Why are the astronauts equipped with a pistol? Is there an alien in space

Astronomers estimate is the world's highest risk factor of occupation, after all other work is more dangerous in the earth, the astronauts are to leave the earth in the vast space, although the space environment is very bad, the temperature difference between day and night can reach hundreds of degrees Celsius, and is in a vacuum, but although but not life the existence of environmental risk, basically there is no need to fight in addition to its own human goals, then why do astronauts also equipped with pistols such weapons? Is there any special use or fear of meeting aliens?

In fact, the astronauts equipped with pistols from 60 years ago to one thing, then Soviet spacecraft landing spacecraft navigation system, some failures, after the pilot was forced to manually operated landing, found from the target site is 3000 kilometers, this is not the worst thing, they found themselves out of the door in the forests, these forests will always haunt all kinds of animals, in this case a handy self-defense weapon is very necessary.

Based on the former Soviet Union began to accident for astronauts, designed a peculiar form of self-defense pistol TP-82, the astronaut exclusive and pistol pistol, with different characteristics are very different, the first is equipped with three barrels, and the equipment of ammunition were not ordinary bullets, in order to meet in vacuum the space environment, the equipment of the three calibre bullet is great, and the pistol shooting in addition to outside, the stock position can be split into machetes, better use can also in the field or in the jungle, and can also launch SOS etc.. So instead of calling this weapon as a pistol, it is better to be a comprehensive defense weapon.