The first commercially operational launch of Europe's Ariane 6 heavy rocket was postponed for a second time on Monday, operator Arianespace said.

The launch, designed to carry a French military observation satellite to orbit, had been due to take place at lunchtime at Europe's spaceport in Kourou, French Guiana, after a previous attempt scheduled for February 26 also had to be called off.

ALSO READ: Europe space chief says cooperation intact despite Italy moves

Arianespace said Monday's launch had been postponed because of work that needed to be carried out on ground equipment connected to the rocket. No new launch date was announced.

READ MORE: Europe's Vega-C rocket returns to space after two-year gap

Europe's newest uncrewed rocket had staged a partially successful inaugural flight on July 9 last year, carrying out a series of trials but leaving its upper stage in orbit after a software glitch that officials later described as fixable.

In its first operational mission, the Ariane 62 version of the launcher is due to carry the CSO-3 optical and infrared satellite into orbit for the French Air Force's Space Command.

READ MORE: Europe 'back in space' despite Ariane 6 debut glitch

Although carrying a military payload, the journey is considered a commercial one by European authorities because it is the first being handled for Ariane 6 by operator Arianespace, rather than the European Space Agency which oversaw development.

Ariane 6 is built by ArianeGroup, co-owned by Airbus and Safran.