Sputnik 3

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Sputnik III

Organization:	Soviet Union
Major Contractors:	Korolev Design Bureau
Mission type:	Earth Science
Satellite of:	Earth
Launch Date:	May 15, 1958 at 07:12:00 UTC
Launch Vehicle:	modified R-7/SS-6 ICBM
Decay:	April 6, 1960
Mission Duration:	692 days
NSSDC ID:	1958-004B
Webpage:	NASA NSSDC Master Catalog
Mass:	1,327 kg
Orbital elements
Semimajor Axis:	7418.7 km
Eccentricity:	.110932
Inclination:	65.18°
Orbital Period:	105.9 minutes
Apoapsis:	1,864 km
Periapsis:	217 km
Orbits:	~10,000
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Instruments
Upper Atmosphere :	Composition of the upper atmosphere
Geiger counters :	Charged particles
Micrometeoroid detectors :	Micrometeoroids

Sputnik 3 (Russian: Спутник-3, Satellite 3) was a Soviet satellite launched on May 15, 1958 from Baikonur cosmodrome by a modified R-7/SS-6 ICBM. It was a research satellite to explore the upper atmosphere and the near space. Due to a hardware failure of its tape recorder, the satellite failed to detect the Van Allen radiation belt.

In July 1956, the Soviet Union's OKB-1 drafted a project to design and build the first Earth satellite, designated ISZ (Artificial Earth Satellite). Sputnik 3 was planned to be the first satellite launched by the Soviet Union. The new R-7 intercontinental ballistic missile was ready to launch before Sputnik 3 was ready. The Sputnik 3 completion date kept slipping and Sergi Korolev substituted the relatively simple Sputnik 1 as the first satellite to be launched, instead. The Sputnik 2 was also ready earlier and launched earlier than Sputnik 3. Korolev was concerned that if he waited for Sputnik 3 to be ready, the United States would be the first to launch an artificial satellite.

Sputnik 3 was an automatic scientific laboratory spacecraft. It was conically shaped and was 3.57 m long and 1.73 m wide at its base. It weighed 1,327 kg. The scientific instrumentation (twelve instruments) provided data on pressure and composition of the upper atmosphere, concentration of charged particles, photons in cosmic rays, heavy nuclei in cosmic rays, magnetic and electrostatic fields, and meteoric particles. The outer radiation belts of the Earth were detected during the flight. Its tape recorder failed, so it could not map the Van Allen radiation belt. The spacecraft remained in orbit until April 6, 1960, when the orbit degraded from drag in upper atmosphere to the point causing the satellite to enter the atmosphere.