It was a moment of joy and relief as Ya Ya the giant panda touched down in China after a 20-year residency in the United States.

The 23-year-old departed from Tennessee on Wednesday, where she had been living at the Memphis Zoo as part of a giant panda research cooperation project between the U.S. and China. She landed in Shanghai Thursday afternoon, where she will quarantine for a month before returning to her birthplace, Beijing Zoo. 

During a press briefing on Wednesday, Chinese Foreign Ministry spokesperson Mao Ning said Ya Ya has been under good care throughout her stay in Memphis and is deeply loved by Americans.

"The cooperative research on giant pandas has facilitated the protection of the animal, public education and people-to-people exchanges. China is willing to continue to work with other partners, the U.S. included, to make contributions to the conservation of endangered species," she said.

Weeks of preparation have made this journey possible, as experts from Beijing Zoo were dispatched to Memphis in March to prepare for Ya Ya's return.

Her meals and excrement were monitored and it is reported that she had a good appetite and a stable weight before she left. She also underwent training to prepare her for traveling in a crate on a plane, while Beijing Zoo staff learned training gestures and commands from their counterparts at Memphis Zoo, to better look after her upon her return. 

"We gained a comprehensive understanding of Memphis Zoo's feeding details and feeding environment, familiarized ourselves with Ya Ya's feeding methods, feed composition, behavioral training and daily physical examinations, and also interacted with her to some degree," a veterinarian of Beijing Zoo told Xinhua News Agency.

Ya Ya was born on August 3, 2000 and made the trip to the U.S. on April 7, 2003 with giant panda Le Le from Shanghai Zoo. After her 20-year stay, Memphis Zoo confirmed it would return the pandas, however Le Le succumbed to heart disease in February, weeks shy of his scheduled return. Le Le's remains have arrived with Ya Ya, and will be sent to Shanghai Zoo.

Memphis Zoo Associate Curator Lauren Caskey told Xinhua that special care is needed for an aging panda but that Ya Ya is adaptable.

"When Ya Ya sees you, she always comes over to say hi and you actually do see a smile on her face… Ya Ya is so smart and adaptable, and I know she is going to do great when she goes back to China," said Caskey.