Work on a secondary instrument for a Pentagon reconnaissance satellite was interrupted when two of the sensor’s focal planes were broken by a subcontractor, but the spacecraft remains on schedule for launch in November, according to the U.S. Air Force.

Fairchild Imaging of Milpitas, Calif., is under contract to provide the sensor for a secondary imaging payload that will fly on the ORS-1 satellite. The company irreparably damaged one of the focal planes Feb. 24, and then another on March 13, Air Force spokeswoman Valerie Skarupa said in an e-mailed response to questions. Spare parts will be used to assemble a replacement unit, and the satellite remains on track for its planned launch date, she said.

The ORS-1 is being built to provide reconnaissance data to U.S. Central Command. It is being managed by the Air Force’s Space Development and Test Wing on behalf of the Pentagon’s Operationally Responsive Space Office. Goodrich ISR Systems of Danbury, Conn., is the ORS-1 prime contractor and is building the satellite’s primary sensor, a modified U-2 spy plane camera.