Washington, Aug 8 (IANS): NASA's Perseverance rover did not collect a rock sample on Mars in its first attempt to gather samples, the US space agency has said.

Early last month, the self-driving six-wheeled robot started its journey across Jezero Crater floor to seek signs of ancient life. The crater harboured a big lake and a river delta in the ancient past.

While Perseverance, using its 2-metre-long robotic arm, drilled a hole on Mars, it could not collect and store samples as intended.

"Telemetry from the rover indicates that during its first coring attempt, the drill and bit were engaged as planned, and post-coring the sample tube was processed as intended," NASA said in a statement.

But recent "data sent to Earth by NASA's Perseverance rover after its first attempt to collect a rock sample on Mars and seal it in a sample tube indicate that no rock was collected during the initial sampling activity", it added.

The teams are now exploring what went wrong and are working to correct it.

"While this is not the 'hole-in-one' we hoped for, there is always risk with breaking new ground," said Thomas Zurbuchen, associate administrator of NASA's Science Mission Directorate in Washington. "I'm confident we have the right team working on this, and we will persevere toward a solution to ensure future success."

To analyse the data, the team will use the WATSON (Wide Angle Topographic Sensor for Operations and eNgineering) imager -- located at the end of the robotic arm -- to take close-up pictures of the borehole.

Previous NASA missions on Mars have also encountered surprising rock and regolith properties during sample collection and other activities.

In 2008, the Phoenix mission sampled soil that's "sticky" and difficult to move into onboard science instruments, resulting in multiple tries before achieving success.

Curiosity has drilled into rocks that turned out to be harder and more brittle than expected. Most recently, the heat probe on the InSight lander, known as the "mole," was unable to penetrate the Martian surface as planned.

Perseverance rover was launched on July 30 last year and arrived at the red planet on February 18 after a 203-day journey traversing 472 million kilometers. It will be the first mission to collect and cache Martian rock and regolith -- broken rock and dust.

Perseverance is currently exploring two geologic units containing Jezero Crater's deepest and most ancient layers of exposed bedrock and other intriguing geologic features. The first unit, called the "Crater Floor Fractured Rough," is the floor of Jezero. The adjacent unit, named "Setah", has Mars bedrock as well, and is also home to ridges, layered rocks, and sand dunes.