A NASA spacecraft today sent pictures showing itself in good condition after making the first successful landing in a polar region of Mars.

The images from NASA's Mars Phoenix Lander also provided a glimpse of the flat valley floor expected to have water-rich permafrost within reach of the lander's robotic arm. The landing ends a 422-million-mile journey from Earth and begins a three-month mission that will use instruments to taste and sniff the northern polar site's soil and ice.

"We see the lack of rocks that we expected, we see the polygons that we saw from space, we don't see ice on the surface, but we think we will see it beneath the surface. It looks great to me," said Peter Smith of the University of Arizona, Tucson, principal investigator for the Phoenix mission.

Radio signals received at 4:53:44 p.m. Pacific Time (7:53:44 p.m. Eastern Time) confirmed that the Phoenix Mars Lander had survived its difficult final descent and touchdown 15 minutes earlier. In the intervening time, those signals crossed the distance from Mars to Earth at the speed of light. The confirmation ignited cheers by mission team members at NASA's Jet Propulsion Laboratory, Pasadena, Calif.; Lockheed Martin Space Systems, Denver; and the University of Arizona.

As planned, Phoenix stopped transmitting one minute after landing and focused its limited battery power on opening its solar arrays, and other critical activities. About two hours after touchdown, it sent more good news. The first pictures confirmed that the solar arrays needed for the mission's energy supply had unfolded properly, and masts for the stereo camera and weather station had swung into vertical position.

"Seeing these images after a successful landing reaffirmed the thorough work over the past five years by a great team," said Phoenix Project Manager Barry Goldstein of JPL. A key milestone still ahead is the first use of the lander's 7.7-foot-long robotic arm, not planned before Tuesday.

"Only five of our planet's 11 previous attempts to land on the Red Planet have succeeded. In exploring the universe, we accept some risk in exchange for the potential of great scientific rewards," said Ed Weiler, NASA associate administrator for the Science Mission Directorate, Washington.

Phoenix carries science instruments to assess whether ice just below the surface ever thaws and whether some chemical ingredients of life are preserved in the icy soil. These are key questions in evaluating whether the environment has ever been favorable for microbial life. Phoenix will also study other aspects of the soil and atmosphere with instrument capabilities never before used on Mars. Canada supplied the lander's weather station.

Transmissions from Phoenix have reported results after a check of several components and systems on the spacecraft. "Phoenix is an amazing machine, and it was built and flown by an amazing team. Through the entire entry, descent and landing phase, it performed flawlessly," said Ed Sedivy, Phoenix program manager at Lockheed Martin Space Systems Company. "The spacecraft stayed in contact with Earth during that critical period, and we received a lot of data about its health and performance. I'm happy to report it's in great shape."

Phoenix uses hardware from a spacecraft built for a 2001 launch that was canceled in response to the loss of a similar Mars spacecraft during a 1999 landing attempt. Researchers who proposed the Phoenix mission in 2002 saw the unused spacecraft as a resource for pursuing a new science opportunity. A few months earlier, NASA's Mars Odyssey orbiter discovered that plentiful water ice lies just beneath the surface throughout much of high-latitude Mars. NASA chose the Phoenix proposal over 24 other proposals to become the first endeavor in the Mars Scout program of competitively selected missions.

The signal confirming that Phoenix had survived touchdown and the transmission of the first pictures were relayed via Mars Odyssey and received on Earth at the Goldstone, Calif., antenna station of NASA's Deep Space Network.

The Phoenix mission is led by Smith at the University of Arizona with project management at JPL and development partnership at Lockheed Martin. International contributions come from the Canadian Space Agency; the University of Neuchatel, Switzerland; the universities of Copenhagen and Aarhus, Denmark; Max Planck Institute, Germany; and the Finnish Meteorological Institute. For more about Phoenix, visit http://www.nasa.gov/phoenix .