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The Pioneer programs were two series of United States lunar and planetary space probes exploration. The first program, which ran from 1958 to 1960, unsuccessfully attempted to send spacecraft to orbit the Moon, successfully sent one spacecraft to fly by the Moon, and successfully sent one spacecraft to investigate interplanetary space between the orbits of Earth and Venus.
The timeline of discovery of Solar System planets and their natural satellites charts the progress of the discovery of new bodies over history. Each object is listed in chronological order of its discovery (multiple dates occur when the moments of imaging, observation, and publication differ), identified through its various designations (including temporary and permanent schemes), and the ...
First communications satellite in geostationary orbit. First Olympic broadcast to international audiences. First tandem satellite broadcast (with Relay 1) August 19, 1964. United States. OSCAR-III. First amateur radio communications satellite (relay/transponder); first OSCAR powered by solar cells. March 9, 1965.
This timeline of artificial satellites and space probes includes uncrewed spacecraft including technology demonstrators, observatories, lunar probes, and interplanetary probes. First satellites from each country are included. Not included are most Earth science satellites, commercial satellites or crewed missions .
There are at least 19 natural satellites in the Solar System that are known to be massive enough to be close to hydrostatic equilibrium: seven of Saturn, five of Uranus, four of Jupiter, and one each of Earth, Neptune, and Pluto. Alan Stern calls these satellite planets, although the term major moon is more common.
Among them is Ganymede, the largest and most massive moon in the Solar System. Its 87 known irregular moons are organized into two categories: prograde and retrograde. The prograde satellites consist of the Himalia group and three others in groups of one. The retrograde moons are grouped into the Carme, Ananke and Pasiphae groups.
Contents. Formation and evolution of the Solar System. There is evidence that the formation of the Solar System began about 4.6 billion years ago with the gravitational collapse of a small part of a giant molecular cloud. [ 1 ] Most of the collapsing mass collected in the center, forming the Sun, while the rest flattened into a protoplanetary ...
United States. The Federal government of the United States has placed in heliocentric orbit: Pioneer 4 – Moon (1959) Ranger 3 – Moon (1961) Ranger 5 – Moon (1963) Mariner 2 – Venus (1962) Mariner 3 – Intended for Mars, communication lost when launch shroud failed to separate (1964) Mariner 4 – Mars (1964–1967) Mariner 5 – Venus ...