TOULOUSE, France — Eutelsat’s W2 telecommunications satellite, which operates at one of the company’s fastest-growing orbital slots, suffered an unexplained on-board failure and placed itself into sun-pointing safe mode late Jan. 27, forcing Eutelsat to off-load customers to three other satellites at the same orbital position, including two that just recently arrived there.

As of Jan. 29, Paris-based Eutelsat and the W2 prime contractor ThalesAlenia Space of France and Italy were still trying to determine what happened and whether the satellite has suffered a permanent failure or only a temporary glitch.

While in emergency sun-acquisition mode, the satellite continues to receive and send commands but cannot perform its full telecommunications mission.

W2, launched in October 1998 with a 12-year contracted in-orbit service life, operates at Eutelsat’s 16 degrees east orbital slot.

Eutelsat announced Jan. 29 that all its W2 customers had been successfully transferred to three satellites that Eutelsat has stationed at the 16 degrees east orbital position.

Eutelsat spokeswoman Vanessa O’Connor said Jan. 28 that Eutelsat is moving some W2 customers to the Eurobird 16 satellite, formerly called Atlantic Bird 4, which is also located at the 16 degrees slot. In addition, O’Connor said Eutelsat’s W2M satellite, which had been located at 3 degrees east without serving a commercial mission, has recently arrived at the 16 degrees east position and will handle at least some of the W2 traffic.

Eutelsat said in its Jan. 29 statement that W2M arrived at 16 degrees east in early January.

Launched in December 2008, W2M was never put into service by Eutelsat because of failures on its power system that became evident just weeks after launch. Eutelsat subsequently filed an insurance claim for W2M and said the satellite would not be integrated into Eutelsat’s commercial fleet.

O’Connor said that despite this, W2M retains about 50 percent of its commercial capacity and will be able to pick up some of the W2 customers, at least on an interim basis.

A third satellite, Sesat 1, which had long been stationed at 36 degrees east, arrived at 16 degrees east on Jan. 28 as part of a broader Eutelsat program to boost capacity at that orbital slot in advance of the arrival of the large W3B satellite to be placed there late this year.

The W2 satellite features a fixed wide beam covering Europe, North Africa and the Middle East. The steerable beam provides broadcasting over the Indian Ocean region to Mauritius and Reunion Island and parts of southeast Africa.

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