India, hoping to become the fourth nation to send humans into space, has unveiled a key element in the effort, an indigenously manufactured astronaut capsule.

The country's space agency has displayed a prototype of its first crew capsule module designed to carry two people into low Earth orbit, ScienceInsider reported.

The Indian Space Research Organization announced plans to send the test prototype into orbit with the first experimental flight of the country's latest rocket, the Geosynchronous Satellite Launch Vehicle Mark III..

Capable of putting 10 tons of payload into a low-Earth orbit, it could launch in May or June from Sriharikota spaceport on the coast of the Bay of Bengal, the agency said.

Currently only the United States, Russia and China have accomplished the feat of putting humans into Earth orbit.

The Indian space agency said it has decided on the test flight even though the government has yet to grant approval and funding for a human space-flight program.

"We thought it better to [go ahead to] gain some confidence in the design of our crew module," said Sundaram Ramakrishnan, director of ISRO's Vikram Sarabhai Space Center in Thiruvananthapuram, Kerala.

The capsule, manufactured by Hindustan Aeronautics Limited, is intended to carry two or three astronauts into a low-Earth orbit on a weeklong mission.