The fastest machine humanity has ever created is not one of the Voyager Spacecraft or New Horizons as one might expect. Instead, it is a space probe going in the other direction, towards the Sun to study it. Back in 2018, NASA's Parker Solar Probe set the record for the fastest human-created object (if you don't count microscopic particles) in the universe and then broke it in May this year. This weekend it's set to break it again.

Parker's previous speed record was 532,000 kilometers per hour (330,000 miles per hour). At that speed, you can get to the Moon and back in about 80 minutes rather than the traditional three-day journey just to get there, but that's still not fast enough for some purposes, so on Sunday, November 21, Parker will up its speed to 587,000 km/h (365,000 mph). That's 163 kilometers (101 miles) per second.

That's not the fastest Parker will ever move. Barring an unfortunate encounter with a space rock (which at these speeds wouldn't have to be large at all to prove catastrophic), Parker will eventually achieve a speed of 692,000 km/h (430,000 mph) in December 2024.

As the Michelson-Morely experiment proved, and Einstein explained, there is no universal cosmic still point, so speed is only meaningful relative to something. Parker's speeds are measured relative to the Sun, not Earth.

This will be the 10th flyby of the Sun by the probe, as it gets closer to the object of its affection. The increase of speed over time comes as the probe travels an elongated orbit, making short forays as close as 6 million kilometers (4 million miles) from the Sun, before hightailing it back out to cool off. In order to get closer to the Sun, Parker makes close approaches to planets to use their gravity to propel itself into orbits that can take it even closer to the Sun, and therefore faster. Last month it made its fifth flyby of Venus to obtain its current orbit. It will make two more major orbital adjustments before its mission is complete.

Setting speed records might be cool, but it's just a side-effect of the mission to learn about the Sun, and its immediate surrounds.“We’re observing higher than expected amounts of dust near the Sun,” Dr Nour Raouafi of Johns Hopkins Applied Physics Labs said in a statement. Parker studies the dust indirectly, using electrical sensors to examine the plasma clouds created when dust collides with the probe.

“What’s exciting about this is it’s greatly improving our understanding of the innermost regions of our heliosphere, giving us insight into an environment that, until now, was a total mystery,” Raouafi said. 

As impressive as these speeds are, Parker's peak will be 0.064 percent of the speed of light. Even if it could somehow maintain that maximum on an outward journey it would take 6,700 years to reach the nearest star. You can see why we need something different.