The remote-sensing satellite Ofeq-9 was successfully placed in orbit by an Israel Aerospace Industries Shavit vehicle launched from Palmachim Air Base, near the cities of Rishon LeZion and Yavnem, defense ministry officials said.
It has already begun transmitting high-resolution images, officials add.
With the Ofeq-9, Israel now has six operating remote sensing satellites in space.
"From now on, no country in the region will be able to conduct clandestine activities at times when there is no Israeli satellite above it, since there will be no such times," Yitzhak Ben-Israel, chairman of the Israeli Space Agency, said.
The estimated 600-pound Ofeq-9 is billed the twin of the Shavit-launched Ofeq-7 and Ofeq-5, which have been operational for 2 and 5 years, respectively. Ofeq-6 was destroyed in an ill-fated launch in September 2004.
Defense News reported that Ofeq-9 will operate "in a constellation with the two other Ofeqs currently in orbit." It said that while precise imaging capabilities remain classified, all offered resolutions that were "much better than a half-meter."
"If each satellite completes an orbit every 90 minutes and with six satellites in space, you can calculate the frequency that we can observe any given target," Brig. Gen. Nimrod Sheffer, Israeli air force chief of staff, told Aviation Week. "Even with the other side being aware it is under observation, it will be hard to conceal activities in the course of time."
Israel worries about Iran because of Tehran's controversial nuclear program, missiles and repeated threats against the Jewish state. Officials in Israel have suggested that it could launch pre-emptive strikes against Iranian nuclear sites if it is shown that Tehran is developing nuclear weapons.
Iran has long spurned the allegation claiming its nuclear program is intended for peaceful purposes.
The Islamic Republic is shielded by a sophisticated ground-to-air missile system. The government recently accused the U.S. administration of trying to scupper a S-300 missile defense deal with Russia for fear that Iran may reverse engineer the system.
Israel Aerospace Industries is the main contractor for the Ofeq satellites and the Shavit launcher. El-Op, a subsidiary of Elbit Systems, is the producer of the satellite's high-specification cameras called the Jupiter.
In addition to its domestic sales, El-Op has long supplied cameras to Indian and Korea for their corresponding space programs.