FARNBOROUGH, England — The designers of Europe’s Vega small-satellite launch vehicle, surveying a commercial landscape that looks increasingly favorable to them, are planning three possible evolutions of the rocket to better align its cost and its capacity to its growing market.

The rocket, built by Italy’s ELV S.p.A, which is owned 70 percent by Avio Group of Turin and 30 percent by the Italian Space Agency, successfully conducted its inaugural flight in February and is set to become the default choice for the launch of most European government science and Earth observation satellites that are within its performance limits.

The current Vega is able to launch a 1,500-kilogram satellite into a 700-kilometer circular polar low Earth orbit.

Vega’s backers say the vehicle appears to be arriving at a time when converted ballistic missiles in Russia and Ukraine are no longer easily available as space launch vehicles. And when they are available, their price is increasing rapidly.

The future of the Russian-Ukrainian Dnepr rocket, for example, which has been used to launch commercial and governmental satellites, is unclear. Kosmotras of Moscow declined to respond to requests for comment on the vehicle’s availability and pricing. Two other industry officials said that the Russian military forces, which maintain Dnepr as a silo-launched missile now being decommissioned under arms control treaties, are asking for much higher prices to convert the missile for space launches.

As the European Space Agency (ESA) recently discovered to its dismay, a Russian submarine-launched missile that had been available for small payloads as part of test firings appears to have been taken off the market by Russian military forces.

These developments, and the temporary withdrawal from the market of Space Exploration Technologies’ Falcon 1 rocket while that company focuses on its larger Falcon 9, have created an opening for Vega.

In interviews here during the Farnborough Air Show, Avio and Italian Space Agency officials said they are hoping that ESA ministers meeting in November will agree to at least one of the multiple routes to Vega’s enhancement.

Italian Space Agency President Enrico Saggese conceded that the funding available at ESA for Vega upgrades will depend in part on what decision the agency takes regarding the future of Europe’s heavy-lift Ariane 5 rocket.

An Ariane 5 upgrade costing around 1.5 billion euros ($1.9 billion) over six years is one alternative under consideration. The other is a 10-year program to produce an Ariane 6 rocket whose cost would be at least double that figure.

Antonio G. Accettura, Avio Defense and Space business development manager, said the company is aware that to capture what looks to be an expanding market and to win investment approval by ESA, Avio must demonstrate that it can maintain Vega’s operating costs within a strict financial envelope.

With the inaugural flight completed, ELV and Avio have five ESA-financed flights planned for the next two to three years. These Verta, or Vega Research and Technology Accompaniment, missions will launch a variety of ESA payloads including an experimental spaceplane demonstrator called the Intermediate Experimental Vehicle, the LISA Pathfinder science satellite and three Sentinel Earth observation spacecraft.

Accettura said ELV and Avio will use the Verta program to trim costs from Vega’s operations to assure that the vehicle is able to attract business from beyond ESA. The more non-ESA customers it books, the easier it will be to reduce the per-launch costs, he said.

Accettura said Vega’s enhancement is separated into a two-part program. The first is referred to as a consolidation of the vehicle’s performance; the second points to an evolution toward a much more powerful vehicle.

The first would better position the rocket to launch satellites weighing around 2,000 kilograms into low Earth orbit. The Italian Space Agency is financing a program called Lyra that would replace Vega’s third and fourth stages with a stage powered by a liquid-propellant engine called Mira.

Another modification, Accettura said, would enhance Vega’s P-80 solid-fueled first stage, which carries some 88,000 kilograms of propellant, to 120,000 kilograms, increasing payload capacity to 1,800-2,000 kilograms into low Earth orbit.

A second series of enhancements would increase the power of the Zefiro 23 second stage, carrying 24,000 kilograms of solid propellant, to a Zefiro 40 model. This modification would be part of a program to permit Vega to lift up to 2,500 kilograms of payload into low Earth orbit.

A program called Vega Evolution would combine the larger first and second stages with the Mira engine to give Vega the power to carry a 3,300-kilogram satellite into low Earth orbit, Accettura said.

Avio and the Italian Space Agency would prefer that the vehicle’s enhancements include the German government’s entry into Vega through the use of a German-built Vega upper stage. The German Aerospace Center, DLR, has said it is open to joining the program.

Saggese said the introduction of all-electric telecommunications satellites ultimately may permit the higher-power Vega to appeal to the telecommunications market. Replacing chemical propellant means that a satellite that would weigh 5,000 kilograms could be launched, with electric propulsion, weighing 3,000 kilograms. In the longer term, he said, an upgraded Vega would be able to replace the Russian Soyuz vehicle, which since 2011 has been operating from Europe’s Guiana Space Center in French Guiana.

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