For NASA's engineers, Discovery's on-time landing on Monday in Florida after a picture-perfect mission erased huge question marks about the shuttle programme - and cleared the way for NASA's next vision of building a base on the moon.
After years of stop-and-go progress on the International Space Station (ISS), after delays from the 2003 Columbia disaster and glitches in last year's return flight, Discovery astronauts carried out repairs on the ISS needed to double its size and weight within the next 18 months.
The ISS programme, supported by NASA and more than a dozen other countries, including Russia, Germany and Japan, is the most ambitious construction programme ever in space.
Within the next 18 months, the ISS will be transformed into the first man-made object in space visible to the naked eye during daylight, the mission's leading flight director Paul Hill says.
The living space is to be expanded to house a permanent crew of six, twice the current capacity.
NASA wants to finish its delivery of construction materials by the end of next year - not that NASA is particularly focused on the end goal of running the space station at full tilt.
In fact, before construction is even finished, NASA hopes to be well into its more ambitious vision - building a launch pad on the moon for Mars-bound human spacecraft.
Finishing the space station in fact seems to have become a chore.
NASA administrator Mike Griffin reassured Congress that the current budget would allow the agency to fulfill its obligations to the ISS programme.
But by 2010, the shuttle spacecraft will be mothballed so NASA can turn its full attention - and the $ 4-billion it spends every year maintaining the 25-year-old spacecraft - to building the moon base.
That vision was proclaimed in 2004 by US President George W Bush.
Just a year before, the Columbia disaster marked one of the blackest episodes in US space history.
The disintegration of seven astronauts and their shuttle as they re-entered Earth's atmosphere devastated NASA's self confidence - and eroded public trust in the programme.
Investigation revealed how NASA had for years taken into stride hair-raising risks for its spacecraft and astronauts - despite the 1986 explosion of the Challenger shuttle.
After the Columbia disaster, NASA invested more than $ 1-billion in design changes to prevent fuel tank insulation from ripping off during the violent take-off and hitting the heat shield tiles - damage blamed for the 2003 disaster.
Bush wants to open a brand new chapter for space exploration, and to put aside the tedious, long-range ISS project and its basis of international cooperation.
With China starting its own space programme, the White House fears such competition could even erode America's standing as the world's dominant political and economic force.
"Imagine if you will a world of some future time - whether it be 2020 or 2040 or whenever - when some other nations or alliances are capable of reaching and exploring the moon, or voyaging to Mars, and the United States cannot and does not," Griffin told Congress in April.
"Is it even conceivable that in such a world America would still be regarded as a leader among nations?" he said.
"And if not, what might be the consequences of this for the global balance of economic and strategic power?"