NASA Denies Funding for Key Satellite
Decision on Orbiter Frustrates Scientists

By Guy Gugliotta
Washington Post Staff Writer
Monday, July 19, 2004; Page A01

NASA is allowing a highly successful satellite to fall out of Earth's
orbit by refusing to fund it for as little as $28 million, dismaying the
scientists and forecasters who use its unique abilities to study climate
change and track hurricanes.

NASA officials said engineers did not order a planned firing of its
rockets in early July to hold the Tropical Rainfall Measuring Mission
satellite in orbit 241 miles above Earth. Without periodic assists from
its thrusters, atmospheric drag will send the satellite's remains to a
watery grave in six to nine months.

Engineers said the satellite, a joint venture with the Japanese
Aerospace Exploration Agency, is working perfectly and could still be
saved, but NASA officials said neither the Japanese nor other U.S.
agencies were willing to contribute to the estimated $28 million to $36
million needed to keep the mission operating for as long as two more years.

The satellite is a unique space platform whose instruments have proved
invaluable not only to researchers studying global change, but also to
meteorologists who use its one-of-a-kind "rain radar" to probe deep into
cloud cover to determine whether the makings of a cyclone lurk there.

In 2002, a NASA study determined that the potential lifesaving value of
the satellite was great enough to justify keeping it aloft until it ran
out of fuel and tumbled unguided back to Earth, possibly killing or
injuring someone.

The decision instead to use a "controlled de-orbit" for the satellite,
known by its initials TRMM, was announced quietly July 13 in an internal
NASA memo, and came at a time when NASA's Earth observation budget is
shrinking as the agency begins to focus on President Bush's plan for
human exploration of the moon and Mars.

NASA officials said the agency decided to de-orbit TRMM because the
money saved could be put to better use on a next-generation satellite
scheduled for launch in 2011.

The Bush administration is already facing harsh public criticism for its
decision to cancel space shuttle servicing of the Hubble Space
Telescope, and congressional critics of the Bush initiative have
publicly warned NASA not to rob Hubble or other valuable programs --
especially in earth science -- to fund the new undertaking.

But congressional sources said lawmakers do not necessarily see TRMM's
problem as the harbinger of cuts to come: "TRMM would be a problem
regardless, because it's an unanticipated expense," and not part of the
NASA budget, said a knowledgeable Republican congressional staffer who
declined to be identified. "NASA may even deserve credit for being
willing to ante up" some of the money.

Or not. NASA has said little about TRMM's demise, but researchers all
over the country and in Japan are questioning the decision. Data from
TRMM on rainfall and storms are used by climate scientists and
meteorologists all over the world.

"Unlike a lot of missions, it's worked great from the beginning --
something of a miracle in satellite meteorology, and we're still on the
rising part of the curve," University of Washington atmospheric
scientist and TRMM team member Robert Houze said in a telephone
interview. "It seems almost unfathomable to me that you would not let it
live out its full lifetime."

House Science Committee chief of staff David J. Goldston acknowledged in
a telephone interview that his office had gotten "probably in the last
week an inch-high pile of letters from researchers around the United
States saying we're missing this great opportunity. We don't have a
position yet, but we are looking into it."

TRMM was launched in Japan on Thanksgiving Day 1997 into an orbit that
girdles the globe ranging from 35 degrees north of the equator -- the
latitude of North Carolina -- to 35 degrees south (Santiago, Chile).

TRMM measures and analyzes rainfall, using microwave, infrared and
lightning sensors supplied by the United States, and the Japanese-built
rain radar. Together they provide the most detailed information on
rainfall patterns ever created, from the part of the world that
influences global climate more than any other.

"Having all these instruments on the same satellite can provide best
estimates of rainfall over oceans and land, can measure the impacts of
the El Niño ocean temperature changes and document the release of heat
when water changes to rainfall," said Goddard Space Flight Center's
Robert Adler, the NASA project scientist in charge of TRMM.

TRMM was supposed to last three years, but instead it lived long enough
to become a victim of its own success. "It has been superb on all
counts," said Ghassem Asrar, NASA's associate administrator for earth
science. "The nominal life was 18 months, the goal was three years, and
we just kept extending."

As the years crept by, scientists found they could use TRMM to improve
the baseline accuracy of computer climate models and weather forecasts,
or to give their local research a global context. And the longer TRMM
operated, the more comprehensive the data became, because climate
patterns take years to develop.

"But the biggest surprise, which I never anticipated, is this whole
ability of the satellite to observe hurricanes in a way that no
satellite can," Houze said. TRMM's radar can peer inside tropical storms
to watch them evolve.

"A lot of times you'll just see a ball of white cloud, but TRMM can go
to the core, see the eye wall start to develop: Is it intensifying? Is
it getting better defined? Is it falling apart?" National Hurricane
Center Director Max Mayfield said in a telephone interview from his
Miami office. "It's been absolutely critical. Ask any of our hurricane
forecasters."

Asrar said that engineers had planned a controlled de-orbit for TRMM
"from the beginning," using onboard thrusters to steer the satellite
into the ocean far from population centers. He said the satellite was
sturdy enough for large pieces of it to survive reentry temperatures and
potentially injure or kill people in the debris path.

As time passed, however, what seemed like a routine maneuver to end a
successful mission loomed as the limiting factor for the mission itself.
Operating systems were working perfectly, instruments were not wearing
out, and the data were impeccable. The only thing being used up was the
fuel needed to maintain orbit.

In 2002, Asrar asked Bryan O'Connor, NASA associate administrator for
safety and mission assurance, to conduct a "disposal risk review." Did
the benefits of using all the fuel to keep TRMM in orbit an additional
five years outweigh the hazards of allowing the spacecraft to fall back
to Earth without guidance?

In his reply on Sept. 4, 2002, O'Connor said the probability of a TRMM
debris casualty would be one in every 5,000 reentries, twice as
dangerous as NASA's standard of one in 10,000. NASA allows about six
uncontrolled reentries a year.

Despite the heightened danger, O'Connor concluded that "these risks
appear to be reasonable when subjectively weighed against the potential
public safety benefits of improved storm analysis and forecasting
capabilities that appear to be realized by extending the TRMM mission."

But uncontrolled reentry was never seriously considered, Asrar said, and
the O'Connor analysis was used to reaffirm what Asrar described as
NASA's original view: "What if the one in 5,000 becomes a reality?"
Asrar said. "Can anybody stand up and say it was worthwhile?" He said he
asked for the O'Connor report simply to show that "we had done due
diligence" in evaluating TRMM's potential hazard .

In 2003, engineers bought some more time by boosting TRMM from its
initial orbit 210 miles above Earth to its current height. At the higher
orbit, the satellite needed station-keeping burns only once a month,
instead of once every three days.

But by mid-2004, NASA had to make another choice: bring TRMM down in a
controlled de-orbit this year for a landing next year or deplete the
fuel for one or two more years, then let the satellite "drift down"
unguided for a couple of years, using the last of the fuel to control
the final reentry.

NASA officials who declined to be quoted by name questioned whether
Asrar ever seriously considered prolonging the mission further, and
disputed his view that it would cost $28 million to $36 million to keep
TRMM running for up to two more years.

Asrar explained that extending TRMM would require payment not only for
the two data years, but also for the two or more "drift-down" years,
when the satellite would not be sending reliable data, but would still
have to be watched. Spending more money now would mean postponing the
2011 launch of a new satellite designed to improve on TRMM's
performance, he said.

Asrar said it was "absolutely incorrect" that NASA decided to begin the
de-orbit now to save money for the Bush initiative, noting that "we
started looking at this issue two years ago," long before the moon-Mars
plan arose.

Instead, he said, NASA asked Japan or another U.S. agency to partner
another extension. Finding no takers, NASA ordered the de-orbit to
begin. "This has been my decision all along," Asrar said. "I can take
full credit or blame for it."

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