From Radio and TV News, Feb, 1958.
The first announcement by Radio Moscow indicated that there were two transmitters in the satellite (launched October 4, 1957-ed.), one operating at 20.005 mhz and the other at 40.002 mhz. The pulse of each signal was 0.3 seconds, followed by a pause of similar length during which the other signals were transmitted. On Oct. 8 the signals were not received for several hours. Later, signals resumed but became continuous. The transmitter was specified to be 1 watt. U.S. Monitors agreed that the signals were modulated with telemetry data.Appropriate instruments within the satellite reported on atmospheric pressure and density. Also, information on micrometeorite bombardment was probably transmitted.
First U.S. radio reception of the satellite's signals was reported by RCA Communications, Inc. at Riverhead, L.I. The observation occurred at 8:07 p.m. EDT October 4, the day of the launching. At 8:15 the signal was strongest from the south. First reception at the Naval Research Laboratoryin Washington, D.C. was at 8:30 p.m. By October 6, six of ten Minitrack stations had been converted from 108 mhz-the frequency to be used by U.S. satellites-to 20 and 40 mhz to track the USSR satellite.
Radio reception was soon general and reports of continuous monitoring were received from Antarctic IGY (International Geophysical Year-ed.) stations including the South Pole-which is in a position to hear the satellite on virtually every passage-as well as from IGY drifting station A, an ice floe located about 500 miles from the North Pole.
Reports from the Amundsen-Scott South Pole Station indicated that the satellite's radio signals cut in abruptly but faded out gradually and that there were numerous variations in signal strength, duration and pulse rate.
The USSR was reported to be encouraging amateur assistance, offering special cards to hams reporting receipt of the satellite's radio signals.
Radio Moscow announced on October 26 that the satellite's radio had used up its power and had stopped working. On the same day, the Naval Research Laboratory reported that no signals had been received by Minitrack stations since 5:50 p.m. EDT, October 25, and that no other information had been relayed to NRL from other receiver sources since 7:10 p.m. EDT October 25.
Thus, after 3 weeks of continuous operation, space's first radio transmitter had gone dead.
This was big stuff when I was a kid. We all watched with bated breath as the Navy launched Vanguard TV3 on December 6, 1957 , which got about ten feet off the deck and exploded in a spectacular fireball. There is a fascinating history of the Vanguard program by Constance Green and Milton Lomask located here, and it's well worth reading-not the least important part is the foreword by the Lone Eagle, Charles Lindbergh.
In 1958 the Army strapped its first Explorer 1 satellite to the nose of a Juno 1 rocket , followed thereafter by the first successful Vanguard launch of what Premier Khrushchev snidely referred to as a grapefruit, weighing only a few pounds. TV4, equipped with solar cells, transmitted until 1964 and is still happily tooling along in earth orbit today, 51 years later.
As technology goes, about all Sputnik 1 did was thumb its nose at Uncle Sugar for three weeks, until its tiresome bleat "I'm here! I'm here!" went dead. Shortly thereafter, Sputnik 1 burned up in earth's atmosphere on January 4, 1958.