Page "Laika" Paragraph 7

According to Russian sources, the official decision to launch Sputnik 2 was made on October 10 or 12, leaving the team only four weeks to design and build the spacecraft.

Sputnik 2, therefore, was something of a rush job, with most elements of the spacecraft being constructed from rough sketches.

Aside from the primary mission of sending a living passenger into space, Sputnik 2 also contained instrumentation for measuring solar radiation and cosmic rays.