It is back to the drawing board for NASA engineers, after the latest test run of a Mars landing system came to an abrupt end.

It happened when the saucer-shaped vehicle's parachute tore away after partly unfurling high over the Pacific Ocean.

The Low Density Supersonic Decelerator (LDSD) was hit by a similar problem on its first outing last year.

The parachute was re-designed for the latest flight, but NASA admits more work will be needed before the system is ready to land heavy loads on the red planet.

"This is exactly why we do tests like this," NASA engineer and LDSD mission commentator Dan Coatta said afterwards.

"When we're actually ready to send spacecraft to Mars, we know that they are going to work when that big mission is on the line."

The 100ft diameter parachute - the largest ever tested - was the second part of a supersonic braking system NASA has been developing for about five years, at a cost of about US$230m (€203m).

The experiment began with a massive helium balloon lifting off from the US Navy Pacific Missile Range Facility in Kauai, Hawaii.

About three hours later, the balloon reached its target altitude of 120,000ft, at which point the LDSD separated.

A solid-rocket motor took it up to around 180,000ft - roughly five times higher than passenger jets fly - and sent it soaring at nearly 4,828kph, or four times the speed of sound.

The speed and altitude were intended to simulate conditions that a spacecraft plummeting through the thin atmosphere of Mars would experience.

Ships were standing by in the Pacific to recover the landing vehicle, parachute and other equipment.

Here's how it all unfolded: