NASA and SpaceX on Monday will launch its SPHEREx and PUNCH spacecraft missions tasked to create a three-dimensional map of hundreds of millions of galaxies in order to better understand our known universe.

The postponement, driven primarily by thick clouds, was the second scrub of the flight since an issue with the rocket on Saturday night.

Watch live as NASA launches the SPHEREx telescope and PUNCH mission aboard a SpaceX Falcon 9 rocket to explore the universe and the sun. SPHEREx will create a 3D all-sky map of 450 million galaxies, while PUNCH will use small satellites to study the sun’s impact on space weather and Earth’s communications.

The spacecraft, SPHEREx and PUNCH, had been expected to launch on a SpaceX rocket on Saturday. Two NASA missions will have to wait longer for a launch aboard a single rocket. Both aim to unravel mysteries about the universe — one by peering far from Earth,