The Phoenix Mars Lander, a robot explorer with a Canadian weather station aboard, was launched Saturday from Cape Canaveral in Florida, boosted into space on a Delta II rocket.

The lander will examine the climate at the north pole of Mars after it arrives next spring.

The Delta II rocket carrying the Phoenix Mars Lander lifts off early Saturday at Cape Canaveral Air Force Station in Florida.
(Terry Renna/Associated Press)

Tom Duck and Cameron Dickinson, two scientists from Dalhousie University in Halifax who helped create a laser probe to study Martian weather, say the next critical stage will be the lander's touchdown, scheduled May 25, 2008.

"There's going to be a parachute to slow it down and retro-rockets will be firing off," Duck told CBC Newsworld on Saturday.

After takeoff and touchdown, the third of what the Dalhousie scientists have dubbed the "three Ts of terror" of the $420-million US mission is the turning on of instruments for the first time.

"That has to go well, because we won't be able to go there and fix it," Duck said.

Phoenix is equipped with a robotic arm that can dig nearly 60 centimetres into the soil next to the three-legged lander to look for signs of organic compounds.

"The hope is that we can dig beneath the surface of Mars and actually get a chunk of ice and deliver it into one of the analyzing instruments that are on board — and for the first time we'll be able to directly measure that there's water on Mars," Dickinson said.

"Other instruments have been orbiting Mars and they've taken pictures and they've inferred water, but we want to really get in there and we want to be sure that there's water there and then try to analyze how much is there," he said.

The green pulsating light of the laser will sweep the atmosphere of Mars, taking measurements of dust and ice particles.

The lander will have about 90 days to conduct experiments before the subfreezing cold of the Mars winter begins and ultimately disables the lander's power-generation and heating systems, NASA officials said.

"There are a lot of features that are similar to the way Earth is," Duck told CBC Newsworld. "It has seasons, just like Earth does. It has weather patterns, just like Earth has. The major force of what drives the winds and so forth is dust. On Earth, it's such things as clouds."

Only five of the world's 15 attempts to land on Mars have succeeded. NASA's ill-fated Mars Polar Lander, for example, went silent as it was about to arrive on the planet's south pole in 1999. It experienced an apparent early shutdown of its rocket engines during descent.

The Phoenix Mars Lander, it's hoped, will successfully make the first ground-level exploration of the planet's arctic region.