Boeing's Starliner successfully docks with the ISS despite helium leaks and engine problems

Boeing's Starliner successfully docked with the International Space Station (ISS) on Thursday afternoon, marking another milestone in the spacecraft's first manned test flight.

NASA and Boeing confirmed that Starliner docked at 1:34 p.m. ET. NASA astronauts Barry “Butch” Wilmore and Sunita “Suni” Williams will soon enter the ISS orbiting laboratory, where they will spend about a week, NASA said in a post on social platform X.

This came after helium leaks and a problem with the engines threatened to delay the Starliner's docking.

MORE: NASA sets new launch date for Boeing Starliner's first manned flight after delays

The Starliner experienced three helium leaks en route to the ISS, according to a post from the agency's Johnson Space Center on X late Wednesday.

One of the leaks “was already discussed before the flight along with a management plan. The other two are new since the spacecraft reached orbit,” the post on X said.

The leaks are similar to those discovered during the Starliner launch attempt scheduled for May 25. That launch was aborted after a small helium leak was discovered in the service module, which contains support systems and instruments for operating a spacecraft.

According to Boeing, helium is used to pressurize the spacecraft's engines and ignite them.

It is currently unclear how much helium is leaking or whether it will affect the Starliner's performance and its ability to return to Earth in eight days.

However, two of the helium valves were closed and the spacecraft was “stable,” NASA said at the time.

Starliner was scheduled to dock with the ISS at 12:15 p.m. ET on Thursday, but had to be delayed after mission control detected a problem with the reaction control system (RCS) nozzles that assist the spacecraft's engine maneuver.

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The spacecraft was kept outside the so-called “keep-out sphere”, a boundary about 200 meters from the ISS, until another docking window opened at 1:33 p.m. ET.

Williams and Wilmore are expected to spend a week aboard the ISS testing Starliner and its systems. Upon re-entry, the spacecraft will deploy parachutes and an airbag system, allowing the pair to land in the western United States.

If the mission is successful, NASA could certify the spacecraft for routine missions to and from the ISS. NASA uses SpaceX's Dragon spacecraft primarily to transport crew and cargo to the ISS.

Boeing's Starliner successfully docks with the ISS despite helium leaks and engine problems. Originally published on abcnews.go.com