NASA has again delayed its planned "flying saucer" launch, as poor weather continues to ground the technology that may one day bring humans to Mars.

The Low Density Supersonic Decelerator, or LDSD, was scheduled to launch Tuesday, but was put off due to a combination of poor weather factors. After a series of delays, NASA now says it will try again on Saturday.

With its unique inflatable doughnut shape, the saucer is designed to help land heavy loads in the Red Planet’s thin atmosphere.

When the planned test goes ahead, NASA will send a balloon carrying the LDSD 36,576 metres into the skies over Hawaii. At that height, the balloon will release the saucer, which will fly at four times the speed of sound to the edge of the atmosphere.

From there, the saucer must slow itself down in order to successfully land in the ocean.

York University physics professor Paul Delaney said the saucer’s large surface area, which can fold up and then inflate, is key for slowing down a load that is "rocketing literally into the Martian atmosphere at tens of thousands of kilometres an hour."

"The saucer inflates. It becomes potentially six to eight metres in diameter. It becomes this huge dish which offers significant air resistance. That’s what slows the vehicle down."

Once the vehicle has slowed, it is designed to deploy a "supersonic parachute" to further slowdown and land in the ocean, and, maybe one day, Mars.

If the technology works, it could help land humans landing on Mars in the future, Delaney said.

"The big advantage on Mars is that the large surface area of the saucer works in a very thin atmosphere," he said. "If it's successful then you could expand the saucer to even larger diameters, and that means more massive payloads, which means, of course, potentially, human beings."

First, however, NASA needs a combination of clear skies, low winds, and calm waters to successfully test launch the LDSD.

"It’s not the vehicle that’s the problem," Delaney said. "When all the other elements align, then we will see the test."

Viewers interested in watching the launch, which is the second of three tests, will be able to tune in on NASA Television.