SpaceX was poised to launch another critical test flight of its massive Starship rocket on Sunday, a mission that comes with heightened stakes following a series of explosive setbacks this year.

SpaceX called off Sunday’s launch attempt of the Starship rocket about 15 minutes from launch.

In space, Starship will attempt to deploy mock Starlink satellites and reignite an engine along its suborbital path around the globe. Atmospheric reentry over the Indian Ocean will test its exterior steering flaps and an array of experimental heat shield tiles as the ship blazes through intense friction and heat.