This story was updated at 7:09 a.m. ET (1109 GMT)
CAPE CANAVERAL, Fla. — NASA's Phoenix Mars Lander lit up the predawn Florida sky Saturday, launching spaceward on a mission to determine whether the planet could have once supported primitive life.
A United Launch Alliance Delta 2 rocket launched Phoenix towards Mars at 5:26:34 a.m. EDT (0926:34 GMT) from Pad 17A at the Cape Canaveral Air Force Station in Cape Canaveral, Florida. The three-stage booster is bound for the flat northern plains of Vastitas Borealis near the Martian north pole, where it is expected to dig into and sample the region's icy soil with its eight-foot (2.4-meter) robotic arm.
"It's a wonderful morning to go to Mars," NASA's Phoenix project manager Barry Goldstein, of the agency's Jet Propulsion Laboratory (JPL), just before liftoff. As predicted, weather conditions were pristine for the early morning space shot. The launch was delayed 24 hours earlier this week due to bad weather during rocket fueling.
Just after the supersonic crackle of the launch, Phoenix officials let out gasps of excitement as the rocket careened toward Mars.
"This is just about the coolest thing you could imagine," said Tim Gasparrini, deputy program manager for the Phoenix mission at Lockheed-Martin. "Phoenix has been a long time coming, and this is really, really exciting."
Ray Arvidson, co-chairman of the Phoenix Landing Site Working Group at Washington University in St. Louis, said the successful launch was an enormous relief.
"It was a great launch, so it means we're going to reach a high northern latitude site on Mars and actually sample ice for the first time," Arvidson said. "Now we can get on with the business of doing great science on mars."
Bound for Mars
The $420 million Phoenix mission is built on the ashes of NASA's canceled Mars Surveyor 2001 Lander and the ill-fated Mars Polar Lander, which crashed during landing in December 1999. Much of the 772-pound (350-kilogram) probe and its seven science instrument packages are built from hardware based on or recycled from those two missions, mission managers have said.
"I started working on this spacecraft in 1997, so it's incredibly gratifying to watch it finally go up," Gasparrini said. "It's not often that you get a second chance in life."
Phoenix coasted through space between a series of engine burns before final spacecraft separation about 90 minutes after liftoff. The spacecraft took longer than mission managers expected to send a signal back to Earth, but eventually notified mission control of its good launch trajectory and fully-operational solar panels.
"It seemed like an eternity," said NASA launch director Chuck Dovale. "We weren't sure that Phoenix would phone home, and she did and we're happy."
"The cruise to Mars will be about nine and a half months," said Ed Sedivy, Phoenix spacecraft program manager for Lockheed Martin - which built the Mars probe for NASA - before liftoff. "And then we'll go through the descent, entry and landing, which is the big enchilada for the mission."
Phoenix is due to land on May 25, 2008, plunging through the Martian atmosphere behind its protective aeroshell before deploying a parachute to slow its descent, extending three landing legs and firing a set of pulse rockets to make a smooth touchdown on the surface of Mars. Managed by JPL in Pasadena, California, the Phoenix mission is expected to last at least 90 Martian days, or sols.
If successful, the landing will mark the first soft touchdown on Mars since NASA's massive Viking lander missions in the 1970s.
"It's going to be a pretty flat plain, but still scientifically fascinating," Arvidson said of the target zone.
Researchers used imagery from NASA's Mars Reconnaissance Orbiter and other spacecraft to make sure Phoenix's landing site was relatively clear of rocks, steep slopes or other conditions that could pose a hazard to the spacecraft. The landing site is at a latitude on Mars similar to that of northern Alaska or Iceland on Earth, mission managers said.
In addition to its backhoe-like robotic arm, Phoenix is equipped with a series of science tools to taste, sniff and peer at Martian soil and ice. The probe won't hunt for evidence of life itself, but rather the conditions required in which microbes or other organisms could exist, mission scientists said.
"This is a stepping stone for future missions because the number one NASA goal is searching for life outside the Earth's boundaries inside the Solar System," said Peter Smith, Phoenix's principal investigator at the University of Arizona, during a prelaunch briefing. "And this is a step in that direction."
Tiny ovens and a wet chemistry laboratory mounted to Phoenix's upper surface, or deck, will scan soil and ice samples for signs of organic molecules and compounds - one ingredient useful for life - while cameras and microscopes image the samples. The probe also carries a laser ranging and detection (lidar) instruments and other tools mounted to a meteorology mast to study Mars weather.
But before Phoenix can study Mars, the probe must first reach the red planet, which has proven to be a challenge in the past. More than half of all Mars-bound missions have failed to date, NASA has said.
"As smart as we like to think we are, we're not clearly as smart as we need to be," Goldstein said before launch, calling Mars a spacecraft eater. "It really is a difficult job. No matter how many times we land successfully, it will never be routine."
SPACE.com Staff Writer Dave Mosher reported from Cape Canaveral, Florida. Staff Writer Tariq Malik reported from New York City.