After Virgin Galactic moved the start of its full commercial service to late next year, shares in the company plummeted.

Stock in Richard Branson’s space exploration company went down more than 20% in premarket trading after the company changed its schedule, delaying a test flight as well as the start of commercial services.

They were originally slated to begin in the third quarter of 2022, but are now set for the fourth.

Virgin Galactic says this delay is unrelated to the recent inquiry into a potential defect in a supplier component and noted that has “been successfully resolved.”

Related: FAA Clears Virgin Galactic for Take Off

The company announced the delays Thursday in a press release that also revealed Virgin Galactic will begin its planned enhancement program for VMS Eve and VSS Unity. The Unity 23 test flight will happen after the enhancement work is completed.

Virgin Galactic CEO Michael Colglazier said in a statement, “Our decisions are driven by detailed and thorough analysis, and we fly based on the most accurate and comprehensive data available. Virgin Galactic vehicles are designed with significant margins for safety, providing layers of protection that far exceed loads experienced and expected to occur on our flights. The re-sequencing of our enhancement period and the Unity 23 flight underscores our safety-first procedures, provides the most efficient path to commercial service, and is the right approach for our business and our customers. We are deeply appreciative of the Italian Air Force Research Mission and grateful for their continued partnership with us in this test flight program.”