Butch Wilmore and Suni Williams were originally scheduled to return to Earth on June 14.
The NASA astronauts who were aboard the first manned space flight aboard Boeing’s Starliner will participate in a press conference Wednesday morning.
Flight commander Barry “Butch” Wilmore, 61, a former U.S. Navy captain, and Sunita Williams, 58, a former Navy member and the flight’s pilot, are both currently aboard the International Space Station (ISS) and will answer questions about the test flight and the mission.
Wilmore and Williams launched from Cape Canaveral Space Force Station in Florida on June 5 and docked with the ISS on June 6.
The duo was initially scheduled to spend a week aboard the ISS to evaluate the spacecraft and its systems, and return on June 14. However, Starliner has experienced several mechanical problems, including helium leaks and a thruster problem, leaving the astronauts stranded aboard the ISS without a set return date.
NASA has insisted that Wilmore and Williams are safe as long as they remain aboard the ISS with the Expedition 71 crew. The agency has said the ISS has enough supplies in orbit and that the station’s schedule is relatively open until mid-August.
“I want to make it clear that Butch and Suni are not stranded in space,” Steve Stich, manager of NASA’s Commercial Crew program, said during a June 28 teleconference. “Our plan is to continue sending them back on Starliner and bring them home at the appropriate time.”
NASA and Boeing say Wilmore and Williams have “integrated” with the Expedition 71 crew aboard the ISS, helping the crew with station operations as needed and completing “objectives” needed for NASA’s potential certification of Starliner.
“Since their arrival on June 6, Wilmore and Williams have completed half of all hands-on research time aboard the space station, allowing their crewmates to prepare for the departure of Northrop Grumman’s Cygnus spacecraft,” NASA wrote in a recent update.
This week, teams at NASA’s White Sands Test Facility in New Mexico are conducting ground tests on Starliner’s booster, subjecting the rocket to conditions similar to those the spacecraft will experience en route to the ISS, according to an update on Boeing’s website.
The tests will simulate Starliner’s docking, which involved some thruster failure, and what the thrusters will go through from the moment they undock until they land on Earth.
“We really want to understand the thruster and how we use it in flight,” Dan Niedermaier, Boeing’s lead engineer for the thruster test, said in a statement. “We’re going to learn a lot from these thruster discharges that will be valuable for the rest of the Crew Flight Test and future missions.”
Starliner has been plagued by pre-launch problems. The flight test was originally tentatively scheduled for May 6 but was canceled after a problem with an oxygen valve on a rocket operated by United Launch Alliance, which manufactures and operates the rockets that carry Starliner spacecraft into orbit.
A new launch date was then set for May 25, but a small helium leak was discovered in the Starliner service module, which contains support systems and instruments for operating the spacecraft.
Those helium leaks and a problem with the booster threatened to delay Starliner’s docking, but it docked successfully. Five days after docking with the ISS, NASA and Boeing announced that the spacecraft had five “minor” helium leaks, but then added that it had enough helium left for the return trip.