The fastest man-made object ever built is the Parker Solar Probe, a spacecraft launched by NASA on August 12, 2018. The probe’s mission is to study the sun’s outer atmosphere and it’s environment, and it’s equipped with a variety of instruments to measure the solar wind, magnetic fields, and other solar phenomena.
As of 2021, the Parker Solar Probe has reached a top speed of 213,200 miles per hour (343,000 km/h) relative to the sun, making it the fastest man-made object ever built. It reached this speed on December 29, 2020, during its fourth close approach to the sun.
The probe is designed to withstand the extreme heat and radiation of the sun’s environment, it’s equipped with a heat shield that can withstand temperatures of up to 2,500 degrees Fahrenheit (1,371 degrees Celsius). It also uses a technique called “gravity assist” to increase its speed as it flies by Venus.
The Parker Solar Probe’s mission is to study the sun’s outer atmosphere and its environment, it’s expected to make 24 close approaches to the sun over the course of its 7-year mission, and each time it comes closer to the sun, its speed will increase, and it’s expected to reach a top speed of 430,000 miles per hour (700,000 km/h) before the end of its mission.
It’s important to note that the speed of the Parker Solar Probe is relative to the sun, because it’s in orbit around the sun, and the reference point is the sun, and not the Earth.