The United States’ National Aeronautics and Space Administration has postponed the launch of a spacecraft that plans to go closer to the sun than any other mission before. The mission was scheduled for launch from Florida on Saturday morning local time.

The next attempt will be made during an hour-long window on Sunday, which starts at 1.01 pm Indian time.

The unmanned Parker Solar Probe was put off to allow engineers more time to investigate a red flag that was raised shortly before the launch, AFP reported. The countdown clock was interrupted when the rocket was on the launchpad, and the time window of 65 minutes for the launch elapsed before the problem could be resolved, reported BBC.

The spacecraft is expected to help scientists learn more about the atmosphere of the sun. The Parker Solar Probe, built at a cost of $1.5 billion, will fly into the sun’s outer orbit, known as the corona. In order to withstand the tremendous heat and solar radiation, the Parker Solar Probe will be protected by a 4.5-inch-thick carbon composite shield.

“The Parker Solar Probe will travel through the sun’s atmosphere, closer to the surface than any spacecraft before it, facing brutal heat and radiation conditions,” NASA said on its website. “The spacecraft will use Venus’ gravity during seven flybys over nearly seven years to gradually bring its orbit closer to the sun.”

The space agency said the probe will travel to within 3.8 million miles (6.11 million km) of the sun’s surface, within the orbit of Mercury. The earth’s average distance from the sun is 93 million miles.