Boeing delays capsule's first space test flight

Boeing has delayed from April to August its test flight for its Starliner capsule, intended to carry American astronauts to the International Space Station.

The US space agency NASA blamed the delay on "limited launch opportunities" in April and May from Cape Canaveral, Florida.

It noted that the August launch target is a "working date and to be confirmed." The Starliner spacecraft, which is in the final phase of ground tests, is set to be launched into space atop a United Launch Alliance Atlas V rocket.

If the unmanned test goes well, the capsule's next flight will have three astronauts aboard -- NASA's Nicole Mann and Mike Fincke, along with Chris Ferguson of Boeing.

Ultimately, Starliner will be one of two American vehicles used to carry NASA astronauts to the ISS -- the other is SpaceX's Dragon capsule.

In March, SpaceX successfully completed a nearly weeklong test mission in space. The Dragon capsule successfully docked at the ISS before returning to Earth.

The first manned mission aboard the Dragon spacecraft is set to take place by the end of the year, with the date due to be confirmed "in the next couple weeks," according to NASA.