Boeing pushed back the flight schedule of its Starliner capsule by several months, the company said on a conference call with reporters Wednesday. The capsule, being built to fly U.S. astronauts to the International Space Station, suffered a failure during a test in June.

"The resulting schedule that we have will support an uncrewed flight test in late 2018 or early 2019," Boeing vice president John Mulholland said.

Boeing's space division was previously targeting August for the uncrewed flight test of Starliner, with the range estimated by the company giving a new target about six months away. The delay of the first Starliner flight means its pad abort test and crewed flight test – the next two critical milestones toward NASA certification — are each delayed to spring 2019 and the middle of 2019, respectively.

The company's announcement comes after a GAO report estimated NASA's Commercial Crew program would suffer further delays, as the capsules Boeing and SpaceX are each developing for the agency's program enter the late stages of their respective testing programs.

"Additional delays could result in a gap in U.S. access to the space station as NASA has contracted for seats on the Russian Soyuz spacecraft only through November 2019," the GAO report said, published July 11.

Commercial Crew is NASA's solution to once again launch U.S. astronauts from U.S. soil. Since the end of the Space Shuttle program in 2011, astronauts have flown aboard Russian Soyuz — at a cost to NASA of more than $70 million per seat. NASA's new program is competitive, with contracts up for grabs for Boeing to win with its Starliner capsules and SpaceX with its Dragon capsules.

NASA gave Boeing a $4.2 billion contract in 2014 to build three spacecraft while SpaceX won a $2.6 billion contract to develop a crew version of its Dragon vehicle. The development programs for both companies' capsules have been steadily delayed. Both were expecting to complete uncrewed test launches in August at the earliest. NASA was expected to certify Boeing in December 2019 and SpaceX in January 2020, according to analysis earlier this year, but the GAO says further delays are expected.

Mulholland confirmed recent news of an "anomaly" during a test of Starliner's propulsion systems, which he said "was designed to verify all of the service module's propulsion capabilities." The test begin normally but after 1½ seconds the engine's shut down and several of the engine's valves "failed to fully closed," Mulholland said. Despite the test failure, Mulholland said Boeing's team is "confident we identified the route cause" and is working toward "implementing a solution." The result of that test have been "rolled into" the new flight scheduled, Mulholland said.

The GAO's report, which Mulholland said was "developed prior to the hot fire test anomaly," already called for delays to both capsules being built for Commercial Crew. The delays threaten to leave NASA without an option once its contract to fly astronauts aboard Russia's Soyuz capsule expires in November 2019, the report found. The timeline before Boeing's announcement Wednesday already causes a one-month gap, at minimum, in NASA's contracts for seats with Russia and the first launches of Boeing and SpaceX.