If a human were traveling at a constant speed in the vacuum of space with no form of protection, survival would be highly unlikely. Here's why:
Lack of breathable air: Space is a vacuum, meaning there is no atmosphere to provide oxygen for breathing. Within seconds or minutes (depending on factors like lung capacity and oxygen reserves), the lack of oxygen would lead to unconsciousness and eventually death due to asphyxiation.
Extreme temperatures: Space is characterized by extreme temperatures. In direct sunlight, temperatures can reach hundreds of degrees Celsius, while in the shadowed areas, temperatures can drop well below freezing. These extreme temperature variations can cause severe thermal stress on the body, leading to rapid and dangerous heat loss or overheating.
Radiation exposure: Space is filled with various forms of radiation, including solar radiation and cosmic rays. These high-energy particles can penetrate the human body, damaging cells and DNA. Prolonged exposure to such radiation would significantly increase the risk of developing radiation sickness, cancer, and other health issues.
Lack of pressure: In the vacuum of space, there is no atmospheric pressure. The absence of pressure would cause the liquids and gases in the body to rapidly boil or evaporate, leading to a condition known as "explosive decompression." This would cause severe damage to the body's tissues, potentially resulting in rapid incapacitation or death.
It's important to note that humans are not adapted to survive in the harsh conditions of outer space. Astronauts are able to travel in space by wearing specialized suits and being inside pressurized spacecraft that provide them with the necessary life support systems, including oxygen, temperature regulation, and protection against radiation.
Therefore, without proper protection and life support systems, survival in space is not feasible for humans or any living organisms as we know them.