SpaceX’s massive Starship rocket just took off shortly after 8AM ET from the company’s Starbase launch facility in Boca Chica, Texas.

A few minutes after the launch and a planned “hot stage” separation, the Super Heavy booster exploded instead of continuing its planned descent and water landing, but Starship itself continued into space. Minutes later, the SpaceX team said it had not received any signal from the booster and that they may have lost the ship.

That far into its flight, the craft was likely no longer in range of ground stations, but it appears the craft’s flight termination system engaged soon after its Raptor engines shut down.

This marks the second launch attempt for the 397-foot-tall rocket, which uses a two-stage system that separates a few minutes into launch, with the booster intended to set back down.

Although the Starship launch was originally scheduled to take place on November 17th, SpaceX pushed back the flight to replace a grid fin actuator, a component that helps guide the Super Heavy booster to its destination.

This launch test made it much farther along than the previous attempt. Starship’s first test flight in April ended in failure. The rocket burst into flames shortly after its launch and fired detonators to self-destruct. SpaceX blamed the failure on leaking propellant from the Super Heavy booster, stating it “severed connection with the vehicle’s primary flight computer.” The company couldn’t conduct another launch until it addressed the Federal Aviation Administration’s 63 corrective actions.