Boeing Starliner launches to International Space Station from Florida

June 5 (UPI) -- NASA said Wednesday Boeing's Starliner carrying astronauts Butch Wilmore and Suni Williams successfully separated from the United Launch Alliance rocket booster following liftoff to the International Space Station.

United Launch Alliance confirmed the successful separation and said in a statement on X, "The names of Wilmore and Williams now join Glenn, Carpenter, Schirra and Cooper as American astronauts to launch into space atop Atlas rockets."

A statement from NASA Wednesday morning said the Centaur upper stage continued to propel Boeing's Starliner into a suborbit.

"The Centaur will continue to help propel Boeing's Starliner to a sub-orbit before the spacecraft boosts itself to orbit, bringing it closer to the International Space Station," NASA said.

Upon its separation, the Centaur will land in the ocean near Australia, according to NASA.

A United Launch Alliance Atlas V rocket was used to propel the spacecraft toward the space station from the Space Launch Complex-41 at Cape Canaveral Space Force Station in Florida.

NASA livestreamed the launch on the agency's website, YouTube channel, the NASA app, NASA Television and the NASA+ APP.

"Boeing engineers and technicians closed the hatch to the CST-100 Starliner after ensuring NASA astronauts Butch Wilmore and Suni Williams were safely secured in their seats ahead of launch," Boeing said in an earlier Wednesday statement. "Mission operators will conduct leak checks on the capsule to prove the hatch has a tight seal and is holding pressure."

The launch of the crewed Starliner flight came after several delays and two scrubbed launches.

A power distribution source failed Saturday to end that launch attempt.

NASA said that was an issue in "a single ground power supply within one of the three redundant chassis that provides power to a subset of computer cards controlling various system functions, including the card responsible for the stable replenishment topping valves for the Centaur upper stage."

In May an oxygen relief valve problem stopped the planned launch.

Starliner will carry the astronauts to the space station to spend over a week in a crewed test to prepare for Starliner certification.

They will return to Earth 10 days after launch in the same capsule for a parachute landing in the Southwest United States.

NASA said the astronauts made some last-minute phone calls before launch Wednesday morning as they prepared to enter an environmentally controlled chamber prior to launch.