Israeli satellite operator Spacecom lost contact at 06:45 a.m Saturday Israeli time with its Amos 5 communications satellite in orbit over Africa, causing service disruption to an unspecified number of customers — mostly in Africa.

Spacecom said it did not know what caused the problem and has been unable to reestablish contact with the satellite, which itself is worth $160 million to $190 million, Haaretz reported.

Amos-5 is where it’s supposed to be at its assigned orbital station but it’s not responding to commands, Spacecom said Monday in response to a question from SpaceNews.

Launched in 2011, Amos 5 is in geostationary orbit over Africa. Its coverage extends over Africa, Europe and the Middle East. In Africa, it plays a major role in the continent’s emerging satellite services market, according to Haaretz.

Geostationary satellites are used for telecommunications because the signal transmitter and receiver can be always fixed to the same spot in the sky, according to GCSEScience. The satellite is always exactly above the same point, about 35,000 kilometers (21747.992 miles) above the Earth’s surface. Telecommunications satellites are used to transmit telephone, radio and TV signals.

The satellite orbits the Earth once in 24 hours — the time it takes the Earth to spin on its axis. Seen from the Earth, the satellite appears not to move, hence “geostationary.”

“Spacecom is working around the clock, doing the utmost to speed service recovery for its customers,” said Spacecom CEO and president, David Pollack, according to BroadbandTVnews. “Our service teams are looking for solutions for our customers to enable their broadcast signals and data communications streams to continue with minimal interruption.”

Amos 5 provides direct-to-home services to the African continent, and a small number of Israeli customers.

Spacecom said it would freeze services to its customers as a result of the disconnect, in a statement sent to the Tel Aviv stock exchange.

Unlike Spacecom’s first four Amos satellites, which were built by the Israel Aerospace Industries, the Amos 5 satellite was built by ISS-Reshetnev, one of Russia’s leading satellite providers, according to Haaretz.

When Amos 5 was launched from Kazakhstan in 2011, Spacecom already had secured a five-year contract for satellite communications in Africa worth nearly $28 million, according to a report in Globes.

Amos-5 has had problems before, BroadbandTVnews reported. In November 2013, it experienced power problems but they were resolved.

Losing contact with Amos 5 means losing about a third of Spacecom’s revenue, Globes reports.

Spacecom signed a $1 billion contract with Facebook for the Amos 6 satellite, due to be launched in February. It will take about three years to launch a replacement satellite for Amos 5, according to capital market expert estimates.

Spacecom’s share price plunged by about 30 percent on the Tel Aviv Stock Exchange on the news. “The company shrank by a third this morning,” a market source said.

Spacecom is controlled by Israeli holding company Eurocom Group, Reuters reports. The company, which has a market value of 1.1 billion shekels ($283 million), has been trying to sell its 64.3 percent stake in the satellite operator, according to Israeli media reports.

Total loss of contact with a satellite is a highly uncommon event, industry experts say, according to Haaretz. But even if that has happened, any losses would be covered by a $158-million insurance policy that would be used to cover a forced early repayment of a $140 million bond series directly linked to Amos-5.

“In the event of a total loss of the satellite there will be a negligible effect on the company’s equity,” Spacecom said in a statement to the Tel Aviv Stock Exchange. “The company is continuing to examine the overall aspects of the event and will update with any development.”

However, loss of the satellite will hurt future revenue. Amos 5 brings in annual revenue of about $40 million and accounts for about a fifth of the company’s order backlog worth about $136 million.

German Satelio direct-to-home service is one of the affected platforms, offering an array of German language TV channels. On its website, Satelio said it is now desperately looking for another satellite to take over its services, according to BroadbandTVnews.

Two years ago, in November 2013, Amos-5 experienced power problems, but these were resolved at the time.

The current issue is not related to the 2013 loss of a battery charger on the satellite and happened without warning, Spacecom told Spacenews.“We had no early signs of trouble whatsoever,” the company said.

Amos-5 is at 65-percent capacity and the company is working to find alternative capacity, Spacecom said.

“There are several options for transferring customers and we are closely working with customers vis a vis other satellite operators to ensure minimal interruption,” the company said, according to Spacenews. “We are working to find solutions for each and every client.”

Spacecom and Paris-based Eutelsat announced a partnership in November 2014 to jointly market each other’s capacity at 16 degrees east – where the Eutelsat 16A is located – and Amos-5 next door at 17 degrees east, Spacenews reports.

The two companies said at the time that their combined business from the two locations totaled “over 100 free-to-air African and international channels that can be received by standard 80-centimeter dishes in a vast footprint covering over 30 million TV homes located notably in Francophone Africa and extending to Ghana and Nigeria.”

When ISS Reshetnev of Krasnoyarsk, Russia, won the contract to build and launch the Amos-5,  it was considered a rare win of commercial non-Russian business by the Russian builder, according to Spacenews.

It was also considered an exceptional deal for Spacecom, costing $157 million for the satellite’s construction and launch in December 2011 aboard a Russian Proton rocket.

Amos-5 carries a pan-African beam and regional beams over French-speaking central and West Africa in C-band, as well as Ku-band beams targeting Central Africa and Southern Africa, Spacenews reports.

Spacecom has scheduled the launch of the larger Amos-6 satellite aboard a California-based SpaceX Falcon 9 rocket sometime in 2016 — depending on when SpaceX returns to flight following a June failure. Amos-6 will operate at 4 degrees west, Spacecom’s core orbital position, according to Spacenews.