A US grand jury has charged one American and five Iranians with conspiring to provide satellite hardware and technology to Iran.
Authorities believe the technology provided, in defiance of US sanctions, helped Iran launch a camera-equipped satellite in October 2005.
The six individuals are accused of creating a front company for the illegal transactions.
The defendants face a maximum of five years' imprisonment for conspiracy.
Several of them may also face a 20-year jail term for money laundering.
Only one of the six accused - a naturalised American citizen called Nader Modanlo, who was born in Iran - is in custody.
Mr Modanlo, 49, lives in Potomac, Maryland, near Washington DC.
Assistant Secretary for US Immigration and Customs Enforcement (ICE) John Morton said the charges should send a signal to those willing to jeopardize American security.
"We will find you, and we will bring you to justice," Mr Morton said.
The defendants are accused of violating a US trade embargo which was established by former President Bill Clinton in 1995.