FNRS-1 was the balloon that carried a human into the stratosphere in 1931.
The craft carried Swiss physicist Auguste Piccard and his assistant Paul Kipfer from Augsburg, Germany, on 27 May 1931. They reached about 15,785 metres, establishing a record for altitude reached by humans and proving that a pressurized gondola could support scientific observations at extreme height.
FNRS-1 was a stratospheric balloon, not an ordinary sport balloon. It used hydrogen for lift and a sealed aluminum gondola to protect its occupants from low pressure and freezing temperatures. Piccard designed the system partly to study cosmic rays.
The name came from the Belgian Fonds National de la Recherche Scientifique, which supported the project. Later flights, including FNRS-2, continued Piccard’s research, but FNRS-1 was the pioneering vehicle that first carried people into the stratosphere.