compton_update_sidebar_000603 WASHINGTON -- Compton's nosediving maneuvers into the ocean this weekend are a prelude of things to come.
NASA has begun an in-depth review of several Earth-observing and space science satellites now circling the planet. The study is assessing which spacecraft carry components that might survive reentry and hit the Earth; how controllable are the satellites; and are certain spacecraft retrievable by space shuttle.
"We're going through spacecraft by spacecraft to make us better prepared than we were for Compton," John Campbell, director of flight programs and projects at NASA's Goddard Space Flight Center, told SPACE.com.
Campbell said he is taking a hard look at between 15 to 20 satellites that are under his purview at the NASA center. "Nothing is panicking us right now," he said.
Failure mode
But receiving early attention is NASA's Tropical Rainfall Measuring Mission (TRMM). That spacecraft was lofted from Japan's Tanegashima Space Center in November 1997.
TRMM is a U.S.-Japanese mission and is part of NASA's Earth Science Enterprise, dedicated to observing and understanding tropical rainfall and how it affects the global climate.
In low orbit above Earth, TRMM is in operating mode, churning out science data.
"It is one of the first ones we're studying," Campbell said. "If it should have some failure that puts us one failure away from being able to safely reenter, then that would be the time to start bringing it in," he said.
TRMM is not shuttle-retrievable, Campbell said. The Extreme Ultraviolet Explorer, another satellite under review, can be plucked from orbit by a shuttle if need be, he said.
Campbell said that if TRMM does come back to Earth on its own, computer predictions show that some spacecraft pieces would hit the ground. "But nothing like the Compton," he added.
Cover your assets
The Goddard study on the overall health of its science-gathering satellites is ongoing, with each spacecraft assessed taking a few months of time.
"It's a long-term job," Campbell said. The whole mentality of NASA in the past, he said, has been to operate a spacecraft for as long as possible, cranking as much science out of the satellite, even when the craft is on its last legs.
Compton has helped change that attitude.
"We have responsibility to the public that we can safely dispose of a satellite. We have to weigh that safety against that last bit of science dataand safety has to come first," Campbell said.
"I think we've gotten a bit of a wake-up call on how we need to think about our assets," he said.
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