The debut launch of Europe's new Vega small satellite launcher could slip until 2011, mainly due to potential delays in the development of ground systems at the rocket's launch site in South America.

Artist's concept of the Vega rocket. Credit: ESA

"I think Vega will be launched around the 31st of December, and we will see in April whether it is just before or just after," said Jean-Jacques Dordain, the European Space Agency director general.

Stefano Bianchi, head of the Vega rocket program, said combined tests of the launch pad and vehicle will begin in April, along with a qualification review of ground systems.

The Vega will blast off from the ELA-1 launch pad at the French-run spaceport in Kourou, French Guiana, along the northeast coast of South America. The 98-foot-tall rocket is tailored to carry small Earth observation and scientific research satellites into orbit for ESA and its member governments.

Dordain said he is confident the Vega rocket will be ready to launch around the end of the year. The biggest uncertainty is now the construction and testing of the Vega ground segment, according to Bianchi.

"The uncertainties today are linked mainly to the readiness of the ground segment for the combined test," Bianchi told Spaceflight Now on Friday. "Obviously, a delay in the start of the combined test will cause a shift in the launch date."

Testing of the launch pad is in the second of three phases, and about half of the planned tests have been completed. Ground segment testing must be finished before workers erect an inert Vega rocket on the pad for combined testing in April.

The bulk of the rocket's systems are already cleared for flight or will soon be qualified, Bianchi said, but engineers are still struggling with issues in the roll attitude control system.

According to Bianchi, roll control thrusters suffered technical problems during ground tests last year. Engineers must finalize a solution to the problem before qualifying the components for flight.

Cramped schedules for key Vega systems could drive the launch date to 2011, more than three years after the rocket was originally due to fly. Dordain maintains the problems still facing Vega are manageable.

"I can say today that the technical and schedule problems are under control," Dordain said. "It's true that it took us longer than expected to develop Vega, which is not surprising."

"We did have a few hitches during development, but Vega is perhaps the ESA project with the most detailed timeline now," Dordain said.

Bianchi said about 80 percent of the flight unit for the first mission are either ready or under final construction in Europe, including the second and third state motors, the interstage and avionics.

"The planning is tight, in particular for the final delivery of the flight software for the first mission, but well under control," Bianchi said.

The first stage for the inaugural Vega launch is already in Kourou, along with inert parts for pathfinder fit checks with the launch pad.

The payload for Vega's first launch is the Italian Space Agency's Laser Relativity Satellite, or LARES, a spacecraft named ALMASat, and nine small CubeSats for European universities.