KOUROU, French Guiana — E urope’s Vega small-satellite launcher , long ridiculed as an expensive Italian folly, is beginning to win converts as its Italian-led contracting team passes successive program milestones and the global launch market offers increasing opportunities.

Vega, whose new-generation P-80 first stage successfully completed the first of two test firings here Nov. 30, has even won praise from what was once its sharpest critic: the French government.

“Providing Europe with the capability of launching all ranges of satellites — small, medium and large — gives us a real advantage,” said Yannick d’Escatha, president of the French space agency, CNES. “I don’t know what the thinking was a few years ago, but today I can tell you that this vehicle has a market that is real and growing.”

When European Space Agency (ESA) governments gave initial provisional approval for Vega in 1997, they did so only to appease the Italian government, which made veiled threats about quitting other ESA programs if its ESA partners did not subscribe to a minimum of Vega support. Italy got only the minimum, and has been forced to shoulder 65 percent of the program’s cost.

Vega marks a departure from 30 years of European rocket development in that it is being managed by a nation other than France. Italian government officials had to battle to secure a final, firm commitment from ESA and France to the project in 2000, a time when outside of Italy, few European officials believed in Vega’s potential. France’s space minister at one point said that leading launcher development in Europe is a role reserved for France only.

D’Escatha dissociated himself from these arguments here Nov. 30, saying France and other nations are increasingly using small satellites for science and Earth observation missions, and that many of these satellites are logical candidates for Vega. He said that many of the Russian and Ukrainian launchers that were once thought to offer unbeatable prices are getting more expensive by the month. Some of them, he said, have doubtful staying power in the market.

D’Escatha provided a list of about 15 satellites under development in Europe that are suitable for Vega. Meanwhile, ESA governments have signed an agreement to use European launchers.

Vega is designed to place Earth observation and scientific satellites weighing up to 1,500 kilograms into low Earth orbit. The vehicle’s debut, originally scheduled for late 2007, has been reset to mid-2008 following a series of small delays that have occurred despite the on-time test firings of Vega’s different stages, according to Stefano Bianchi, Vega’s program manager at ESA. Bianchi said the six-month delay will not lead to an increase in Vega’s budget of 560 million euros ($733 million).

ESA governments have agreed to spend an additional 258 million euros on price supports and other assistance to cover Vega’s first five launches. The inaugural flight will carry a dummy payload; the next four launches will be of ESA science and Earth observation spacecraft.

ESA governments have an option to purchase Vega’s next five launches at a price of 21 million euros apiece. Vega’s contracting team, led by Avio SpA of Italy, has agreed to supply Vega rockets — including hardware and launch services — for that price at ESA’s insistence.

Industry officials said that when margins for the Arianespace commercial-launch provider and other costs are added in, Vega’s retail price is likely to end up at around 25 million euros. That’s still higher than today’s prices for Russian Rockot or Russian-Ukrainian Dnepr vehicles, both of which have been used by European governments. But these converted ballistic missiles are increasing in price and their long-term availability remains unclear.

The 12-meter-tall P-80 motor, carrying 88,000 kilograms of solid propellant, burned for 115 seconds on a test stand at Europe’s Guiana Space Center here in the first of two planned dress rehearsals. Philippe Pascal, project manager for the P-80 at CNES, said the burn went “exceptionally well based on early indications. Six months ago when we set a November date, no one believed us.”

A second and final P-80 test firing is scheduled for mid-2007. Pascal said that advances in computer modeling and simulation have permitted Vega developers to stop at two test firings, in contrast to a decade ago when a similar solid-rocket stage now used for the Ariane 5 rocket was test-fired seven times before its first demonstration flight.

To secure the needed financing, Avio agreed to invest 63 million euros of its own money in P-80 development — equivalent to 52 percent of the cost of the P-80 program. The investment was made through a low-interest loan available to Italian companies investing in technology development in Italy. Vega’s contractors also have agreed to provide the first demonstration flight model free of charge.

“Vega is a strategic investment for our company,” Avio Technical Director Francesco Depasquale said. “Certainly we expect to recover our investment over the years, but we believe P-80 has applications for Ariane 5 and for future vehicles, and that this potential justified the financial effort.”

The P-80’s lightweight filament-wound composite casing replaces the stainless steel casing used on Ariane 5’s solid strap-on boosters, and offers savings in manufacturing time as well as in weight, project managers say. Arianespace for the moment says its current Ariane 5 strap-on booster design is sufficient, but the company is not ruling out an eventual switch to using the same filament-wound composite technology to save weight and production time. The Avio-led Vega contracting team includes the same companies that produce the current Ariane 5 strap-on boosters.