Boeing and Space-X, NASA's Commercial Crew program partners, have pushed back the target launch dates for the first major test flights of their respective passenger spacecraft.
Earlier this year, NASA said the two companies would conduct unmanned tests flight in August. Now, SpaceX is targeting November for its inaugural Crew Dragon test flight. Boeing won't launch its passenger spacecraft Starliner until "late 2018/early 2019."
The news, announced on NASA's Commercial Crew program blog, doesn't come as a surprise. Like many spaceflight programs, development has been slow-going, with milestones regularly delayed.
Last month, news broke that Starliner's launch-abort engines cut off during a test fire's cool-down phase. The engines reportedly shut off as a result of a propellant leak.
The news confirmed what a recent report issued by the U.S. Government Accountability Office had predicted — that the program's timeline was unrealistically optimistic. The report cited safety concerns and testing delays, and warned that future delays could interrupt the access of American astronauts to the International Space Station.
NASA's updated timeline did not provide reasons for the delays.
"After the uncrewed flight tests, both companies will execute a flight test with crew prior to being certified by NASA for crew rotation missions," NASA communications specialist Stephanie Martin wrote in a blog post.
A second round of test flights — manned flights — will follow the inaugural flights. According to the updated timeline, SpaceX will conduct a manned Crew Dragon flight in April 2019. Boeing will conduct a manned Starliner flight in mid-2019.
