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. ...
... a) As source material for the high-school or college curriculum, especially in physics. astronomy and their history. (b) As a source of supplemental projects by high school students or by undergraduates. (c) As material for independent studies, In particular by motivated students who seek to know more about space . ... Those wishing to look up specific topics are advised to use the index file, accessible from the end of any "Exploration" file. ... files not listed and at other resource material. ...
... Jupiter's big moon Ganymede is not only the size of a planet -- it sounds like one too, as heard in audio recordings made from data returned by NASA's Galileo spacecraft released today. ... Characterized by a soaring whistle and hissing static, Ganymede's song reveals that the Solar System's largest moon is also the only one known to possess a planet-like, self-generated magnetic cocoon called a magnetosphere , which shields the moon from the magnetic influence of its giant parent body, Jupiter. ...