Minotaur Rocket Orbits COSMIC Constellation to Scan Earth's Atmosphere

Despite a rainy start and one countdown abort, six small satellites launched spaceward Friday on a mission to study the Earth's atmosphere and track climate change.

An Orbital Sciences-built Minotaur rocket shot the multi-satellite mission into orbit at 9:40 p.m. EDT (0140 April 15 GMT) from California's Vandenberg Air Force Base, where rain and clouds reigned for most of the day. It was the second attempt to loft the spacecraft Friday after a last-minute glitch prevented a liftoff almost 90 minutes earlier.

A joint effort between researchers in the U.S. and Taiwan, the $100 million COSMIC mission - short for Constellation Observing System for Meteorology, Ionosphere and Climate - will use a network of six satellites and a method called radio occultation to measure the Earth's atmosphere along thousands of data points.

The spacecraft use a set of four global positioning system (GPS) antennas and a suite of other instruments to track how GPS satellite signals are distorted by the Earth's atmosphere.

From that distortion, researchers can track atmospheric conditions such as air density, temperature, moisture or electron density. Mission scientists hope the system, which is expected to take 2,500 occultation soundings all over the globe - included the Earth's oceans - every 24 hours, will provide a data boon for weather forecasters and atmospheric researchers.

"You guys did a fantastic job," said William Kuo, director of the COSMIC office at the University Corporation for Atmospheric Research (UCAR) in Boulder, Colorado, to launch controllers just after the sixth COSMIC satellite was deployed in orbit.

UCAR designed the satellite system used for COSMIC's planned two-year mission, but about $80 million of the mission's cost was covered by Taiwan's National Science Council and National Space Organization.

The U.S. National Science Foundation and its partners - which included NASA, the U.S. Air Force Space Test Program, the Office of Naval Research and the National Oceanic and Atmospheric Administration - covered the rest.

Each of the six COSMIC satellites - known together as FORMOSAT 3 in Taiwan - is just a few inches wide and weighs about 137 pounds (62 kilograms). Originally developed by Orbital Sciences for the ORBCOMM data communications network, the probes were modified for the COSMIC mission and are expected to reach their final circular orbits - between 435 and 500 miles (700 and 800 kilometers) above Earth - in about 13 months.

The mission relies on some radio occultation techniques and hardware developed by NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, the space agency said.

"COSMIC is a prime example of transitioning NASA remote sensing technology into operational weather forecasting," explained Tony Mannucci, supervisor of JPL's Ionospheric and Atmospheric Remote Sensing Group, in a statement. "The expected improvements in forecasting skill and COSMIC's contribution to long-term climate monitoring are a direct result of NASA's research investments in radio occultation, a technology originally developed by JPL in the 1960s for planetary atmospheric studies and later refined in the 1990s for Earth orbit use."

While the spacecrafts are expected to perform for two years, they carry enough fuel for a five-year study, Orbital officials said.

Friday's successful space shot marked the fifth launch of an Orbital-built Minotaur rocket since its debut in 2000.

• Launch Coverage for COSMIC Satellite Constellation
• Probing the Atmosphere: A 'COSMIC' Connection