PARIS — Russia’s long-delayed Spektr-R astronomy satellite was successfully launched July 18 aboard a Russian-Ukrainian Zenit rocket from Russia’s Baikonur Cosmodrome in Kazakhstan, Russia’s Roskosmos space agency said.

There was no immediate word on the satellite’s operational status beyond the fact that it was placed into the planned elliptical orbit with an apogee of some 330,000 kilometers above the Earth, and a perigee of about 1,000 kilometers.

Featuring a 10-meter-diameter antenna, Spektr-R is part of the international Radioastron astronomy project. Scientists from more than 20 nations, including the United States, are participating in the project, either through contributions of on-board hardware or access to the terrestrial antennas that, working with Spektr-R, will permit interferometry measurements during the satellite’s planned five years of operations.

Spektr-R was originally scheduled for launch in 2004 or 2005 before encountering multiple delays in its construction. It has been in development for more than a decade.

Most recently, the launch date was put into question following a dispute between commercial and Russian government satellite missions over which Zenit customer would receive the limited supply of Zenit rocket parts.

Spektr-R was launched aboard a Zenit-3M rocket equipped with a Fregat-SG upper stage. It was built by Lavochkin Association of Moscow.

The Radioastron mission is being coordinated by the Astro Space Center of Moscow, which is part of the Lebedev Physical Institute of the Russian Academy of Sciences.

Russia’s Spektr-R Sat Slated for July Launch