The European Space Agency is readying the 2 May second flight of its Vega light launcher in expectation of repeating the success of last year's maiden launch despite a far more complicated flight plan and the added burden of carrying a commercial payload.

The second mission - carrying an experimental ESA vegetation-mapping mini-satellite and an Estonian student-built cubesat designed to test electric solar sail technology - will have as its principal payload Vietnam's VNREDSat Earth observation mission. For Vietnam and Estonia, the mission marks the countries' first forays into space.

For ESA and Arianespace, which is taking a bigger role in this second Vega flight as part of a plan to shift commercial and operational control of Vega to the launch operator as the rocket is fully validated over its first several flights, the mission represents the first step in their multi-launch VERTA (Vega Research and Technology Accompaniment) campaign to establish Vega as an unsubsidised, cost-competitive vehicle to orbit scientific, Earth observation and even telecommunications satellites for European and non-European institutions and commercial customers.

Vega's 13 February 2012 maiden flight went off with apparent perfection and indeed was described by programme manager Stephano Bianchi in an 18 April briefing on the second flight plan as a "remarkable" performance. The one hitch in that first mission was a several-second loss of telemetry as the second stage dropped away and the third took over. The performance of the rocket was flawless, but the third stage plume interfered with reception, an issue not experienced until that first-ever launch from ESA's Kourou, French Guiana spaceport of a rocket with three solid-fuel stages. ESA launchers director Antonio Fabrizi says data was later recovered from memory, and the addition of a extra ground station north of Kourou should resolve the problem.

The second mission is more complex than the first, as it involves five burns of the upper stage, to orbit the Proba-V mini satellite at about 870km, release the VESPA dual payload adaptor - which is being used for the first time - then the VNREDSat about 650km and then de-orbit the stage, another first for the Vega programme. And, at 9,300s the total burn time will be more than twice as long as for the maiden flight.

The first flight orbited an Italian scientific payload, an experimental satellite engineering platform and nine cubesats.

The flexibility that allows such complexity, though, is part of Vega's intended appeal. Fabrizi believes that the price of a mission will come down into the €35-45 million ($45.7-58.8 million) range that ESA and Arianespace believe will make Vega a launcher of choice. The rocket's sweet spot is to place a 1.5t payload into a 750km orbit, ideal for Earth observation or scientific missions, but the VESPA adaptor and restartable upper stage allow for a mix of large and small payloads.

Even the experience of one launch has cut the launch campaign time down by more than 20%, and, says Fabrizi, the market for launches is strong, so he is confident that three flights per year can be achieved - a volume that will allow ESA's industrial partners to bring the cost down enough to meet that €35-45 million launch price target.

For the second flight, payload integration on the launch pad at Kourou will begin on 19 April, and the satellites will be fuelled during the week of the 22nd, with a launch readiness review scheduled for 30 April, followed by the launch at 11:06 local time on 2 May.

Source: Flight International