The final, final frontier

The final mission of Shuttle Discovery is a worthy epilogue for a long, storied chapter in space exploration.

From flying foam to fiery re-entries, Nasa's shuttles are a battered bunch. That the final mission of Shuttle Discovery - which began this week - has so far gone off without a hitch is a worthy epilogue for a long, storied chapter in space exploration.

When Nasa's most trusted shuttle touches down next month, it will mark the beginning of the end of an era. Discovery in particular has had a historic run, making 39 missions since 1984. It transported the Hubble Space telescope into orbit. Now, it's headed for a less taxing berth at the Smithsonian Museum in Washington, DC.

Shuttle proponents were never able to make good on their grandiose plans for a cheap, reusable orbiter. That doesn't mean manned space flight is over. Private entrepreneurs are already rushing to fill a demand for space tourism. Some companies have even promised to send customers to the moon by 2020. Nasa, meanwhile, will turn to others to explore the heavens. European capsules and private contractors will ferry astronauts to and from the International Space Station.

To be sure, an American presence will remain in space. Tucked inside the Discovery's payload is Robonaut 2, the first-ever humanoid robot bound for full-time residency in the space station. As Nasa regroups, we're confident R2 will keep the lights on.