NASA will phase out its multimillion-dollar deals with the Russian Space Agency to transport U.S. astronauts to the International Space Station, switching to private U.S. companies over the next four years.
NASA will seek proposals for its Commercial Crew Program contracts next week and will select companies that meet its safety requirements, NASA said in a statement Wednesday.
The first "crewed demonstration missions" to the ISS are expected to begin before 2017, the statement said.
One of the companies competing for the contracts is Boeing, which proposed to launch a first test flight to the ISS in 2016, USA Today reported. But U.S. spending cuts threaten to impede the program, critics of the fiscal measure said.
Private companies, such as Boeing, won't participate "if they don't have the money from NASA to do all the redundancies and all of the escape systems in order to make it safe for humans," said Senator Bill Nelson, a Democrat from Florida and one of NASA's most ardent supporters.
Since the space shuttle program was scrapped in 2011, the U.S. has paid Russia more than $70 million per trip to carry astronauts to the space station aboard Soyuz spacecrafts.
In recent years, NASA has also signed deals with two private companies, Space Exploration Technologies, or SpaceX, and Orbital Sciences, to take supplies and science experiments to the space station, NASA said.
SpaceX completed a test flight to the space station in 2012, for the first time since the space shuttle program was retired a year earlier.