NEW YORK — NASA announced the new target launch date for the first astronaut-crewed flight into space aboard Boeing's Starliner after several delays.
The first flight will attempt to launch on Saturday, June 1, at 12:25 p.m. ET, with backup dates set for June 2, June 5 and June 6, the federal space agency said in a blog post late Wednesday.
It comes after the launch of Starliner was delayed several times. The crewed flight test was tentatively scheduled for May 6, but was scrubbed after a problem with an oxygen valve on a rocket from United Launch Alliance (ULA), which manufactures and operates the rockets that launch spacecraft into orbit.
A new launch date had been set for May 25, but a small helium leak was discovered in the service module, which contains support systems and instruments for operating a spacecraft.
"There has been a great deal of exceptional analysis and testing over the last two weeks by the joint NASA, Boeing, and ULA teams to replace the [valve] and troubleshoot the Starliner Service Module helium manifold leak," Steve Stich, manager of the NASA Commercial Crew Program, said in a statement. "It has been important that we take our time to understand all the complexities of each issue."
The Starliner is designed to carry a seven-person crew, but aboard the "test drive" launch will be NASA astronauts Barry Wilmore, 61, a former U.S. Navy captain who will be commanding the flight, and Sunita Williams, 58, a former Navy service member who will be piloting the flight.
Williams and Wilmore are continuing to practice in Starline simulators to prepare for the flight and remain in quarantine at the Johnsons Space Center in Houston. When the new launch date approaches, they will fly back to NASA's Kennedy Space Center in Florida, NASA said.
After Starliner launches into orbit, it will be about a 24-hour journey to the International Space Station (ISS), during which the crew will test several flight objects, such as checking equipment, according to NASA.
Williams and Wilmore are expected to spend one week aboard the ISS and will be evaluating the spacecraft and its systems. Upon re-entry, the spacecraft will deploy parachutes and an airbag system, landing the pair in the western U.S.
NASA and Boeing said a media teleconference will take place on Friday, May 24, during which officials "will provide insight into the next targeted launch opportunity and updates regarding ongoing work."
If the mission is successful, NASA could certify the spacecraft to perform routine missions to and from the ISS. NASA has primarily been using SpaceX's Dragon spacecraft to transport crew and cargo to the ISS.
The missions are part of the larger Commercial Crew Program at NASA, which uses American rockets and spacecraft to launch astronauts and cargo to the ISS with the hope of helping the federal space agency prepare for its upcoming moon and Mars missions.
ABC News' Leah Sarnoff and Gina Sunseri contributed to this report.