A lightweight rocket aimed at securing Europe a stake in the market to launch small satellites lifted off from Kourou space base on itsmaiden flight on Monday.
Vega, whose development has cost more than a billion dollars, raced into the sky from the launch site in French Guiana in a streak of light, carrying a test payload of nine satellites, mission controllers reported.
The 81-minute mission is a "qualification" flight, aimed at proving a rocket that incorporates several important innovations, engineers said.
"The trajectory is normal," flight supervisor Aimee Cippe said after the first three stages, driven by solid fuel, separated on schedule and the final stage, which uses liquid propellant, ignited as expected.
Thirty metres (100 feet) long and three metres in diameter, Vega is designed to hoist multiple payloads loads ranging from 300 kilos (660 pounds) to 2.5 tonnes into various orbits from 300 to 1,500 kilometres (190-940 miles) depending on mass.
The lightweight launcher complements the heavyweight Ariane 5, capable in its beefed-up version of lifting more than 20 tonnes, and the mid-range Soyuz, the Russian-Soviet veteran deployed to Kourou last year under a deal between Russia and the European Space Agency (ESA).
Jean-Yves Le Gall, head of Arianespace, which commercialises ESA's launchers, said the outlook for Vega was good.
Its main competitors are Russian ballistic missiles, transformed to carry satellites in a swords-to-ploughshares scheme, and all of these Cold War launchers will be used up in the coming years, he said in a webcast.
"Vega is going to be extremely important for Arianespace because in just a few years it's going to be the only launcher of its capability on the market," Le Gall said.
Development of Vega dates back to 1998. It has cost 776 million euros (over one billion dollars), of which Italy has contributed nearly 60 percent.
Vega uses four stages to propel a small payload into low orbit, a design that is unusual in a small rocket. Its stages are also made out of wrapped bandages of carbon fibre, in order to reduce weight.
Three of these stage use solid fuel, while the fourth and final stage, called AVUM, uses liquid fuel. It will carry out three "burns" in order to slot the payloads into their various orbits.
The main payload on Monday was a tungsten sphere called Lares, which is designed to study the so-called Lense-Thirring effect.
This is a component of Einstein's theory of general relativity which says that as a large mass such as the Earth rotates, it drags space and time around with it.
To measure the theorised effect, Lares is studded with reflectors on which ground-based laser beams will be trained to measure the satellite's time and distance as it zips around the globe.
The other principal satellite, AlmaSat-1, will test new civilian technologies in Earth observation.
The rest of the payload is taken up by seven so-called picosatellites, essentially cubes each weighing less than a kilo (2.2 pounds), in which European universities have each packed a separate experiment.