Washington, (IANS) Indian-origin astronaut Sunita Williams is among the nine astronauts named by NASA on Friday for its first human spaceflight programme since the retirement of the space shuttle in 2011.

The astronauts will fly on spacecarft developed by SpaceX and Boeing as part of the the US space agency's Commercial Crew programme to send humans to the International Space Station (ISS) on private US spacecraft.

Williams has been named for the Boeing programme to the ISS, the first test flight scheduled to take place in the middle of 2019.

"For the first time since 2011, we are on the brink of launching American astronauts on American rockets from American soil," NASA Administrator Jim Bridenstine said while announcing the names of the astronauts.

In 2014, Boeing and SpaceX were awarded a combined $6.8 billion in contracts from NASA to develop spacecraft capable of flying crews to the space station, The Washington Post reported.

NASA on Thursday confirmed a delay in the first piloted flights of Boeing and SpaceX.

SpaceX is targeting November 2018 for Crew Dragon's first uncrewed demonstration mission (Demo-1), three months later than the previous schedule released by NASA early this year. The crewed demonstration flight, with two astronauts on board, will follow in April 2019, four months later than previously announced.

Boeing's CST-100 Starliner, on the other hand, will likely perform two crucial test flights next year, instead of this year as planned.

Each test flight will provide data on the performance of the rockets, spacecraft, ground systems, and operations to ensure the systems are safe to fly astronauts.

The crew for Boeing's Crew Flight Test and SpaceX's Demo-2 flights will each include at least a flight commander and pilot aboard to test out the systems.

After successful completion of the flight tests with crew, NASA will review flight data to verify the systems meet the agency's safety and performance certification requirements and are ready to begin regular servicing missions to the space station, the US space agency said.