Iran has launched a research rocket to inaugurate a newly built space centre.
The test-launch for the country's first low-orbit research satellite was shown on Iranian state television to cries of "God is Great" from the announcer.
Correspondents say advances in Tehran's missile technology are likely to alarm Western powers, as Iran presses on with a controversial nuclear programme.
The White House called the launch "unfortunate", warning it would further isolate Iran from the global community.
The BBC's Jon Leyne in Tehran says it is a highly symbolic moment for the launch, coinciding with the 29th anniversary of the Iranian revolution.
Reporting of the story on Iranian TV has been accompanied by a great deal of patriotic music.
The successful test-launch bodes well for Iran's low-orbit satellite project, with its scheduled launch date of March 2009.
The space centre, at an unidentified desert location, includes an underground control station and launch pad for the satellite which will be named Omid (Hope).
"We need to have an active and influential presence in space," President Mahmoud Ahmadinejad said in a televised ceremony before the launch.
"Iran took its first step very strongly, precisely and wisely," he said. "Building and launching a satellite is a very important achievement."
In February 2007, Iran said it had launched a rocket capable of reaching space - before it made a parachute-assisted descent to Earth.
In October 2005, a Russian rocket launched Iran's first satellite, the Sina-1, which carried photographic and telecommunications equipment.
Western countries also fear Iran wants to produce nuclear weapons.
Tehran denies this, insisting its uranium-enrichment programme is solely to generate electricity.
Tehran is already thought to have missiles which can reach Israel and this launch is seen as further evidence that it is developing its rocket technology.