4 October 1957: Sputnik satellite blasts into space (2 clips)

A Russian satellite has been launched into space -- the first man-made object ever to leave the Earth's atmosphere. The Russian news agency, Tass, said the satellite Sputnik was now 560 miles (900 kilometres) above the Earth and circling it every hour-and-a-half. Scientists predict the metal sphere will eventually burn up in the atmosphere but they hope it will send important data back to Earth before doing so. Dr A A Blagonravov, who is believed to have been closely involved with the preparations for the launch, described Sputnik as"the simplest kind of baby moon". He attributed its weight -- 180lb (83.5kg) -- largely to heavy batteries. The satellite's weight has led some American experts to speculate that the rocket which launched it might also be capable of carrying a nuclear weapon thousands of miles. The fact that Sputnik is expected to fly over the US seven times a day has also caused unease. There have already been calls for an immediate review of US defences, given the implications of the technological leap ahead by a political enemy. More clips: Sputnik Launched, October 4, 1957 on Matt's Today in History.