Engineers install heat shield on NASA's Parker Probe

July 6 (UPI) -- For the first time in months, the Parker Solar probe is fully integrated. Engineers have reinstalled the spacecraft's next-generation heat shield, NASA announced this week.

For NASA's Parker Solar Probe, a spacecraft tasked with studying the sun, protection from extreme heat is obviously essential. The Thermal Protection System will provide that essential shielding.

The protective layer was installed last fall but was removed shortly afterwards. In the months since, the shield and spacecraft have been subjected to a series of intensive tests.

On its mission to study the sun's corona, the probe will fly within 4 million miles of the sun. The outside of the heat shield will reach 2,500 degrees Fahrenheit, but its insides, instruments included, will never get hotter than 85 degrees.

The Thermal Protection System features a 4.5-inch-thick carbon foam core sandwiched between layers of superheated carbon-carbon composite. The outside composite layer is sprayed with a heat-deflecting white coating. Because the foam core is 97 percent air, the entire heat shield weighs just 160 pounds.

"Because Parker Solar Probe travels so fast -- 430,000 miles per hour at its closest approach to the Sun, fast enough to travel from Philadelphia to Washington, D.C., in about one second -- the shield and spacecraft have to be light to achieve the needed orbit," NASA said in a recent update.

Scientists hope observations collected by the Parker Solar Probe will help them understand a variety of solar phenomena, including solar storms and coronal mass ejections. The probe's data is also expected to help NASA scientists better predict space weather.

Last month, NASA announced the probe -- originally scheduled to be launched at the end of July -- would blast-off "no earlier than Aug. 4, 2018."