Like an Olympic gymnast who attempts the riskiest maneuvers to score maximum points, NASA staged a brilliant engineering feat 154 million miles from Earth early Aug. 6. And the space agency definitely stuck the landing — an elaborate seven-minute sequence that slowed the 1-ton space lab Curiosity from 13,000 mph to a soft touchdown on Mars.

Most amazing fact: The landing sequence could not be tested from start to finish on this planet because scientists could not simulate all conditions on Mars. So the landing system either had to work the first time, or Curiosity would join the 1999 Mars Polar Lander as an expensive, embarrassing space flop.

Crowds in Times Square, some decked out in tinfoil hats and alien-themed T-shirts, cheered the spacecraft’s landing. Scientists at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., whooped and hugged. NASA’s website promptly collapsed as space fans tried to get a peek at new Mars photos.

And John Holdren, the president’s science adviser, crowed that “if anybody has been harboring doubts about the status of U.S. leadership in space, well, there’s a 1-ton automobile-size piece of American ingenuity, and it’s sitting on the surface of Mars right now.” Point taken, Mr. Holdren. After the mothballing of the uninspiring space shuttle program and the outsourcing of some spacecraft business to nimbler commercial companies, NASA couldn’t afford a Mars fiasco.

Curiosity, the largest and most advanced machine ever dispatched to another planet, takes the next giant leap: It has lasers that can vaporize rock as it looks for hints of past organic life.

Was there — is there — life on Mars? Curiosity, the aptly named probe, should bring us closer to answers.