The United States space agency, NASA, has postponed the launch of the unmanned Parker Solar Probe rocket, which was due on a voyage to the Sun, until Sunday to allow engineers more time to investigate a red flag that was raised in the last moment before liftoff. The $1.5 billion rocket was set to launch from Cape Canaveral, Florida on Saturday in a bid to move closer to the Sun than ever before. NASA had a weather window of 65 minutes to launch, but the time elapsed before the issue could be resolved. The rocket was on the launch pad when the countdown clock was interrupted, as officials investigated an alarm. Engineers detected the gaseous helium pressure alarm on the spacecraft, which was way heavier than expected. The launch is now scheduled for 3:31am (0731 GMT) on Sunday. The Parker Solar Probe spacecraft, which is the size of a car, aims to plunge into the Sun’s sizzling atmosphere and become humanity’s first mission to explore a star. The probe’s main goal is to unveil the secrets of the corona, the unusual atmosphere around Sun.