Scientists Exploring Options for QuikScat Successor

by












  Space News Business

Scientists Exploring Options for QuikScat Successor

By BEN IANNOTTA
Space News Correspondent
posted: 13 June 2007
03:22 pm ET










SUMMERLAND KEY, Fla.





NASA and NOAA scientists have begun studying options for a new hurricane-wind-measuring satellite the White House does




not believe is needed yet, according to interviews with the National Oceanic and Atmospheric Administration (NOAA), NASA and White House officials.

NASA’s Quick Scatterometer, or Qui




kScat
,




satellite bounces radar signals off the ocean to measure the roughness of the surface. Software processes those readings into estimates of wind speed and direction. Though it was conceived by NASA as a research spacecraft, U.S. hurricane forecasters have come to rely on Qui




kScat
to measure the size of a developing storm’s wind field, and in some cases to locate its center of circulation.

U.S. forecasters are nervous because the eight-year-old Qui




kScat
satellite




now is operating on a backup downlink transmitter, and the administration of U.S. President George W. Bush has no plans to develop a backup or replacement for it.

National Hurricane Center Director Bill Proenza has said in a series of recent speeches and interviews that Qui




kScat
could fail at any time, and he has called forcefully for a replacement plan.





Bush’s




science adviser, John Marburger, who is the director of the White House Office of Science and Technology Policy, told Space News June 5




he stood by the administration’s position on Qui




kScat
.

The health of Qui




kScat
is “nowhere near as shaky” as Proenza’s comments imply, he said. “We don’t see this as a kind of urgent situation …




I don’t know whether it’s because the director of the National Hurricane Center is new and wasn’t aware of the situation … when he made the comments that triggered this whole flurry of interest,” Marburger said. Proenza became director of the center in January.

Marburger
also noted that the National Research Council’s draft report, “Earth Science and Applications from Space: National Imperatives for the Next Decade and Beyond,” better known as the






Decadal Survey,




does not reflect Proenza’s sense of urgency. That review, which is still in preliminary form, calls for launching a Qui




kScat
successor between 2013 and 2016




.

“This expression of concern came more or less out of the blue for us,” Marburger




said.

Hurricane forecasters disagree with the White House position. Though it cannot detect a hurricane’s highest winds or see through heavy rain, “Qui




kScat
really is the only source of data that can give you the wind speed and direction over the entire circulation of a cylone,” said forecaster Richard Knabb.





M




embers of Congress from Louisiana and Florida introduced earmark legislation May 29 that would authorize $375 million for NASA to “design and launch” a replacement for Qui




kScat
. Almost simultaneously,




NASA’s Jet Propulsion Laboratory (JPL) and NOAA officials agreed on a new teaming arrangement under which JPL would build a successor to Qui




kScat
for NOAA should money be allocated through one or both of the agencies, said Ernesto Rodriguez, the project scientist for ocean wind measurements at JPL.

The arrangement would represent “a new way of doing business,” Rodriguez added. As a NASA field center, JPL generally builds research instruments for NASA and university scientists. U.S. weather forecasters sometimes test readings from those instruments, which was how hurricane forecasters came to rely on Qui




kScat
.

If the new arrangement holds, it would mark the first time JPL has built an operational satellite or instrument for NOAA, said Paul Chang, the team lead for ocean wind work at NOAA’s Center for Satellite Applications and Research in Camp




Springs, Md.

Exactly what a Qui




kScat
replacement might look like and what it would cost are the subjects of an initial




study that will be paid for this year by NOAA’s internal discretionary funds,




Chang said. The estimated cost of the study is $500,000 to $1 million.

The choice is to either build a backup satellite quickly to provide a “Qui




kScat
-like capability,” or build a more powerful successor called the Extended Ocean Vector Winds Mission (XOVWM), Chang said.

Hurricane forecasters believe the study will confirm that the wisest choice would be to go directly to the XOVWM mission. “That is the option that the hurricane center prefers,” said Knabb, the hurricane forecaster.

Officials from JPL and NOAA said it will be difficult if not impossible to dust off the Qui




kScat
blueprint and rebuild the satellite.

Qui




kScat
was built in the 1990s with 1980s technology, Rodriguez said. “A lot of that stuff is no longer around,” Rodriguez said, noting that building a more advanced Qui




kScat
might not cost much more.

However, even with an earmark, Chang said the earliest such a satellite could be ready would be 2012. “The urgency is we need to at least start down the path of planning something,” Chang said.

NOAA spokesman Anson Franklin said the




agency’s staff would study the Qui




kScat
options with open minds. “We’re not in a position to draw any conclusions about the technology available,” Anson said. As for the proposed congressional earmark, Franklin said: “We appreciate the congressional interest in [Qui




kScat
] and we have talked to these members who have proposed this legislation.”

Knabb
said








forecasters like the XOVWM concept because it would overcome the major shortcomings of Qui




kScat
, which is that




Qui




kScat’s
Ku-band radar signals are scattered by rain.




Qui




kScat
data is nevertheless useful because rainfall in hurricanes and other storms tends to be localized.



Forecasters would like to measure wind speed and direction throughout storms, said Chang. Qui




kScat’s
radar also cannot sense wind speeds above 90 miles per hour, the equivalent of a minimal hurricane. The new satellite would add longer wavelength, lower frequency C-band signals to penetrate the rain and measure winds as high as 180 miles per hour.

The new satellite also would show more detail for mapping winds closer to the coast, Rodriguez said. If Qui




kScat
died suddenly, U.S. hurricane forecasters would not be left without




coverage.

Under an agreement with European weather managers, U.S. forecasters soon will receive wind maps from the new Advanced Scatterometer instrument on Europe’s first MetOp polar-orbiting weather satellite launched last October. The European instrument would not be a perfect replacement for Qui




kScat
, however. It provides less coverage and its data is not as detailed is that from Qui




kScat
, said Chang


.