With just another month until lift-off, the space agency on Wednesday revealed a commemorative plate attached to the rover, aptly named Perseverance.

The rover team calls it the COVID-19 Perseverance plate, designed in the last couple of months.

The black and white aluminum plate - 13 centimetres across - shows planet Earth atop a staff entwined with a serpent, a symbol of the medical community.

The path of the spacecraft also is depicted, with its origin from Cape Canaveral.

Health care workers were "on front lines keeping us safe" during launch preparations, said deputy project manager Matt Wallace of NASA's Jet Propulsion Laboratory in Pasadena, California.

"They really inspired us, I think, through this period, and we hope that this plate and we hope that this mission in some small way can inspire them in return," Wallace told reporters.

The rover's name, Perseverance, has taken on added meaning the last few months, according to NASA officials.

It's hard enough preparing a spacecraft for Mars, but doing it in the middle of a pandemic made it even harder, Wallace said. Additional work shifts were added to reduce the number of people working on the rover at any one time and ensure social distancing. Others had to work from home.

NASA is pressing ahead with a July 20 launch, even as the number of COVID-19 cases continue to rise in Florida.

This mission - to seek signs of past microbial life on Mars and collect rock and soil samples for eventual return to Earth - is considered essential by the space agency.

If the rover isn't launched by mid-August, it would need to wait until 2022 when Earth and Mars are back in proper alignment. A two-year delay could add another $US500 million ($A723 million) to the nearly $US3 billion mission.

Perseverance is one of three upcoming missions to Mars. The United Arab Emirates and China also are preparing spacecraft for launch to the red planet by mid-August.

Australian Associated Press