Starliner astronauts won’t return until 2025: The NASA, Boeing mission explained

• Astronauts Barry Wilmore and Sunita Williams are looking at another six months at the International Space Station while they await Crew-9 to arrive on a SpaceX dragon and complete their rotation.
• The Starliner will undock in September and return autonomously to Earth without its crew.
• NASA officials have signaled their plans to review data to see if certification for Starliner is still possible.

The two NASA astronauts who flew to space aboard the Boeing Starliner thought they might be home in time for Independence Day, but turns out they won't even be back on Earth to ring in the New Year.

Ahead of Barry "Butch" Wilmore and Sunita "Suni" Williams are another six months to spend 250 miles above Earth. That's on top of the nearly three months the veteran spacefarers have already been at the International Space Station after arriving June 6 for what was initially scheduled to be a little more than a weeklong stay.

But after a thorough analysis of the Starliner spacecraft, NASA officials deemed that the vehicle wasn't up to the task of reliably transporting Wilmore and Williams for the return trip, the space agency announced Saturday. That responsibility will now instead fall to Boeing's aerospace competitor, SpaceX.

Meanwhile, the Starliner spacecraft will return to Earth empty handed.

The decision puts to rest the question surrounding the fate of Starliner and its crew, but plenty of questions may still remain. Here's everything to know about Starliner, where the mission went wrong and what may be next.

When did the Starliner launch?

The Starliner capsule – built with the intention of running crews and deliveries regularly to the station on behalf of NASA – launched June 5 atop an Atlas V rocket from the Kennedy Space Center in Florida.

The highly-anticipated liftoff came after several delays over the course of about a month due to troubles detected with the spacecraft, including issues with a valve in the rocket's upper stage.

Watch another launch:Polaris Dawn civilian crew prepares to head to orbit on SpaceX craft

What is the purpose of the mission?

The mission marked the first crewed demonstration of the spacecraft, which is intended to compete with Elon Musk's SpaceX to make routine trips to space on behalf of NASA.

The partnership signifies a shift in recent years for the U.S. space agency, which has pivoted to paying private companies for missions it once would carry out itself as a way to cut costs. Certifying the Starliner for such missions would provide NASA with a second operational spacecraft to carry astronauts and cargo to the space station after it shelled out billions of dollars to both Boeing and SpaceX to develop the vehicles.

What is wrong with the Starliner spacecraft?

Wilmore and Williams were initially scheduled to be aboard the International Space Station for little more than a week.

But when they made it to the orbital outpost a day after the launch, engineers discovered a slew of helium leaks and problems with the craft's propulsion system that have hampered Starliner's return to Earth.

Who are the two Starliner astronauts? 

Williams, 58, and Wilmore, 61, were selected for the inaugural crewed flight of the Starliner, which completed two previous flight tests with no one aboard.

Both astronauts are Navy veterans who have each ventured to space twice before.

Prior to the Starliner mission, Williams, selected as an astronaut in 1998, had logged 322 days in space since her first flight in 2007. Wilmore, a retired Navy captain, joined NASA in 2000 and had spent 178 days in space prior to Starliner after his first trip to orbit in 2009.

How and when will the Starliner spacecraft, astronauts return to Earth?

The Starliner spacecraft will return in September autonomously to Earth to free up a docking port for the delayed SpaceX Crew-9, which is scheduled to reach the space station Sept. 24 for a six-month rotation mission.

The Dragon capsule that Crew-9 will take to orbit is also now Williams and Wilmore's ride home.

For that reason, Crew-9 will include just two members instead of four, NASA said. The Starliner crew will then hitch a ride Feb. 25, 2025 with Crew-9 on the Dragon after the SpaceX astronauts complete their six-month rotation at the station.

What are Williams and Wilmore doing at the International Space Station?

Now that they have no choice but to wait it out until February, Wilmore and Williams will continue to help with scientific research and routine maintenance aboard the International Space Station.

How many astronauts are aboard the ISS right now?

As of now, the Starliner astronauts are living among the seven members of Expedition 71 who arrived at the space station in April. Of those in Expedition 71, four are part of the SpaceX Crew-8 mission that was slated to depart the station in August before the Crew-9 delay.

The eight months Wilmore and Williams will ultimately spend in orbit is lengthy compared to the typical six-month rotations. History was made in September when astronaut Frank Rubio returned to Earth after 371 days in orbit, making him the American with the record for the longest spaceflight.

Does the space station have enough supplies for the astronauts?

NASA has insisted that Wilmore and Williams are sufficiently provisioned for the long-haul with food, water, clothing and oxygen.

And if you're wondering, Wilmore and Williams can indeed still vote in the upcoming presidential election from the space station.

Can Starliner still get NASA certification?

Hopes were high that a successful crewed Starliner mission would pave the way for NASA to approve the craft for routine missions ferrying astronauts and cargo to and from the International Space Station.

Despite the craft's imminent return without its crew, it doesn't appear NASA officials have ruled out the possibility of a coveted certification. Up next, the agency signaled its intent to review mission data and determine what additional steps are required for Boeing.

"This flight test is providing critical information on Starliner’s performance in space," said Steve Stich, manager of NASA’s Commercial Crew Program. "Our efforts will help prepare for the uncrewed return and will greatly benefit future corrective actions for the spacecraft.”

Boeing officials have largely remained mum on Starliner for most of August and have not participated in media conferences with NASA. Though the company had been routinely sharing Starliner updates on its website, the last one came Aug. 2, under the title, "Boeing’s confidence remains high in Starliner’s return with crew."

Eric Lagatta covers breaking and trending news for USA TODAY. Reach him at elagatta@gannett.com