Washington, March 19 : NASA's Parker Solar Probe spacecraft has successfully made another close approach to the Sun. The spacecraft braved blisteringly hot temperatures as high as 1,400 degrees Celsius as it made its 15th close approach to the Sun, or perihelion, Space.com reported. According to NASA's Parker Solar Probe website, during the 15th flyby, the spacecraft reached within around 8.5 million km of the Sun's surface, the photosphere. That is closer than the innermost planet to the Sun, Mercury, which orbits the planet at over 6 times further away, around 54 million kilometres from the Sun. This close approach means Parker will come close to the Sun's outer atmosphere known as the corona. Parker Solar Probe is travelling at a speed of 559,530 kmh. Launched in 2018, the Parker Solar Probe aims to explore the mysteries of the Sun. The primary science goals for the mission are to trace the flow of energy and understand the heating of the solar corona and to explore what accelerates the solar wind. Parker Solar Probe also provides a statistical survey of the outer corona. Unlike Earth, the Sun doesn't have a solid surface. But it does have a superheated atmosphere, made of solar material bound to the Sun by gravity and magnetic forces. As rising heat and pressure push that material away from the Sun, it reaches a point where gravity and magnetic fields are too weak to contain it, according to NASA. /IANS