And now there is only one. With Wednesday's landing of Endeavour, just one more space shuttle flight remains, putting an end to 30 years of Florida shuttle launches and more than 535 million miles of orbits controlled at Houston's Johnson Space Center. Now a sense of melancholy has permeated the community that calls itself "the space shuttle family."
George Mueller, the man considered "the father of the space shuttle," explained why he's not going to watch the final launch next month.
"It's like going to a funeral. I'm never enthusiastic about funerals," said Mueller, who at 92 is still flying cross-country to talk about space. But he's not going to Cape Canaveral, Fla., to watch the liftoff of Atlantis on July 8.
Neither is former astronaut Joe Tanner, who reflected the same thinking in an e-mail: "I have so many absolutely wonderful memories of my 24 years at NASA that I don't want to tarnish them by going to a funeral, if you understand what I mean."
In regions that identify so closely with the space program - cities like Houston, where the local sports teams are the Astros and the Rockets, and Cape Canaveral which calls itself the Space Coast and even has an area code of 3-2-1 - the end of the shuttle era is an emotional punch in the gut. The emotions people describe in dozens of interviews resemble the stages of grief in psychology books: Denial, Anger, Bargaining, Depression, and Acceptance. And the shuttle program isn't dead quite yet.
"The grieving is totally normal; that period of bereavement that we have over this kind of loss is pretty well documented in the research literature," said Sharon Hall, head of the psychology department at the University of Houston Clear Lake which is next door to Johnson Space Center. "It's kind of a transitioning en masse."
Hall says the fact that the community is going through it together will help speed up the healing process, along with a natural human resilience. It helps that the phrase "space shuttle family" is more than just management-speak, she said: "They are so supportive of each other, very protective, all the characteristics you associate with a family."
From orbit Monday, Endeavour Commander Mark Kelly, pilot Gregory Johnson and astronaut Drew Feustel all used the word "bittersweet" to describe their feelings.
"It'll be sad to see it retired," Kelly said. "But we are looking forward to new spacecraft, new destinations. We're all excited about the future."
Some people are trying to bask in the remarkable achievements of the shuttle program, like launching and fixing the Hubble Space Telescope and building the International Space Station. Houston Mayor Annise Parker, who talked about how space is part of her city's inner and now hurting psyche, said, "I feel like it's a wake. We celebrate the good stuff."
Rice University scholar Neal Lane, who was President Bill Clinton's science adviser, said the shuttle's impending retirement "marks the end of an era. It's an example of one of America's greatest peacetime accomplishments. It's a sad time for many, but it's a time to celebrate and remember."
Some of NASA's old-timers are not celebrating, however.
Christopher Kraft, the legendary engineer who began Mission Control nearly 50 years ago and presided over the initial shuttle flights, expressed pride, melancholy and anger all in little more than a minute.
"It's a sad day for the country. I'll be damned proud of what I did," Kraft said. "We're all very proud of what we've done. But I think we recognize that the country is the one that will suffer - not us."
The plan to retire the space shuttle was made by President George W. Bush in 2004. Bush wanted to replace it with new spacecraft that would return astronauts to the moon.
Former astronaut Jerry Linenger looked at the bright side then, dreaming of a new future. But the Bush moon plan ran into money and technical problems and couldn't meet its schedule. It was cancelled by President Barack Obama last year and replaced with a plan to go to an asteroid by 2025, and ultimately go on to Mars. But those plans are far from detailed.
And when that happened, the measured joy Linenger expected to feel with the end of the shuttle program just evaporated and dismay took its place.
"To me, you were talking one giant leap forward and now you're talking a leap backward," Linenger said.
NASA Administrator Charles Bolden, a former shuttle commander, chokes up when talking about the end of the shuttle fleet: "For me it's personal and to be quite honest, it's quite emotional."
But Bolden, who lives in the same neighborhood as Kraft and chats with him and other NASA legends, says the future is not bleak, but exciting.
"Everybody who has ever been associated with human spaceflight knows we're not giving up on human spaceflight. We're committed to it," Bolden said. "We're going to do some pretty exciting stuff."
When he became an astronaut in 1980, NASA was looking beyond Earth's orbit. The space shuttle era kept America flying in circles for 30 years. Bolden views the new space plan as "an opportunity to go back and do a do-over... go beyond low Earth orbit and explore our solar system and other planets."
But Mueller in an interview with The Associated Press would have none of that: "It's the end of a career, not the beginning of a new one. What we lack is the beginning of a new one."
Explore further: NASA's Webb Telescope mirror tripod in action (Video)