SOLAR SYSTEM

Detailed explanation-1: -In the earlier days of space exploration, nobody knew if people could survive a trip away from Earth, so using animals was the best way to find out.

Detailed explanation-2: -Without animal testing in the early days of the human space program, the Soviet and American programs could have suffered great losses of human life. These animals performed a service to their respective countries that no human could or would have performed.

Detailed explanation-3: -Soviet rocket scientists wanted to send dogs to space to better understand what launch, microgravity and other aspects of spaceflight might do to a human body. So they collected stray dogs, who they thought would be suitable scrappy.

Detailed explanation-4: -Before humans went into space in the 1960s, several other animals were launched into space, including numerous other primates, so that scientists could investigate the biological effects of spaceflight.

Detailed explanation-5: -Five months later, after 2, 566 more orbits, Sputnik 2 reentered the atmosphere and was incinerated by the heat of reentry, cremating Laika in the process. More animals would follow, and just three years later, in April of 1961, so would Yuri Gagarin, the first human being in space.