President Xi Jinping has called on members of the Communist Party of China (CPC) to maintain their loyalty and devotion to the Party and the people, on the 94th anniversary of CPC's founding.Xi made the remarks on Wednesday in a letter to six members of the No.1 land survey team of the National Administration of Surveying, Mapping and Geoinformation.

Founded in 1954 when the country was in dire need of survey data for national defense and economic development, the team has paid nearly 100 visits to uninhabited areas of Tibet, Inner Mongolia and Xinjiang.

Their tracks have covered more than 57 million kilometers -- equivalent to go around the Earth 1,400 times.

This year is the 40th anniversary of China's first independent survey of Mount Qomolangma. The six senior team staff, all CPC members, were involved in the survey.

"Forty years ago, your team bravely entered the forbidden zone and overcame hardships to complete our first calculation of the mountain's height, along with military survey personnel and mountaineers. The Party and the people haven't forgotten your meritorious services," Xi wrote.

The team's major work included mapping islands and reefs as well as reconstruction after the 2008 earthquake in Wenchuan, southwest China. They were once awarded the title of "Heroic Survey Team With Eminent Achievement and Selfless Dedication" by the State Council, China's cabinet.

Xi noted that generations of surveyors had endured difficulties and made sacrifices to measure the beauty of the country, making prominent contributions to the country's development.

Xi praised the team for their patriotic spirit and achievements, urging all CPC members to love and contribute to the Party while maintaining ties with the people.

"The Party cause and the people's cause rely on the loyalty and devotion of millions of Party members. Keeping to our original aspirations will lead us to ultimate success," Xi said, quoting a Chinese proverb.

DEDICATION OF GENERATIONS OF SURVEYORS

Among the team's numerous stories, one dates back to 1960 when members were stranded in a desert in Xinjiang. Wu Zhaopu volunteered to stay behind to look after data and equipment while giving the last of his food and water to those who set off to find help.

Three days later, teammates returned from a water source 200 kilometers away, only to find Wu's dried up body and his mouth filled with sand. His toothpaste and ink were all eaten up, and the equipment was protected by his clothes from the sand, with all data papers arranged in order.

Sixteen years later, when Wu's son Wu Yong'an followed in his father's footsteps and joined the No.1 team, his first mission was to the same desert. Failing to find his father's grave, Wu sprinkled water on every unnamed grave along the way, had a good cry, and continued survey.

Over the 61 years, the team has lost a total of 46 members to drowning, road accidents, hunger, frost and lightening strikes, among other disasters and incidents.

"It's not that we're obsessed with pain or rough living. The nature of our work demands that we are not afraid of sacrifice, otherwise, we couldn't do our jobs," Liu Jian, Party secretary of the team, told Xinhua.

"We can only gain a foothold in the survey field with hardworking spirit and devotion," Liu said.

MONUMENTAL CALCULATION OF MOUNT QOMOLANGMA

The team conducted surveys on Mount Qomolangma in 1966, 1968 and 1975.

Yu Qiqing, 76, still vividly recalls the 1975 expedition which led to the final announcement of the altitude of Mount Qomolangma.

"We had to endure extreme weather with poor equipment. We had to climb ice cliffs and endure the threat of avalanche, with bulky equipment weighing 40 to 50 kilograms on our back," Yu said.

When the team conducted experiments on the Mount Qomolangma, four of them were hit by altitude sickness. They were sustained on a little more than one kilogram of rice for eight days, but still worked over ten hours a day.

Yu himself got pulmonary edema following a gravity test at an altitude of 7,050 meters and spent 40 days in an intensive care unit, where his bodyweight dropped from 70 to 35 kilograms. He lost nearly all his teeth.

After 80 days of supreme effort, the team ascended Mount Qomolangma and on July 23, 1975, China announced to the world the altitude of Mount Qomolangma was 8848.13 meters.

Three decades later, the No.1 team repeated the task, as the altitude is not stable over time. The team again made it to the top of Mount Qomolangma on May 22, 2005, and announced the new altitude of 8844.43 meters.

WHEREVER NEEDED

Over the years, the team ventured to the country's most forbidding territory and obtained valuable data.

An area of 2 million square kilometers in the west had not featured on the 1:50,000 topographic map, which had held back the region's development. From 2007 to 2009, 90 team members waded through uninhabited swamps to survey over 500 square kilometers of the 5,000-meter high Qinghai-Tibet plateau, and ventured 200 kilometers into the Taklamakan Desert.

Data they collected has helped the country to dig mines, build hydropower stations, facelift cities and develop the countryside.