Several NASA scientists -- of Indian origin and foreigners alike -- are knocking the door of Indian Space Research Organisation looking for opportunities to work in future 'desi' space missions following the success of Chandrayaan-1 launch, a senior ISRO official said on Saturday.

Project Director of Chandrayaan-1, India's first unmanned lunar mission, Mayilsamy Annadurai says he definitely sees a "small trend" of what he calls "reverse brain-drain".

"Some of my friends and juniors working there (NASA) are looking for opportunities for working in ISRO," Annadurai said.

He said at least half-a-dozen of them had approached him seeking openings in the Indian space agency and he knew that "a good number of foreigners" were also looking for such jobs.

Other senior ISRO officials sure would have got similar calls, he said. The question they are all asking is: "Is there any opportunity for working in future missions of ISRO".

India's Chandrayaan-1, launched on Oct 22, is carrying 11 payloads (scientific instruments) -- two from NASA, three from European Space Agency, one from Bulgaria and five from India.

"Fifty per cent of the instruments have come from outside. It's symbolic. Instead of we going there, they have come along with us as co-passengers," Annadurai said.

ISRO Chairman G Madhavan Nair said "comments and observations with envy that have come from overseas after Chandrayaan-1's launch reaffirms ISRO's matured and advanced technologies."

After the launch, US Democratic Presidential nominee Barak Obama had said India's mission should be a wake-up call to America, and should remind his nation that it was getting complacent or sloppy about maintaining its position as the foremost nation in space exploration.