HOUSTON --A few hours before Endeavour's early Wednesday morning return, crews at Kenned Space Center rolled Shuttle Atlantis from the vehicle assembly building to launch pad 39-A. Atlantis is set to launch on July 8. That mission will mark the end of the 30-year shuttle program. This is all bittersweet. Yes, the shuttle has done tremendous work, which is worth celebrating, but its end means the end of jobs for thousands of our neighbors and the loss of our only American way into space for at least four more years -- all that swirling while four shuttle astronauts try to focus on a risky mission. NASA's been doing rolling shuttles to the launch pad since 1980. But it will never happen again. "As a country we can look back and say my gosh to my grandkids I remember when we flew the space shuttle and I remember the proud moment when I felt the rumble in my chest when I felt the space shuttle launch and I long for those days again," Atlantis commander Chris Ferguson said. Ferguson and the rest of the final shuttle crew were in Florida Tuesday night for Atlantis' crawl to the launch pad. But they've spent the last eight months mostly in Houston, training to take Atlantis out for its last ride on July 8. "We're trying to appropriately recognize and mark these milestones, but at the same time we're heads down, forward and very busy," Ferguson. This final crew, who calls themselves "the final four," is smaller than usual -- just four instead of the normal seven astronauts; all are Americans, all space veterans. And their mission is light on science and heavy on lifting. "This is a big resupply mission; the way I think about it is kinda like Sherpas," Atlantis astronaut Rex Walheim said. This is the last time something this large will go to the space station. Part of the beauty of the shuttle is that it's always been able to carry huge payloads; think the Hubble telescope for instance. But for this mission it's far less advanced. Think dinner: hundreds and hundreds of pounds of dehydrated food for the space station crews and supplies to keep them working and then bringing all sorts of unneeded equipment home. It's a different mission but also potentially more dangerous. Ever since the Challenger disaster, there's always been a shuttle waiting to launch on a rescue mission if something went wrong. But tonight, the rest of the shuttles are all heading to museums. "It's sad to see her land the last time," a NASA dispatcher said about the Endeavour as it landed early Wednesday morning. So if something goes wrong, this crew will have to sit tight on the space station, waiting for an eventual ride home on the Russian Soyuz capsule. "If it ends up happening, you get a year on Space Station for nine months of training," Atlantis astronaut Doug Hurley said. The wait would turn a two-week mission into a yearlong wait for two of the astronauts. The chance of it happening though is miniscule. This final crew is planning on a safe mission and a safe launch in front of huge crowds in Florida just a month from now. "There's going to be a heck of a traffic jam and four people that have one ticket out of here," Walheim said. The rescue mission is the biggest reason this crew is so small. Getting four people home two at a time in the Soyuz is tough enough. Seven would take a long time. Thirty-eight days and counting.