It will take six years for the probe to make to reach its closest point to the sun, in 2024, by using Venus’ gravity to bring itself nearer and nearer to the star.
The craft’s mission is to help scientists understand more about the nature of the sun by taking measurements of solar winds, a flow of ionised gases.
If scientists understand more about solar activity, they could use it to predict large solar eruptions that pose a threat to satellites orbiting the Earth.
Scientists also hope the probe can help them to answer why the corona, the outermost layer of the sun’s atmosphere, is 300 times hotter than its surface.
This is a phenomenon that has baffled NASA scientists because the sun’s atmosphere “gets much, much hotter the farther it stretches from the sun’s blazing surface”.
The probe, named after the American astrophysicist Eugene Parker, is scheduled to launch on 11 August 2018 at 8:33am (BST) from the Kennedy Space Centre in Cape Canaveral, Florida.