VLBI-experiments were constantly carried out between Soviet and American radio telescopes, despite the political winds. One such experiment is related to astronautics.
The VEGA balloons for study Venus atmosphere were tracked by two networks of 20 radio telescopes in total back on Earth: the Soviet network, coordinated by the Soviet Academy of Sciences and the international network, coordinated by Centre national d'études spatiales of France (CNES).
In the book "Infinity Beckoned: Adventuring Through the Inner Solar System, 1969–1989 Jay Gallentine, U of Nebraska Press, 2016, 504 pp" tells little-known facts of cooperation between the United States and the USSR.
Scientists from the two nations had finally connected in early September ’83. They met on neutral ground, at the French space agency in Paris, and a palpable tension clouded the occasion because Soviet fighter jeta is had just shot down a Korean airliner on September 1. As soon as Preston got in he was accosted by men from the U.S. State Department who told him, “Don’t meet the Soviets.” Accordingly, the Yanks took one floor of offices and conference rooms, while the Reds had another.
“For radio tracking, the U.S. and the Soviets were the real experts,” not the French. During such early meetings as this one, procedures for accurate shadowing of the balloons dominated all conversation. Getting in even an edgewise word about more payload seemed, for the time being, near impossible.
Via many interpreters, Preston’s team now suggested that they provide .1 device on the balloon payloads to measure cloud density. It seemed perfectly applicable to something like an airship and met with rapturous support. Instead of just helping to track balloons, the United States was now going to Venus.