Launch of Explorer 1 . Click here for a full size version of this image. ... The USSR was first, sending off its first "Sputnik" ("satellite") on October 4, followed by Sputnik II on November 3. ... News conference following the launch of Explorer 1 . ... Unlike the orbits of the Sputniks, that of Explorer 1 was quite elliptical and it rose to an altitude of about 2500 kilometers. ... Explorer 2 failed to orbit, but Explorer 3, launched March 26, was successful, and it did carry a tape recorder. ...

... This realization, in the years after World War II, turned the military into a major supporter of rocket development, especially in the US and in the USSR, the Soviet Union (now the Russian republic and its allies). ... launched the Sputniks. ... Today all space launches employ clamps to hold the rocket down during those seconds, until full thrust is achieved; if you ever watch the countdown of a spaceflight launch, you might note that "ignition" comes a short instant before "lift-off. ...

... ESA/NASA Solar Probe . ... Mission Operations . ... Ulysses is a solar probe launched in 1990 that has made the first-ever measurements of the Sun from a polar orbit. ... Formerly called the International Solar-Polar Mission (ISPM), Ulysses is an exploratory mission carried out jointly by ESA and NASA. ... NASA provided the launch aboard the Space Shuttle Discovery (together with the upper-stage motor) and the spacecraft power generator, and is responsible for the remaining experiments. ...