U.S. and French cloud-monitoring satellites were successfully orbited April 28 by a Boeing Delta 2 rocket launched from California’s Vandenberg Air Force Base — a launch that had been delayed for nearly 10 months because of a variety of issues ranging from a labor strike to failed communications links between France and the United States.

The U.S.-French Calipso and NASA’s CloudSat spacecraft will join three other satellites currently in low Earth orbit as part of the “A-Train” system to study different atmospheric phenomena. NASA and the French space agency, CNES, confirmed that their respective satellites had arrived at their orbital positions and were working well.

At an altitude of 705 kilometers, the five A-Train satellites — NASA’s Aqua and Aura satellites and the French Parasol spacecraft are already in orbit — will be flown along the same orbital path with eight minutes separating the first and last satellites.

Aqua leads the pack, followed by CloudSat one minute later and Parasol two minutes after that. Calipso will trail Parasol by just 15 seconds, followed by Aura in the rear position four minutes and 45 seconds behind Calipso.

The CloudSat radar satellite is expected to operate for at least 22 months. It was built by NASA’s Jet Propulsion Laboratory, Pasadena, Calif., with contributions from the Canadian Space Agency, U.S. Department of Energy and the U.S. Air Force. The total budget is $217 million, according to NASA.

Calipso — carrying an advanced lidar, or light detecting and ranging, laser instrument — was built by the French space agency, CNES, using a Proteus platform produced by Alcatel Alenia Space. It is designed to operate for three years.

NASA estimates its share of the Calipso budget at $223 million. CNES has said its costs for Calipso totaled 50 million euros ($62.3 million) not including CNES personnel costs.

Originally scheduled for July 2005, the launch fell victim to a series of delays both technical and non-technical. The April 28 success followed three earlier attempted launches since April 21 that were scrubbed because of failed communications links, the lack of a launch-monitoring aircraft in the South Pacific and weather-related issues.

“This was quite a difficult mission, almost from start to finish,” NASA Launch Manager Chuck Dovale said after the launch.

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