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A U.S. spacecraft named Phoenix is speeding toward Mars - and Canadian scientists are admittedly nervous. That's because the probe, which is supposed to touch down on Mars later this month, is carrying a Canadian-built weather station.
The $37-million package of meteorological instruments represents the Canadian Space Agency's first major investment in the exploration of the Red Planet. And if everything goes according to plan, the Canadian weather station will provide the first daily temperature, pressure and wind measurements from the surface of another planet.
But landing on Mars isn't easy. Many earlier missions have failed. To complicate matters, the 410-kilogram Phoenix Lander, which is packed with a host of scientific devices from numerous countries, is too heavy to rely on air bags to cushion its fall.
The iconic Mars rovers, Spirit and Opportunity, were encased in airbags and literally bounced their way to a soft landing.
Phoenix, however, will touch down on three sturdy legs, using pulsing retro-rockets to slow its descent. This type of landing hasn't been done successfully since the 1970s.
If one of its legs plops down on a boulder, the spacecraft could topple over, bringing a quick end to the $422-million mission. So, U.S. scientists, using photos taken from spacecraft orbiting Mars, have tried to select a smooth rock-free landing site in the northern polar region of the planet.
But even if the landing, which is set for May 25, goes without a hitch, the Canadian scientists won't be celebrating until they know their weather station is working properly.
"Turning on the instruments will be the most anxious moment because that will determine whether we did a good job," said Jim Whiteway, an associate professor at York University in Toronto and lead scientist for Canada's contribution to the Phoenix mission.
Aside from temperature, pressure and wind sensors, the weather station includes a "lidar" - a laser device that sends pulses of light into the sky and uses the data that bounces back to monitor dust and ice particles in the atmosphere. "We will be able to measure clouds," Prof. Whiteway said, "and clouds are very important for controlling the transport of water in the atmosphere."
Mars is an extremely cold, dry planet with a thin atmosphere composed primarily of carbon dioxide. But evidence from previous Mars missions, especially photos showing what look like deeply cut river valleys and flood plains, suggest the planet was once a much warmer and wetter place.
"The big question about Mars is: Where has all the water gone?" said Vicky Hipkin, a program scientist of planetary exploration at the Canadian Space Agency.
In fact, some scientists believe vast stores of frozen water lie just beneath the surface in the polar region where Phoenix is meant to touch down. The main goal of the mission is to find that water.
The lander is equipped with a two-metre-long robotic arm that can dig a trench and deposit samples, hopefully containing ice-rich soil, into on-board mini-labs for analysis. The samples will also be tested for the presence of organic molecules, the basic building blocks of life.
Locating water "would be enormously significant," said Barry Goldstein, project manager for Phoenix at the U.S. National Aeronautics and Space Administration's Jet Propulsion Laboratory in Pasadena, Calif.
"Wherever we find water on Earth, we find life," he explained. "Now, that is not to say there is life where there is water on Mars. But, clearly, we are looking for the biological potential for life on Mars."
Phoenix will be arriving in what is essentially summer in the northern hemisphere of Mars. At first, the lander will be able to operate under round-the-clock sunlight - resembling Canada's far north in summer, when the sun never sets. The length of the Martian day is also remarkably close to Earth's - 24 hours and 39 minutes.
However, those extra 39 minutes per day will create challenges for the scientists. To stay on top of the mission, and its daily in-flow of data from Mars and out-flow of operational commands to the lander, the scientists will have to live on Red Planet time. That means waking up and going to bed 39 minutes later every day. In some respects, they will be living in a constant state of jet lag.
About a dozen Canadians will be working in shifts at the science operations headquarters at the University of Arizona in Tucson. The mission is expected to last at least 90 days.
As the Martian winter approaches, and total darkness descends on the arctic region, the solar-powered craft will cease to function.
Plunging temperatures will lead to a build-up of frost, composed of frozen carbon dioxide and water-ice from the atmosphere. "The vehicle eventually will disappear" under a blanket of ice, Mr. Goldstein said.
So long as the craft is operating, the Canada Space Agency plans to post daily Martian weather reports on its website - http://www.space.gc.ca.
Those figures will likely provide some bone-chilling reading. The climate near the north pole of Mars is exceedingly cold. The temperature isn't expected to rise above minus 33 C and could dip as low as minus 73 C.
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A Martian lab and a Canadian weather station
NASA's Mars Phoenix Lander, carrying the most ambitious laboratory hardware ever sent to another planet - including a Canadian-built weather station - is on schedule to touch down in the northern polar region of Mars later this month after a 10-month voyage. Phoenix
is designed to detect organic molecules in the planet's icy arctic in search of evidence that the Red Planet is capable of supporting life.
TARGET: MARS'S ICY ARCTIC
LANDING SITE
Vastitas Borealis, Mars's arctic plain, has abundant water-ice.
OLYMPUS MONS
At 25 km in height, the solar system's tallest volcano.
VALLES MARINERIS
A 6 km-deep canyon that stretches 4,000 kilometres.
MARS PHOENIX LANDER
When it unfurls its solar arrays, the lander will measure 5.5 metres across. Its sophisticated suite of instruments will collect and analyze samples of soil and ice in order to sniff out complex carbon-containing molecules associated with life and to construct a climate profile of Mars's polar region.
LANDING SEQUENCE
1Phoenix is travelling at 20,400 km/h as it nears the Red Planet.
2Phoenix jettisons the cruise stage just before it enters the atmosphere.
3Friction with the atmosphere slows the craft and heats the aeroshell.
4After the lander has decelerated to Mach 1.7, the parachute is deployed.
5Phoenix jettisons its heat shield, activates the landing radar and extends its lander legs.
6The lander separates from the parachute one kilometre above the planet's surface.
7Phoenix fires its landing thrusters and decelerates to 2.4 metres/second.
8The landing engines power down when sensors on the footpads detect touchdown.
SOLAR ARRAY
SURFACE STEREO IMAGER
Three-dimensional images from two mast-mounted cameras will help the Phoenix team choose where to dig.
ROBOTIC ARM
The 2.35-metre aluminum and titanium arm will dig up water-ice from up to 50 centimetres below the surface to be analyzed by onboard instruments.
ROBOTIC ARM CAMERA
Fastened to the arm just above the scoop, it will snap colour images of soil and ice showing details finer than the width of a human hair.
LIDAR
This Canadian-made tool beams a laser into the atmosphere and measures reflected light to determine how clouds and dust plumes form.
THERMAL AND EVOLVED GAS ANALYZER
Tiny ovens heat soil samples and examine the vapours that are given off to determine the chemical composition of the samples.
MICROSCOPY,ELECTROCHEMISTRY, AND CONDUCTIVITY ANALYZER
Four tools examine the chemistry and electrical conductivity of the soil.
DEAN TWEED/THE GLOBE AND MAIL, GRAPHIC NEWS; SOURCES: NASA, NEW SCIENTIST
