Ye, who did not respond to an interview request, is one of China’s most celebrated figures in astronomy. She oversaw the development of the country’s universal time system and its use of low-frequency radio waves as a form of measurement, which laid the groundwork for the space programme. She represented China on an international astronomy body, and she even has an asteroid named after her.

Born in the southern city of Guangzhou in 1927, Ye was just 10 when the second Sino-Japanese war broke out, prompting her family to flee their home. They spent the next seven years moving around cities, including Hong Kong and Shaoguan, until the Japanese forces retreated and they returned to Guangzhou.

Ye wanted to study literature at university, but her father had other ideas – he wanted her to take up medicine, she told state news agency Xinhua. As a compromise, she agreed to try maths at Sun Yat-sen University, in the Department of Mathematics and Astronomy.

She graduated in 1949 and after two years of teaching in Hong Kong, Ye joined Xujiahui, part of the Purple Mountain Observatory under the Chinese Academy of Sciences in Shanghai.

But in those early years of the People’s Republic of China, a lack of standardised astronomical time was having an impact, particularly on the accuracy of surveying and mapping. China in 1957 was known for having the world’s least precise measurements of Universal Time.

02:35

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At the observatory, Ye was responsible for sending measurements of astronomical time to the Bureau of International Time. After she was questioned about her fluctuating data, she ended up finding and fixing a 15-day margin of error that had gone unnoticed for 20 years.

That investigation led Ye to establish a team of scientists in 1958 to improve the precision of China’s measurement of Universal Time. By 1964, it had vastly improved to become the second-best in the world, after the Paris Observatory, and two years later it became the official national standard, known as Beijing Time.

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It was then that she became interested in what is known as very-long baseline interferometry, or VLBI – a technique that uses low-frequency radio waves to track objects with a resolution a dozen times higher than traditional observing instruments.

Although VLBI was still in its infancy back then – and far more expensive than the observatory’s existing technology – Ye saw its potential for determining the position of objects thousands of kilometres away. In 1973, she proposed a plan to develop this wavelength technology in China.

For her contributions to the field, Ye was elected as the first female member of the Chinese Academy of Sciences in 1980. The following year she became the first woman director of the Shanghai Astronomical Observatory.

Ye then launched her VLBI project at the observatory, but the research funding would not stretch to the 25-metre radio telescope that was needed.

She went to the director of the machinery and industry ministry but he refused to even consider the request, a moment Ye recalled in a speech at the Chinese Academy of Sciences last year. The nonagenarian said she had stood her ground – quite literally standing silently in front of the director for 15 minutes until he allowed her to make an appointment with the ministry chief.

Ye got approval for the telescope and it paved the way for China’s moon exploration programme in the 1990s, which required highly precise spatial measurements made in real time.

After decades in the field, Ye became the first Chinese astronomer to be elected as vice-president of the International Astronomical Union, in 1988. She also initiated the Asia-Pacific Space Geodynamics research programme, an international project that she went on to lead, and a newly discovered asteroid – No 3241, Yeshuhua – was named after her. She is still contributing to the Shanghai observatory as a researcher, according to state media reports.

That coincided with the Shanghai premiere of a documentary on Ye and her 70-year relationship with astronomy, One Leaf in the Galaxy – a reference to her surname, which uses the same Chinese character as the word “leaf”.

“We have escaped through war, and we know the suffering of national subjugation. Therefore, we all know how precious our country is, and the experience of our generation,” she says in the film. “I hope that the younger generation can understand that science has no borders. Only scientists have borders.”