WASHINGTON — Virgin Galactic said Feb. 5 it is investigating why a pin fell from the aircraft used by its VSS Unity suborbital spaceplane on its most recent flight last month, adding that the incident did not pose a safety risk to those on board.

The company said in a statement that it notified the Federal Aviation Administration Jan. 31 of the incident, which took place during its Galactic 06 suborbital flight Jan. 26 from Spaceport America in New Mexico. The company said it is reviewing the incident in conjunction with the FAA.

Virgin Galactic said the alignment pin fell from its VMS Eve mothership aircraft, the plane that carries VSS Unity aloft. The pin is used to ensure Unity is aligned to Eve when mated during preflight preparations. After takeoff, the pin helps transfer drag loads from Unity into the pylon and center wing section of the aircraft.

The alignment pin detached after Unity separated from Eve, although the company did not state how long afterwards the pin came off. The pin, along with a separate shear pin fitting assembly, do not play a role in flight activities after the release of the spaceplane.

“Galactic 06 was a safe and successful flight that was conducted in accordance with Virgin Galactic’s rigorous flight procedures and protocols. At no time did the detached alignment pin pose a safety impact to the vehicles or the crew on board,” the company said in a statement.

The company did not elaborate on the issue, or explain why it announced the incident publicly five days after notifying the FAA. The statement, issued after markets closed for the day, did not affect the company’s share price, which rose slightly in afterhours trading.

Virgin Galactic added it will provide an update after the completion of the investigation about plans for Galactic 07, the next and potentially last commercial flight of VSS Unity. The company previously said the flight would take place in the second quarter, flying a researcher and private astronauts.

The company said in November it was winding down Unity flights so it can conserve its cash on hand to complete development of its next generation of suborbital spaceplanes, the Delta class. While Unity performed six flights in as many months last year, Virgin Galactic said it would shift to a quarterly cadence and halt flights entirely by mid-2024. That included flying Galactic 06 in January, Galactic 07 in the second quarter and possibly Galactic 08 in the middle of the year.

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...