Hours after Israel launched its latest spy satellite Tuesday, officials said they were unsure if all was well with the satellite. The satellite, called Ofek-11 (ofek or ofeq means horizon in Hebrew), reached its low Earth orbit successfully, after which Israel announced the launch.

The reconnaissance satellite was launched aboard Israel’s indigenous Shavit rocket, making it the 11th spacecraft in its series which began in 1988. Soon after Tuesday’s launch, Amnon Harari, who heads the space department within Israel’s Ministry of Defense, told reporters there were “indications of some things that aren’t working as we expected.” He added that work to stabilize the spacecraft would carry on over the coming days.

Ofer Doron of Israel Aircraft Industries — the state-owned company that manufactured the satellite — said of the problems with Ofek-11: “There are a few matters that don’t seem routine, but the process of diagnosing the satellite’s situation is continuing.”

Operational viability of the 815-pound satellite was unclear despite the successful launch, making it a matter of concern, Tal Inbar from the Fisher Institute for Strategic Air and Space Studies in Israel, said. “There is still a chance to bring all the satellite systems to an operational state and that the satellite will perform as planned. But at the moment, it is unclear whether efforts being conducted by the ground crews will end up solving the problem,” he added.

Ofek-11 was originally scheduled for launch on Monday, but it was delayed by 24 hours due to adverse weather conditions.

Two weeks ago, Amos-6, an Israeli civilian communications satellite, was destroyed in an explosion when the SpaceX Falcon 9 rocket that was carrying it burst into a fireball on the launch pad. Among other things, the satellite was to be used by Facebook for beaming internet to sub-Saharan Africa.

Israel already has about 10 military satellites in orbit, the last one being Ofek-10 which was launched in April 2014.