Probe breaks all speed records

In the Parker Solar Probe’s quest to venture ever closer to the Sun’s atmosphere, the probe has reached incredible speeds – and will keep getting faster until Christmas.

On 27 September last year, the Parker Solar Probe roared past the Sun at a speed of 635,266km/h – that’s 700 times faster than any airliner. It was the closest a craft has ever gone to the Sun, and easily the fastest speed any human-made craft has achieved.

The solar probe gained its amazing speed record by harnessing the Sun’s gravitational field to pull it ever faster towards the Sun. The 685kg NASA probe is the size of a small car, and flew past the Sun at a distance of 7.26 million km, just 5% of the approximately 150 million km between the Earth and Sun. The previous record for orbiting close to the Sun was set by the Helios-B probe back in 1976, when it passed 44 million kilometres from the Sun.

The Parker Solar Probe’s mission is to study the Sun, including why the Sun’s outer atmosphere – known as the corona – is millions of degrees hotter than the star’s surface.

The Parker Solar Probe will also gather new knowledge about the solar wind, the flow of electrically-charged particles emitted by the Sun at high speeds. These particles produce auroras when they strike Earth’s atmosphere.

En route, the temperature of the solar probe’s 11.5cm-thick carbon heat shield reached 1377°C, because the sunlight close to the star is 475 times brighter than on Earth. The shield was an essential part of the probe’s design, to protect the relatively sensitive intruments it carries. The shield has managed to maintain the probe’s instruments at around 30°C.

The solar fly-past on 27 September was the Parker Solar Probe’s 17th encounter with the Sun so far. During its seven-year-long mission, the probe will orbit the Sun a total of 24 times. With each orbit, the probe will get ever closer to the surface until 24 December 2024, when Parker is expected to pass by the Sun at a distance of just 6.2 million kilometres.

And the closer it gets to the surface, the faster the probe will travel – so the Parker Solar Probe is not done setting records yet. During the December 2024 fly-past, NASA’s Goddard Space Flight Center predicts the probe will reach speeds of up to 692,000km/h.