Vega, the European Space Agency's new small launch vehicle, will carry a science satellite and not a dummy payload on its maiden flight in 2008.
The science satellite will orbit at 1,000km (620 miles) and is to be covered in mirrors to reflect ground-based lasers. Experiments using the lasers will test the theory of general relativity.
Vega is a three-stage solid rocket that will place up to 1,500kg (3,300lb) into low-Earth orbit. Its development is largely being paid for by the Italian government.
"We are now aiming for a small satellite mission every two years. Small means 300-400kg spacecraft and a cost of €50-100 million [$67-135 million]," said Italian Space Agency president Giovanni Frabizio Bignami at the third workshop on international co-operation for sustainable exploration.