While orbiting the Earth, astronauts do experience a phenomenon known as time dilation, but it is not the same as time travel in the conventional sense. Time dilation is a consequence of the theory of relativity, specifically the principle of time passing differently for objects in motion relative to each other.
According to the theory of relativity, as an object moves at high speeds relative to another object, time will appear to pass more slowly for the moving object when observed from a stationary reference frame. This effect is known as time dilation.
Astronauts aboard the International Space Station (ISS) experience a small degree of time dilation compared to people on Earth. However, the difference in time is extremely small due to the relatively low velocities involved in the ISS's orbit. The effect is on the order of a few milliseconds or microseconds over extended periods of time. Therefore, the time dilation experienced by astronauts in Earth orbit is not significant enough to have practical implications or noticeable effects on their daily lives.
For significant time dilation effects, such as those depicted in science fiction or discussed in theoretical physics, extremely high speeds or massive gravitational fields would be required. These conditions are not currently achievable with our current technology and understanding of the universe.
So, while astronauts experience a minuscule amount of time dilation during their space missions, it does not result in them traveling through time or having substantial differences in the passage of time compared to people on Earth.