CAPE CANAVERAL, Fla. – The four astronauts who will close out NASA’s 30-year space shuttle program arrived Monday for their history-making launch week, saluting the nation’s birthday and all those who contributed to Atlantis’ final flight.

The launch countdown begins today. Liftoff is set for 11:26 a.m. Friday before an estimated crowd of up to 1 million people.

Commander Christopher Ferguson and his crew received small American flags as launch director Mike Leinbach greeted them out on the runway.

“It’s wonderful that you’ve all came out to join us,” Ferguson told the approximately 65 photographers and other journalists who swarmed the runway. He urged them to go and enjoy some barbecue, fireworks and apple pie.

Altogether, about 2,500 members of the news media have requested credentials to cover the launch. As of Monday, the estimated total crowd count also had risen: NASA spokesman Allard Beutel said between 750,000 and 1 million people now are expected to jam the area to witness the end to shuttle history.

NASA hasn’t launched so few shuttle astronauts since mission No. 6 in 1983. That’s because there are no more shuttles left to retrieve them from the space station in the event of serious launch damage to Atlantis; the shuttle crew would have to be rescued by Russia’s much smaller Soyuz capsules.

Atlantis will make a supply run to the International Space Station, before joining Discovery and Endeavour in retirement.