LOS ANGELES — NASA is ending a satellite mission that kept tabs on the hole in Earth's ozone layer because the space agency can't afford the $10 million-a-year bill.

The Upper Atmosphere Research Satellite will cease scientific operations by Sept. 30, 10 years after it was deployed by space shuttle Discovery.

NASA said the 6 1/2-ton, 35-foot satellite will either be plucked from orbit by the space shuttle or allowed to crash back to Earth sometime between 2016 and 2027.

The mission was originally designed to last for just three years, though seven of its 10 instruments still work. A replacement mission, AURA, is scheduled to be launched in 2003.

NASA faces budget overruns on a number of projects, including its stake in the international space station.

"Scientists are screaming, 'How can NASA turn off a satellite?' We have planned this for years," said David Steitz, a NASA spokesman. "Sorry guys, but it's over. We can't afford to continue to feed it, and we have other priorities."

The satellite was designed to provide information about the upper atmosphere by measuring its winds, temperatures, chemistry and energy received from the sun. It is best known for monitoring a hole in the ozone layer over Antarctica.

Scientists on the ozone project are angry. They have proposed temporarily suspending operations, then restoring them in a year or so when the satellite could work in tandem with a European satellite being prepared for launch.

"It's a $1 billion asset we're throwing down the drain because we can't come up with a couple of million to keep it running," said Mark Schoeberl, the mission's former project scientist at NASA's Goddard Space Flight Center in Greenbelt, Md.

There would be no way of controlling where the satellite debris would hit Earth, said Bill Ailor, director of the El Segundo-based Center for Orbital and Re-entry Debris Studies. But he said it would likely land in the ocean, as did chunks of both the Mir space station and Compton Gamma Ray Observatory.

"It's not really cause for alarm," Ailor said.