According to our current understanding of physics based on Einstein's theory of relativity, it is not possible for any object, including a spacecraft, to travel faster than the speed of light in a vacuum. The speed of light, denoted as 'c', is considered an absolute speed limit in the universe.
If we assume that a spacecraft could somehow surpass the speed of light, it would violate the principles of causality and lead to paradoxes such as time travel into the past. This is because as an object approaches the speed of light, time dilation effects become significant, and time itself slows down relative to an observer in a stationary frame of reference. However, reaching or exceeding the speed of light is currently considered impossible for massive objects.
Therefore, based on our current scientific understanding, it is not feasible for a spacecraft to travel faster than the speed of light and return to Earth within a single day. The vast distances between planets and stars would still require considerable travel time, even with advanced propulsion systems.