U.S. space agency NASA is seeking new astronauts as the latest batch of space explorers is now ready for possible missions to the moon and Mars.

On Tuesday, NASA celebrated the completion of training for 10 U.S. citizens – four women and six men – as well as a female and a male astronaut from the United Arab Emirates (UAE) with a gala in Houston, Texas.

According to NASA, some 12,000 people responded to a call for aspiring astronauts in 2020. Candidates needed to be U.S. citizens and hold a master's degree in science, technology, engineering or mathematics.

The 10 Americans, aged between 32 and 45 at the time, were selected from the 12,000 applications, while the two UAE candidates were added later.

Anyone wishing to join them can apply for the next NASA training course until April 2.

"With NASA's plans for the future of exploration, new astronauts will fly farther into space than ever before on lunar missions and may be the first humans to fly on to Mars," the space agency said in its recruitment ad.

In total, NASA has selected around 360 astronauts in its history, with about 50 of them currently active.