 30 km in altitude. It could also be spread literally all over the world, allowing for a more complete picture of the Venusian atmosphere than other mission designs, which would only capture a small vertical slice of the atmosphere.

Given the potential impact of what we might find in the Venusian atmosphere, any mission designs that allow us to capture a large amount of information about a wide swath of it would be welcome. Dr. Balcerski and his colleagues think they have advanced the LEAVES concept to a Technology Readiness Level of 3-4. However, they haven’t yet received further support for LEAVES, and development appears to be on hold. But, given the increasing interest in exploring the Venusian atmosphere, perhaps it’s time to look at this lightweight, inexpensive way of doing so again.

Learn More:
Balcerski et al. – LEAVES: Lofted Environmental and Atmospheric Venus Sensors
UT – There are Mysteries at Venus. It’s Time for an Astrobiology Mission
UT – Scientists Have Re-Analyzed Their Data and Still See a Signal of Phosphine at Venus. Just Less of it
UT – The Clouds of Venus Could Support Life

Lead Image:
Artist’s depiction of several LEAVES falling through Venus’s atmosphere.
Credit – Balcerski et al.