A liquid nitrogen spray developed by Washington State University researchers can remove almost all of the simulated moon dust from a space suit, potentially solving what is a significant challenge for future moon-landing astronauts.

The sprayer removed more than 98% of moon dust simulant in a vacuum environment with minimal damage to spacesuits, performing better than any techniques that have been investigated previously. The researchers report on their work in the journal, Acta Astronautica.

While people have managed to put men on the moon, they haven't figured out how to keep them clean there. Similar to the clingiest packaging peanuts, moon dust sticks to everything that it touches. Worse than the packing peanuts, the dust is composed of very fine particles that are the consistency of ground fiberglass.

"Moon dust is electrostatically charged, abrasive and gets everywhere, making it a very difficult substance to deal with," said Ian Wells, first author on the paper and a senior in WSU's School of Mechanical and Materials Engineering.

China says it will soon begin training foreign astronauts for trips to its newly completed orbiting space station.

Long a source of national pride and symbol of technological advancement, the Chinese space program is taking on a new diplomatic and political role, much in the way the United States and former Soviet Union leveraged theirs.

Japan's space agency JAXA named its first new astronaut candidates in over 13 years on Tuesday, with a surgeon and a climate scientist chosen from more than 4,000 applicants.

Ayu Yoneda, a 28-year-old surgeon for Tokyo's Japanese Red Cross Medical Center, will become just the third woman ever to join the space training programme. Japan's six current astronauts are all men.

She will be joined by Makoto Suwa, 46, a senior disaster risk management specialist at the World Bank, who made the cut after an unsuccessful first application more than a decade ago.

Yoneda said she was "elated and surprised" to learn she had been chosen.

"I felt a sense of responsibility and mission," she told reporters.

Suwa, speaking by video from the United States, said he was "so excited that I haven't been able to sleep".

The pair, chosen from 4,127 applicants, will now begin a two-year training programme and, if successful, could join International Space Station missions and become the first Japanese astronauts to reach the Moon.