We overlooked an important anniversary in the history of technology yesterday. So we'll attempt to make amends by celebrating it a day late (call it a tardy birthday card of sorts). Thirty years ago yesterday, the Viking 1 spacecraft touched down on the surface of Mars. The occasion marked the first space mission to land successfully on another planet. Even now, the achievement stands out as one of the major milestones of human exploration.
As it was a first, the landing of Viking 1 on the Chryse Planitia of Mars—which was incorrectly thought to be a barren plain by project planners at the time—was anxiously anticipated on 20 July 1976 by the scientists and engineers who had designed and built the tiny space vehicle and its massive delivery components. Simply put, they had no idea what to expect, potential failure loomed at every critical sequence as the Viking 1 lander separated from its orbiter and made its descent, recalled its mission planning director yesterday.
"The Viking team didn't know the Martian atmosphere very well, we had almost no idea about the terrain or the rocks, and yet we had the temerity to try to soft land on the surface," said Chief Engineer Gentry Lee of Solar System Exploration at NASA's Jet Propulsion Laboratory, in Pasadena, Calif. "We were both terrified and exhilarated. All of us exploded with joy and pride when we saw that we had, indeed, landed safely."
After successfully landing and deploying its cameras and sensors, the NASA project teams in Pasadena and Hampton, Va., discovered via the television images sent from the surface of the Red Planet across tens of millions of miles to this planet that they had somehow managed to place their spacecraft right side up and in perfect working order in the middle of rock-strewn plateau.
The next big surprise came after the similarly successful landing of Viking 2 in the Utopia Planitia—9600 miles away from the Chryse site—on 3 September 1976. Both vehicles performed as planned, sending back pictures and running tests on the Martian atmosphere and soil to test for evidence of possible past life on the planet. Each was designed for a functional lifespan of 90 days, but neither stopped operating for an astounding six years.
The landers accumulated 4500 images of the Martian surface, according to NASA. Their accompanying orbiters sent back more than 50 000 images, mapping 97 percent of the planet. These images and data from chemical and biological tests are still being evaluated, thirty years later. Even now, scientists still debate this very data on the possible biology of Mars, which a consensus of scientists—but not all—believe indicate that conditions favorable to life may have existed far in the past.
The Viking missions were followed, decades later, by the highly successful Pathfinder (1997) and Spirit and Opportunity (2004) missions, the last two of which are still operational, long past their expected functional lifetimes, too. There is, though, that unmistakable cachet of being first.
"The Viking mission looms like a legendary giant, an incredible success against which all present and future missions will be measured," said Doug McCuiston, Mars Exploration Program director at NASA Headquarters, in Washington, D.C.
Today, there are two quieted planetary spacecraft resting on the Martian plains that are silent monuments to the quest for discovery. One day, we'll visit them and pay them the respect due to the longest successful residents sent from Earth to another planet.