THIRUVANANTHAPURAM: Ask Marc Vales about future collaborations between his company and the Indian Space Research Organisation (ISRO) and he turns amiably taciturn, letting slip only a cryptic, “We have identified topics for collaboration.”But Vales, the head (Future Programmes) of ArianeGroup (formerly Airbus Safran Launchers), is all smiles when you ask him about his company’s two flagship projects: The Ariane 6 heavy-lift rocket, big brother to Ariane 5, and Prometheus, the much-awaited rocket engine which burns methane, the fuel of the future. Vales spoke to ‘Express’ about the two European Space Agency (ESA) projects for which ArianeGroup is the primary contractor.
“Compared to Ariane 5, Ariane 6 will be more flexible, less expensive – at least by 40 percent. We will fly it by mid-July of 2020,” Vales said.Expected in two versions, Ariane 6 will be powerful enough to carry an 11-tonne payload to Geostationary Transfer Orbit (GTO) and more than 20 tonnes to Low Earth Orbit (LEO). (ISRO’s own giant, the GSLV Mk-III, lifts four tonnes to GTO and eight tonnes to LEO).
Ariane 6 will have solid boosters, but the core and upper stages will have liquid propulsion. The core stage is powered by the Vulcain 2.1 engine, while the upper stage will have Vinci engines. Both engines will use Liquid Hydrogen (LH2) and Liquid Oxygen (LOX) as propellants. (ISRO’s own cryogenic engines use them, incidentally).
In many ways, Prometheus is a bigger project, burning methane instead of liquid hydrogen, with better prospects for reusability. The engine, reportedly, is expected to fly rockets by 2030. The prototype will be fire-tested before 2020, Vales said. Space agencies like ISRO are currently working on the semi-cryo engine which uses LOX/refined kerosene as propellant. But ArianeGroup has different ideas.
Methane is easier to store, has a lower bulk density which means smaller and less expensive fuel tanks. In addition to reusability, the engine will offer vastly reduced expenses. Vales said a major reason for the reduced cost will be additive manufacturing (3D printing).