There is so very much wrong with that article.
NASA has tried looking for signs of life on Mars precisely once, in the 1976 Viking mission.
NASA has looked for signs of life on Mars many, many, many times. The landings in 1976 just happen to be the only successful landings on Mars by NASA before the latest two rovers arrived. But there have been other lander attempts, as well as a bunch of orbiters and fly-bys that looked for signs of anything interesting.
Nor was it the 1976 Viking mission. It was two separate missions, with two sets of orbiters and landers.
The result was positive. The reason nobody says there is life on Mars is that another experiment, part of the same mission, couldn
