Bangalore, Sep 11 : The Chandrayaan-I satellite has successfully undergone the thermal vacuum test even as Indian space scientists achieved a major milestone inching closer to the country’s first mission to the moon.

A formal announcement on the date of the eagerly awaited launch is expected to be made by Chairman of the Bangalore-headquartered Indian Space Research Organisation (ISRO) G Madhavan Nair next week.

The two-week vacuum test to evaluate the thermal design of the spacecraft and to verify its endurance in the harsh environment of space, has just been completed at ISRO Satellite Centre here, sources in the space agency said.

"The test was satisfactory," an ISRO official said. "Environment and acoustics tests will follow, and the pre-shipment review is expected by this month-end".

The ambitious moon mission is slated for second half of October. An ISRO official said on condition of anonymity that the first available date is October 22, and the launch window has been fixed between October 22 and 26. (ANI)