Following two days of delays, NASA’s Low Density Supersonic Decelerator test flight has been cleared for launch Thursday at Kauai’s Pacific Missile Range Facility.

The flight, which will reach Earth’s stratosphere and end in a splashdown some 25 miles from Kauai, will begin no earlier than 7:30 a.m., mission managers said Wednesday.

The event, involving a flying saucer that aims to test two devices designed to slow spacecraft with heavy payloads for landing on Mars, was delayed Monday and Tuesday because of rough seas that would have made recovery of the test vehicle and its data too risky.

Thursday’s flight will start with a high-altitude balloon lifting the saucer-shaped test vehicle to 120,000 feet. That’s when the craft will be dropped and its powered flight will begin.

First, four small rocket motors will fire up to spin and stabilize the saucer, and then the craft’s main rocket engine will kick in with 17,500 pounds of thrust, sending the test vehicle to 180,000 feet at four times the speed of sound.

The near-space environment high over the Pacific is similar to the thin atmosphere of Mars, NASA officials said.

NASA TV and NASA Jet Propulsion Laboratory’s Ustream channel will carry live coverage beginning at 7 a.m. with commentary starting 30 minutes before. launch.