Space is a vacuum, devoid of air and atmospheric pressure. Surviving in this environment requires sealed and pressurized spacesuits or spacecraft that provide a life-sustaining atmosphere for astronauts. Additionally, space experiences extreme temperatures ranging from extreme cold to intense heat, necessitating thermal control systems to protect astronauts and equipment.

In space, the effects of gravity are significantly reduced, leading to a microgravity environment. This poses challenges to human health, as prolonged exposure to microgravity can result in muscle and bone loss, cardiovascular changes, and weakened immune systems. Countermeasures such as exercise regimens, specialized equipment, and advanced medical monitoring are employed to mitigate these effects.

Space is filled with different forms of radiation, including cosmic rays and solar radiation, which can be harmful to living organisms and sensitive electronics. Shielding materials, such as layers of metal or specialized radiation-resistant materials, are utilized to minimize radiation exposure and protect astronauts and equipment.

Space is populated with micrometeoroids and space debris, which pose a significant threat to spacecraft and astronauts. Protective shielding, such as reinforced hulls and shielding materials, is employed to reduce the risk of impacts and damage.