SES-2. Credit: Orbital ATK

PARIS — The scheduled Sept. 20 launch of a European Ariane 5 rocket carrying commercial satellites for U.S. and Middle Eastern customers was canceled early in the day following a labor strike among employees of the company responsible for tracking the rocket’s launch by radar.

The workers in question are members of the Union des Travailleurs Guyanais (UTG) and employees of Telespazio France at Europe’s Guiana Space Center spaceport in French Guiana.

Officials familiar with the issue said UTG and Telespazio have been negotiating the conditions of a transfer of some union employees to another company following Telespazio’s loss of a contract at the launch base. Negotiations had begun over whether the employees would be granted the same contracts with their new employer.

With negotiations apparently not advancing, UTG on Sept. 20 decided on a work stoppage as a means of putting pressure on Telespazio and the other organizations involved in the spaceport’s operations, notably the French space agency, CNES.

“UTG is taking advantage of the fact that there was a launch today to apply pressure so that their new employment does not take away any advantage they had with Telespazio,” one spaceport official said Sept. 20.

The Ariane 5 rocket is scheduled to carry two satellites into geostationary transfer orbit.

The SES-2 spacecraft for Luxembourg-based SES is equipped with a communications payload for SES’s North American business, plus a U.S. Air Force infrared experimental payload, called CHIRP, or Commercially Hosted Infrared Payload.

The Arabsat 5C telecommunications satellite is owned by the Arabsat intergovernmental organization, based in Riyadh, Saudi Arabia.

Peter B. de Selding was the Paris bureau chief for SpaceNews.