SS2 Unity flight two
Virgin Galactic's second SpaceShipTwo, VSS Unity, during a powered test flight. Credit: & Trumbull Studios

HUNTSVILLE, Ala. — Virgin Galactic will postpone a SpaceShipTwo suborbital spaceflight that had been scheduled for this month, electing to instead immediately begin an extended maintenance period for the spaceplane and its carrier aircraft that will further delay the start of commercial flights.

The company said Oct. 14 that it decided to move directly intended a planned maintenance period after a recent lab test of materials used on the vehicles “flagged a possible reduction in the strength margins of certain materials used to modify specific joints” that “requires further physical inspection.”

“While this new lab test data has had no impact on the vehicles, our test flight protocols have clearly defined strength margins, and further analysis will assess whether any additional work is required to keep them at or above established levels,” Virgin Galactic stated. “Given the time required for this effort, the Company has determined the most efficient and expedient path to commercial service is to complete this work now in parallel with the planned enhancement program.”

That decision means that the company will delay Unity 23, a mission for the Italian Air Force that had been scheduled for as soon as mid-October, until after the maintenance period is completed next year. That flight had been previously scheduled for late September or early October but postponed to look into a potential manufacturing defect with a component in a flight control actuation system.

Virgin Galactic said this new issue is not related to that earlier investigation. The component under investigation was not on either SpaceShipTwo or the WhiteKnightTwo aircraft, and the company “completed detailed inspections and scans which found all components met quality and safety standards and were ready for flight.”

The Federal Aviation Administration also temporarily suspended Virgin Galactic’s launch license in early September while it investigated why SpaceShipTwo flew out of its assigned airspace during its previous flight in July. The FAA concluded that investigation and cleared SpaceShipTwo to fly Sept. 29.

Those investigations delayed the start of the maintenance period, which Virgin Galactic announced in August, by a month. In August, the company said it expected to begin commercial flights late in the third quarter of 2022. It now expects those flights to begin in the fourth quarter of 2022, after the rescheduled Unity 23 flight.

“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,” Michael Colglazier, chief executive of Virgin Galactic, in a company statement.

Jeff Foust writes about space policy, commercial space, and related topics for SpaceNews. He earned a Ph.D. in planetary sciences from the Massachusetts Institute of Technology and a bachelor’s degree with honors in geophysics and planetary science...