Delivery of American astronauts to the ISS is currently being decided by the Soyuz spacecraft. US aircraft companies are working on alternatives for manned orbit flights. As part of the space program of the National Aeronautics and Space Administration (NASA), two companies Boeing and SpaceX are developing manned spacecraft to deliver astronauts to the ISS. It became known that the first unmanned flight of the CST-100 Starliner spacecraft will be carried out in August 2019. In the initial plans, the test flight was supposed to take place in April, and before that it was planned to conduct tests at the end of August 2018. Meanwhile, SpaceX has already carried out a successful test unmanned launch of the Crew Dragon and is preparing to send the first astronauts into space in the summer. The manned spacecraft Starliner can accommodate up to 7 astronauts and ensure their operation in open space for 60 hours. Starliner can be in orbit for more than six months. Boeing project managers said the reason for the postponement of the flight date was technical problems with ULA Atlas 5 rockets, which was responsible for putting the ship into orbit. Despite the fact that the ULA engineering service could launch in May, Boeing representatives decided not to speed up the preparation process and postponed the flight to August.