The unveiling of the cone-headed craft dubbed Dragon V2 took place at the southern California headquarters of Musk's company, SpaceX. Musk declared the spacecraft a big leap forward in technology.
SpaceX is one of several private companies competing to build "taxis" for Nasa to replace the retired space shuttle fleet. It previously flew four cargo missions to the space station, delivering food and supplies.
Nasa has been relying on Russian Soyuz rockets to carry astronauts to low-Earth orbit until a commercial spacecraft is ready to take over the task.
Since the shuttle fleet retired in 2011 Nasa has depended on Russian rockets to transport astronauts to orbit and back, paying nearly $71m per seat. The space agency has said it wants US companies to fill the void by 2017 and has given out seed money to spur innovation.Elon Musk with the SpaceX Dragon V2 spacecraft. Photograph: Jae C Hong/AP
SpaceX, short for Space Exploration Technologies Corp, has made four cargo runs to the orbiting outpost 200 miles above Earth. Last month a Dragon capsule splashed into the Pacific, returning nearly two tonnes of science experiments and old equipment.
Companies competing for the right to ferry astronauts need to design a spacecraft that can seat four or more and be equipped with life support systems and an escape hatch in case of emergency. SpaceX has said it is designing a seven-seat spacecraft.
John Logsdon, professor emeritus of political science and international affairs at George Washington University, said SpaceX and longtime Nasa contractor Boeing were "more or less neck and neck" in the competition but progress overall was slower than anticipated, mainly because Congress had not fully funded Nasa's budget request for the effort. He said it was important for the US to move away from reliance on Russia for space travel given the political tension over the annexation of Crimea from Ukraine.
"It's essential to have our own capability to transport people to space, " he said. "This is an important step in that direction."
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