Sputnik 19
Sputnik 19 was a
Soviet Venera-type spacecraft intended to make a landing on
Venus. The SL-6/A-2-e launcher put the spacecraft into
Earth orbit on
August 25,
1962, but the escape stage failed and the probe remained in geocentric orbit for three days until the orbit decayed on
August 28 and it re-entered Earth's atmosphere.
US Naval Space Command Satellite Situation Summary identified this vehicle as Sputnik 23. It is also known as Alpha Pi 1.