NASA Satellite Still Earthbound

NASA scrubbed the launch of the Aura atmospheric research satellite Wednesday for a fourth time in less than a week after a problem developed in a rocket battery system.

A "red alarm" prompted the launch team to call a halt three minutes before the planned 3:02 a.m. launch, the National Aeronautics and Space Administration said.

It appeared there was a problem with battery current measurements as the spacecraft was being transferred from external to internal power, a NASA announcer said.

Carried by a two-stage Boeing Delta II rocket, the satellite is to be put into orbit 438 miles above the Earth. The six-year, $785 million mission is to study pollution and the health of Earth's atmosphere.

The Aura campaign has seen five launch dates come and go — June 19, July 10, 11, 13 and 14 — because of a combination of technical problems and a records check to make sure suspect components had not been used aboard the spacecraft, reports CBS News Space Consultant Bill Harwood.

The launch initially had been set for Saturday. It was delayed a day to check whether a transistor problem on an unrelated mission would affect Aura, and then put back two days more to fix a misalignment of a structure that encloses the satellite.

On Tuesday, the launch was postponed yet again because of a problem with Aura's recorder, used to collect data from scientific instruments. That problem was fixed by the end of the day.

After the battery problem developed Wednesday, launch manager Chuck Dovale said the next delay could be more than 24 hours because of a possible tropical storm developing off the coast of Mexico. Such a storm could prevent a support aircraft from tracking the launch.

Aura is the latest in a series of Earth Observation System satellites designed to monitor the health and behavior of the planet's atmosphere, reports Harwood. Two are already in orbit: the Terra satellite, which observes land, and Aqua, which studies water. Once in polar orbit, Aura's four sophisticated instruments will:

• Determine the amount of ultraviolet radiation reaching Earth from the sun and whether a global halt in production of chlorofluorocarbons, or CFCs, is helping the planet's protective ozone layer recover from earlier damage.
• Measure ozone levels in the lower atmosphere and map the sources and movement of aerosols and chemical pollution.
• Study how Earth's climate is changing by monitoring how water vapor and ozone absorb or reflect solar radiation, affecting global temperature.