BRUSSELS — Astrium Space Transportation will pursue work on an upgraded Ariane 5 rocket and spend six months designing the next-generation Ariane 6 vehicle under contracts with the European Space Agency (ESA) totaling 108 million euros ($146 million), Astrium announced Jan. 30.

The Ariane 5 Midlife Evolution (ME) vehicle, featuring a new, restartable cryogenic upper stage, is scheduled to make its inaugural flight in 2017 or 2018. ESA governments in November agreed to pursue development of this rocket for at least two years. More funding will be needed to finance its completion. ESA governments are scheduled to meet to approve this new funding, totaling about 1 billion euros, in mid-2014.

“Manufacturing of Ariane 5 ME will begin immediately, and with more than three years’ work already completed by us, we are on target for the first flight in five years’ time,” Astrium Space Transportation Chief Executive Alain Charmeau said in a Jan. 30 statement.

The Ariane 5 ME is designed to increase the power of the current Ariane 5 ECA rocket by about 20 percent to permit it to carry two heavy commercial telecommunications satellites, with a combined weight of some 11,000 kilograms, into geostationary transfer orbit.

Under a separate six-month contract with ESA, Astrium will review design options for Ariane 6, which would launch single satellites weighing between 3,500 and 6,500-7,000 kilograms to geostationary-transfer orbit.

The industrial team that will build Ariane 6 has not been selected, and it remains unclear whether the estimated 4 billion euros needed to fully develop the vehicle will be approved at the 2014 ESA conference of ministers.

Astrium Space Transportation said its six-month study “will identify the concept and architecture” of Ariane 6 within the borders of what ESA governments approved at their November conference. Ministers said Ariane 6 should use two solid-propellant stages topped by the same upper stage used by Ariane 5 ME.

Peter B. de Selding was the Paris Bureau Chief for SpaceNews.