How was Pioneer 10 able to escape the solar system with an initial speed less than escape speed?

Pioneer 10 was able to escape the solar system despite an initial speed less than the escape velocity due to a combination of gravitational assists and its trajectory. After its launch in 1972, it performed a close flyby of Jupiter in 1973, where the planet's massive gravity provided a significant boost to its speed. This gravitational slingshot effect increased Pioneer 10's velocity enough to allow it to surpass the solar system's escape velocity and continue its journey into interstellar space.