Parker Solar Probe Becomes Fastest-Ever Spacecraft

At about 10:54 p.m. EDT, Parker Solar Probe surpassed 153,454 miles per hour relative to the sun

Of course, it’s going downhill, so that makes it easier. And as it’s still approaching the sun, it will continue to accelerate. At perihelion in 2024 (it will reach perihelion for the first time this coming November 6, and do so again April 4, but it will also do a number of passes by Venus which will gradually shrink its orbit and drop its perihelion), it’ll be zipping along at about 430,000 mph. That’s about 1/1560 the speed of light. If it could keep that speed – and it can’t – it could get to Alpha Centauri in a mere 6700 years. If it was heading towards Alpha Centauri, which it won’t be.

Compratively, the New horizons probe to Pluto achieved it’s top speed relative to Earth just after launch… 36,373 mph. But it, of course, was going uphill.