Research on critical questions in climate change is endangered because nearly half of the earth-observing instruments on U.S. satellites will stop working by 2010, according to a report released this week by the National Research Council.

The report, written largely by academics, blames the situation on budget pressures at the National Aeronautics and Space Administration — which has placed highest priority on sending astronauts to the moon and Mars — and on cost overruns for a new satellite system planned by the National Oceanic and Atmospheric Administration. The report offers a list of 17 priority satellite missions that those agencies should support over the next decade.

The federal government also should support better-coordinated research using land-based instruments, and improved analysis, in order to help solve serious environmental problems facing the world, the report says. Among them are the melting of polar ice sheets, increases in severe storms, shortages of fresh water, degradation of ecosystems, and declines in fisheries.