Nasa has started full testing on a remarkable next-generation 'Dream Chaser' mini space shuttle, developed by a private company.
The Sierra Nevada Corporation Dream Chaser is a sleek new space craft reminiscent of the classic - now retired - Space Shuttle.
It is reusable, has wings that allow it to fly back to Earth, can carry seven astronauts and runs on a hybrid engine partly powered by laughing gas.
Designed to launch atop an Atlas V rocket, the craft could see Nasa not only launch its own explorers into space again - instead of continuing to rely on ageing Russian Soyuz technology - but also return them home without ditching in the sea (or the Kazakh desert).
Oddly enough the little-known project is actually based on an idea originally developed by the Soviet Union, which Nasa reverse-engineered into the abandoned HL-20 concept, later picked up by Sierra Nevada.
And while it's only one of several craft being developed by private companies vying for Nasa funding, along with projects by SpaceX, Boeing and others, it is the only true 'space plane' in development.
The Dream Chaser recently arrived at Nasa's Dryden Flight Research Center in California. There are no guarantees that it will ever be fully built, let alone make it to space, but if the tests are successful Sierra Nevada could receive the funding needed to push the 'Dream' towards reality.
The tests, part of Nasa's Commercial Crew Program to develop a craft to take astronauts to the Space Station and back, will include tow, captive-carry and free-flight experiments.
"Unique public-private partnerships like the one between Nasa and Sierra Nevada Corporation are creating an industry capable of building the next generation of rockets and spacecraft that will carry US astronauts to the scientific proving ground of low-Earth orbit," said William Gerstenmaier, Nasa's associate administrator for human exploration and operations in Washington.
"Nasa centers around the country paved the way for 50 years of American human spaceflight, and they're actively working with our partners to test innovative commercial space systems that will continue to ensure American leadership in exploration and discovery."