Their lease is up. It's time for the three giant pandas at the to return to China.
On the morning of Nov. 8, 26-year-old Tian Tian, 25-year-old Mei Xiang, and their began their trip to Chengdu, China.
The journey started at the National Zoo with the pandas loading into their individual 800-pound steel and plexiglass crates built by FedEx to be chauffeured to the Dulles International Airport.
The pandas are set to take off on a Boeing 777F aircraft with giant panda decals dubbed the "FedEx Panda Express" on the afternoon of Nov. 8. The flight to Chengdu is 19 hours, with a refueling stop in Anchorage, Alaska.
Joining the pandas on the trip are a veterinarian and two panda keepers, who will supply the animals with approximately 220 pounds of bamboo, 8 pounds of leafeater biscuits, 5 pounds of low starch biscuits, 6 pounds of apples, 5 pounds of carrots, 6 pounds of sweet potatoes, 3 pounds of sugar cane, 1 pound of pears, and 1 pound of cooked squash during the flight.
Giant pandas typically spend much of their day eating, so the staff will see to it that the bears' routines don't change. Tian Tian has an affinity for sugar cane, Mei Xiang especially loves pears, and Qi Ji favors cooked sweet potato or butternut squash, so the crew will feed them their favorite foods to keep them occupied on the flight.
The pandas' crates are also prepared for the long trip; each carrier includes a tray underneath to catch any waste from bathroom breaks.
The departure of these three beloved bears marks the first time the National Zoo has been without pandas since 2000. The zoo entered its first Giant Panda Cooperative Research and Breeding agreement with the China Wildlife Conservation Association in December 2000 with Mei Xiang and Tian Tian's arrival. Per the agreement, China loaned the two bears to the zoo, which provided funds and expertise to panda conservation programs in exchange. The initial agreement was renewed three times, with the final agreement expiring on Dec. 7 of this year.
Despite news reports that claimed that the pandas were leaving earlier than scheduled, zoo spokesperson Annalisa Meyer says Nov. 8 is the departure date the zoo has been preparing for since creating the pandas' exit plan.
"The good news is that we've done this before," Meyer tells PEOPLE about preparing for the send-off. "What makes this journey unique is that there are three pandas departing."
Before the departure date, panda keepers trained the three animals to voluntarily enter their travel crates and get comfortable with the enclosures.
Upon arrival in China, Xiao Qi Ji will enter a breeding program, like the three National Zoo cubs that moved to China ahead of Xiao Qi Ji. Mei Xiang and Tian Tian will enjoy their retirement at the China Conservation Research Center for the Giant Panda.
Collaborations with zoos like the National Zoo have helped China save giant pandas from extinction. "Our breakthroughs in giant panda biology, behavior, reproduction, health, and habitat research helped move the giant panda off the endangered species list," Meyer says.
Discussions with the China Wildlife Conservation Association about obtaining new giant pandas for the National Zoo are expected to start after Xiao Qi Ji, Tian Tian, and Mei Xiang settle into their new home in China.