CAPE CANAVERAL, Fla. — A “technical issue” with a pressure regulation valve on the liquid oxygen tank caused a Boeing crew flight test to be scrubbed Monday night.

NASA, Boeing, and United Launch Alliance are targeting no earlier than Friday for launch of the agency’s flight test to the International Space Station, pending resolution of the technical issue.

The delay allows teams to complete data analysis on the Atlas V rocket ‘s Centaur upper stage and determine whether it is necessary to replace the valve, NASA said in a news release.

Mission managers discussed the details that led to the decision during a news conference Monday night at NASA’s Kennedy Space Center.

Following the scrub, NASA astronaut Butch Wilmore and Suni Williams exited the Starliner spacecraft and launch pad at Space Launch Complex-41 at Cape Canaveral Space Force Station and returned to the astronaut crew quarters at Kennedy.

ULA, as per the normal recycle process, also removed liquid oxygen and hydrogen from the Atlas V first and second stages.