— European Space Agency (ESA) officials are cautiously optimistic that they will be able to secure up to 550 million euros ($864 million) in funding needed to build and launch an Enhanced ExoMars rover and lander when ESA governments meet in November to decide a broad range of policy issues. The mission would be launched in 2013.

ESA also will ask its governments to approve a proposal for spending between 50 million and 70 million euros over three years to start early design work on European participation in an international Mars sample return mission.

ESA governments in 2005 agreed to spend 650 million euros on the original ExoMars mission, but program managers and scientists subsequently judged the modest scientific package proposed for the mission to be insufficient.

ESA officials have spent the last several months trying to make the case that the Enhanced ExoMars mission price tag is not a cost overrun in the original package, but a revamped mission that some suggested should no longer carry the ExoMars name to avoid confusion.

Enhanced ExoMars Project Manager Don McCoy, in a July 9 presentation to a Mars sample return conference here, said the work already started on Enhanced ExoMars, with the approval of ESA governments, means that a formal program approval at the ESA governments’ conference in November leaves just enough time to get the mission ready for a 2013 launch.

McCoy said the Enhanced ExoMars is budgeted at 1 billion euros, plus 200 million euros for a communications capability that would be either a small orbiter that could be launched separately aboard a medium-lift Soyuz rocket or a Mars-based communications system attached to the lander. The 1.2 billion-euro figure does not include the cost of developing most of the mission’s experiment hardware, which is the responsibility of individual European governments.

The 250-kilogram Enhanced ExoMars rover and lander would be launched on a heavy-lift Ariane 5 rocket.

In addition to keeping ESA in the forefront of nations concentrating on Mars, Enhanced ExoMars would be the first time European governments have built an entry, descent and landing system. ‘s successful Huygens probe that descended through the atmosphere of Titan, Saturn’s largest moon, in 2005 was never intended to survive the landing.

Enhanced ExoMars is intended to include a 5,000-kilogram carrier module housing a 1,200-kilogram descent module that will bring the rover and lander package of experiments to the surface of Mars.

McCoy said ESA and the Russian government have struck an agreement permitting ESA to purchase radioisotope heater units from to keep the experiments warm. Using nuclear material would require what McCoy described as a modest investment in in to permit the arrival of the plutonium-based heater units from , and also would require the approval of as the state responsible for the launch.

ESA also needs to negotiate a commercial purchase of the nuclear heaters in . McCoy said negotiations have begun.

ESA already has spent more than 100 million euros in preparing the original ExoMars, and since December, on Enhanced ExoMars, successfully has persuaded its government delegations that the 2013 launch date would be missed unless work started before the full program was approved.

McCoy said that, notwithstanding the early start, getting Enhanced ExoMars ready for a late- 2013 launch will not be easy. Assuming approval in November, the agency would transition to a full hardware-development contract in April.

“It’s a tight, but doable, schedule,” McCoy said. “But for our government ministers meeting in November, the time to decide is now. If it’s not now it will be too late” to make the 2013 date.

Bruno Gardini, who manages ESA’s space exploration initiative, said the agency has yet to select what technologies it would provide to a Mars sample return mission that could be launched, with the as a principal partner, in 2020.

Gardini said the three-year program studying Mars sample return work packages would be sufficient to permit a full decision on hardware development in 2011 at the next meeting of ESA government ministers.