Wernher von Braun was a rocket scientist, not an astronomer. He was not known for using astronomical instruments. His work was primarily focused on the development of rockets and spacecraft.

While he may have used some basic astronomical tools for navigation or celestial observations, it's not something he's known for. His primary tools were:

* Wind tunnels: To test the aerodynamics of rockets.

* Test stands: For static firings of rocket engines.

* Calculators: For complex engineering calculations.

* Computer simulations: For modeling rocket performance and trajectories.

It's possible you're thinking of a different scientist, or perhaps you're remembering a specific event related to astronomy that he was involved in.

Could you please provide more context about what you're looking for?