This never gets easier.
Bei Bei, one of the National Zoo's giant pandas, is set to bounce in November... which is required as part of an agreement between the US and China...
According to the Smithsonian, his departure is part of a deal with China that any panda born to Bei Bei’s parents, Mei Xiang and Tian Tian, who will remain at the zoo, must move to China after turning four years old, for research purposes and breeding. Pandas are classified as a “vulnerable” species by the International Union for Conservation of Nature, and the best way for Bei Bei to help his fellow pandas is to successfully breed in China.
Fortunately for fans of the National Zoo and the Pandas, they've scheduled some going away events... and you can read all about 'em in the link above.