The end of NASA’s Quick Scatterometer, or QuikScat, environmental monitoring mission is noteworthy for several reasons, beginning with the fact that it succeeded beyond all expectations. Built and launched for the relatively modest sum of about $100 million, the satellite operated more than 10 years — five times its design lifetime — measuring wind speed and direction over 90 percent of the world’s oceans, data that proved extremely valuable to climate scientists and operational weather forecasters alike.
Although QuikScat continues to collect data, the failure Nov. 23 of the spin motor on its main sensing antenna effectively brings an end to its primary mission.
QuikScat was a trailblazer from the beginning. Conceived as a gap-filler following the sudden failure of a Japanese satellite carrying a NASA-supplied scatterometer, it was the first mission to utilize a catalog of preapproved satellite platforms created by the Rapid Spacecraft Development Office at NASA’s Goddard Spaceflight Center. The catalog was set up to reduce the time it takes to get satellites under contract and built, and QuikScat lived up to the concept: Ball Aerospace won the QuikScat contract in November 1997 and the spacecraft was on orbit a year-and-a-half later.
The rapid spacecraft catalog was a true innovation that, unfortunately, hasn’t been exploited much of late, despite its availability to other U.S. government agencies. The five-and-a-half-year period following QuikScat’s launch saw four additional catalog spacecraft launched, although one was lost in a rocket failure. Since the end of 2004, only one has been launched, with two more under development.
Once on orbit, QuikScat quickly proved its worth to scientists and forecasters, particularly those who monitor hurricanes and severe storms. Such was the utility of its ocean-wind data that NASA’s lack of plans for a follow-on satellite generated controversy as QuikScat advanced in age. In 2007, William Proenza was fired as director of the U.S. National Hurricane Center after criticizing his bosses at the National Oceanic and Atmospheric Administration for not moving fast enough to replace QuikScat and publicly warning that its demise would significantly degrade the accuracy of hurricane forecasts. Mr. Proenza said he was fired for airing his concerns; White House officials said he was reassigned for other reasons, including disagreements with his own staff on QuikScat’s importance to hurricane-track forecasting.
Regardless of which version of the story is closer to the truth, the U.S. government clearly was not serious about replacing QuikScat. A spokesman for the National Hurricane Center said recently that the loss of QuikScat will not adversely affect hurricane warning in the United States, which relies on aircraft, ground-based radars, ocean buoys and geostationary spacecraft. But the ability to monitor and characterize distant storms likely will suffer. According to one estimate, the shipping and container industry saved $135 million annually because of the improved warning and forecasting capability provided by QuikScat data.
In the immediate future, climate researchers and weather forecasters will rely on scatterometer data from international environmental spacecraft such as Europe’s Metop-A, launched in 2006, and India’s OceanSat-2, which reached orbit in September. Meanwhile, U.S. government officials are looking at the possibility of supplying a scatterometer for Japan’s Global Change Observation Mission, slated to launch in 2016.
While it is encouraging that nations are exploiting the growing cooperative opportunities in space-based environmental monitoring, this seems to be done largely on an ad hoc basis — the agreement with India on OceanSat-2 was signed less than a week before QuikScat’s antenna motor failed, for example. There needs to be a systematic way to identify critical Earth observation measurements along with planned missions around the world that can keep the data flowing, either as originally designed or perhaps with the addition of a sensor. The 80-member Group on Earth Observations seeks to accomplish this through the Global Earth Observation System of Systems, but this is a 10-year plan that still has a long way to go. In the near term, it will be up to a handful of countries to coordinate observation efforts to ensure data continuity.
QuikScat’s demise also underscores once again the U.S. government’s lack of set procedures for bringing experimental measurements that find a key role in critical government functions — weather forecasting being the most obvious example — into its permanent environmental monitoring architecture. Europe has a similar issue, which stems in part from the fact that the civil space agencies on both sides of the Atlantic have mandates to focus on research and development. Whether QuikScat data would meet the necessary criteria to gain operational status is not clear only because there are no such criteria. What is clear is that the forecasting community had gotten used to having QuikScat data at its disposal. Time will soon tell how badly that data will be missed.