The company also had to add the seven seats for the crew, as well as life support systems and instrument panels. At one point, a stairway was brought on stage, and Musk climbed into the craft's gleaming metal interior to show off the setup. The crowd watched on huge video screens as Musk hopped from seat to cushioned seat, and finally climbed out again.
"That's going to be a lot easier in zero-G, by the way," he quipped.
Musk said most of the equipment on the Dragon V2 unveiled on Thursday was ready for flight. SpaceX is gearing up for a series of launch abort tests for NASA this year and next. If all goes well, and if NASA continues funding development, Musk said the Dragon V2's first uncrewed flight to orbit could take place by the end of 2015. The first orbital launch with test pilots aboard could follow in 2016, he said, leaving plenty of time to meet NASA's 2017 deadline.
Eventually, SpaceX plans to add landing legs as well, so that the craft can make a science-fictiony touchdown on land rather than having to go through the current routine of splashdown and recovery at sea. "That is how a 21st-century spaceship should land," Musk said.
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Test flights of a leg-equipped version of the Dragon, known as the DragonFly, are expected to proceed at SpaceX's facility in Texas once the Federal Aviation Administration gives its approval.
If all those pieces fall into place, the sky would no longer be the limit. SpaceX's Dragon, or other U.S.-built spaceships, could serve as transports to private-sector space stations like the one being designed by Nevada-based Bigelow Aerospace.
"This is going to be a fabulous machine," Robert Bigelow, the billionaire founder of Bigelow Aerospace, told NBC News after trying out the Dragon's seats. "SpaceX deserves all the credit in the world. ... This is really a fork in the road for space exploration."
Musk has said a fully loaded Dragon could even be sent to make a touchdown on the moon or Mars — perhaps powered into deep space by SpaceX's Falcon Heavy rocket, which is still under development. SpaceX is also said to be working on an even more powerful launch vehicle, nicknamed the BFR (which could be construed as the "Big Falcon Rocket").
Musk declined to talk about those ultra-long-range projects on Thursday night, but said he hoped the Dragon V2 would help spark a resurgence in America's space ambitions.
"Maybe, to some degree, this helps revive the dream of Apollo," he said.
—By Alan Boyle, NBC News