LES MUREAUX, France — Astrium Space Transportation, a company that has seen its rocket-development division’s revenues fall sharply with the completion of design work on Europe’s Ariane 5 heavy-lift rocket, is urging European governments to fund development of a medium-lift rocket to replace Russia’s Soyuz vehicle, Astrium Space Transportation officials said March 31.

Company officials also called on Europe to finance its own ballistic missile defense system, starting with a flight demonstration of an exoatmospheric kill vehicle that would knock out a dummy missile in space at about 300 kilometers in altitude.

“I don’t think Europe’s response to the American missile defense offer should simply be, ‘Thank you very much, sir. How much?’” said Alain Charmeau, chief executive of Astrium Space Transportation, whose French division is based here. The United States has proposed to build missile defense sites in the Czech Republic and in Poland. “What we propose is that, before 2015, we demonstrate an exoatmospheric kill vehicle to prove our ability in this area.”

Charmeau said a missile defense demonstration of this type would cost around 200 million to 300 million euros.

Astrium Space Transportation reported revenue of about 1.97 billion euros ($2.6 billion) in 2008, a 21 percent increase over 2007. The company’s biggest business in 2008 was related to the French M51 strategic missile, which accounted for 39 percent of the company’s revenue.

Production of Ariane 5 rockets, for which Astrium is prime contractor, accounted for 36 percent of the company’s revenue.

Exploration-related business, including work on the international space station, was 14 percent, with satellite antennas and other components accounting for 7 percent.

Just 4 percent of the company’s 2008 revenue was Ariane rocket development, a natural decline resulting from the completion of design work on the Ariane 5 ECA rocket, the vehicle’s most powerful variant. European Space Agency (ESA) governments have approved early work on a new upper stage, but full development will not be started until 2012 at the earliest.

As has been the case for several years, Astrium’s biggest near-term problem is how to generate work for its design teams. Judging from remarks here during the press briefing, company officials think replacing the Russian-built Soyuz with a made-in-Europe medium-lift rocket is a proposal worth pursuing.

Astrium officials said the same drive for European autonomy that resulted in the Ariane 5 and the Vega small-satellite launcher, now in development, should push European authorities to reconsider Soyuz.

Russia’s Soyuz rocket, which is generally considered the most reliable space-launch vehicle ever made, is scheduled to begin operations from Europe’s Guiana Space Center spaceport either late this year or early in 2010. Soyuz will be used to carry European government satellites into low medium-altitude orbits, and to launch commercial telecommunications satellites weighing 3,000 kilograms or less into geostationary-transfer orbit.

European Space Agency (ESA) governments, led by France, are financing the new Soyuz launch pad, and the Arianespace launch consortium of Evry, France, is buying Soyuz rockets from Russian industry with the oversight of the Russian space agency, Roskosmos.

Charmeau said European governments should be concerned that Russia is under no obligation to supply Soyuz rockets to Europe forever and could stop supplying Soyuz rockets for European use at a moment’s notice. An Arianespace official confirmed April 1 that the Euro-Russian Soyuz agreement does not include a guarantee of supply over a given number of years.

Charmeau said that in addition to being Russian, Soyuz is also a design that dates from the 1950s, a fact he sought to portray as a disadvantage.

“I am not sure Europe’s space program [should] lean heavily on a vehicle that is both Russian and is 50 to 60 years old,” Charmeau said. An all-European medium-lift rocket, he said, could replace Soyuz by around 2025.

Peter B. de Selding was the Paris bureau chief for SpaceNews.