Iran has test launched a rocket it plans to use to carry a research satellite into orbit, state television reported Sunday.

Saturday's test of the two-stage rocket, called the Safir-e Omid, or Ambassador of Peace, was successful, state TV said, broadcasting images of the nighttime launch.

The rocket released equipment that beamed flight data back to ground control, said Reza Taghipoor, the head of Iran's Space Agency, in a live television interview.

Iran has long held the goal of developing a space program.

In 2005, it launched its first commercial satellite on a Russian rocket in a joint project with Moscow, which appears to be the main partner in transferring space technology to Iran.

Iran first tested a rocket it said was capable of delivering a satellite in February, saying that trial was also successful. It said then that it planned two more test launches before attempting to put its first domestically built satellite into orbit.

The country's fledgling space program, like its nuclear program, has provoked unease abroad. The same technology used to put satellites into space can also be used to deliver warheads.

The United States called the Feb. 4 launch "just another troubling development," saying it was a cause for concern about Iran's continuing development of medium- and long-range missiles.

Despite the anxiety over Iran's space program, it is not exactly clear how developed it is.

Iran has said it wants to put its own satellites into orbit to monitor natural disasters in the earthquake-prone nation and improve its telecommunications. Iranian officials also point to America's use of satellites to monitor Afghanistan and Iraq and say they need similar abilities for their security.

Iran hopes to launch four more satellites by 2010, the government has said.

Iran also announced on Sunday that it had extended the range of its military aircraft to just over 1,800 miles without refueling.

The television report, which quoted Iranian Air Force chief Gen. Ahmad Mighani, did not specify what kind of aircraft or how the range was extended. Such a feat could be accomplished, however, by adding extra fuel tanks to the plane which are dropped when empty.

Israel, which is about 600 miles away, from Iran, has often traded threats with the Islamic republic.