(CNN) – The persistent rover successfully drilled into the Martian rock on Thursday, creating an intact core sample that could one day be returned to Earth. But NASA wants better images to make sure the sample is safe in the tube before it’s sealed and stored in the rover.

So far, data sent back by the rover and initial images indicate an intact specimen was inside the tube after Perseverance dug up a rock selected by the expedition’s science team.

After taking the initial images, the rover vibrated the tube top and tube for five one-second bursts to remove any residual material from outside the tube.

The hole was drilled on Perseverance’s second attempt to collect samples.

This may have caused the sample to slide down the tube.

Subsequent photos taken afterwards “were not conclusive due to poor sunlight conditions,” according to an agency. Perseverance will use its cameras to take more pictures in better lighting conditions before taking the next steps in the sampling process.

The additional step of taking additional images before sealing the sample tube and storing it was added after a persistent attempt to dig another rock target on August 5. During that attempt, the rock collapsed and there was no specimen in the tube once it was put away.

“The project has got its first core rock under its belt, which is an enormous achievement,” Jennifer Trosper, mission project manager at NASA’s Jet Propulsion Laboratory in Pasadena, California, said in a statement. “The team sited, selected and extracted the core from a viable and scientifically valuable rock. We did what we came here to do. We’re going to work around this little problem with the lighting conditions in the pictures and we’re going to continue to encourage us that there are shows in this tube.”

The rover uses a rotary hammer drill and socket drill to drill into the rocks and collect samples slightly thicker than a pencil. This sampling system is located at the end of the vehicle’s 2-meter robotic arm.

Tenacity sample tube has rock core inside.

Perseverance is currently exploring the Citadelle site on Jezero Crater, which billions of years ago was the site of an ancient lake. The vehicle’s specific target was a rock called Rochette, which is the size of a small suitcase and is part of an 800-meter-high ridge of rocky outcrops and boulders.

The mission team should receive more images of what’s inside the sample tube by September 4. If images taken while the sun is at a better angle don’t help the team determine if there is a sample, the tube will be closed and the traveling vehicle will measure its volume.

If Perseverance can successfully collect samples from Mars, future missions will bring them back to Earth, and could reveal whether microbial life exists on Mars.