In 2009, astronaut Leland Melvin was photographed for his official NASA portrait. But instead of it just being of him, he brought along his two rescue dogs named Jake and Scout. The endearing images that followed show that while the canines can behave when they want, sometimes they just can't contain their excitement. One photo features the dogs sitting calmly at Melvin's side, while the other shows them standing in his lap and licking his face.
Melvin tweeted that he snuck the dogs into the NASA photo studio on the day of the shoot. He still uses the sillier of the two portraits for his Twitter profile picture, but NASA has a dogless photo (below) in his official astronaut biography.