September 28

On September 28, 1889, the third General Conference on Weights and Measures (CGPM) adopted the International Prototype Metre, a platinum-iridium bar stored in Sèvres, France, as the definitive standard for the metre. The decision provided a uniform basis for length measurement worldwide, replacing earlier diverse national standards. The bar was precisely machined to maintain stability and was compared against national prototypes to ensure consistency. This agreement laid the foundation for modern metrology and facilitated international scientific and commercial collaboration. The original prototype remained the official reference until newer definitions based on the speed of light were introduced in the 20th century.

On September 28, 1924, the U.S. Army Air Service completed the first successful aerial circumnavigation of the globe, concluding a journey that began on April 6 of that year. The mission used four Douglas World Cruisers and covered approximately 27,528 miles with stops in Europe, Asia, and the Pacific. Despite mechanical breakdowns and adverse weather, three of the four aircraft returned together, demonstrating the feasibility of long-distance air travel. The expedition tested navigation techniques and highlighted the potential of aviation technology. Capturing global attention, it marked a milestone that paved the way for commercial airlines and military air transport.

On September 28, 1928, Sir Alexander Fleming observed that a Petri dish containing Staphylococcus bacteria had been contaminated by a mold that created a clear, bacteria-free zone. He identified the mold as Penicillium notatum and realized it produced a substance capable of killing a wide range of bacteria. Fleming named this substance 'penicillin' and published his findings in 1929, although he was unable to purify it fully at the time. His discovery laid the vital groundwork for the development of antibiotics that would save millions of lives. Penicillin revolutionized modern medicine by enabling effective treatment of bacterial infections and is widely regarded as one of the greatest medical breakthroughs of the 20th century.

On September 28, 1951, CBS began selling its color TV Model CT-100 in select markets across the United States. The system used a field-sequential color method that delivered vivid images but required a rotating color wheel. Early sets were expensive and incompatible with existing black-and-white broadcasts, limiting consumer adoption. RCA's later all-electronic color standard ultimately became the industry norm. CBS discontinued its model less than a month after launch due to production costs and low demand. This brief venture paved the way for the color television revolution that followed in the late 1950s and 1960s.

On 28 September 2008, SpaceX successfully launched Falcon 1 on its fourth flight—designated the RatSat mission—from Omelek Island in the Pacific. Falcon 1 became the first privately developed, liquid-fueled rocket to place a satellite into Earth orbit, carrying a 165-kilogram mass simulator built by the Malaysian space agency. The achievement marked a turning point in commercial spaceflight, proving that private companies could conduct reliable orbital missions previously reserved for national governments. Prior test flights had ended in engine failures and structural issues, making this success especially significant. The mission paved the way for the development of larger Falcon 9 rockets and the Dragon spacecraft, transforming access to low Earth orbit. SpaceX's milestone spurred investment and innovation in the emerging private aerospace sector.