The Phoenix Mars Lander has communicated with the Mars Odyssey orbiter, but it appears to be running out of steam.

NASA announced Thursday that the lander is losing solar-electric power because of shorter daylight hours and dust storms on Mars. The Phoenix communicated with the Odyssey, but its communication has been intermittent over the last several days. NASA believes the Phoenix is in safe mode, but engineers continue to assess the situation and figure out how to get the lander working properly again.

NASA said its mission controllers believe the Phoenix's power shortage triggered a sleep mode in which the lander "wakes up" for about two hours a day. They aren't sure exactly when it happened.

The Phoenix touched down on Mars' arctic surface in May. It has taken soil samples and made scientific observations about the atmosphere on Mars that could help scientists determine whether the planet has ever supported life or whether it could support life in the future. NASA originally believed that the lander would operate for three months, but they extended the mission an additional two months. During that time, the sun remained above the horizon around the clock, but the sun now falls below the horizon for about seven hours each day, NASA said.

Engineers at NASA's Jet Propulsion Laboratory and Lockheed Martin Space Systems, Denver, operate the Mars lander. The Mars Reconnaissance Orbiter and Mars Odyssey orbiter relay communications from the Phoenix.

"We will be coordinating with the orbiter teams to hail Phoenix as often as feasible to catch the time when it can respond," Phoenix project manager Barry Goldstein said in a statement from JPL in Pasadena, Calif. "If we can re-establish communication, we can begin to get the spacecraft back in condition to resume science. In the best case, if weather cooperates, that would take the better part of a week."