Launch of Sputnik 1: How soon to the moon?
来源：未知 作者：融绕豢 时间：2019-03-02 07:09:00
By Sir Harold Spencer Jones FRS This is a classic article from New Scientist’s archive, republished as part of our 50th anniversary celebrations THE successful launching by the Russians, at the first attempt, of an Earth satellite is undoubtedly a major technical triumph. In order to orbit the Earth in a circular orbit, a satellite must be projected with a speed of about 18,000 mph or 5 miles per second. Each orbital revolution is then completed in about 90 minutes. If the satellite is launched in a horizontal direction with a higher speed,