LOS ANGELES -- Billionaire Elon Musk is set to unveil the new SpaceX spacecraft designed to fly astronauts to the International Space Station.

The Southern California-based rocket maker is one of several private companies vying to develop "space taxis" for NASA to replace the retired space shuttle fleet.

The reveal will take place at SpaceX's headquarters Thursday evening near Los Angeles International Airport. The company says it'll show flight hardware and not a mock-up.

SpaceX has flown an unmanned version that has made several cargo trips to low-Earth orbit. The new craft is designed to carry crew.

Since the shuttle retired in 2011, NASA has relied on Russian rockets, paying nearly $71 million per seat. The space agency has said it wants U.S. companies to fill the void in several years.