Iran says it has launched its second space rocket, the Kavosh 2, in a successful follow-up to the first launch in February.
State media said that two more tests would be needed before an Iranian-built satellite could be launched into orbit.
Iran denies that its long-range ballistic technology is linked to its atomic programme.
It is already under international pressure to give up its nuclear work, which it says is purely civilian.
The US referred to the February satellite launch as "unfortunate", given the questions over its nuclear work.
Iranian state TV says the rocket was carrying a space lab and a data-monitoring and processing unit.
"Kavosh 2 completed its mission and returned to earth with a special parachute after 40 minutes," the channel reported.
It added that the rocket had been designed and built by Iranian aerospace experts.
Much of Iran's technological equipment derives from modified Chinese and North Korean kit.
Earlier this month Iran said it had test-fired a new medium-range missile.
Its 2,000-km (1,240-mile) range would be capable of reaching Western Europe.