NASA astronauts Butch Wilmore and Suni Williams are aboard Boeing’s Starliner, but their return to Earth was pushed back. The extra time at the International Space Station will allow the team to finalize departure planning and remain clear for emergency return scenarios, NASA said at a news conference on Tuesday. NASA wants to add more time to look at Starliner's thrusters and helium leaks.The new target departure is now no earlier than Tuesday, June 25. The plan would be to depart ISS at 10:10 p.m., then make the 6 ½ hour trip home with a landing at 4:51 a.m. Wednesday, June 26. They would be landing at White Sands Space Harbor in New Mexico. A backup landing date would be July 2, NASA said. The original plan was supposed to be about an eight-day visit to the ISS. This is the first human spaceflight for a commercial capsule. Starliner launched from Cape Canaveral, Florida, on June 5 and reached the ISS a day later. NASA says as Starliner approached the station, five of its thrusters, went offline, forcing Boeing to troubleshoot the issue. NASA and Boeing were able to bring four of the five back online.Over the weekend, NASA says they fired the thrusters while the spacecraft was attached to the station, and all of them worked well. However, they did not try to test-fire the one thruster that didn’t come back online during the flight. NASA says out of an abundance of caution, they won’t try to use it during Starliner’s return flight.Our sister station WESH 2 asked Professor Don Platt from the Florida Institute of Technology about the importance of having working thrusters on the spacecraft. "These thrusters are used for maneuvering the spacecraft, and it is important that they are aligned properly. They are so critical to have, so if one fails there are others that can pick up for it and complete that process," Platt said. NASA says Starline has also experienced helium leaks. Crews discovered a fifth one. NASA says it's small and won't be a problem for the return."For the helium leaks, we are now looking at what is left in the remainder of the flight. We need about 7 hours of helium, and we have about 70 hours of margin," said Steve Stich, NASA’s commercial crew program manager.NASA originally said Starliner would come home June 18, then pushed the landing back to June 22. Aside from the technical issues, NASA says the mission has satisfied 77 of the original 87 flight test objectives. They will evaluate the remaining 10 during undocking and landing. "Any kind of contingency, or emergency we would be very confident in putting Butch and Suni in this vehicle and returning them if we need to," Stich said. NASA says they are confident that Starliner will return to Earth safely. “We’ve always said this as a test flight and we’re going to learn some things,” said Mark Nappi, a Boeing vice president who oversees the Starliner program.