High res radar instrument fails on Earth observation satellite

Only seven months after launch one of the two instruments on NASA’s Soil Moisture Active Passive (SMAP) Earth observation satellite has failed.

Launched on Jan. 31, the Soil Moisture Active Passive spacecraft’s objective is to map global soil moisture and to detect whether soils are frozen or thawed. It is the first mission where scientists have attempted to collect high-resolution, high-accuracy soil moisture data, said Kent Kellogg, SMAP’s JPL-based project manager.

NASA budgeted $916 million for the mission and has been working on it for the past eight years. “We do a lot of testing on the ground to make sure the designs will be built properly and will last in the environment,” Kellogg said. “But space is a very unforgiving place, and we can have these kinds of problems where despite our best efforts with design and vigorous testing, something surprises us. It’s very uncommon, but these things can happen occasionally.”

SMAP’s two scientific tools are an active radar and a passive radiometer. They complement each other, making up for the other’s measurement limitations. The broken radar collected soil moisture and freeze-thaw measurements at a higher resolution of up to 1.9 miles. The still functioning radiometer generates more accurate measurements but its resolution is lower at about 25 miles. [emphasis mine]

I am not satisfied by the explanation for the failure expressed above. NASA spent a lot of money for this science satellite over almost a decade. In addition, we have been launching instruments like this for almost half a century, and have by now learned quite well the engineering necessary to keep them operating under the conditions in low Earth orbit. I suspect a screw-up somewhere, which we might or might not ever identify.