KOUROU, French Guiana — The launch of France’s Helios 2B optical and infrared reconnaissance satellite was canceled several hours before the scheduled liftoff Dec. 9 following the discovery of a leak in the helium-pressurization system. Launch managers said the suspect valve will be replaced and re-tested, with a new launch attempt likely to occur the week of Dec. 14.
The 4,200-kilogram Helios 2B is the sole passenger on the flight, which will be the last of the Ariane 5 GS models and the last of the first-generation Vulcain 1 main-stage cryogenic engines. Launch officials said the helium tank and the valve in question are identical to those used in the standard Ariane 5 ECA vehicle, and that the necessary spare parts are available at Europe’s Guiana Space Center spaceport.
Helium is used to maintain pressure in the main-stage propellant reservoirs, which are filled with liquid hydrogen and liquid oxygen.
The launch will be the seventh Ariane 5 flight for 2009 and will set a record for calendar-year liftoffs of Europe’s heavy-lift rocket.