Thursday, June 14, 2007

QuikScat In Trouble?

The QuikScat Weather Satellite is reported to be running into problems and could fail at any moment. This would indeed have a major impact on reporting hurricanes, as recently reported by the Associated Press.


NASA's Quick Scatterometer (QuikSCAT) was lofted into space at 7:15 p.m. Pacific Daylight Time on Saturday, June 19, 1999 atop a U.S. Air Force Titan II launch vehicle from Space Launch Complex 4 West at California's Vandenberg Air Force Base. The satellite was launched in a south-southwesterly direction, soaring over the Pacific Ocean at sunset as it ascended into space to achieve an initial elliptical orbit with a maximum altitude of about 800 kilometers (500 miles) above Earth's surface.

Built in a record time of just 12 months, QuikScat provides climatologists, meteorologists and oceanographers with daily, detailed snapshots of the winds swirling above the world's oceans. Labeled as NASA's next "El NiƱo watcher," QuikSCAT is used to better understand global weather abnormalities and to generally improve weather forecasting.

QuikSCAT's predecessor, NSCAT (NASA Scatterometer), a microwave radar scatterometer, measured near-surface wind vectors (both speed and direction) over the global oceans starting in August 1996. The QuikSCAT mission is a "quick recovery" mission to fill the gap created by the loss of data from NSCAT, after the satellite it was flying on lost power in June 1997.

Winds play a major role in every aspect of weather on Earth. They directly affect the turbulent exchanges of heat, moisture and greenhouse gases between Earth's atmosphere and the ocean. To better understand their impact on oceans and improve weather forecasting, QuikSCAT carries a state-of-the-art radar instrument called a scatterometer for a two-year science mission. Known as "SeaWinds," this scatterometer operates by transmitting high-frequency microwave pulses to the ocean surface and measuring the "backscattered" or echoed radar pulses bounced back to the satellite. The instrument senses ripples caused by winds near the ocean's surface, from which scientists can compute the winds' speed and direction. The instruments can acquire hundreds of times more observations of surface wind velocity each day than can ships and buoys, and are the only remote-sensing systems able to provide continuous, accurate and high-resolution measurements of both wind speeds and direction regardless of weather conditions.

SeaWinds uses a rotating dish antenna with two spot beams that sweep in a circular pattern. The antenna radiates microwave pulses at a frequency of 13.4 gigahertz across broad regions on Earth's surface. The instrument is currently collecting data over ocean, land, and ice in a continuous, 1,800-kilometer-wide band, making approximately 400,000 measurements and covering 90% of Earth's surface each day.

The Problem

Last year, the satellite suffered a major set back with the failure of a primary transmitter used to send data to Earth about every 90 minutes. It appears that there was a software glitch that seems to happen more than NASA likes. Now QuikScat is operating on back up transmitters that could last for years or fail without warning. With the only back up being a European satellite with similar technology but with limited capabilities. There would be about a 16% loss of information. However, forecasters will still be able to predict a hurricane and its path, but it could mean evacuations over a wider area than the hurricane center normally orders when it has more precise forecasts.

But the problem does not end there. NASA is having it's semi monthly budget fights and of course we can't forget the never ending internal battles for a new design. Maybe by 2012 we will get a new bird. Maybe? Either that or if QuikScat fails like NSCAT failed and the next Cat 5 takes out another major city, we will have another satellite just as quick as we got QuikScat in the first place.


Flying Through A Thunderstorm

Ever wonder what it feels like flying into a Thunderstorm in a armor-plated airplane? This is a great video (Complements of Storm Chaser Tom Warner) of a T-28 Storm Penetrating Aircraft. This T-28 was retired last year and now resides in a museum in Ashland NE,

Here is a little history on the T-28 Storm Penetrating Aircraft.

T-28 Flies Into History

T-28 History

The original concept of a meteorological research aircraft capable of penetrating hailstorms was developed and promoted by Dr. Paul MacCready in the late 1950s. At the time, this was widely regarded as not feasible because of potential danger to pilots and aircraft. The idea of developing a storm penetration aircraft persisted, however, and began to approach reality following Project Hailswath in 1966, when the National Science Foundation provided funds to support a detailed investigation. MacCready commissioned an associate, Robin Williamson, to do the aircraft feasibility study. Williamson considered all aircraft in the military and civilian fleet of the Vietnam War era. All aspects of aircraft operation including survivability, maintainability, costs, and performance were analyzed. Strictly on the basis of performance characteristics, he concluded that the best aircraft for hailstorm penetrations would be a Douglas “Dauntless” dive bomber, a World War II-era combat aircraft. His second choice was a T-28 military trainer, developed in the late 1940s as a high-performance, prop-driven, pre-jet trainer. When costs and maintainability were factored in, however, the T-28 was judged to be the overall top choice.

Using the results of Williamson's study, MacCready successfully presented his idea to the National Science Foundation (NSF) in 1967. MacCready's company, Meteorology Research, Incorporated, under contract to the South Dakota School of Mines and Technology Institute of Atmospheric Sciences’ NSF-funded Hailstorm Models Project, acquired and registered a T-28. Williamson Aircraft Co. (headed by Robin Williamson) contracted to outfit the aircraft for hailstorm penetrations. This work began in 1968 and was carried on through 1969.

After the modifications, the T-28 was capable of performing hailstorm penetrations to altitudes up to about 25,000 feet, and was able to withstand impacts of hailstones up to 7.5 cm in diameter at 100 m/s relative speed, with minimal damage. Meteorological instrumentation was installed, and the aircraft made test flights during the summer of 1969 at Rapid City, S.D., and Flagstaff, Ariz., to determine its capacity for carrying heavy loads of structural ice. It was found that the aircraft could handle up to an inch of ice with only a relatively small increase in speed to maintain controllability. Since the T-28 was to be used in summer thunderstorms where a layer of warm air would be present between icing zones and the ground, icing was not felt to be a major problem.

At this time, the T-28 resides with the Institute of Atmospheric Sciences at South Dakota School of Mines and Technology. The T-28 has participated in summer field programs almost every year from 1970 through 2004. This began with the National Hail Research Experiment in northeast Colorado and continued through projects across North America from Florida to Texas to Alberta, Canada. It even included one two-summer project in Switzerland. The T-28 has provided critical pieces to the puzzle of severe storm development and behavior.

Because of its contributions to science, the T-28 will be retired to a place where a national audience can view it, and be inspired by its work and by the ingenuity of those who developed and operated the aircraft for the past 34 years. The Strategic Air and Space Museum was chosen because of its specialized commitment to atmospheric related research.

Enjoy the ride!