January 28

Born in 1858 in Wales, Tannatt William Edgeworth David moved to Australia where he pursued a career in geology. He joined the faculty of the University of Sydney and became a leading earth science researcher. David led the first party to reach the summit of Mount Erebus during an Antarctic expedition. He conducted extensive surveys of Australia's geological resources, including coal and mineral deposits. His work earned him recognition as a pioneering explorer and academic administrator. David served as President of the Royal Society of New South Wales and shaped scientific policy. He passed away in 1934, celebrated for his contributions to geology and exploration.

Born in 1884, Auguste Piccard was a professor of physics at the University of Brussels. In 1931, he co-designed a pressurized gondola for a stratospheric balloon that broke altitude records. Piccard and his assistant reached over 15,000 meters, gathering valuable atmospheric data. Later, he developed the bathyscaphe, enabling manned descents into ocean depths. His 1954 dive reached nearly 3,150 meters in the Mediterranean Sea, expanding deep-sea research. Piccard's inventions advanced both aeronautical and oceanographic sciences. He received international acclaim and inspired future generations of explorers and inventors. Piccard died in 1962, leaving a legacy of scientific curiosity and daring exploration.

David Carl Hilmers (born 1950) is a U.S. Marine Corps colonel, physician, and NASA astronaut. He earned a medical degree from Stanford University and served as a flight surgeon with the Marines. Selected by NASA in 1980, Hilmers flew on four Space Shuttle missions between 1985 and 1993. His flights included satellite deployment, medical experiments, and materials research in microgravity. Hilmers logged over 566 hours in space and contributed to the development of space medicine. After retiring from NASA and the Marine Corps, he taught medicine and worked in emergency services. His unique career bridges military service, medical practice, and human spaceflight exploration.

Leonid Kostyantynovych Kadeniuk (1951–2018) was a Ukrainian Air Force pilot and the first astronaut of independent Ukraine. He earned his pilot wings in the Soviet Air Force before being selected for Ukraine’s inaugural astronaut program. In 1997, Kadeniuk flew aboard STS-87 on Space Shuttle Columbia, conducting botanical and materials science experiments. His flight included planting a tree seedling in microgravity symbolizing Ukraine’s future. After his mission, he served as a colonel and later held leadership roles in Ukraine’s space agencies. Kadeniuk received national honors for his contributions to science and exploration. He passed away in 2018, leaving a legacy as a pioneer of Ukrainian spaceflight.