NASA chief of the science mission directorate, Thomas Zurbuchen, said on Saturday that Parker is an "incredible hero of our scientific community", and called the probe one of NASA most "strategically important" missions.

Scientists have wanted to build a spacecraft like this for more than 60 years, but only in recent years did the heat shield technology advance enough to be capable of protecting sensitive instruments.

Tools on board will measure high-energy particles associated with flares and coronal mass ejections, as well as the changing magnetic field around the Sun.

When it nears the sun, the probe will travel rapidly enough to go from New York to Tokyo in one minute, making it the fastest human-made object.