Future light European institutional missions are slated to shift from using Russian launchers to the Vega rocket when it begins flying late next year, but officials with Russian launch providers say they are not giving up on the market just yet.

File photo of Rockot launcher. Credit: Eurockot Launch Services

Monday's launch of the European Space Agency's Soil Moisture and Ocean Salinity satellite left the Rockot launcher with a single future mission on its books.

The Rockot is made by combining two stages of the SS-19 missile with a Breeze KM upper stage to deliver satellites to orbit.

But Eurockot, the joint German-Russian company that oversees commercial Rockot flights, is still discussing potential deals with ESA for upcoming Earth observation satellites.

"We're just presently preparing a proposal for the European Space Agency to address the future launches of additional Earth observation missions," said Peter Freeborn, director of sales and marketing at Eurockot's headquarters in Bremen, Germany. "This is a set of satellites which normally would have flown automatically on Vega."

It is ESA's formal policy to award small institutional missions to the agency's Vega rocket, a new launcher being built to haul light satellites into space from the Guiana Space Center in South America.

The ESA Ministerial Council, the agency's policy-making governing body, issued a decree in 2005 naming Vega the go-to rocket for all ESA small satellite missions. The council chose Rockot as a back-up option if Vega was not available.

"That means as long as Vega doesn't exist or is not qualified, ESA has a leaning toward us to use our launch vehicle to do what Vega is supposed to do," Freeborn said.

Eurockot was formed in 1995 between EADS Astrium and Khrunichev, the Russian contractor for the Rockot vehicle. Freeborn said about 150 SS-19 missiles, which were built in the 1980s, are available for launch. Khrunichev keeps 10 units in storage for speedy conversion to the Rockot configuration.

Artist's concept of Rockot launching an ESA satellite. ESA

The Vega's debut launch is scheduled for late 2010. That flight that has been delayed several years after trouble with the rocket's development.

ESA is planning a flurry of new Earth observation missions to study the planet's climate and magnetic field.

"Vega is not around, not yet. Therefore, ESA is writing out the launches for these satellites. We'll have to see how we fare," Freeborn said.

The first two Earth Explorers have launched on Rockot, and the third satellite will launch in Feburary on the Dnepr rocket, another launcher made of old Soviet missile parts.

"We are not afraid of Vega because we think that Vega will be prized in a category which is somewhat higher than ours, despite the fact that Vega does have very similar capabilities, payload performance and so on, to Rockot or Dnepr," Freeborn said.

The Dnepr is based on the Ukraine-built SS-18 missile and is marketed commercially by Kosmotras, a Moscow-based company partially owned by Ukrainian shareholders.

The Rockot has amassed 11 successful launches in 12 attempts since 2000. The Dnepr has completed 13 launches since entering service in 1999, and 12 of those flights were successful.

Both rockets have garnered large chunks of the launch market for small Earth observation satellites, having launched payloads for ESA, NASA, Germany, France, Japan, Thailand, Russia and a host of other countries.

Three more ESA Earth Explorers are scheduled for launch between 2011 and 2013, but rockets for those missions have not been selected.

One of the Earth Explorers, called Swarm, features three satellites that will not fit on a single Vega rocket. EarthCARE, a larger satellite, may have to launch on a heftier Soyuz rocket in 2013.

Artist's concept of Vega rocket. Credit: ESA

Vega launches will be conducted by Arianespace under contract with ESA. Arianespace says the Vega is specifically tailored for missions like Earth Explorers.

"Vega has a niche market for Earth obervation and science satellites," said Jean-Yves Le Gall, Arianespace chairman and CEO.

Antonio Fabrizi, head of ESA's launchers program, says the Vega's first flight will be a qualification launch without a primary payload. Five subsequent flights will be demonstration launches with ESA missions, if satellites are ready.

But with Rockot submitting proposals to launch the next round of Earth observation satellites, is it not clear if enough ESA payloads will be available to launch on Vega's demo flights.

Volker Liebig, director of ESA's Earth observation program, told Spaceflight Now late Thursday that the Swarm mission and the Sentinel 1 radar mapping satellite have been tendered to launch providers in an open competition.

Liebig also said ESA is seeking proposals for a "generic fall-back launcher for the first five Vega launches."

In an interview last month, Fabrizi said the agency would turn to its 18 Member States for Vega payloads if there are no ESA satellites ready.

"Vega is the small rocket which is going to cover the needs of ESA member states especially for Earth observation satellites. So we have great expectations for the use we can make of these launchers for institutional purposes," Fabrizi said.