Two US payloads will ride piggyback on India's first spacecraft to the moon to be launched as part of its lunar mission, Chandrayan-I, thus strengthening ties between the two sides in space science.

"Discussions are on to decide the final design of the US payloads," official sources said. The design will have to take into consideration the carrying capacity of the satellite launch vehicle being used for the purpose, they said.

The two US payloads are Mini Synthetic Aperture Radar to map and gather data on lunar poles and Moon Mineralogy Mapper will assess minerals on the lunar surface, they said.

The data generated by the payloads will be shared by the two countries, they said adding some US research institutes have shown interest in studying lunar surface.

India has received 30 proposals from other countries for the mission, which will be launched in 2007-08. Six payloads have been selected. Payloads of UK, Bulgaria, Sweden and Germany will also be carried, they said.