NASA's Phoenix lands on Mars
Spacecraft begins 3-month mission Will test water for signs of life
LOS ANGELES - The first spacecraft designed to taste the water of an alien planet landed safely on Mars's northern pole last night, beginning a three-month mission to determine whether the Red Planet ever did, or still might, support rudimentary forms of life.
The Phoenix spacecraft parachuted to the planet's surface at 7:53 p.m. Eastern time, successfully ending a 10-month, 422-million mile journey through space. Cheers and applause echoed through the halls of the Jet Propulsion Laboratory in La Canada Flintridge, Calif., which is managing the mission.
It was the first successful soft landing on Mars since two Viking landers touched down in 1976. Two NASA rovers, which successfully landed on the planet four years ago, used parachutes and cushioned air bags to bounce to the surface.
"Touchdown signal detected," said Richard Kornfeld, a communications specialist. "Welcome to the northern plains of Mars."
Scientists and technicians were elated and relieved. The landing was an elegant feat of engineering and artistry.
"We have the best team in the world," said an exultant Barry Goldstein, the project manager, who has devoted the past five years of his life to this mission.
The entry-descent-landing period, during which the lander separates from the spacecraft, enters the atmosphere and brakes from 12,000 miles per hour to 5 miles per hour, has been described as "seven minutes of terror."
The landing appeared to be al most picture perfect. Each event, from the deployment of the parachute to the firing of the thrusters that brought the lander the final 300 feet to the surface, occurred just as the laboratory had planned.
Early indications showed that the spacecraft appeared to be in fine condition, although that will have to be confirmed.
Now the hard work begins. The lander last night deployed the solar arrays that will supply power for the three-month mission. After that, Phoenix was to begin assessing its environment, from temperature and humidity to wind conditions.
The first images transmitted from the craft about two hours after landing showed one of its feet sitting on Martian soil amid tiny rocks and a view of the arctic plain. Another showed that the lander's solar panels had deployed. Phoenix landed almost level, tilted at a quarter of a degree.
Tomorrow, it is scheduled to deploy its 7.7-foot-long robotic arm, which will be used to dig into the soil. Lying just beneath the lander is an ice layer that Phoenix will dig into, searching for evidence of organic molecules that could provide a habitat for life.
The 7-foot-tall, 904-pound Phoenix lander touched down after a 296-day trek across space.
About half of past missions to Mars have failed. The name Phoenix, referring to the mythical bird rising from its own ashes, was derived from the 1999 Mars Polar Lander, which was lost as it descended to the surface.
As Phoenix whisked through the Martin atmosphere temperatures on its heat shield reached 2,600 degrees. After slowing in the Martian atmosphere, the craft's parachute opened, reducing its descent to 5 miles per hour as it approached within 100 feet of the surface.
Phoenix's landing site was chosen with safety in mind. Pictures taken from space showed a mostly featureless plain in the northern reaches of an area called Vastitis Borealis. One small area contained a pile of rocks, and mission controllers had considered changing the spacecraft's course to avoid it. In the end, they decided the chance of hitting it was so small, about one in 1,000, that there was no point in correcting the course.
Because radio signals take about 15 minutes to make the journey to Mars, there was no way for controllers to make corrections once descent had begun.
Phoenix's science instruments will look for molecules such as carbon and hydrogen, which are the building blocks of life on Earth.
These compounds can be produced without the presence of life, but their presence would encourage scientists who still believe Mars could support some form of life. The two Viking spacecraft that landed on Mars in 1976 made the only previous tests for organic chemicals in Martian soil. Both came up empty.
Phoenix also will check for other ingredients of life. It will examine the acidity of the soil at different layers, and will look for sulfates, which could be an energy source for microbes.
Scientists speculate that if some of the ice in the soil melts during warm periods, some form of microbial life could persist, potentially for millions of years.
Besides the robotic arm and mast camera, the lander's instruments include a Thermal and Evolved-Gas Analyzer, a Microscopy, Electrochemistry and Conductivity Analyzer, and a meteorology station that will track weather patterns, particularly the winds that could carry humidity southward.
Next year, the Mars Science Laboratory, a lander as large as an automobile and equipped with a ray-gun type laser to zap rocks at a distance of 30 feet, is scheduled to follow up on Phoenix's discoveries.
The ground beneath Phoenix will be different from the land forms explored by the twin Mars Exploration Rovers, Spirit, and Opportunity, which landed in 2004. The rugged rovers have been searching more equatorial regions of the planet, focusing on rock forms that show evidence of ancient standing pools of water.
Built by
Although carbon dioxide ice comes and goes with the seasons, large stores of water ice remain underground all year long.
