History will remember these final four as bookending an era that began with two pilots who boldly took a shuttle for a two-day spin in 1981 without even a test flight. That adventure blasted space wide open for women, minorities, scientists, schoolteachers, politicians, even a prince.
On Friday aboard Atlantis, this last crew will make NASA's 135th and final shuttle flight. It will be years before the United States sends its own spacecraft up again.
Commander Christopher Ferguson, co-pilot Douglas Hurley, Rex Walheim and Sandra Magnus are delighting in their luck.
"We're very honored to be in this position. There are many people who could be here," said Ferguson, a retired Navy captain. "When the dice fell, our names were facing up."
NASA managers were looking for space vets when they cobbled together this minimalist crew with seven spaceflights among them, to deliver one last shuttle load of supplies to the International Space Station.
They were originally recruited to be a rescue team in May, if anything seriously damaged Endeavour during its final flight, Ferguson and his team would have rushed to the space station and brought those astronauts home. If no rescue was needed, the original plan went, Ferguson's crew simply wouldn't fly, and Atlantis would be sent to a museum with the two other retired shuttles.
But early this year, NASA decided to add one more flight. Since Atlantis was being groomed for a potential rescue anyway, NASA reasoned, why not make a cargo run with a year's worth of food and other provisions to keep the space station well-stocked?
But what if Atlantis is damaged? There are no more shuttles to launch a rescue.
The only viable option is the Russian Soyuz spacecraft. The capsules can carry three people at a time, and at least one must be Russian. That's why this crew was capped at four, instead of the usual six or seven.
It will be NASA's first four-person shuttle crew since 1983.
Ferguson and his short-handed crew know there's a chance -- about 1-in-560 -- that they could be stranded at the space station because of flight damage to Atlantis. If that happens, it will take close to a year to get the last person home. Hurley, a Marine, drew the long straw. The travel sequence is based on robotic-arm and spacewalking skills, along with accumulated exposure to cosmic radiation. That last factor alone prevents Magnus, a former space station resident, from spending too long a time in space.
Until private companies get piloted spacecraft flying -- an estimated three to 10 years out -- NASA will have to stick with the pricey Russian Soyuz to get U.S. astronauts to and from the space station. For Americans, that means just a handful of flying opportunities a year. Compare that with the 35 to 50 seats that the shuttles typically provided each year.
Ferguson rejects suggestions the U.S. space program is headed downhill with the shuttle's retirement.
"Hopefully, we'll see 10 years of good quality science out of the space station," he said. "We still have a vibrant program going on."
Despite two horrific accidents that killed 14 astronauts and destroyed two spacecraft, the shuttle program has carried more people than any other space fleet -- 355 people from 16 countries.
Space miles logged by the five shuttles: 537 million, with 4 million more to come this mission.
"There is not an American who doesn't look upon an ascending shuttle with a certain sense of American pride, hair on the back of your neck, chills, call it what you will," Ferguson said.
The space shuttle is "a quintessential American vehicle," said Walheim, a retired Air Force colonel who will serve as the flight engineer. "You point to that and people know it's from the United States, so I think we're losing that piece of identity."
The four astronauts feel the extra burden of putting "the best possible face forward for the last go-around of this," as Ferguson describes it.
This should not be a time of mourning, these astronauts say, or for second-guessing the shuttle retirement decision made seven years ago by President George W. Bush in the wake of the Columbia disaster.
Ferguson and his crew want this final flight to be a celebration.