On 23 September 1999, NASA lost contact with the Mars Climate Orbiter after a catastrophic navigation error caused by one team using imperial units and another using metric. The spacecraft, which cost $125 million and had travelled for nine months, burned up in the Martian atmosphere. This episode examines that expensive mistake alongside three other moments from the same date: the deification of Drusilla, sister of Roman Emperor Caligula, in 38 AD, making her the first Roman woman granted divine status; the fatal 1910 Alpine crossing by 23-year-old aviator Jorge Chávez, who became the first person to fly over the Alps in a Blériot XI monoplane before his aircraft collapsed on landing; and the 1884 grounding of the steamship Arctique near the Strait of Magellan, which accidentally triggered the Tierra del Fuego gold rush when survivors discovered gold deposits nearby. Each story reveals the often uncomfortable gap between human intention and historical outcome.
