STEVE INSKEEP, HOST:
It's MORNING EDITION from NPR News. I'm Steve Inskeep.
They were pretty cheerful at NASA this morning after an unmanned vehicle set down on the surface of Mars.
JOHN HOLDREN: If anybody has been harboring doubts about the status of U.S. leadership in space, well, there's a one ton automobile-size piece of American ingenuity...
(SOUNDBITE OF CHEERING AND APPALUSE)
HOLDREN: ...and it's sitting on the surface of Mars right now, and it should certainly put any such doubts to rest.
INSKEEP: That's President Obama's science adviser, John Holdren, after the landing, which took place a little after 1:30 in the morning Eastern Time. There was a lot riding on this mission, starting with its $2.5 billion price.
NPR's Joe Palca was at the Jet Propulsion Laboratory, Mission Control, for this landing.
JOE PALCA, BYLINE: You can't believe the tension and uncertainty here at JPL in the days and then hours before landing. Everybody had a brave face and there was a lot of joking around, but the anxiety just couldn't be denied. At last, the landing time approached and engineers could put on their headsets in the control room and run through the landing sequence they had practiced.
About 90 minutes before hitting the top of the atmosphere, the endgame began.
UNIDENTIFIED MAN #1: We just severed our command uplink to the vehicle and she is truly on her own.
PALCA: Earth was no longer able to send commands to the rover.
So many things could have gone wrong but everything went just right. Shortly before entering the Martian atmosphere, Curiosity began sending tones to Earth indicating its health.
UNIDENTIFIED MAN #2: We are receiving heartbeat tones at this time. Things are looking good.
PALCA: The clock ticked down to the moment Curiosity reached the top of the atmosphere. Then it began - the final landing sequence began, the so-called seven minutes of terror to the surface of Mars.
UNIDENTIFIED MAN #2: We are beginning to feel the atmosphere as we go in here. The vehicle has just reported via tones that it has started guided entry.
PALCA: At this point Curiosity was going more than 13,000 miles per hour.
UNIDENTIFIED MAN #2: At this time the vehicle is beginning to steer its way to the target.
PALCA: There was a question whether a Mars orbiter called Odyssey would be able to relay data from the rover back to Earth. But on this night where everything worked, of course it could.
UNIDENTIFIED WOMAN #1: We are processing data from Odyssey.
UNIDENTIFIED MAN #3: We are now getting telemetry from Odyssey.
PALCA: At this point, the rover was in a capsule with a heat shield on the bottom. The friction of the atmosphere slowed the rover down to about 800 miles per hour.
UNIDENTIFIED MAN #4: Parachute deploy. Parachute...
PALCA: The heat shield was jettisoned and a supersonic parachute slowed things down to about 200 miles per hour. After the parachute did its job, a rocket powered jet pack strapped to the rovers back took over.
UNIDENTIFIED MAN #4: We are in powered flight.
PALCA: That meant the jet pack's eight rocket engines were all working properly. And finally the crazy maneuver.
UNIDENTIFIED MAN #4: Sky crane has started.
PALCA: The sky crane is what engineers called the final phase of landing. The jet pack separated from the rover. And as it hovered 60 feet or so above the surface, it lowered the rover on a cable to a gentle landing.
UNIDENTIFIED MAN #4: Fuel ejectors good. Touchdown confirmed. We are safe on Mars.
UNIDENTIFIED MAN #4: Time to see where our Curiosity will take us.
PALCA: And after this, it only go better.
UNIDENTIFIED MAN #5: Flight EDL images are starting to come down.
UNIDENTIFIED MAN #4: We're beginning to get imaging from...
UNIDENTIFIED MAN #5: Alright. We've got images coming down, folks.
UNIDENTIFIED MAN #6: It's the wheel. It's the wheel.
UNIDENTIFIED MAN #4: We can see a wheel image.
UNIDENTIFIED MAN #4: We are wheels down on Mars.
UNIDENTIFIED MAN #5: Oh, my God. We'll do a proper hug on the other side.
PALCA: At a joyous news conference about an hour after landing, Curiosity Project Manager Pete Theisinger reminded everyone that now comes a patient check-out period to make sure the rover is in good health after its picture-perfect landing.
PETE THIESINGER: We have - now have, as I said to the team, on 10:32 tonight we would have a priceless asset, a priceless national asset. OK? And we are not going to, pardon the French, screw it up.
PALCA: So far, at least, the Curiosity team hasn't shown much of a capacity for screwing things up.
Joe Palca, NPR News at the Jet Propulsion Laboratory in Pasadena. Transcript provided by NPR, Copyright NPR.