Damian Dovarganes, Associated Press
Mars Science Laboratory Curiosity team member Miguel San Martin, Chief Engineer, Guidance, Navigation, and Control at Jet Propulsion Laboratory, left, celebrates with Adam Steltzner, MSL entry, descent and landing (EDL) of the Mars Science Laboratory (MSL), right, after the successful landing of Curiosity rover on the surface of Mars at NASA's Jet Propulsion Laboratory in Pasadena, Calif., Sunday, Aug. 5, 2012.

Since the heady days of Apollo 40 years ago, NASA hasn't had a lot of dramatic successes that capture the nation's attention. That's understandable. It's hard to follow manned missions to the moon, which required a tremendous investment in resources and national will.

That's what makes the landing of "Curiosity" on Mars so noteworthy. No, it is not a manned craft. But its successful landing was a triumph of technology and engineering, and of software that allowed for years of tests using virtual simulations, saving a lot of money that otherwise would have been needed for physical tests. The data Curiosity will send back to earth, beginning with color photos published this week, will expand knowledge of the red planet and its past, even as it expands the imaginations of earthlings who observe it.

Mankind has a natural curiosity about the unknown. That, and the hope of finding riches, is what led early explorers to risk their lives crossing uncharted oceans in search of new continents. Space provides limitless opportunities for exploration, and the knowledge gained through NASA's previous successes has unlocked riches in the form of new technologies in a range of applications from medical equipment to everyday GPS devices.

But, for all that, the space program in recent years had become too pedestrian to fuel the spirit of exploration. Mars is the natural next goal to conquer.

A big part of the joy and fascination surrounding the Mercury, Gemini and Apollo programs was in seeing how engineering and human intelligence could surmount problems and accomplish what once had been thought impossible. Since 1969, few phrases in the English language have better captured the frustration of a problem better than the one that begins, "They can put a man on the moon, but they can't ..."

The "they" in reference generally is not the same as the "they" who accomplished the lunar feat. But space flight has taught mankind that limits to achievement tend to be self-imposed. Imagination and hard work really can pull dreams into reality.

Curiosity had all of that old-fashioned engineering wizardry going for it. The craft had to perform acrobatics as it descended through Mars' thin atmosphere and slowed from 13,200 mph to 2 mph in about seven minutes, then touched down and sent signals back to earth.

Washington has been agonizing lately over how to proceed with space exploration. President Obama has decided to turn much of the low-orbit duties to the private sector. The recent success of a craft built by a company called SpaceX also was reason to cheer. There is no reason why public and private efforts cannot combine to carry this ultimate exploration further. For all of NASA's successes through the years, perhaps the most daunting frontier left to conquer is to engineer a way to fund the enormous costs of continuing to explore.

Given the benefits to mankind from space travel so far, that's a frontier that needs to be explored.