Shuttle Atlantis Could Still Fly One More Mission Before Retiring

This story was updated at 3:25 p.m. EDT.

CAPE CANAVERAL, Fla. ? The Wednesday landing of NASA's spaceshuttle Atlantis may have capped a successful mission slated to be thespaceship's last trek to space, but the orbiter's immediate future is not yet setin stone.? Debate is still underway to determine whether the shuttle should getone more flight or be sent straight to a museum.

As Atlantis' most recent mission demonstrated, the orbiteris in good shape, NASA shuttle officials said today just after the shuttlelanded here at the agency's Kennedy Space Center.

"Not only is this mission fantastic, but the entirelife of Atlantis, the folks who built it, all the missions it's flown over itscareer have been just amazing," shuttle launch integration manager MikeMoses said. "I can't even begin to talk about how proud I am of Atlantisand the whole team that put it together."

The shuttle finished a 12-day mission to the InternationalSpace Station to deliver a new Russian room and outfit the station with spare partsfor the era after NASA's three-orbiter space shuttle fleet retires.

"She's a great ship and it was a real honor to be onthe last flight, if this turns out to be the last flight," Atlantismission specialist Michael Good said after landing. "Atlantis treated usvery well. She was just an incredible ship, she just worked perfectly."

Two more shuttle missions are currently planned ? one each forAtlantis' sister ships Discovery and Endeavour.

But what about Atlantis?

Whether or not the STS-132 mission will actually be theorbiter's last spaceflight has not been decided. Starting tonight, Atlantiswill be processed and refurbished just in case it has to fly again.

The orbiter is on call to serve as the emergency rescue shipto be on reserve in case of a serious problem with NASA's final planned shuttleflight, the STS-134 mission of Endeavour slated for no earlier than lateNovember. If something goes awry on that flight, shuttleAtlantis could be readied to retrieve Endeavour's astronauts from thestation and return them back to Earth.

However, NASA and lawmakers are also considering whether to shiftthis so-called "launch on need" mission to a full-fledged finalshuttle flight. The hardware, including an expendable external fuel tank, isalready in place to fly one more mission. But that plan would require more fundingto retain space shuttle workers for longer than currently planned.

It costs NASA about $200 million a month to keep its spaceshuttle program running, program managers have said.

One more mission, which NASA would likely launch with a crewof four in June 2011, would allow the agency to stock up on more supplies forthe space station since the outpost is slated to continue running through atleast 2020. Beyond the shuttle era, the station will be serviced by mannedRussian Soyuz vehicles and unmanned Russian, Japanese, European and Americancommercial cargo-carrying spacecraft.

Eventually, U.S. President Barack Obama and NASA hope privatecompanies can build spaceships to ferry astronauts to the orbiting laboratory,too.

In the meantime, NASA simply doesn't have the funds tocontinue flying the space shuttle and work on developing next-generation rocketsand vehicles at the same time.

"I think we'd all love to have kept flying shuttlewhile we set up the new system ? we just don't have the budget to do that, andthat's the reality of the world we live in," Moses said.

Yet just because the shuttles are headedfor retirement doesn't mean they're not in good health and capable offlying at least one more flight, he said.

"It's true they are 30 years old but they are not oldat all," Moses said. "They're in fantastic shape, they fly perfectlyand they do exactly what we mean them to."

Whenever it finally comes, the retirement of the spaceshuttle fleet will be a bittersweet time for NASA.

"It's just an amazing machine, and it's a testament toAmerica's prowess in space that we're able to reuse the spacecraft over andover," shuttle launch director Mike Leinbach said. "I'm going to hateto see that go away."

• Gallery - Photos From the Last Launch of Atlantis
• Space Shuttle Atlantis By the Numbers: A 25-Year Legacy
• What Will NASA Do With the Retired Space Shuttles

SPACE.com is providing complete coverage of Atlantis'STS-132 mission to the International Space Station with Senior Writer ClaraMoskowitz in Cape Canaveral, Fla., and Managing Editor Tariq Malik based in NewYork. Click herefor shuttle mission updates and a link to NASA TV.