Yes, the International Space Station (ISS) is constantly changing its vector due to its orbit around the Earth. It orbits the Earth at an altitude of approximately 400 kilometers (250 miles) and travels at a speed of about 28,000 kilometers per hour (17,500 miles per hour).
The ISS is in a state of freefall around the Earth, which means it is constantly falling towards the Earth due to gravity but moving forward with enough horizontal velocity to miss the Earth and keep orbiting. This balance between the gravitational pull and the forward velocity creates a curved path around the Earth.
Since the ISS is constantly changing its direction and velocity, the astronauts on board do experience the effects of acceleration. However, the acceleration they feel is not due to the change in velocity itself, but rather due to the change in direction or centripetal acceleration. In other words, the astronauts feel a force pushing them towards the center of the curved path they are following.
This centripetal acceleration is always directed towards the center of the circular orbit, perpendicular to the velocity vector. As a result, astronauts on the ISS feel a sensation of weightlessness because the centripetal acceleration counteracts the force of gravity, making them effectively weightless.