2016.A.1.2. Venus – many science goals for CubeSats / smallsats
Colin Wilson (1)
- University of Oxford, United Kingdom
Venus is an ideal target for cubesat / smallsat exploration: it is close to Earth (allowing quick access and high rate communications) and to the Sun (allowing ample power). Furthermore, it is Earth’s closest twin in many aspects, almost identical in size, apparently similar in bulk composition, and very likely still geologically active as evidenced by recent results from Venus Express. Understanding how and why Venus and Earth diverged in their evolution is one of the most pressing questions in comparative planetology today. Did Venus ever have liquid water oceans, or even life?
Here are some scientifically valuable mission goals for small spacecraft at Venus:
(1) Venus atmospheric escape orbiter – A small orbiter equipped with a neutral mass spectrometer, magnetometer and related payload could help understand water loss (and more generally atmospheric escape) at Venus.
(2) Lightning detecting orbiter – A simple UHF receiver would allow mapping the electromagnetic signatures of lightning. This could be complemented by a high-speed optical camera looking for coincident flashes.
(3) Atmospheric dynamics/chemistry orbiter – A ‘generic’ small or cube-sat equipped with a simple payload of imagers at different wavelengths could measure winds at different altitude levels, as demonstrated by the Japanese Akatsuki orbiter. Another topic of interest is sulphur dioxide: its extreme variability on Venus, which may be associated with volcanic activity, can be traced using UV imagers with 2-3 spectral bands.
(4) Surface mapper – Although Venus is completely enveloped by cloud, the surface can be mapped on the nightside using 1µm imaging; these can search for emissivity or temperature anomalies associated with volcanism.
(5) Gravity mapper – Measuring the distance between two small satellites following each other in orbit allows sensitive mapping of gravity field, as was demonstrated by the GRAIL lunar mission. Implementation of this at Venus would be useful for probing tectonics.
(6) Small entry probes – Venus, with its proximity to Earth, is an ideal first target for cubesat-class interplanetary entry probes. These could measure noble gases to trace Venus’ formation and evolution, either in the upper atmosphere from a skimming craft (e.g. JPL’s Cupid’s Arrow proposal) or from lower in the atmosphere. A traditional entry probe reaching the 1 bar level could address a number of topics in cloud science without trying to survive the hellish near-surface conditions.
Many of the above may be addressed by cubesat-class payloads. Viable mission architectures may require piggyback delivery by a larger Venus spacecraft.
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