The reason for the scrub was "unstable wind conditions near the surface that would prevent the launch," NASA said, adding it would assess chances for the next possible launch, tomorrow.
If conditions improve, the test flight of the flying saucer, known as the Low-Density Supersonic Decelerator, will be broadcast live on NASA's website beginning at 1:30 pm (1730 GMT).
If not, the US space agency has until June 12 to try again. Should no dates in June work out, weather-wise, another launch window opens in July.