Space: Mission to Mars

The planet Mars follows such an eccentric orbit around the sun that it is accessible to probing spacecraft from earth only one month out of every 25—a period referred to by scientists as "the window." All through November the window was open, but the first U.S. attempt to peek inside failed when the Mariner C spacecraft, unable to jettison its 300-lb. fiber-glass protective shield, could not attain the necessary speed.

Last week the U.S. tried again, barely two days before the window would have slammed shut until December 1966.

At Cape Kennedy a three-stage, 100-ft. Atlas-Agena rocket blasted downrange over the South Atlantic missile track in a perfect launch. Five minutes later, the protective shield, a redesigned shroud of magnesium thorium, was jettisoned right on schedule. Thirty-seven minutes after that, from a 115-mile-high parking orbit over the Indian Ocean, the rocket engine reignited, kicking the 575-lb. Mariner D payload toward Mars at the required speed—25,600 m.p.h. At week's end all was going well with Mariner D and its 138,-000 individual parts. But the spacecraft still has quite a way to travel—325 million miles along a route that is expected to carry it past Mars by mid-July.

Mariner's mission is manifold. During its journey away from the sun, it will radio back information on radiation, magnetic fields and micrometeorites. If all goes perfectly, it is supposed to, transmit data on the density of the Martian atmosphere that could be invaluable to U.S. scientists who are hoping to land a capsule there by 1969. As a final dividend, it will also try to take 22 still pictures with a television camera during a 30-minute flyby some 8,600 miles from the red planet. The pictures will be transmitted to earth from 150 million miles in space, but scientists think they could be as detailed as photos of the moon taken by the strongest telescopes on earth. If they are right, new light may at last be thrown on the mystery of the Martian canals.