NASA is preparing for a planned May launch of an Atlas-V rocket, built in Alabama. The booster is set to carry the first crewed flight of Boeing’s Starliner space capsule to the International Space Station. Once the vehicle docks with the orbiting outpost, there will be a meeting of two “penguins."Here’s an explanation…Astronaut Sunita Williams will command the mission of the Boeing Starliner spacecraft nicknamed “Calypso” for famed oceanographer Jacques Cousteau’s research ship. A current member of the International Space Station crew is astronaut Tracy Caldwell-Dyson. Around NASA, they’re both known as “penguins.” It comes from their shared astronaut class. The space agency picks groups of candidates to train for missions in orbit. These groups are known as classes, and each class gets a nickname. Williams and Dyson were both members of the class of 1998, which are called “penguins.”The story goes, the nickname came about because the candidates were selected in 1998, which was so late in the life of the Space Shuttle program, they were considered less likely to fly in space. Classmate, astronaut Clayton Anderson, another “penguin,” explains it further.“Penguins are all dressed up with no place to go,” said Anderson. (They’re) flightless and more marketable than ‘do-do’s.’ We picked ‘penguins’ rather than let the 1996 stick us with ‘do-do’s.’” Another NASA tradition allows the previous astronaut class to name the latest batch of rookies. The 1996 class, Anderson referred to, were known as the “sardines.”Anderson’s comments are on a signed astronaut class photograph that currently hangs on the wall of my office at Alabama Public Radio.Along with Sunita Williams and Tracy Caldwell-Dyson meeting up in space as reunited “penguins,” the orbiting laboratory is the current home of a robotic cargo carrier named for another astronaut from the class 1998. Patricia Hilliard was killed in a 2001 plane crash before flying to space. Northrop-Grumman builds the automated supply ships, and names each one after a notable person in the space program. One was dubbed the “S.S. John Glenn,” for America’s first astronaut in orbit. Another is called the “S.S. Katherine Johnson,” the NASA mathematician depicted in the motion picture “Hidden Figures.” Ther current cargo ship docked to the International Space Station is called “S.S. Patty Hilliard.”The Atlas-V rocket set to carry the Boeing Starliner capsule to orbit was built at the United Launch Alliance factory in Decatur. It will be the first such rocket to carry astronauts.