Another German military radar reconnaissance satellite launched from Russia Thursday, joining an orbital constellation of craft designed to peer through the night to spy on locations around the world.

File image of a Kosmos 3M rocket launching a SAR-Lupe spacecraft. Credit: OHB-System AG

The craft, called SAR-Lupe 4 by the German military, began a half-hour trip to space at 1715 GMT (1:15 p.m. EDT) from the Plesetsk Cosmodrome in far northern Russia, according to OHB-System, the prime contractor.

The 105-foot-tall Kosmos 3M rocket lofted the 1,700-pound satellite to an orbital perch about 300 miles high.

The launch was postponed two days due to unfavorable upper level winds, according to Russian media reports.

Engineers at a German control center successfully contacted SAR-Lupe 4 about 90 minutes after liftoff, confirming the satellite was in good health, OHB-System said in a written statement.

Officials expect to receive the first images from the satellite by the end of next month, the company said.

SAR-Lupe 4 joins a fleet of three identical spacecraft already in orbit to provide detailed imagery for the German armed forces. Each satellite is fitted with a radar system to beam radio light toward Earth and process the reflected pulses to produce high-resolution images.

The synthetic aperture radar, or SAR, can spot objects on the ground as small as three feet, according to OHB-System.

Radar beams can pierce darkness and clouds, providing an all-weather system able to generate useful imagery 24 hours a day. Optical systems are obscured during nighttime and bad weather conditions.

A final SAR-Lupe satellite is scheduled to launch later this year to complete the system, which will spread the five spacecraft among three orbital planes to provide regular global coverage.

The German military took control of the early members of the SAR-Lupe fleet in December to begin operational reconnaissance work, which is expected to last at least ten years.

The SAR-Lupe system is part of an agreement between Germany and France to share imagery between the nations' space-based reconnaissance networks. Germany will receive data from the French Helios optical and infrared satellites.