Two federal agencies have granted a key research and weather satellite a five-month reprieve in orbit -- until at least the end of the year -- to keep it tracking tropical storms during the hurricane season, officials said yesterday.

Officials at NASA and the National Oceanic and Atmospheric Administration also said they had asked the National Academy of Sciences to examine the satellite's future and perhaps prolong its life for as much as 18 additional months.

The decision to keep the Tropical Rainfall Measuring Mission in orbit followed NASA's July announcement that it could not find $28 million needed to continue tending the satellite. The agency said it would bring it down, even though it was operating perfectly after seven years.

The announcement provoked a groundswell of outrage from meteorologists and researchers who use the satellite, known by its initials TRMM, for everything from modeling global climate change to witnessing the birth of hurricanes in the Atlantic's nether reaches. Leading members of Congress asked NASA to reexamine the decision.

But the critical intervention came from NOAA Administrator Conrad C. Lautenbacher Jr. The retired Navy vice admiral called NASA counterpart Sean O'Keefe "and asked him to reconsider and keep TRMM up during the hurricane season," NOAA spokesman Jordan St. John said in a telephone interview.

"The ability to monitor the storms was the major consideration," agreed Ghassem Asrar, NASA associate administrator for earth science. "We will look for a complete de-orbit at the end of the next calendar year."

Asrar said adding five months to TRMM's life would require between $5 million and $10 million in additional funds, but "the cost perspective is secondary" and "is something we can work out." He said in a telephone interview that NASA and NOAA will meet to settle the details.

TRMM, launched in 1997, is a joint venture between NASA and the Japanese Aerospace Exploration Agency. It was designed as a research satellite to measure and analyze rainfall using microwave, infrared and lightning sensors as well as a one-of-kind Japanese "rain radar" that can peer deep inside tropical depressions.

TRMM, orbiting 241 miles above Earth's midsection, has proved fabulously successful, far outliving its three-year design life while providing a steady stream of data for the world's climate researchers and enabling meteorologists to spy on tropical cloud formations that may conceal the beginnings of cyclonic storms.

"It is not absolutely critical, but it's a valuable asset for those storms that are not very clear-cut," retired Air Force Brig. Gen. David L. Johnson, director of NOAA's National Weather Service, said in a telephone interview.

But in early July, NASA ordered engineers to cancel the monthly thruster burn that keeps TRMM in orbit, and instead let it drift down for an eventual guided reentry to a watery ocean grave next year.

Asrar said then that NASA could keep TRMM aloft for as much as an additional 18 months but needed $28 million to do it. He said yesterday NASA has asked the National Academy of Sciences to hold a workshop next month to examine the feasibility of prolonging the mission beyond year's end.