Because the Sputnik program ended with Sputnik 3. Albeit there was a Sputnik 40 and 41 but these were to commemorate the 40th anniversary of Sputnik 1.
Sputnik 1 was launched on the 4th of October, 1957. The booster used by it had been used in August of that year to launch a long range missile.
The Explorer 1 was launched on January 31,1958 one year after the Sputnik 1,and Sputnik 11
Sputnik 1
First Soviet SatelliteIt was called the 'Sputnik' and was put into orbit on October 4th, 1957. The timing was 'tweaked' to mark the 40th anniversary of the Russian Revolution of 1917.
The USSR built the Sputnik.
The USSR built the Sputnik.
Sputnik 1 was the first human-built thing that was launched into orbit and functioned while there.
Sputnik was a series of satellites built and launched by the then Soviet union. Sputnik 1 and 2 became the first two man made objects to attain orbit around the Earth.
Russia, I believe
1957
It was basically a metal shell around some electronics and a couple of batteries.
the 2 in Sputnik 2 means it is the second to be built.
It means it was the first sputnik.
Sputnik 1 was a Russian satellite.
Sputnik was the "family name" for a series of satellites, so there never was a satellite named only Sputnik. They all had numbers with Sputnik 1 being the first.
Because the Sputnik program ended with Sputnik 3. Albeit there was a Sputnik 40 and 41 but these were to commemorate the 40th anniversary of Sputnik 1.