Sierra Nevada Corporation says its Dream Chaser spacecraft had a successful free-flight drop test on Saturday.
The Sparks-based company tweeted photos of the craft gliding to a landing at Edwards Air Force Base.
In previous tests this year, a helicopter carried the Dream Chaser aloft but did not release it.
The company says it will release more information about the test Monday afternoon.
The Dream Chaser is being developed to carry cargo to and from the International Space Station without a crew aboard.
It's 30 feet long, about one quarter the length of a space shuttle. It's been in development by Sierra Nevada for more than 10 years.