Editing First Persistent Venus Aerostat (section)

=== Early Atmospheric Probes and Precursor Work ===
The FPVA did not emerge from a vacuum. Between 2089 and 2097 CE, the Venus Balloon Probe Series VB-12 flew a succession of uncrewed robotic platforms at various altitudes in the Venusian cloud deck. These missions, managed by the Venus Atmospheric Survey Consortium under Director Aleksei Vronsky, established baseline data on atmospheric chemistry, wind shear profiles, and envelope material degradation rates. The VB-12 series confirmed that sulphuric acid aerosol concentrations at 54 kilometres were lower than at 48 kilometres, and that envelope lifetimes of three to five years were achievable in principle — if material science could be advanced sufficiently.

The failure modes of the VB-12 probes were exhaustively catalogued by Vronsky's team. Micro-perforations caused by acid crystallisation at envelope seams accounted for the majority of losses. Two probes survived their full planned mission durations; three failed within 14 months. The data from the surviving probes, combined with analysis of the failure records, formed the engineering brief that Tanaka and Orvantes received when the Consortium issued a design competition in 2098 CE.