A spacecraft designed to unlock the mysteries of the sun was launched early Sunday from Cape Canaveral, Fla.

United Launch Alliance sent the $1.5 billion Parker Solar Probe on a voyage that will bring it within 3.8 million miles of the sun at the highest speeds ever attained by a human-made device.

Scientists say that data should help them better understand the sun’s workings by tracing the flow of its energy, studying the solar corona and exploring the acceleration of solar wind.

Using Venus’ gravity to pick up speed, the probe will complete seven flybys in seven years to bring its orbit closer to the sun.

On its closest approach in 2024, the probe will travel at about 430,000 mph.