Perigean spring tide Perigean spring tide A proxigean spring tide (also known as a perigean spring tide) is a tide that occurs three or four times per year when the Moon's perigee (its closest point to Earth during its 29.5-day elliptical orbit) coincides with a spring tide (when the Earth, Sun and Moon are nearly aligned every two weeks). This tide usually adds only a couple of inches to normal spring tides. The Moon's orbit around Earth is elliptical, which causes the Moon to be closer to Earth and farther away at different times. The Moon and the Sun are aligned every two
Earth orbit rendezvous and Gemini 7 rendezvoused in orbit in 1965, but without Agena. Next, Gemini 8 successfully docked with the Agena on March 16, 1966. The Agena-Gemini rendezvous also achieved other objectives in later Gemini launches, including docked orbital maneuvering (Gemini 10 and Gemini 11), inspection of the abandoned Gemini 8 ATV (Gemini 10) and space walks (Gemini 12). The EOR proposal for Apollo consisted of using a series of small rockets half the size of a Saturn V to put different components of a spacecraft to go to the Moon in orbit around the Earth, then assemble them in orbit. Experiments