May 15

Events - Science & Technology

1602day.year

Cape Cod is sighted by English navigator Bartholomew Gosnold.

In 1602, English navigator Bartholomew Gosnold became the first European to sight Cape Cod.
Embarking from England in the ship Concord, Bartholomew Gosnold sought a shorter route to the spice-rich East Indies. Instead, he landed on the coast of present-day Massachusetts on May 15, 1602. Gosnold named the area Cape Cod for the abundance of fish along its shores. His voyage is recognized as one of the earliest English expeditions to New England. The crew charted local rivers and made contact with Indigenous peoples. Although they did not establish a settlement, their maps aided future colonization efforts. Gosnold’s discovery marked a significant moment in the exploration of North America.
1602 Cape Cod Bartholomew Gosnold
1618day.year

Johannes Kepler confirms his previously rejected discovery of the third law of planetary motion (he first discovered it on March 8 but soon rejected the idea after some initial calculations were made).

In 1618, Johannes Kepler confirmed his third law of planetary motion, relating orbital periods to distances from the Sun.
After his initial discovery on March 8, Johannes Kepler revisited his calculations and validated the third law of planetary motion. On May 15, 1618, he published his confirmation of the law stating that the square of a planet’s orbital period is proportional to the cube of its semi-major axis. This breakthrough completed Kepler’s set of laws describing planetary orbits. His work provided critical support for the heliocentric model proposed by Copernicus. The third law enabled more accurate predictions of planetary positions and laid groundwork for Newton’s theory of universal gravitation. Kepler’s achievement marked a milestone in the Scientific Revolution and transformed astronomy.
1618 Johannes Kepler third law of planetary motion March 8
1836day.year

Francis Baily observes "Baily's beads" during an annular eclipse.

During the annular solar eclipse of 1836, astronomer Francis Baily observed the phenomenon now known as Baily's beads.
On May 15, 1836, British astronomer Francis Baily witnessed bright points of sunlight peeking through lunar valleys at the moment of annularity. This phenomenon, later named Baily's beads, occurs due to the rugged lunar surface. Baily's detailed observations advanced the understanding of eclipse mechanics and lunar topography. His report spurred further scientific observations and precise mapping of the Moon's limb. The term Baily's beads honors his contribution to astronomy and eclipse studies.
1836 Francis Baily Baily's beads annular eclipse
1933day.year

All military aviation organizations within or under the control of the RLM of Germany were officially merged in a covert manner to form its Wehrmacht military's air arm, the Luftwaffe.

In 1933, Germany covertly merged its military air units to form the Luftwaffe, its official air force.
On May 15, 1933, the Reich Ministry of Aviation secretly consolidated all military aviation units into the Luftwaffe. This integration directly violated the Treaty of Versailles, which had prohibited Germany from maintaining an air force. Under the leadership of Hermann Göring, the Luftwaffe expanded rapidly, training pilots and developing advanced aircraft. The clandestine buildup laid the foundation for Germany’s air supremacy in the early years of World War II. By 1939, the Luftwaffe had become one of the largest and most technologically advanced air forces in Europe.
1933 RLM Wehrmacht Luftwaffe
1940day.year

USS Sailfish is recommissioned. It was originally the USS Squalus.

The USS Sailfish, formerly USS Squalus, was recommissioned in 1940 as a US Navy submarine.
Originally commissioned as USS Squalus and tragically sunk during trials in 1939, she was salvaged and renamed USS Sailfish. Recommissioned on May 15, 1940, the submarine returned to active duty. The refitted vessel served throughout World War II with distinction, earning multiple battle stars. Her resurrection symbolized American naval innovation and resourcefulness in wartime. The Sailfish continued to operate until decommissioning in 1945, leaving a legacy of survival and service.
1940 USS Sailfish
1941day.year

First flight of the Gloster E.28/39 the first British and Allied jet aircraft.

The Gloster E.28/39, the first British and Allied jet aircraft, made its maiden flight in 1941.
On May 15, 1941, the Gloster E.28/39 took to the skies as the first British jet-powered aircraft. Developed by Sir Frank Whittle’s team, this experimental plane demonstrated the potential of turbojet propulsion. Piloted by Flight Lieutenant P. E. G. S. Bulman, its successful flight validated key concepts that would revolutionize aviation. The E.28/39 paved the way for the iconic Gloster Meteor, the Allies’ first operational jet fighter. Its innovations accelerated the end of piston-engine dominance in military and commercial aviation. The jet age had truly begun, forever altering the course of aeronautical engineering and aerial combat.
1941 Gloster E.28/39 jet aircraft
1957day.year

At Malden Island in the Pacific Ocean, Britain tests its first hydrogen bomb in Operation Grapple.

Britain tested its first hydrogen bomb at Malden Island in Operation Grapple in 1957.
On May 15, 1957, the United Kingdom conducted its first hydrogen bomb test as part of Operation Grapple at Malden Island in the Pacific. This achievement made Britain the third nation, after the United States and the Soviet Union, to develop a thermonuclear weapon. The test’s success demonstrated advanced British nuclear capability and influenced Cold War deterrence strategies. British leaders hailed the milestone as a triumph of science and engineering. The series of Grapple tests in 1957–58 solidified Britain’s status as a nuclear power. The legacy of these tests continues to shape debates on nuclear policy and international security.
1957 Malden Island hydrogen bomb Operation Grapple
1963day.year

Project Mercury: The launch of the final Mercury mission, Mercury-Atlas 9 with astronaut Gordon Cooper on board. He becomes the first American to spend more than a day in space, and the last American to go into space alone.

Final Project Mercury mission launched, carrying Gordon Cooper on a solo flight that lasted over 34 hours, marking the first American day-long spaceflight.
On May 15, 1963, NASA launched Mercury-Atlas 9, the last mission of the Project Mercury program. Astronaut Gordon Cooper piloted Faith 7 in a solo flight that lasted over 34 hours. He completed 22 Earth orbits, becoming the first American to stay in space for more than a day. Cooper conducted scientific experiments and took photographs to gather data on human endurance. The mission demonstrated the feasibility of extended human spaceflight. Mercury-Atlas 9 paved the way for the Gemini and Apollo programs that followed.
1963 Project Mercury Mercury-Atlas 9 Gordon Cooper space
1997day.year

The Space Shuttle Atlantis launches on STS-84 to dock with the Russian space station Mir.

On May 15, 1997, the Space Shuttle Atlantis launched on STS-84 to dock with the Russian Mir space station, reinforcing U.S.-Russian cooperation in orbit.
NASA launched Space Shuttle Atlantis on the STS-84 mission on May 15, 1997. The shuttle docked with the Russian Mir space station, marking the sixth shuttle–Mir docking. The crew transferred supplies, experiments, and personnel between the two spacecraft. This mission furthered U.S.-Russian collaboration in preparation for the International Space Station. Astronauts conducted scientific research in microgravity conditions aboard Mir. STS-84 demonstrated the growing partnership in space exploration following the end of the Cold War era.
Space Shuttle Atlantis STS-84 Mir