today's spacecraft typically travel at a fraction of the speed of light that is much lower than the speed of light itself. Most of our current spacecraft, including those used for crewed missions and interplanetary probes, travel at speeds much slower than 1% of the speed of light.
For example, some of the fastest spacecraft sent to date, like NASA's Parker Solar Probe, which launched in 2018, can reach speeds of about 430,000 miles per hour (700,000 kilometers per hour) relative to the Sun. While this is incredibly fast compared to everyday speeds on Earth, it's still only a tiny fraction of the speed of light, which is approximately 670,616,629 miles per hour (299,792,458 meters per second).
It's worth noting that there are ongoing research and theoretical proposals for spacecraft propulsion systems that could potentially achieve higher velocities in the future, such as solar sails, ion propulsion, or even nuclear propulsion. However, none of these propulsion systems have been used for spacecraft that travel anywhere near a significant fraction of the speed of light.