On August 19, 1887, Dmitri Mendeleev made a solo ascent by balloon to an altitude of 11,500 feet to observe an eclipse. An excerpt from the article:
"Intent on observing a solar eclipse, a celebrated Russian chemist uses a hot-air balloon to make a solo ascent above the clouds near Moscow, even though he has never been in a balloon before and has no idea how to land one.
Even if Dmitri Ivanovich Mendeleev had never gotten around to outlining the principles of Periodic Law and ordering the original Periodic Table of the Elements — the achievements for which he is best remembered — this hare-brained balloon stunt would be enough to earn him a coveted spot in our This Day in Tech pantheon.
Mendeleev was a man of varied interests and appetites (he divorced his wife in order to marry the much younger friend of a niece), and among those interests was ballooning. Yet he never made an ascent until he decided to risk life and limb in order to get above the cloud cover for a proper look at the eclipse.
Clearing the clouds on that summer day over Klin required him to soar to an altitude of 11,500 feet. Mendeleev, who was famous for ignoring ancillary details to focus on the job at hand, stayed true to form. The eclipse was where his interest lay on this particular day, so he made the ascent over the objections of his family and without a care to navigation. His objective achieved, he finally turned his attention to landing the balloon, which he figured out, literally, on the fly."