The unmanned Delta rocket carrying the Phoenix Mars Lander rose from its seaside pad at 5:26 am, exactly on time, and hurtled through the clear moonlit sky. It was easily visible for nearly five minutes, a bright orange speck in a spray of stars.
If all goes as planned — a big if considering only five of the world’s 15 attempts to land on Mars have succeeded — the spacecraft will set down on the Martian Arctic plains on May 25, 2008, and spend three months scooping up soil and ice, and analyzing the samples in minuscule ovens and mixing bowls.
Evidence of life
The Phoenix Mars Lander won’t be looking for evidence of life on Mars but rather traces of organic compounds in the baked and moistened samples, which would be a possible indicator of conditions favorable for life, either now or once upon a time. If organic compounds are present on Mars, they’re more likely to have been preserved in ice. That’s why NASA is aiming for the planet’s high northern latitudes, where ice is almost certainly lurking just beneath the surface.
Only about six inches of soft red soil should cover the ice, and so the digger shouldn’t have to probe too deeply. The ice is expected to be as hard as concrete, and a drill on the scoop will help gather enough frozen samples. Some dirt and ice samples will be baked and their vapors analyzed. Other soil samples will be mixed with onboard water and the muddy soup examined by onboard microscopes.
“We’re really going there just to understand whether the conditions might have been hospitable for microbial life at some point,” said the University of Arizona’s William Boynton, lead scientist for the oven experiment. Even if organic molecules pop up, they could be from incoming meteorites, Boynton noted.
Mars landings are especially risky. Only five of the 15 US, Russian and European attempts have worked, all of them American successes beginning with the 1976 Viking touchdowns. The Phoenix team said it did everything possible to test for failures and will continue to do so as the spacecraft flies to Mars. The mission costs $420 million.
NASA has never attempted to land a spacecraft on Mars at such a high northern latitude. A lander intended for the red planet's South Pole went silent immediately upon arrival in 1999.
That failure, combined with the loss of the companion Mars orbiter, prompted NASA to cancel a 2001 lander mission. The parts from that scrapped mission were used for Phoenix, thus its name, which alludes to the mythological bird that rises from its own ashes.
Mars' North Pole would have been too cold for Phoenix to operate, and so scientists opted for a little lower latitude for touchdown. Phoenix will be shooting for 68.35 degrees north latitude, comparable to Greenland or northern Alaska, and 233 degrees east longitude. The lander will parachute down, with pulse thrusters easing its final descent.
Scientists chose the flattest, rock-free zone they could to ensure success. The target landing area is ''Kansas flat,'' according to the spacecraft team, with few if any big rocks that could overturn the stationary three-legged lander or bump against its circular solar panels and jam them. The 772-pound lander will stretch 18 feet across once its solar panels are deployed on Mars, and its weather mast will tower 7 feet.