Sunday is a Mars landing for Phoenix spacecraft

A new Mars lander, checking for water and signs of life, past or present:

NASA preps for '7 minutes of terror' on Mars

(CNN) -- In the wake of the wildly successful Spirit and Opportunity rover missions, you would think NASA would approach the landing of the next Martian probe with high confidence.

But the truth is sometimes not what you would think.

"I do not feel confident. But in my heart I'm an optimist, and I think this is going to be a very successful mission," said principal investigator Peter Smith, an optical scientist with the University of Arizona. "The thrill of victory is so much more exciting than the agony of defeat."

Indeed, the truth is that the planetary scientists and engineers who make up the Mars Phoenix Lander team will be biting their nails Sunday evening as they cluster around computer monitors in mission control at the Jet Propulsion Laboratory in Pasadena, California.

That's when their spacecraft, which launched to Mars in August, will finally arrive on the Red Planet.

Everyone on the team is primed and ready to get down to business, putting the suite of scientific instruments aboard Phoenix to work analyzing the soils and permafrost of Mars' arctic tundra for signatures of life, either past or present.

But first, they have to get the lander on the ground, and that's where the worry comes in. In fact, they have a name for it in the Mars exploration community: "seven minutes of terror."

Seven minutes is all it takes for a spacecraft travelling neary 13,000 miles per hour to hit the Martian atmosphere, slam on the brakes and reach the ground.

During that time, onboard computers will be working at a manic pace as the spacecraft deploys its parachute, jettisons its heat shield, extends its three legs, releases the parachute and finally fires its thrusters to bring it down for a soft landing. Hopefully.

"Everything has to go right," NASA Associate Administrator Ed Weiler said. "You can't afford any failures."

It's risky business. Historically, 55 percent of Mars missions have ended in failure. And tensions will be particularly high with the Phoenix spacecraft. [...]

See the rest of the article for details of the risks. I saw a video simulation of the landing on Fox News. It involves thrusters and landing on legs. If even one sequence proceeds incorrectly, the whole mission could be ruined. But if they succeed, it will be marvelous. Lets hope for the latter!



There are more details about the mission at NASA's Website. Check out the videos on the right side bar.


UPDATE 05-25-08: Success!

NASA Spacecraft Makes Historic Landing on Mars